Prasanna

MP Board Class 12th Biology Important Questions Chapter 11 Biotechnology: Principles and Processes

Biotechnology: Principles and Processes Important Questions

Biotechnology: Principles and Processes Objective Type Questions 

Question 1.
Choose the correct answer:

Question 1.
Which is used in DNA cultivation :
(a) Allesa
(b) Bloting technique
(c) PCR
(d) None of these.
Answer:
(c) PCR

Question 2.
Which is stained by Ethidium bromide :
(a) DNA
(b) RNA
(c) Protein
(d) All of these.
Answer:
(a) DNA

Question 3.
(a) Bacteria
(b) Virus
(c) Yeast
(d) Plant cell.
Answer:
(a) Bacteria

Question 4.
Plasmids are:
(a) Circular
(b) Extra – nuclear
(c) Vector
(d) All of these.
Answer:
(d) All of these.

Question 5.
Resistant gene found in pBR 322 :
(a) Ampicillin
(b) Tetracycline
(c) Both (a) and (b)
(d) None of these.
Answer:
(c) Both (a) and (b)

Question 6.
Eco RI is :
(a) A virus
(b) A bacteria
(c) A restriction enzyme
(d) A cyanobacteria.
Answer:
(c) A restriction enzyme

Question 7.
Plasmid and cosmid are :
(a) DNA vector
(b) RNA vector
(c) A bacteria
(d) A virus.
Answer:
(c) A bacteria

Question 8.
When stablised, bio technical department by Indian government :
(a) 1948
(b) 1985
(c) 1986
(d) 1987.
Answer:
(c) 1986

Question 9.
Who gave the name plasmid :
(a) Jacob and Monod
(b) Laderberg
(c) Ruth senger
(d) Khurana.
Answer:
(b) Laderberg

Question 10.
What is vector DNA :
(a) Breaker of DNA
(b) Cutter of DNA
(c) Transfer in DNA in one
(d) None of these.
Answer:
(c) Transfer in DNA in one

Question 11.
RI plasmid is obtained from :
(a) E. coli
(b) Yeast
(c) Agrobacterium
(d) Rhizobium.
Answer:
(c) Agrobacterium

Question 12.
pBR 322 is :
(a) Bacteria
(b) Virus
(c) Plasmid
(d) Recombinant protein.
Answer:
(c) Plasmid

Question 2.
Fill in the blanks:

1. …………….. is used for DNA staining.
2. …………….. joins DNA segments.
3. …………….. are small sized cloning vectors.
4. In …………….. disturbed genes can be replaced by proper genes.
5. Small segments of DNA are moved to …………….. pole through power steering.
6. PCR is first discoverd by ……………..
7. …………….. bacteria is responsible for tumor formation.
8. …………….. enzyme is used in PCR.
9. …………….. is used for gene transfer in dicot.
10. …………….. is done by electrophorasis.
11. …………….. DNA polymerase is also activeted in high temperature.
12. Sticky ends of helpfull in the function of …………….. enzyme.

Answer:

1. Ethidium bromide
2. DNA ligase
3. Cosmid
4. Gene therapy
5. Distant
6. Kary muilis
7. Agrobacterium tumefaciens
8. Taq polymerase
9. Ti plasmid
10. Isolation of DNA segment
11. Taq DNA polymerase
12. DNA Ligase.

Question 3.
Match the followings:

Answer:

1. (c)
2. (a)
3. (b)
4. (e)
5. (d)

Question 4.
Write the answer in one word/sentances:

1. Biomolecule that destroy viruses and produce immunity in human being.
2. Name of the first cloned animal.
3. Where does CCMB situated?
4. What kind of charge found in DNA segment?
5. Name the technique in which seperate DNA segments.
6. Name the molecular scissors.
7. Write the full name of PCR.
8. Which metal is used in gene gun method?
9. Who discover the enzyme restriction?
10. What is meant by GM organism?
11. Write the full name of FEB.

Answer:

1. Interferon
2. Dolly
3. Hyderabad
4. Negative
5. Bio power steering
6. Re – striction, enzyme
7. Polymerase chain reaction
8. Tungstun or Gold
9. Werner Arber
10. Genetically Modified organism
11. European Federation of Biotechnology.

Biotechnology: Principles and Processes Very Short Answer Type Questions

Question 1.
Which enzyme is used for isolation of target gene?
Answer:
Restriction endonuclease is used for isolation of target gene.

Question 2.
Which DNA polymerase is active in high tempereature?
Answer:
Taq DNA polymerase is active in high temperature.

Question 3.
Name three restriction endonuclease enzyme.
Answer:

1. EcoRI
2. Hind II
3. Hind III.

Question 4.
Write full form of PCR. Which enzyme is used in?
Answer:

1. Polymerase Chain Reaction (PCR).
2. Taq DNA is used in PCR.

Question 5.
What is bacteriophage?
Answer:
Viruses, they are infected to bacteria are called Bacteriophage.

Question 6.
First recombinant DNA was formed in.
Answer:
In bacteria Salmonella typhimurium.

Question 7.
What is molecular scissors?
Answer:
Restriction enzyme is called molecular scissors.

Question 8.
Where does Hind II cuts the DNA molecule?
Answer:
It cuts the DNA molecule at a specific 6 base pair sequence.

Question 9.
What is the funtions of sticky ends?
Answer:
It helps enzyme DNA ligase.

Question 10.
Which type of charge found in DNA?
Answer:
Negative charge.

Question 11.
How does ethidium bromide cause DNA to fluorescence in electrophoresis?
Answer:
The most commonly used stain for detecting DNA is ethidium bromide.

Question 12.
What is electrophoresis?
Answer:
Electrophoresis is a technique used in laboratories in order to separate micromolecules based on size.

Question 13.
Give the function of circular DNA which is found in bacterial cell.
Answer:
It works as a vector.

Question 14.
Name the technique in which we should isolate DNA segment.
Answer:
Electrophoresis.

Question 15.
Name two antibiotic restriction gene which is found in plamid pBR 322.
Answer:
Ampicillin and Tetracycline.

Question 16.
What is plasmid?
Answer:
A plasmid is a small DNA molecule within a cell that is physically separated from a chromosomal DNA and can replicate independently.

Question 17.
What is DNA ligase?
Answer:
DNA ligase is a specific type of enzyme, a ligase that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiesterbond.

Question 18.
What is C – DNA?
Answer:
C – DNA is a single stranded RNA. C – DNA is often used to clone eukaryotic genes in prokaryotes.

Question 19.
What is Ti – plasmid?
Answer:
Ti or tumour inducing plasmid is a plasmid that is a part of the genetic equipment that Agrobacterium tumifaciens use to transduce their genetic material to plants.

Biotechnology: Principles and Processes Short Answer Type Questions

Question 1.
From what you have learnt, can you tell whether enzymes are bigger or DNA is bigger in molecular size? How did you know?
Answer:
DNA is bigger in molecular size than enzymes. Because DNA is a long double stranded molecule which can go up to a few meters in length when stretched end to end but enzymes although variable in size, would still be smaller than the DNA.

Question 2.
What would be the molar concentration of human DNA in a human cell? Consult your teacher.
Answer:
The average molecular weight of a nucleotide in human DNA is 130.86. The molecular weight of human DNA will therefore be 6 x 10⁹ nucleotides (based on the human genome project) x 130.86 = 784.56 x 109 gm/mol. The molar concentration of DNA can be calculated accordingly.

The molarity can be calculated as
Molar concentration = \(\frac { No. of molecules}{ Molecular weight }\)

Question 3.
Do eukaryotic cells have restriction endonucleases? Justify your answer.
Answer:
No, of eukaryotic cells do not have restriction endonucleases. All the restriction endonucleses have been isolated from the various strains oi bacteria arid they arc also named according to the genus and species of prokaryotes. The first letter of the enzyme comes from the genus and the second two letters come from the species of the prokaryotic cell from which they have been isolated.

Question 4.
Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks ?
Answer:
Shake flask are used for growing microbes and mixing the desired materials on a small scale in the laboratory. However, the large-scale production of a desired biotechnological product requires large stirred tank bioreactors.

Besides better aeration and mixing properties, bioreactors have the following advantages:

1. It has an oxygen delivery system.
2. It has a foam control, temperature and pH control system.
3. Small volumes of culture can be withdrawn periodically.

Question 5.
Name the scientist who discovered artificial DNA synthsizing method.
Answer:
The Nobel prize in physiology 1968 was awarded jointly to Robert W. Holley, Hargobind Khorana and M. Nirenberg for their interpretation of the genetic code.

Question 6.
What is gene manipulation or genetic engineering? Explain it.
Answer:
Genetic engineering, also called genetic modification is the direct manipulation of an organisms genes using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes and across species boundaries to produce improved organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA.

It may also mean extracting DNA from another organisms genome and combining it with the DNA of that individual. Genetic engineering is used by scientists to enhance or modify the characterstics of an individual organisms genetic engineering can be used to produce plants that have a higher nutritional value or can tolerate exposure to herbicides.

Question 7.
Write application of genetic engineering in crop improvement.
Answer:
Genetic engineering has placed an important role in improvement of plant production. There are following applications of genetics in plant improvement.

1. Production of polyploidy crops.
2. Hybridization : Hybridization is used to produce plants with, desirable traits.
3. Transgenic plants : It helps a lot in improving the yield and quality of crops.
4. Insect and herbicides resistant plants are engineered.

Question 8.
Can you recall meiosis and indicate at what stage a recombinant DNA is made?
Answer:
A recombinant DNA is made in the pachytene stage of prophase I by crossing over during meosis cell division. Recombination nodules are visible in synaptonemal complex in pachytene sub stage. Crossing over occurs in this time between chromatids than recombinant DNA is formed.

Question 9.
Can you think and answer how a reporter enzyme can be used to monitor transformation of host cells by foreign DNA in addition to a selectable marker?
Answer:
Reporter enzyme can differentiate recombinants from non – recombinants on the basis of their ability to produce a specific colour in the presence of a chromogenic substrate. DNA is inserted within the coding sequence of the enzyme β – galactosidase. (MPBoardSolutions.com) This results into inactivation of the enzyme which is referred to as insertional inactivation. The presence of a chromogenic substrate gives blue – coloured colonies if the plasmid in the bacteria does not have an insert. The presence of the insert results in insertional inactivation of β – galactosidase and the colonies do not produce any colour. These are identified as recombinant colonies.

Question 10.
Make a chart (with diagrammatic representation) showing a restriction enzyme, the substrate DNA on which it acts, the site at which it cuts DNA and the products it produces.
Answer:
The substrate DNA on which a restriction enzyme acts :

Question 11.
Write the uses of animal cloning.
Answer:
Applications (Uses) of Animal cloning :

1. By this technique desired genotypes of any organism can be conserved.
2. It produces organisms with better characters.
3. Endangered plant and animal species can be conserved by this technique.
4. Animals with good quality of milk and protein can be produced.

Question 12.
Write applications of genetic engineering in medical field.
Answer:

1. The hereditary diseases like colour – blindness, haemophilia which are caused by recessive genes therapy.
2. Substances like vitamins, hormones, amino acids and antibiotics can be synthe – sized in bacteria by introducing the genes which code these substances.
3. Production of insulin : It is a medicine used for the treatment of diabetes. It is produced by gene splicing.
4. Hepatitis – B vaccine : Hepatitis – B is a viral disease of liver, today this vaccine is prepared with the help of genetic engineering.

Question 13.
What do you understand by gene bank? What are its significances?
Answer:
Gene bank:
The institution which conserves the genes of the organisms is called as gene bank. The genetic material (DNA) found in the cells of organisms are conserved in gene banks. The best measure of conserving genes is to conserve endangered organisms. The tissues or cells of organisms are also conserved in gene banks.

Significance:
Genes stored in gene bank are used for the production of improved varieties of species and for scientific tests.

Question 14.
What do you understand by gene cloning? What are its significance?
Or
What is gene cloning? Write its importance.
Answer:
Gene cloning:
It is a process in which DNA of an organism is cut into smaller DNA fragments by the use of restriction endonuclease enzymes. Each DNA fragment is introduced into a bacterial, yeast, insect, plant or animal cell. The cells are grown on a suitable medium under suitable conditions. Each cell containing a particular DNA fragment multiplies to give rise a group of cells, all containingthe same foreign DNA.

These groups of cells are known as clone of cells. These copies of DNA resulting from the multiplication or recombinant DNA are called as cloned DNA and the process is known as gene cloning,

Significance:

1. Useful hereditary characters are obtained by this process.
2. Many diseases are cured by this process.
3. Many medicines are synthesized with the help of this process.
4. This process should also be used in eugenics.

Biotechnology: Principles and Processes Long Answer Type Questions

Question 1.
Collect 5 examples of palindromic DNA sequences by consulting your teacher. Better try to create a palindromic sequence by following base – pair rules.
Answer:
Some palindromic DNA sequences and the restriction enzymes which act on them are:

1.  5′ – AGCT – 3 Alul (Arthrobacter lutens)
3′ – TCGA – 5′

2. 5′ – GAATTC – 3’EcoRI (Escherichia coli)
3′-CTTAAG-5′

3.  5′- AAGCTT – 3’HindIII (Haemophilus influenzae)
3′ – TTCGAA – 5′.

4. 5′ – GTCGAC – 3’SalI (Streptomyces albus)
3′ – CAGCTG – 5′

5. 5′ – CTGCAG – 3’PstI (Providencia stuartii)
3′ – GACGTC – 5′.

Question 2.
Describe briefly the followings :

1. Origin of replication
2. Bioreactor
3. Downstream processing.

Answer:
1. Origin of replication:
Origin of replication (ori) is a sequence on the chromosome, form where replication starts and any place of DNA when linked to this sequence can be made to replicate within the host cells. This sequence also controls the copy number of the linked DNA. So, if we want to recover many copies of the target DNA it should be linked to the ‘ori’ site and should be cloned in a vector whose origin supports high copy number.

2. Bioreactor:
Bioreactor is large vessels in which raw materials are biologically converted into specific products, individual enzymes, etc., using microbial, plant, animal or human cells. (MPBoardSolutions.com) A bioreactor provides the optimal conditions for achieving the desired production levels by providing optimum growth conditions of temperature, pH, substrate, salts, vitamins, oxygen, etc.

3. Downstream processing:
Downstream processes include separation and purification, formulation with suitable preservatives, etc. which are collectively referred to as downstream processing. Such formulation has to undergo through clinical trials as in case of drugs. Strict quality control testing for each product is also required. The downstream processing and quality control testing vary from product to product.

Question 3.
Explain briefly:

1. PCR
2. Restriction enzymes and DNA
3. Chitinase.

Answer:
1. PCR:
PCR stands for polymerase chain reaction, a method of amplifying fragments of DNA. This method can make multiple copies of even a single DNA fragment or the gene of interest in a test tube. The reaction ntixture requires:

1. Double – stranded DNA fragment (gene of interest).
2. Primers – small chemically synthesized oligonucleotides that are complementary to the regions of this DNA.
3. The special thermostable DNA polymerase (isolated from a bacterium, Thermus aquaticus), that does not denature and remain active even at high temperature.

Unwinding of two strands of DNA by heating the sample at 92 – 94°C helps primers to get positioned on the exposed nucleotides as per base pairing rules. DNA polymerase recognizes primes as ‘start’ tags and begins to extend the primes using the free nucleotides provided in the reaction and the genomic DNA as template. With each round of reactions, the DNA doubles.

2. Restriction enzymes and DNA:
These enzymes are used in genetic engineering to cut the large DNA molecule into smaller fi agments. When DNA from two different sources are cut by the same restriction enzyme, the resultant DNA fragments have the same kind of’sticky – ends’ and these can be joined together (end – to – end) using DNA ligases. This new DNA created by joining fragments, from two different sources/genomes together is recombinant DNA.

3. Chitinase:
Chitinase is an enzyme that breaks down chitin, a component of fungal cell wall. It is useful for isolating the fungal cell DNA.

Question 4.
Discuss with your teacher and find out how to distinguish between :

1. Plasmid DNA and Chromosomal DNA
2. DNA and RNA
3. Exonuclease and Endonuclease.

Answer:
1. Distinguish between Plasmid DNA and Chromosomal DNA :

Plasmid DNA:

• Plasmid DNA is the naked double – stranded DNA which forms a circle
• It is associated with few proteins but contains RNA polymerase enzyme.
• They are smaller than the host chromosomes and can be easily sparated.
• It has no free ends.

Chromosomal DNA:

• Chromosomal DNA is a double – stranded linear DNA molecule.
• It is associated with large proteins.
• This DNA exists in relaxed and super – coiled forms and provides a template for replication and transcription.
• It has free ends represented as 3′ – 5′.

2. Distinguish between DNA and RNA :

DNA:

• It is mainly confined to the nucleus. A small quantity occurs in mitochondria and chloroplasts.
• Its quantity is constant in each cell of a species.
• It contains deoxyribos sugar.
• Its pyrimidines are adenine and thymine.
• The amount of adenine is equal to the amount of thymine. Also, the amount of cytosine is equal to the amount of guanine.
• It can replicate itself.

RNA:

• It mainly occurs in the cytoplasm. A small quantity is found in the nucleus.
• Its quantity varies in different cells.
• It contains ribose sugar
• Its pyrimidines are adenine and uracil. Adenine and uracil are not necessarily in equal amounts, nor are cytosine and
• guanine necessarily in equal amounts.
• It cannot replicate itself. It is formed by DNA. Some RNA viruses (paramyxo virus) can produce RNA from an RNA template.

3. Distinguish between Exonuclease and Endonucleases:
Exonucleases are nucleases which cut off the nucleotides from the 5′ or 3′ ends of a DNA molecule, whereas endonucleases are nucleases which cleave the DNA duplex at any point except at the ends.

Question 5.
Describe the useful and harmful effects of genetic engineering.
Or
Give importance and uses of DNA recombinant technique.
Or
Describe the Genetic engineering. Write the importance of it in human life.
Answer:
The branch of molecular genetics in which we can manipulate or transplant the genes or the genetic material or DNA according to our will is called gene manipulation or genetic engineering. The main objective of genetic engineering is to synthesize recombinant DNA (formed of the DNA segments of two different organisms).

The useful and harmful effects of genetic engineering are as follows :

(A) Useful effects or Utility:
1. Industrial uses:
Various types of substances such as vitamins, hormones and antibiotics can be-synthesized in bacteria by introducing genes that code these substances. In this way, bacteria can function as living factories for the synthesis of these substances. Humulin (human insulin) is synthesized by this method.

2. Treatment of diseases:
A new system of medicines, gene therapy may develop to cure several genetic disorders such as haemophilia, colour-blindness, etc. Also many inborn meta¬bolic disorders due to defective genes such as alkaptonuria, phenylketonuria, etc. can be cured.

3. Use in agriculture:
The genes for N₂ fixation found in symbiotic bacteria Rhizo – bium leguminosarum or blue-green algae may be transferred to the major food crops, increases food production without using expensive fertilizers. Thus, we can save millions of rupees spent otherwise on fertilizers and manures to boost food production.

4. Changes in the structure and expression of genes:
We can obtain new plants, animals having traits tailored according to our will.

(B) Harmful effects:

1. Normal harmless bacteria can be transformed into cancer causing forms thus ushering a new era of biological warfare.
2. During experiments, it is quite possible to obtain super viruses for which we might have no defence.
3. By the use of recombinant DNA, the bacteria may be made resistant to antibiotics.

Question 6.
Explain the mechanism of recombinant DNA technology in genetic engineering by using plasmid as carrier of genes.
Answer:
Mechanism of Recombinant DNA Technology : Mechanism of recombinant DNA technology involves the following steps :

1. Isolation of desired gene or functional DNA segment:
From the eukaryotic cell desired DNA segment is isolated with the help of enzyme restriction endonuclease. Now this segment of DNA is known as foreign DNA.

2. Transfer of DNA segment from one organism to other:
Plasmid is an extra chromosomal circular DNA found mostly in bacteria over and above the main genome. When bacteria multiplies the plasmid DNA also multiplies along with the chromosomal DNA. These plasmids can be easily isolated from the bacterial cell with the help of restriction endonucleases. Plasmid serves as a vector for transferring the foreign DNA into a suitable recipient.

Foreign DNA and plasmid sliced with the help of endonucleases has free sticky ends through which they join each other with complementary base pairing with the help of enzyme DNA ligase. Thus, a recombinant DNA is formed,

Such a recombinant DNA when introduced into a recipient bacterium (transformation), it replicates and expresses itself, within the bacterial cell, the recombinant DNA molecule replicates along with the endogenous DNA of the host cell and produces copies of cloned DNA. This process is known as gene cloning. The cloned recombinant DNA produced in large quantities’can be isolated, purified and analysed.

Question 7.
Describe the role of genentic engineering in artificial synthesis of human insulin.
Answer:

1. Aldric and his supporter prepared two DNA sequences corresponding to the A and B chains of human insulin.
2. Sticky ends were produced in the E.coli plasmid and the insulin gene by treating them both with the same restriction endonucleases.
3. These two are then joined together by the enzyme DNA ligase.
4. The bacteria are then grown in sterilised bioreactors in the appropriate growth medium.
5. The chain A and B are produced separately, extracted and purified.

Question 8.
What is clone? Give its preparation, extraction and purification.
Answer:
An organism or cell or group of oiganisms, produced a sexually from an ancestor, to which they are genetical.

1. Gene cloning : Following steps are used by gene cloning :
(i) Preparation of gene:
DNA extracted from an organism, with the gene of interest is cut into gene size pieces with restriction enzyme.

(ii) Insertion into vector:
Bacterial plasmids are cut with the same restriction enzyme. Plasmids are small circles of DNA in bacterial cells that are naturally present in addition to the bacterial other DNA.

(iii) Transformation of host cells:
The recombinant plasmids are then transferred into bacteria using either electroporation. The plasmid are small enough to pass through the holes into the cells. However rather than using electricity to create holes in the bacterium, it is done by alternating the temperature between hot and cold.

The bacteria is grown on a culture dish and allowed to grow into colonies. All the colonies on all the plates are called a gene library.

2. Plant cloning:
Plant tissue culture is a method of propagation that has been sprouting in popularity throught as an altemative.to cloning. Plant can be cloned artificially using tissue culture. (MPBoardSolutions.com) Vegetative propagation works because the end of the cutting forms a mass of non specialized cells called a callus, the callus will grow divide and form various specialized cells eventually forming a new plant.

Question 9.
Can you list 10 recombinant proteins which are used in medical practice? Find out where they are used as therapeutics (use the internet).
Answer:

MP Board Class 12th Biology Important Questions

MP Board Class 12th Biology Important Questions Chapter 10 Microbes in Human Welfare

Microbes in Human Welfare Important Questions

Microbes in Human Welfare Objective Type Questions 

Question 1.
Choose the correct answer:

Question 1.
Name the place from which viruses entered into the plant:
(a) From lenticels
(b) From wound
(c) From stomata
(d) From root.
Answer:
(b) From wound

Question 2.
Fertilizer elements are :
(a) Nitrogen
(b) Phosphorus
(c) Potassium
(d) All of these.
Answer:
(d) All of these.

Question 3.
Fertilizer that supplies least % of nitrogen is :
(a) Urea
(b) (NH₄)SO₄
(c) (NH₄)NO₃
(d) Organic nitrogen fertilizer.
Answer:
(d) Organic nitrogen fertilizer.

Question 4.
VAM is:
(a) Bacteria
(b) Yeast
(c) Fungi
(d) Virus.
Answer:
(b) Yeast

Question 5.
Nitrifying bacteria converts :
(a) N₂ into nitrates
(b) Ammonia into nitrates
(c) Nitrates into N₂
(d) CO₂ into carbohydrates.
Answer:
(b) Ammonia into nitrates

Question 6.
Who discovered the virus :
(a) Stanley
(b) Ivanowski
(c) Herel
(d) Beijerinck.
Answer:
(b) Ivanowski

Question 7.
Name the virus which has double helical stranded DNA :
(a) Hepatits A
(b) Hepatits B
(c) Hepatits C
(d) Flepatits D.
Answer:
(b) Hepatits B

Question 8.
Spirally coiled bacteria is known as :
(a) Spirilla
(b) Cocci
(c) Bacilli
(d) Vibrio.
Answer:
(a) Spirilla

Question 9.
Name the bacteria in which flagella are found in whole body :
(a) Peritrichous
(b) Atrichous
(c) Monotrichous
(d) Cephalotrichous
Answer:
(a) Peritrichous

Question 10.
Useful activities of microbes is :
(a) Nitrogen fixation
(b) Nitrification
(c) Biogeochemical cycle
(d) All of the above.
Answer:
(d) All of the above.

Question 11.
Which of the following is prokaryotes :
(a) Chlorella
(b) Clamydomonas
(c) Protomyces
(d) Ossiletoria.
Answer:
(d) Ossiletoria.

Question 12.
Yeast is used in the production of :
(a) Ethyl alcohol
(b) Acetic acid
(c) Cheese
(d) Curd.
Answer:
(a) Ethyl alcohol

Question 13.
B.T. cotton provides immunity from :
(a) Pest
(b) Weeds
(c) Salt
(d) Animal.
Answer:
(a) Pest

Question 14.
Which is the used for making bread :
(a) Lactobacillus
(b) Straptobacillus
(c) Aspergillus
(d) S. cerevisiace.
Answer:
(c) Aspergillus

Question 2.
Fill in the blanks:

1. Rhizobium, Azolla and Anabaena are the example of …………………….. fertilizers.
2. …………………….. bacterium is found in the roots of leguminous plants.
3. Nostoc and Anabaena are called ……………………..
4. …………………….. is nitrogen fixing bacteria.
5. …………………….. is the fungal resistant, bacterial antibody component.
6. …………………….. is the other name of mycoplasma.
7. …………………….. is the other name of Archaebacteria.
8. …………………….. type of ribosome is found in Moneran.
9. Bacterial cell wall is made by ……………………..
10. …………………….. is the meaning of word virus.
11. Butter milk is obtained from the activation of ……………………..
12. Ethanol is produced in a large scale through …………………….. yeast.
13. …………………….. bacteria is helpful in vinegar production.

Answer:

1. Bio
2. Rhizobium
3. Cyanobacteria
4. Rhizobium
5. Polymixin
6. PPLO
7. Living fossils
8. 70S type
9. Mucopeptides
10. Poison
11. Streptococcus lactis
12. Saccharomyces cerevisiae
13. Azotobacter aceti.

Question 3.
Match the followings :
I.

Answer:

1. (d)
2. (a)
3. (e)
4. (b)
5. (c).

II.

Answer:

1. (e)
2. (d)
3. (a)
4. (b)
5. (c)

Question 4.
Write answer in one word/ sentences:

1. Name the bacteria which is used in making swiss cheese.
2. Write the name of the microorganism which converted milk into curd.
3. Name the fish which control mosquito.
4. Write the name of two bacteria which are found in soil in free state.
5. Write the full name of IPM.
6. What is yogurt?
7. What is interferon?
8. Write the full name of B.O.D.
9. Write the name of an autotrophic nitrogen fixing microorganism.
10. Which microbes are used in industries for making citric acid?
11. Who discovered the penicillin?
12. Write the name of an alcoholic drink which is made by without distillation.
13. Microbes which is respire without oxgyen is called?
14. Synibiotic relationship which is found between fungi and higher plant root.

Answer:

1. Propionibacterium shermanii
2. Lactobacillus
3. Gambussia
4. Azotoba – cterium and Clostridium
5. Integrated Pest Management
6. Milk product
7. Antiviral protein
8. Biochemical Oxygen Demand
9. Anabaena
10. Aspergillus niger
11. Alexander Fleming
12. Beer
13. Anaerobic
14. Micorrhiza.

Microbes in Human Welfare Very Short Answer Type Questions

Question 1.
Name the fungus which produce these products:

1. Citric acid
2. Vitamin B₂

Answer:

Question 2.
What is yoghurt?
Answer:
Yoghurt is a semi – solid sourish food prepared from milk fermented by added bacteria.

Question 3.
Why does the river Ganga water not spoil even kept for long – time?
Answer:
Bacteriophages are present in Ganga river which feed on bacteria which spoil water. So, this water does not get spoil for long –   time.

Question 4.
Who discover penicillin?
Answer:
Alexander Fleming.

Question 5.
Name the microorganism/fungi which gave penicillin.
Answer:
Penicillium notatum.

Question 6.
Which organism is used for making citric acid in industries?
Answer:
Aspergillus niger.

Question 7.
Write the name of methanogen bacteria.
Answer:
Methano bacterium species.

Question 8.
Which bacteria is found in anaerobic sludge?
Answer:
Methanogen.

Question 9.
What is lady bird?
Answer:
It is an insect which is used as biocontroller for Aphid control.

Question 10.
Give the name of autotrophic nitrogen fixing microbes.
Answer:
Anabaena.

Question 11.
Name the mineral absorbed by mycorrhiza, which is not absorbed by plant roots.
Answer:
Phosphorus.

Question 12.
Name the microorganism which changes to milk into curd.
Answer:
Lactobacillus spp.

Question 13.
Which fungi is used in treatment of plant due to biological control?
Answer:
Trichoderma spp.

Question 14.
Which bacteria is used in swiss paneer?
Answer:
Propionibacterium shermanii.

Question 15.
Which paneer is completed by the growth of fungus?
Answer:
Roquefort cheese.

Question 16.
Name two alcoholic drink which are formed without distillation.
Answer:
Beer and Wine.

Question 17.
Name two alcoholic drink which are formed by distillation.
Answer:
Whiskey and Rum.

Question 18.
What is the full form of BOD?
Answer:
Biochemical or Biological Oxygen Demand.

Microbes in Human Welfare Short Answer Type Questions

Question 1.
Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes under a microscope, which sample would you carry and why?
Answer:
Curd can be used as a sample for the study of microbes. Curd contains numerous Lactic Acid Bacteria (LAB) or Lactobacillus. These bacteria produce acids that coagulate and digest milk proteins. A small drop of curd contains million of bacteria, which can be easily observed under a microscope.

Question 2.
Give example to prove that microbes release gases during metabolism.
Answer:
The examples of bacteria that release gases during metabolism are :

1. Bacteria and fungi carry out the process of fermentation and during this process, they release carbon dioxide.
2. The dough used for making idli and dosa gives a puffed appearance. This is because of the action of bacteria which releases carbon dioxide. This CO₂ released from the dough gets trapped in the dough, thereby giving it a puffed appearance.

Question 3.
In which food would you find lactic acid bacteria? Mention some of their useful applications.
Answer:
Lactic acid bacteria can be found in curd. It is this bacterium that promotes the formation of milk into curd. The bacterium multiplies and increases its number, which converts the milk into curd. They also increase the content of vitamin B₁₂
in curd. Lactic acid bacteria are also found in our stomach where it keeps a check on the disease causing microorganisms.

Question 4.
Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes.
Answer:

1. Wheat product: Bread, Cake etc.
2. Rice product: Idli, Dosa.
3. Bengal gram product: Dhokla, Khandvi.

Question 5.
In which way have microbes played a major role in controlling diseases caused by harmful bacteria?
Answer:
Several microorganisms are used for preparing medicines. Antibiotics are medicines produced by certain microorganisms to kill other disease causing microorganisms. These medicines are commonly obtained from bacteria and fungi. They either kill or stop the growth of disease causing microorganisms. (MPBoardSolutions.com) Streptomycin, tetracycline and penicillin are common antibiotics. Penicillium notatum produces chemical penicillin, which checks the growth of staphylococci bacteria in the body. Antibiotics are designed to destroy bacteria by weakening their cell walls.

Question 6.
Name any two species of fungus, which are used in the production of the antibiotics.
Answer:
Antibiotics are medicines that are produced by certain microorganisms to kill other disease causing microorgainsms. These medicines are commonly obtained from bacteria and fungi. The species of fungus used in the production of antibiotics are:

Antibiotic:

• Penicillin
• Cephalosporin

Fungus source:

• Penicillium notatum
• Cephalosporium acremonium

Question 7.
What is sewage? In which way can sewage be harmful to us?
Answer:
Sewage is the municipal waste – water collected from city or town homes, that contains toilet, bathroom and kitchen waste.
It contains large amounts of organic matter and many pathogenic microbes which are harmful to humans as they can cause many diseases like cholera, typhoid, polio.

Question 8.
What is the key difference between primary and secondary sewage treatment?
Answer:
Differences between Primary and Secondary sewage treatment:

Primary sewage treatment:

• It is a physical process.
• Primary treatment involves the removal of large sized floating and suspended solids.
• BOD is not affected in this treatment.

Secondary sewage treatment:

• It is a biological process.
• Secondary treatment involves decomposition of organic matter by microbial action which produce methane, hydrogen sulphide and carbon dioxide.
• BOD is less by secondary treatment.

Question 9.
Do you think microbes can also be used as source of energy? If yes, how?
Answer:
Yes, microbes can be used as a source of energy. Bacteria such as; Methane bacterium is used for the generation of gobar gas or biogas. The generation of biogas is an anaerobic process in a biogas plant, which consists of a concrete tank (10 – 15 feet deep) with sufficient outlets and inlets. The dung is mixed with water to form the slurry and thrown into the tank. The digester of the tank is filled with numerous anaerobic methane producing bacteria, which produce biogas from the slurry. Biogas can be removed through the pipe which is then used as a source of energy, while the spent slurry is removed from the outlet and is used as a fertilizer.

Question 10.
Microbes can be used to decrease the use of chemical fertilizers and pesticides. Explain how this can be accomplished.
Answer:
Microbes play an important role in organic farming which is done without the use of chemical fertilizers and pesticides. Biofertilizers are living organisms which help in increasing the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients. Biofertilizers are introduced in seeds, roots or soil to mobilize the availability of nutrients. Thus, they are extremely beneficial in enriching the soil with organic nutrients.

Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen, Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. (MPBoardSolutions.com) Azospirilhum and Azotobacter are free living nitrogen – fixing bacteria, whereas Anabena, Nostoc and Oscillitoria are examples of nitrogen – fixing cyanobacteria. Biofertilizers are cost effective and eco – freindly. Microbes can also act as biopesticides to control insect pest in plants. An example of biopesticides is Bacillus thuringiensis, which produces a toxin that kills the insect pests.

Dried bacterial spores are mixed in water and sprayed in agricultural fields. When larvae of insects feed on crops, these bacterial spores enter the gut of the larvae and release toxins, thereby it. Similarly, Trichoderma are free living fungi. They live in the roots of higher plants and protect them from various pathogens. Baculoviruses is another bio – pesticides that is used as a biological control agent against insects and other arthropods.

Question 11.
Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B, and C were recorded as 20mg/L, 8 mg/L and 400mg/L, respectively. Which sample of the water is most polluted ? Can you assign the correct label to each assuming the river water is relatively clean?
Answer:
The BOD values of the three samples A, B and C were recorded as 20 mg/L, 8 mg/L and 400 mg/L. Greater the BOD of waste water more is its polluting potential. So, sample C is more polluting as compared to sample A. Hence, sample A is the secondary effluent, sample B is river water and sample C is untreated sewage water.

Question 12.
What is paneer? Give its preparation method.
Answer:
Paneer is a milk product, which has 20 – 30% protein first filtered and the milk in thin cloth than heat on 60°C at 30 minutes and heat on 75°C at 15 second later it cold till 30°C. Add some quantity of lactic acid bacteria Streptococcus lactis, Streptococcus cremoris and enzyme renin. By this fat and casein protein is detached from milk after 45 minutes this mixture became solid. Now, they are cut into small pieces and boild in hot water, when it starts floating, they are separated and squeezed. Then they are put in salt water for treating. Paneer is now ready.

Question 13.
What is the utilization of bacteria in agriculture?
Answer:
Uses of Bacteria : Uses of bacteria for agriculture are as follows :

1. They increase soil fertility due to decomposition of dead organisms.
2. They increase soil fertility through nitrogen fixation in soil.
3. Blue – green algae is used the form of fertilizers.
4. They balance the quantity of mineral salts.

Question 14.
How are the bacteria used in vinegar industry?
Answer:
Fermentation of sugar by yeast in vinegar industry. Due to this manner, wine is prepared. This ethyl alcohol abandoned in direct air for much time now, it is changed in vinegar.

Question 15.
Name live fungi which give antibiotics.
Answer:
The fungi which give antibiotics are as follows:

Question 16.
Name five bacteria which produce antibiotics.
Answer:
The bacteria which produce antibiotics are as follows:

Microbes in Human Welfare Long Answer Type Questions

Question 1.
Write seven useful activities of Bacteria.
Answer:
Useful activities of bacteria :

1. N₂ fixation : Some bacterias play an important role in nitrogen fixation example Azo – tobacter, Clostridium, Rhizobium. These bacterias increase the fertility of soil by the fixation of atmospheric nitrogen.
2. Lactic acid synthesis : Lactobacillus lacti converts the milk sugar into lactic acid.
3. Acetic acid synthesis: Acetobacter aceti takes part in synthesis of acetic acid or vinegar.
4. Rating of fibres: Isolation of wood fibres from the stem of plants is called rating. Clostridium butyricum is used in rating of fibres.
5. Tobacco and Tea industry : Some bacteria like Micococcus candisens is used to increase the flavour of the leaves of tobacco and tea. This process is called as seasoning.
6. Medicine production : Bacteria are the chief source of antibiotics, hence, they are used to extract antibiotics, example Streptomyces gresius (Streptomycine).
7. As symbionts: Bacteria presents in our body, helps in the various metabolic reactions example E.coli.

Question 2.
Write economic importance of fungi.
Answer:
Following are the economic importance of fungi:

1. As food : Mushrooms like Agaricus, Lycoperdon, Romaria, Clavasia are used as food. These mushrooms contain about 50% protein. Morchella is also used as food.
2. As medicine : Fungi provides various types of antibiotics as example Penicillin, Griseofulvine, Citrinine, Clavicine, Gliotoxine, etc. which are used in the treatment of disease.
3. Fertility of soil: Many fungi species increase the soil fertility by decomposition of dead organic matter.
4. Nitrogen fixation : Many fungus like Rhodotorula increases the soil fertility by nitrogen fixation.
5. In bakery industry : Yeast cells are used in bakery to produce spongy breads.
6. In wine industry : Yeast cells contain enzyme zymase which ferment sugar into alcohol.
7. In chemical industry : Many fungi species are used in the production of various types of acid like citric acid.
8. In cheese industry : Fungus Penicillium roqueforti is used in the preparation of camembert type of cheese from milk.

Question 3.
Explain the uses and types of virus.
Answer:
Uses of Viruses:

1. As it forms a link between non – living and living thus, it helps us to understand organic evolution.
2. Cyanophage (Blue – green algae) viruses are used to destroy blue – green algae grown in different areas.
3. Bacteriophages are used as biocides to destroy many harmful bacterias present in polluted area.

For example : Water of the river Ganga always remain pure and clean in bottles year after year due to presence of bacteriophage in it.

Nucleic acids of viruses : Viruses generally contain only one type of nucleic acid DNA or RNA. DNA is found in animal viruses, whereas RNA is found in plant viruses.

Human Immuno Virus (HIV):
It causes AIDS disease in human. Full form of AIDS is Acquired Immune Deficiency Syndrome. This virus destroys immune system of the body, thus, the patient of AIDS suffers from number of diseases at a time and at last he dies. This virus is found surrounded by protein and a ring of RNA is found at the centre. Whole body of virus is surrounded by a covering of glycoprotein.

Type of viruses:
On the basis of host infected, viruses are grouped into following four groups:

1. Animal viruses : Viruses which infect animals are called animal viruses. These viruses contain DNA as genetic material.
2. Plant viruses : Viruses which infect plants are called plant viruses. These viruses contain RNA as genetic material.
3. Cyanophages : Viruses that infect blue – green algae are called cyanophages. These viruses contain RNA as genetic material.
4. Bacterial viruses or Bacteriophages : Viruses that infect bacteria are called as bacteriophages. They contain DNA as genetic materials.

Question 4.
Find out the role of microbes in the following and discuss it with your teacher:

1. Single Cell Protein (SCP)
2. Soil.

Answer:
1. Single Cell Protein (SCP):
It refers to harmless microbial cells that can be used as an alternate source of good protein. Just like mushrooms (a fungus) is eaten by many people and yeast is used by athletes as a protein source; similarly, other forms of microbial cells can also be used as food rich in protein, minerals, fats, carbohydrate and vitamins. (MPBoardSolutions.com) Microbes like Spirullina and Methylophilus methylophus are being grown on an industrial scale on materials containing starch like waste water from potato processing plants, straw, molasses, animal manure and even sewage. These single cell microbes can be used as source of proteins.

2. Role of microbes in soil:
Microbes play an important role in organic farming which is done without the use of chemical fertilizers and pesticides. Biofertilizers are living organisms which help in increasing the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients.

Biofertilizers are introduced in seeds, roots or soil to mobilize the availability of nutrients. Thus, they are extremely beneficial in enriching the soil with organic nutrients. Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen, Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirilhum and Azotobacter are free living nitrogen-fixing bacteria, whereas Anabena, Nostoc and Oscillitoria are examples of nitrogen – fixing cyanobacteria. Biofertilizers are cost effective and eco – freindly.

Microbes can also act as biopesticides to control insect pest in plants. An example of biopesticides is Bacillus thuringiensis, which produces a toxin that kills the insect pests. Dried bacterial spores are mixed in water and sprayed in agricultural fields. When larvae of insects feed on crops, these bacterial spores enter the gut of the larvae and release toxins, thereby it. Similarly, Trichoderma are free living fungi. (MPBoardSolutions.com) They live in the roots of higher plants and protect them from various pathogens. Baculoviruses is another bio – pesticides that is used as a biological control agent against insects and other arthropods.

Question 5.
Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer. Biogas, Citric acid, Penicillin and Curd.
Answer:
The order of arrangement of products according to their decreasing importance is:
Penicillin – Biogas – Citric acid – Curd.

Penicillin is the most important product for the welfare of human society. It is an antibiotic, which is used for controlling various bacteral diseases. The second most important product is biogas. It is an eco – friendly source of energy. The next important product is citric acid, which is used as a food preservative. The least important product is curd, a food item obtained by the action of lactobacillus bacteria on milk. Hence, the products in the decreasing order of their importance are as follows :
Penicillin – Biogas – Citric acid – Curd.

Question 6.
How do biofertilizers enrich the fertility of the soil?
Answer:
Biofertilizers are living orgainsms which help in increasing the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients. These are introduced to seeds, roots, or soil to mobilize the availability of nutrients by their biological activity. Thus, they are extremely beneficial in enriching the soil with organic nutrients. (MPBoardSolutions.com) Many species of bacteria and cyanobacteria have the ability to fix free atmopheric nitrogen. Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirillium and Azotobacter are free living nitrogen – fixing bacteria, whereas Anabaena, Nostoc and Oscillitoria are examples of nitrogen – fixing cyanobacteria. Biofertilizers are cost effective and eco – friendly.

Question 7.
Describe role of microorganisms in biogas production.
Answer:
The gas produced by anaerobic fermentation of waste biomass or waste bi – product is called as biogas.

Role of microorganisms in biogas production:
In biogas production under anaerobic condition, microorganism including methanogenes convert the bio – degradable organic waste into biogas and humus. The whole process is completed in three stages:

1. Solubilization
2. Acidogenesis
3. Methanogenesis.

1. Solubilization : In this step methanogenic bacteria hydrolyse the complex polymers into organic acids, alcohol by hydrolytic fermentation.

2. Acidogenesis : It is a biological reaction where simple monomers are Converted into volatile fatty acids, then into acetic acid, CO₂ and hydrogen.

3. Methenogenesis: Anaerobic digestion occurs in which acetate and CO₂ are converted into methane.

MP Board Class 12th Biology Important Questions

MP Board Class 12th Economics Important Questions Unit 7 Determination of Income and Employment

Micro Economics Determination of Income and Employment Important Questions

Micro Economics Determination of Income and Employment Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
Income and employment are determined by:
(a) Total demand
(b) Total supply
(c) Total demand and total supply both
(d) By market demand.
Answer:
(c) Total demand and total supply both

Question 2.
The relation between consumption and savings are:
(a) Inverse
(b) Direct
(c) Inverse and direct both
(d) Neither inverse nor direct.
Answer:
(a) Inverse

Question 3.
When an economy their to save all its extra income then investment calculation will be:
(a) 1
(b) Uncertain
(c) 0
(d) Infinite.
Answer:
(a) 1

Question 4.
“Supply creates it own demand”. This statement was given by the economist:
(a) Keynes
(b) Pigou
(c) J. B.Say
(d) Adam Smith.
Answer:
(c) J. B.Say

Question 5.
Classical theory is based on the assumption of:
(a) Say’s law of market
(b) Flexibility in wage rates
(c) Flexibility in interest rate
(d) All of the above.
Answer:
(d) All of the above.

Questions 2.
Fill in the blanks:

1. ……………………. refers to highest rate of return over cost expected from marginal or additional unit of a capital asset.
2. Deflationary gap is the measurement of ……………………. demand.
3. Deficit demand indicates ……………………. gap.
4. In case of excess demand bank rate …………………….
5. Multiplier can also ……………………. in opposite direction.
6. The point at which aggregate demand and aggregate supply are equal is known as …………………….
7. Unemployment is the result of …………………….
8. Propensity to consume shows relation between ……………………. and distributed income.

Answer:

1. Marginal efficiency of capital
2. Deficit
3. Deflationary gap
4. Increase
5. Work
6. Effective demand
7. Deficit
8. Consumption

Question 3.
State true or false:

1. Full employment does not mean zero unemployment.
2. Increase in interest rate in future, will reduce the savings.
3. Consumption expenditure does not increase in the same proportion as income increases.
4. Theories of employment was propounded by Marshall.
5. Unemployment is the result of deficit demand.
6. Keynes theory also applies to underdeveloped countries.
7. Keynes theory is based on the concept of full employment.

Answer:

1. True
2. False
3. True
4. False
5. False
6. False
7. True.

Question 4.
Match the following:

Answer:

1. (d)
2. (a)
3. (c)
4. (f)
5. (b)
6. (e).

Question 5.
Answer the following in one word / sentence:

1. What will be the effect of multiplier, if multiplier leakage is high?
2. Excess demand gives birth to?
3. Which is the most appropriate measure to check deficit demand?
4. Who propounded the deficit demand theory of unemployment?
5. Name the interest theory propounded by Prof. Keynes.
6. Which is the most effective measure to check it deficit demand?

Answer:

1. Less
2. Money inflation
3. Increase in public expenditure
4. Keynes
5. Liquidity preference
6. Increase in exports.

Determination of Income and Employment  Very Short Answer Type Questions

Question 1.
What do you mean by marginal propensity to consume?
Answer:
Marginal Propensity to Consume (M.P.C.):
It refers to the ratio of change in the consumption to the change in income. It may be algebraically expressed as under:

or
M.P.C = \(\frac { ∆C }{ ∆Y } \)

Question 2.
What is meant by marginal propensity to save?
Answer:
Marginal Propensity to Save (M.P.S.):
It refers to the ratio of change is saving to a change in income. It can be obtained by dividing change in savings by change in income. Algebraically it can be expressed as:

M.P.S = \(\frac { ∆S }{ ∆Y } \)

Question 3.
What is the difference between actual investment and induced investment?
Answer:
Actual investment:
Actual investment refers to realizing investment. It is what the investors actually make at different levels of income and employment in the economy.

Induce investment:
Induce investment in that investment which depends on the expected profitability of level of income.

Question 4.
What is effective demand?
Answer:
Effective demand means that amount of money which people of a country spend on consumption and investment in a specific time. That level of demand is effective which is equal to aggregate supply. According to Keynes, “By point of aggregate demand at which the aggregate curve intersect the price at that point is called effective demand.”

Question 5.
Explain voluntary and involuntary unemployment.
Answer:
Voluntary:
It signifies the situation where in all the person willing to work at existing rate of remuneration are getting employment.

Involuntary:
It refers to that situation where in all the persons are willing to work at existing rate of remuneration do not get employment. It signifies the state where the available resources are not fully utilized.

Question 6.
Explain any two measures which can be taken to remove the excess demand (Write any two).
Answer:
Followings are the two measures to be taken to check the excess demand:
1. Bank rate:
The rate at which the central bank lends money to its member banks is called bank rate. In a situation of excess demand, the central bank should raise the bank rate.

2. Open market operations:
The buying and selling of government securities and bonds in the open market by the central bank are called open market operations. In the time of excess demand, central bank sells government securities to commercial banks or to their customers.

Determination of Income and Employment Short Answer Type Questions

Question 1.
Write the characteristics of traditional theory of income and employment.
Answer:
Followings are the characteristics of theory of income and employment:
1. Automatic balance between demand and supply:
According to J.B. Say, the supply creates its own demand. When goods are produced and supplied, it automatically creates demand for some other goods, the classical economists always believed in automatic full employment through the free play of market mechanism, the forces of demand and supply.

2. Idea of unemployment is baseless:
The classical economist were not scared of the problem of unemployment. There cannot be any involuntary unemployment in classical and neoclassical world. According to them excess production is impossible so there is no question of normal unemployment.

3. Non – Interference society:
According to traditional economists, if there is no interference of the government in the economy of a nation then the situation of unemployment will never rise. If the government interferes in the matters then unemployment will always arise.

4. Supply creates its own demand:
According to classical theory supply, creates its own demand. Supply leads to production, expenditure income and demand. Therefore aggregate supply becomes equal to aggregate demand.

Question 2.
Write assumptions of traditional theory or classical theory of income and employment
Answer:
Assumption of Classical theory: Followings are the assumptions of classical theory of economics:

1. The economy enjoys the state of full employment as the aggregate demand is equal to aggregate supply.
2. There is no saving in the economy as all that is earned is invested.
3. There is free competition among the products and factors.
4. There is always possibility of extension of market.
5. There is end of interference of government and non – government and no protection is given.
6. There is no accumulation of wealth.
7. This theory works only when all the goods produced are sold in market.

Question 3.
What is unemployment according to Keynes?
Answer:
According to Keynes, there cannot be an automatic equality between aggregate demand and full employment. He holds the state of full employment rarely exits. It is possible that aggregate demand may full short of aggregate supply and state of full employment is disturbed. According to him there is a state of involuntary unemployment where able persons work at current rates of remuneration face unemployment. Unemployment exits due to lack of effective demand and lack of expenditure on consumption and investment.

Question 4.
What are the components of aggregate demand? Explain.
Answer:
Followings are the components of aggregate demand:

1. Household consumption demand:
In this category comes, the goods and services to satisfy their consumption needs. The aggregate consumption expenditure constitutes consumption demand. Household consumption depends on level of income.

2. Investment demand:
This component of aggregate demand comes from the business firms. Investment goods like machines, factory buildings are not demanded by household consumer but by business or firms.

3. Government demand for goods and services:
Like consumers and firms, government may also demand goods and services either for consumption or for investment purposes.

4. Net export demand:
To find out aggregate demand of a country items of net export demand is included in it. For this, import is subtracted from exports.

Question 5.
Write short note on:

• Full employment
• Under employment.

Or
What do you mean by full employment and under employment?
Answer:
Full employment:
The term “full employment” signifies the situation wherein all the persons willing to work at existing rate of remuneration are getting employment. Full employment never means zero unemployment.

Under employment:
It refers to that situation wherein all the persons are willing to work at existing rate of remuneration do not get employment. It signifies the state where the available resources are not fully utilized the aggregate supply of goods and services.

Question 6.
State measures to correct excess demand.
Answer:
1. Bank rate:
The rate at which the central bank lends money to its member banks is called bank rate. In a situation of excess demand, the central bank should raise the bank rate. Increase in bank rate will automatically lead to increase in banks lending rates to their borrowers. This, in turn, will reduce the volume of banks loans and advances. Consequently, expenditure on both consumption and investment is reduced.

2. Increasing the reserve ratio:
Reserve ratio refers to a minimum percentage of deposits of a commercial bank in the Reserve Bank. If the reserve ratio is increased it will reduce the credit creation capacity of the banks. When there is a situation of excess demand, central bank can increase this ratio and thereby cash resources of the banks can be reduced. This will force the commercial banks to contract credit.

3. Open market operations:
The buying and selling of government securities and bonds in the open market by the central bank are called open market operations. In the time of excess demand, central bank sells government securities to commercial banks or to their customers. This will reduce the cash reserves with the commercial banks directly and indirectly thereby affecting their capacity to make loans. It will reduce the cash reserves of the commercial banks.

4. Reducing credit inflation:
To reduce the excess demand or to reduce inflation it is essential to reduce credit inflation. By selling securities, by increasing bank rate by central bank credit inflation can be reduce. ‘

5. By taking old currency and circulating new currency:
In situation of excess demand the government cancel the old currency and in place of it new currency was introduced for circulation.

Question 7.
Distinguish between Aggregate Demand and Aggregate Supply.
Answer:
Differences between Aggregate Demand and Aggregate Supply:
Aggregate Demand:

1. Aggregate demand is refers to the total volume of goods and services demanded in an economy in a year.
2. It implies the total amount of expenditure incurred by the community on purchase of all goods and services.
3. Aggregate demand and aggregate expenditure is the same thing.

Aggregate Supply:

1. Aggregate supply refers to the total supply of goods and services in the economy in a year.
2. According to classical concept aggregate supply is perfectly in elastic with respect to the price.
3. According to Keynesian concept the aggregate supply is perfectly elastic with respect to price level.

Question 8.
Differentiate between Induced Investment and Autonomous Investment
Answer:
Differences between Induced Investment and Autonomous Investment:
Induced Investment:

1. Induced investment is that investment which depends on the expected profitability of level of income.
2. It is income elastic.
3. This investment is generally made in private sector.
4. Induced investment curve tends to move upwards indicating increased investment of the increased level of income.

Autonomous Investment:

1. Autonomous investment is that investment which is not influenced by the expected profitability.
2. It is not income elastic.
3. This investment is generally made in public sector.
4. Autonomous investment curve is a horizontal straight line parallel to X-axis. It indicating that autonomous investment is independent of the level of income.

Question 9.
Explain paradox of thrift.
Answer:
Paradox of thrift:
The paradox of thrift, in brief, states that the higher ratio of saving in an economy will create condition that result in a fall in aggregate savings. This can be explained as follows If all the people in the economy start saving more, the aggregate demand for consumption will decrease which will lead to low investment, low production and low income. Consequently the savings will reduce. This is known as paradox of thrift.

Question 10.
Are the following entered:

• On the credit side or the debit side and
• In the current accour or cap Hal account in the Balance of Payment account. You must give reasons for your

(a) Investments from abroad
(b) Transfer of funds to relatives abroad.

Answer:
(a) Investment from abroad:
Investment from abroad is a component of capital account. It comes on the credit side of capital account of balance of payment. It implies investment from abroad in shares of Indian companies, in Indian branches of foreign companies, in real estate, etc. It also includes repatriation of Indian investment abroad etc. These bring in foreign exchange.

(b) Transfer of funds to relatives abroad:
This is shown on the credit side of current account of balance of payment under the heading “invisibles” .Transfer means receipts/ payments between residents and non-residents for which the provider does not receive a quid proquo in return.

Question 11.
Measure the level of ex-ante aggregate demand when autonomous investment and consumption expenditure (A) is Rs 50 crores and MPS = 0 – 2 and the level of income (Y) is Rs 4000.00 crores. State whether the economy is in equilibrium.
Answer:
MPC = 1 – MPS = 1 – 0 – 2 = 0-8
AD = (C +1) + CY
= 50 + 0 – 8 x 4000
= 50 + 3200
= ₹ 3250
crores AS (Y) = ₹ 4000 crores
Here,
AD < AS. So, the economy is not in equilibrium.

Question 12.
What do you mean by marginal propensity to consume? How is related to marginal propensity to save?
Answer:
Marginal Propensity to Consume (MPC):
Marginal propensity to consume can be defined as,“The ratio of change in consumption (∆C) to change in income (∆Y). It indicates that part of additional income which is not spent on consumption”.
Symbolically, MPC=\(\frac { ∆C }{ ∆Y } \)
Here, DC indicates change in consumption whereas DY means change in income. For example, if national income of a country increases from 11,000 crore to ₹ 1,200 crore and, as a result, consumption expenditure goes up from ₹800 crore to ₹ 1900 crore, then
MPC will be 0-5 = \(\frac { 100 }{ 200 } \)
Relation between M.P. save and M.P.S.
Marginal propensity to save: It is the relation between change in saving and change in income.
Equation,
MPS = \(\frac { ∆S }{ ∆Y } \)
The sum of M.P.C. and M.P.S. is equal to 1
Y = C + S
Or
∆Y = ∆C +∆S.
Dividing both sides by ∆Y,we get the following:
= \(\frac { ∆Y }{ ∆Y } \) \(\frac { ∆C }{ ∆Y } \) + \(\frac { ∆S }{ ∆Y } \)
Or
1 = MPC + MPS.
So, it is proved that sum of MPC and MPS = 1.

Determination of Income and Employment Long Answer Type Questions

Question 1.
Distinguish between Classical and Keynesian Theory of Income.
Answer:
Differences between Classical and Keynesian Theory of Income:
Classical Theory:

1. The classical economist always believed in automatic full employment through the free play of market mechanism (The force of demand and supply).
2. According to it, full employment is the most normal situation of capitalistic economy.
3. This theory is based on the market.
4. According to it, “the supply creates its own demand”. Supply leads to the production, expenditure income and demand. So aggregate supply becomes equal to aggregate demand.
5. This principle is based on long term assumptions.
6. According to this principle in economy there is no possibility of more production and normal unemployment.
7. According to this principle, similarity between savings and investment is established by change in rate of interest.

Keynesian Theory:

1. According to Keynes, the state of full employment rare exists. He says that income and employment level is fixed on that point where aggregate demand fixed on that point where aggregate demand is equal to aggregate supply. So there is no need of full employment.
2. According to him, there is the state of involuntary unemployment.
3. It is based on psychological principle of consumption.
4. In the opinion of Keynes tustiy there cannot be an automatic equality between aggregate demand and full employment. It is possible that aggregate demand may fall short of aggregate supply and the state of full employment is disturb.
5. This principle is based on short term assumption.
6. According to this principle normal more production and normal unemployment is possible.
7. According to this principle similarity between saving and investment is established by change in income.

Question 2.
Explain the concept of multiplier.
Answer:
Multiplier:
According to J. M. Keynes, of all the variables involved in the determination of income and employment, investment is most important. Change in investment leads to change in national income. According to him, change in national income is a multiple of change in investment. This multiple is termed as the multiplier or investment multiplier. Thus, investment multiplier is a measure of change in national income as a result of change in investment.

Put symbols:
K = ∆Y/∆I
Where,
K = Multiplier
∆Y = Change in income
∆I = Change in investment

For example, if national income of a country increases by ₹ 300 crore as a result of increase in investment of ₹100 crore, the value of multiplier here will be 3. Because change in income is three times more than change in investment.

“Investment multiplier tells us that when there is an increment of aggregate investment income will increase by an amount which is K times the increment of investment. ” —Keynes

“Investment multiplier is the ratio of an increase in income to given increase in investment. ” —Dillard

Question 3.
Explain the factors affecting marginal efficiency of capital.
Answer:
Followings are the factors affecting marginal efficiency of capital:
1. Demand tendency:
If the demand for a product is expected to increase in future then marginal efficiency of capital goes up. This result in increases in investment. On the contrary if the demand for a product is expected to fall the marginal efficiency of the capital also goes down.

2. Cost and Prices:
If the cost of production and price of a product is expected to fall in future then the marginal efficiency of capital also falls. This reduces investment also. On the contrary if the cost of production and prices is expected to increases in futures then marginal efficiency of capital increases and investment also increases.

3. Liquidity of resources:
If an entrepreneur has a large amount of resources in terms of cash he then tries to earn profit from different types of investment. This increases the marginal efficiency of capital. On the contrary if the entrepreneur has less amount of resources as cash he has problem in making new investment and marginal efficiency of capital also reduces.

4. Changes in income:
Sudden changes in income due to unexpected profits and loss and heavy taxes or concession in taxes also affects marginal efficiency of capital.

5. Consumption tendency:
If consumption tendency is high in short-term then the marginal efficiency of capital also increases. On the contrary if consumption tendency is less in the short-term then marginal efficiency of capital also decreases.

Question 4.
Explain income and employment equilibrium with aggregate demand and aggregate supply with the help of diagram.
Answer:
According to Keynes, equilibrium level of income and employment is deter-mined where aggregate demand and aggregate supply are equal. This can be explained with the help of imaginary figures.

AD is smaller than AS, AD > AS
In the above aggregate table, the aggregate demand and aggregate supply are equal at Rs. 400 crores of National, Income. At this level saving is also equal to investment and any change on this level cannot be stable and remain for a long period of time.

Explanation with the help of curve:
This equilibrium between income and employment can be further explained with the help of given curves:

In the above figure of part-A aggregate demand (AD) cuts aggregate supply (AS) at the point E. A1 this point the equilibrium level of income and employment is determined at Rs. 400 crores. In figure of part-B show the saving and investment at the same income level.

At the equilibrium point income, saving and investment is also equal. Keynes has defined it as “Effective demand”. According to Keynes, the point at which the aggregate demand intersects with the aggregate supply the price of that point is called effective demand. According to Keynes, for equilibrium full employment is necessary.

According to him determination of equilibrium is possible only at full employment level or before and after full employment also. If equilibrium is established before full employment then it is called “imperfect employment equilibrium”. The equilibrium at full employment is called “full employment equilibrium”, which is a special situation of economy of a country.

Question 5.
Write any four factors determining propensity to consume.
Answer:
The following factors determines, propensity to consume:

1. Money income:
If there is increase in money income, the consumption expenditure will also increase.

2. Distribution of income:
If the income reaches the hands of poor people in stead of rich people, the consumption expenditure will rise. The consumption expenditure will reduce if the distribution of income is unequal and it will rise if the distribution of income is equal.

3. Fiscal policy:
The propensity to consume will decrease if more indirect taxes are imposed and it will rise if more direct taxes all imposed indirect taxes adversely affect the poor while direct taxes adversely affect the rich.

4. Future expectation of rise or fall in prices:
If the prices are expected to rise in future, present consumption will be more. If the prices expected to fall down in future present consumption will be less.

5. Effect of exposure:
The countries where goods are exposed or advertise more, there propensity to consume is more.

Question 6.
Throw light on the concept of full employment and involuntary unemployment.
Answer:
(1) Full employment: The term “Full employment” signifies the situation. Where in all the persons willing to work at existing rate of remuneration are getting employment. Full employment never means zero unemployment. According to Ward “Full employment refers to level of employment associated with a normal level of unemployment.” The full employment equilibrium refers to that equilibrium which is arrived at by equality of aggregate demand and aggregate supply.

The point of full employment will be where, the aggregate demand curve and the aggregate supply curve both intersect each other as is shown in the following diagram. Here, at O.P. (National income level) aggregate demand curve and aggregate supply curve both meet at point E. Hence, EP is represents full employment and E is called the point of full employment equilibrium.

(2) Involuntary unemployment or Under employment:
The term “unemployment” refers to that situation where in all the persons are willing to work at existing rate of remuneration do not get employment. It signifies Y the state where the available resources are not fully utilized. The aggregate supply of goods and services is perfectly elastic.

In other words the supply of can change when there is a change in demand. In this situation, the equilibrium level of output and employment will depend on the aggregate demand. It is a situation below full employment. The aggregate anticipated expenditure is less than the available aggregate output.

This can be explained by diagram:
In diagram point ‘E’ is of full employment. At this point the demand of labours is equal to the supply of labours. On OW₁ . wages ON₁ labours are willing to work. Enterprises requires only ON₂ labour demand. Thus N₁ N₂ will be known as involuntary employment.

Question 7.
What do you mean by deficit demand? What is the impact of deficient demand on production output, employment on prices.
Answer:
Deficit demand is a situation where the equilibrium between aggregate demand and aggregate supply takes place at a point below the full employment point. It is also known as under employment equilibrium. In other words deficient demand refers to the situation where available aggregate output exceeds the anticipated aggregate expenditure.

In such situation the available resources are not fully utilized. This shortage of aggregate demand does not enable us to reach the level of full employment so it is called deficient demand.

The impact of deficient demand can be studied under the following heads:

I. Impact of deficit demand on output:
if the aggregate demand is less in compare to the aggregate supply is an economy it means that what ever goods and services are available in the country are not fully demanded by people. This situation has impact on total output.
The impact are as follows:

• Due to less demand the producers will be forced to reduce the production.
• In such situation producers will not be able to utilize their present production capacity fully.
• Thus factors of production will not be fully utilized by the producers.
• Due to the situation of deficient demand the present existing firms will stop their work and new firms will not enter in the market.
• The cost of production will be high in this situation.

II. Impact of deficit demand on employment:
In an economy when the situation of ‘ deficit demand arises then it affect the employment situation also. The impact is seen in the following way:

1. Due to shortage of demand the producers will reduce the production and thus less no. of workers will be required.
2. If in the country there is a situation of partial employment then some people will have to lose their jobs.
3. If in a country already the situation of under employment prevails then the condition will became from bad to worse.

III. Impact of deficit demand on prices:
When the situation of deficit demand arises there is impact on prices of goods also. The impact is as follows:

1. If aggregate demand is less as compared to aggregate supply then in the country price level will be less.
2. Due to reduction in price level the difference of profit to the producers will be less.
3. The consumers will get the profit of this situation because they will get the goods and services at less price.

Question 8.
Explain the determination of effective demand.
Answer:
The principle of effective demand is the foundation stone of income and employment theory of Prof. Keynes. According to Keynes in an economy, employment depend on effective demand. Due to reduction in effective demand unemployment spreads in a country and only by increasing effective demand unemployment can be removed. By effective demand we mean the amount of money which people of a country spent on consumption and investment in a specific time. That level of demand is effective which is equal to aggregate supply.

According to Keynes, “The point of aggregate demand at which the curve of aggregate curve intersect the price at that point is called the effective demand. Here, AD curve represent aggregate demand function and A₁S curve represent aggregate supply function, AD and A₁S curves meet each other at N point which is a point of effective demand. At this point OP is the employment available and here OQ = receipts = costs. At any other point two curves cannot be in equilibrium. Here AD and AS are exactly equal.

Question 9.
Write the importance of effective demand.
Answer:
Following are the importance of effective demand:
(1) Determination of employment:
According to Keynes, the employment depend on effective demand and aggregate demand is equal to aggregate supply. Thus effective demand determines the quantity of demand on one hand and on the other hand the amount of income produced by it.

(2) Receiving income:
Effective demand also determines income. Labour get employment due to effective demand. Employment gives wages to labours. This is the effect of effective demand only.

(3) Importance of investment:
Effective demand also determines investment. Due to it producers are motivated to produce more. To increase production the investors and producers are encouraged to invest in new-new capital resources.

(4) The concept of full employment is rejected:
The concept of full employment is fully rejected with the help of effective demand. In practical life this concept is not accepted because employment is created by effective demand. When effective demand increases the employment is also created.

By getting employment the situation of employment is improved. By decrease in effective demand the level of employment reduces and unemployment spread in the society. Thus retrenchment of people is done even if he is capable. i > o the concept of full employment is not accepted.

Question 10.
What do you mean by excess demand? Write it causes.
Answer:
Meaning: When planned aggregate expenditure (i.e., aggregate demand) is greater than the aggregate supply (i.e., available output) at full employment level, the situation is termed as excess demand. When the anticipated expenditure in the economy is more than the value of full employment output, there exists a gap between aggregate demand and aggregate supply.

The gap is technically termed as inflationary gap. (Excess demand or Inflationary gap is a situation of escalating expenditure in the economy without a rise in the flow of goods and services.
Excess demand = Inflationary gap = ADE – ADF = FC.

Causes of Excess demand:
Excess demand may caused by several factors. Important among them are mentioned below:

• Excess demand may be caused by an increase in money supply due to deficit financing.
• It may also be caused by increase in consumption demand due to rise in propensity to consume.
• An increase in autonomous investment without corresponding increase in savings may cause excess demand.
• A fall in the supply of consumer goods and services due to diversion of resources from the production of consumer goods to the production of defense goods, will result in excess demand. The available output for the households will not be sufficient to meet their aggregate demand.
• Excess demand may also arise when demand for exports increases.

Question 11.
Explain the employment principle by Keynes.
Answer:
Keynes, in his book ‘National Principle had analyzed income and employment principle. He propounded this principle during the depression period of 1930. According to his theory the level OL. Income and employment is maintained by effective demand. In the absence of effective demand unemployment increases. Effective demand is determined by

1. Aggregate demand,
2. Aggregate supply.

The point where AD = AS, at this point Effective demand is determined. At this point the amount of production, and level of employment is determined. This can be explained by chart:
Effective Demand = Total production
Total income = Employment

Question 12.
What do you mean by Deficit demand? What are its causes?
Or
State any five causes of Deficit demand.
Answer:
Deficit demand is a situation where the equilibrium between aggregate demand and aggregate supply takes place at a point below the full employment point. It is also known as under employment equilibrium. In other words deficient demand refers to the situation where available aggregate output exceeds the anticipated aggregate expenditure.

In such situation the available resources are not fully utilized. This shortage of aggregate demand does not enable us to reach the level of full employment so it is called deficient demand. Cause of Deficient demand: In any economy the situation of Deficient demand arises due to following reasons:

• Fall in public expenditure,
• Reduction in export demand,
• Fall in investment demand.
• Fall in disposable income,
• Fall in consumption demand,
• Fall in supply of money,
• Fall in creation of credit.

Question 13.
State measures to correct excess demand.
Answer:
1. Bank rate:
The rate at which the central bank lends money to its member banks is called bank rate. In a situation of excess demand, the central bank should raise the bank rate. Increase in bank rate will automatically lead to increase in banks lending rates to their borrowers. This, in turn, will reduce the volume of banks loans and advances. Consequently, expenditure on both consumption and investment is reduced.

2. Increasing the reserve ratio:
Reserve ratio refers to a minimum percentage of deposits of a commercial bank in the Reserve Bank. If the reserve ratio is increased it will reduce the credit creation capacity of the banks. When there is a situation of excess demand, central bank can increase this ratio and thereby cash resources of the banks can be reduced. This will force the commercial banks to contract credit.

3. Open market operations:
The buying and selling of government securities and bonds in the open market by the central bank are called open market operations. In the time of excess demand, central bank sells government securities to commercial banks or to their customers. This will reduce the cash reserves with the commercial banks directly and indirectly thereby affecting their capacity to make loans. It will reduce the cash reserves of the commercial banks.

4. Reducing credit Inflation:
To reduce the excess demand or to reduce inflation it is essential to reduce credit inflation. By selling securities, by increasing bank rate by central bank credit inflation can be reduce.

5. By taking old currency and circulating new currency:
In situation of excess demand the government cancel the old currency and in place of it new currency was intro duced for circulation.

MP Board Class 12th Economics Important Questions

MP Board Class 11th Chemistry Important Questions Chapter 3 Classification of Elements and Periodicity in Properties

 Classification of Elements and Periodicity in Properties Important Questions

Classification of Elements and Periodicity in Properties Objective Type Questions

Question 1.
Choose the correct answer:

Question 1.
Variable valency is represented by:
(a) Metallic elements
(b) Normal elements
(c) Transitional elements
(d) Non – metallic elements.
Answer:
(c) Transitional elements

Question 2.
Of the following, whose size is the largest:
(a) Al
(b) Al⁺
(c) Al²⁺
(d) Al³⁺
Answer:
(a) Al

Question 3.
Electronic structure of the last shell of highly electronegative element is:
(a) ns²p³
(b) ns² np⁴
(c) ns²p⁵
(d) ns² np⁶
Answer:
(c) ns²p⁵

Question 4.
Electron affinity enthalpy depends on:
(a) On atomic size
(b) On nuclear charge
(c) On atomic number
(d) On both atomic size and nuclear charge
Answer:
(d) On both atomic size and nuclear charge

Question 5.
Electron gain enthalpy of noble gases is:
(a) Less
(b) Nearly zero
(c) High
(d) Very high.
Answer:
(b) Nearly zero

Question 6.
Alkali metals behave:
(a) As a good oxidising agent
(b) As a good reducing agent
(c) As a good hydrolyser
(d) None of these.
Answer:
(b) As a good reducing agent

Question 2.
Fill in the blanks:

1. Electron affinity of noble gases is …………………..
2. Electron affinity of Be and Mg of second group is …………………….
3. In a period, on moving from left to right, ionisation energy …………………………
4. Periodic law made by taking atomic mass as the basis is called …………………………….
5. …………………. is called Eka Boran
6. Na⁺ is …………………….. than Na.
7. Li shows diagonal relationship with ………………………..

Answer:

1. Zero
2. Zero
3. Increases
4. Mendeleev’s periodic law
5. Aluminium
6. Smaller
7. Mg.

Question 3.
Answer in one word/sentence:

1. Which scientist gives Modem periodic law?
2. Which element have highest electronegativity?
3. An element having atomic number 20, will be kept in which group in periodic table?
4. What is electron affinity of Noble gases?
5. What is the change in ionization energy on moving left to right in periodic table?
6. How many periods and groups in modem periodic table?
7. What is the other name of Eka – silicon?
8. How many elements are their in first period of modem periodic table?
9. What is the reason for the similarity in properties of Li and Mg?
10. Which oxidation state of A1 is most stable?

Answer:

1. Mosle (1913)
2. Fluorine
3. In second group
4. 0 (Zero)
5. Increases
6. Period = 7 and Group = 18,
7. Germanium
8. 2 (Two)
9. Diagonal relationship
10. +3.

Question 4.
Match the following:

Answer:

1. (c)
2. (a)
3. (b)
4. (e)
5. (d)

Classification of Elements and Periodicity in Properties Short Answer Type Questions – I

Question 1.
What is Mendeleev’s periodic law?
Answer:
Mendeleev’s periodic law:
“The physical and chemical properties of the elements are a function of their atomic masses”. This means that the physical and chemical properties of the elements get repeated after a fixed interval.

Question 2.
What is Modern periodic law?
Answer:
Modern periodic law: “Physical and chemical properties of elements are periodic functions of their atomic number”. This means when the elements are arranged in their increasing atomic numbers then after a fixed interval the elements having similar properties are repeated.

Question 3.
What is Doebereiner’s triad?
Answer:
This law was given by Doebereiner. According to this law atomic mass of the middle element was an arithmetic mean of the atomic masses of the other two.
Li₇ Na₂₃ K₃₉
That is \(\frac{39 + 7}{2}\) = 23.

Question 4.
Prove on the basis of quantum numbers that the 6th period of periodic table should have 32 elements?
Answer:
The sixth period begins with the filling of principal quantum number n = 6. In this period, the electrons enters in 6s, Af 5 d and 6p. In this sub – shells total 16 (1 + 7 + 5 + 3) orbitals are present. According to Pauli’s exclusion principle every’ orbital have maximum two electrons. So 16 orbitals should have only 32 electrons. So, in 6^th period 32 elements are present.

Question 5.
How many periods and groups were present in Mendeleev’s periodic table? What are the number of elements in each period?
Answer:
In Mendeleev’s periodic table 7 periods and 9 groups are present. In first period 2 elements, in second and third period 8 – 8 elements, fourth and fifth period, 18 – 18 elements, in sixth period 32 elements and seventh period is incomplete. In this period elements of atomic number 90 to 103, including actinides were present.

Question 6.
What change takes place on moving from left to right in period?
Answer:
On moving from left to right in period, ionization energy and electron affinity increases, but metallic property, basicity of oxides and atomic radii decreases.

Question 7.
What change occur on moving from top to bottom in a group?
Answer:
On moving top to bottom in a group atomic radii and ionic radii increases but ionization potential, electron affinity and melting point decreases.

Question 8.
What is diagonal relationship? Explain giving example?
Answer:
Diagonal relationship:
It has been observed that some of the elements of second period show similarities with the elements of third period present diagonally to each other, though belonging to different groups. For example, lithium resembles with magnesium of (group 2) and beryllium resembles with aluminium (of group 3) and so on. This similarity in properties of elements present diagonal is called diagonally relationship.

Question 9.
What is the difference between electron gain enthalpy and electro negativity?
Answer:
Electron gain enthalpy is the amount of energy released when an electron is added to the neutral gaseous atom. But electronegativity is the power of an element to attract covalent electron towards it.

Question 10.
Tell in the form of periods and group that Z = 114 will be placed?
Answer:
By writing the electronic configuration the maximum value of n will show the period.
₁₁₄Z = ₈₆[Rn]7s², 5f¹⁴, 6d¹⁰, 7p².
(∵ n = 7) period = 7
Group = 14(10 + 2 + 2).

Question 11.
Why the ionization potential of noble gases are high?
Answer:
Due to fully filled orbitals and complete octet, the electronic configuration of noble gases are stable. So to remove an electron from outer orbit high energy is required.

Question 12.
Why the electron affinity of halogen elements are high?
Answer:
Halogens have the large (-ve) value of (∆_egH) electron affinity because of their largest effective nuclear charge (Z_eff) and smallest size in their respective period. Also they have strong tendency to gain one electron to attain the stable noble gas configuration i.e., from ns², np⁵ to ns², np⁶ configuration. Thus, the electron gain process is highly exothermic for halogens. However, as we move from Cl to I, the electron enthalpies becomes less and less negative due to corresponding increase in their atomic size.

Question 13.
Whose electron affinity is more among F and Cl and why?
Answer:
Electron affinity of F is less than Cl because of small size of F, there is more repulsion among the electrons of 2p orbitals. So additive electron does not stabilize the atom.

Question 14.
Why the electron affinity of noble gases is zero?
Answer:
Noble gases have zero electron gain enthalpy. All noble gases have fully – filled valence shells (ns², np⁶). Due to their highly stable (ns², np⁶). Configurations, noble gases have absolutely no tendency to take an additional electron. Hence, noble gases have zero electron gain enthalpy.

Question 15.
Differentiate between Atomic radii and Ionic radii?
Answer:
Differences between Atomic radii and Ionic radii:
Atomic radii:

1. Atomic radius gives us idea about size of the atom. Atomic radius may be taken as the distance between the centre of the nucleus and the outermost shell of the atom. It can be measured either by X – ray or by spectroscopic methods.
2. Atomic radii of atom is more than ionic radii.

Ionic radii:

1. Ionic radius tells us about size of the ion. It is defined as the distance between centre of the nucleus and the point upto which the ion has influence in the ionic bond.
2. Ionic radii of anion is more than atomic radii.

Question 16.
Why the value of second IE₂ is more than IE₁ for any element?
Answer:
IE₁ value is the energy needed to remove first electron from the gaseous atom. With the loss of the electron. Therefore, Z _eff increases for the remaining electron. Therefore, greater energy is needed to remove the second electron from the gaseous atom. Therefore, IE₂ value of an element is always more than its IE₁ value.

Question 17.
Ionic radii of cation is less than atomic radii. Why?
Or, Size of cation is smaller than the related atom. Why?
Answer:
Cations are positively charged ions and are formed when a neutral atom loses ‘ one or more valency electrons. Thus a cation possesses the same nuclear charge but less number of electrons as compared to the parent atom. Therefore effective nuclear charge on remaining electrons increases. This causes the decrease in size. Hence, the radius of a cation is always smaller than the radius of the atom from which it is formed.

Question 18.
Ionic radii of anion is less than atomic radii. Why?
Answer:
Radii of anion:
Anions are negatively charged ions and are formed when one or more electrons are added to the valence shell of a neutral atom. Thus, an anion contains the same nuclear charge but more electrons as compared to its parent atom. This decreases the effective nuclear charge i.e., nucleus exert less influence on the valence electrons. The valence electrons move away from the nucleus and the size increases due to expansion of electron cloud. Hence, the radius of an anion is always larger than that of parent atom.

Question 19.
Why the value of electron affinity of N and Be is near zero?
Answer:
The 2s orbital of Be is complete so it is stable, so it does not allow the entry of any electron. Similarly the p orbitals of N is half filled and so stable and does not accept any electron. That is why the value of electron affinity for Be and N is near zero.

Question 20.
The size of Mg⁺² ion less than O^-2 ion whereas the electron configuration of both is same. Explain?
Answer:
The electronic configuration of Mg⁺² ion and O^2- ion is same. Both have eight electrons in valence shell but the nuclear charge of Mg⁺²2 ion is +12 whereas that of O^2- ion is +8. That is why the nuclear charge for outer electron in Mg⁺² is more than O^2-, so the size of Mg⁺² ion is less than O^2- ion.

Question 21.
The value of electron affinity increases on moving left to right in a period. Why?
Answer:
On moving across a period, the size of the atom decreases and nuclear charge 1 increases. Due to this the attraction for incoming electron increases. That is why the value of electron affinity increases in a period.

Question 22.
Explain the trend of metallic character of elements in periodic table?
Answer:
Metallic and non – metallic character:
Metallic character of an element is measured in terms of tendency of that element to lose electron i.e., electropositivity. Similarly, non – metallic character of an element is measured in terms of tendency of that element to gain electron i.e., electronegativity.

We know that ionisation enthalpies as well as electronegativities of the element increases along a period from left to right. This implies that the metallic character is maximum on extreme left (alkali metals) while the non – metallic character is the maximum on extreme right (halogens).

Question 23.
Among the O and N whose electron gain enthalpy is more?
Answer:
Among O and N, the electron gain enthalpy of O is more than N, because in N the valence orbital 2s²2p³ is half filled and so stable. So the tendency to accept the incoming electron is more in O than in N. Other than this the size of O atom is smaller than N atom so due to high nuclear charge the incoming electron added fastly.

Classification of Elements and Periodicity in Properties Short Answer Type Questions – II

Question 1.
The first IE₁ of Al is less than Mg, Why?
Answer:
The electronic configuration of A1 and Mg is:
Al₁₃ – 1s², 2s², 2p⁶, 3s², 3p¹
Mg₁₂ – 1s², 2s², 2p⁶, 3s²
The atom will be stable if it have full – filled or half – filled orbitals. In Al the p – orbital is vacant whereas in Mg the s orbital is fully filled. That is the orbital of Al is less stable than Mg. So, the energy required to remove an electron from Al atom is less in compare on to Mg atom, that is why the IE₁ of Al is less than Mg.

Question 2.
What do you mean by Shielding effect?
Answer:
Electrons have negative charge and they repel each other and this force of repulsion decreases the attractive force from nucleus to outer shell, due to this the electrons present in valency shell bounded loosely with the nucleus. In this way, the electrons present between nucleus and outer electrons causes shield and this effect is called Shielding effect.

Question 3.
Discuss the trend in ionization potential from moving left to right in a periodic table?
Answer:
On moving left to right in a periodic table the nuclear charge increases and atomic radius decreases, due to this the outer electrons are attracted more towards the nucleus and to remove an electron from outer shell more energy is required. So the ionization energy increases on moving left to right.

Question 4.
What do you think that the second electron gain enthalpy of O will be positive, more negative or less negative than first electron gain enthalpy? Give reason for your answer:
Answer:
O(g) + e^–_g → O^–_g; ∆_egH = – 141 kJ mol^-1
O^–(g) + e^–_g → O^2-_g; ∆_eg H = + 780 kJ mol^-1
When, on gaining one electron O atom forms O^– ion than energy is released. So first electron gain enthalpy is negative. But when an electron added in O^– ion than O^2- ion forms and it feels a strong repulsive force and so energy is required for addition of electron. Due to this the second electron gain enthalpy of O is positive.

Question 5.
The electron gain enthalpy of F is less negative than Cl, Why?
Answer:
Electron gain enthalpy of F is less – ve than that of Cl because when an electron is added to F, the added electron goes to the smaller n = 2 quantum level and suffers repulsion from other electrons present in this level. In case of Cl, the added electron goes to the larger n = 3 quantum level and suffer much less repulsion from other electrons.

Question 6.
Why the long form of periodic table is better than Mendeleev’s periodic table?
Answer:
The long form of periodic table is better than Mendeleev’s becasuse it has several advantages over Mendeleev’s table. The important advantages are:
1. The arrangement of elements is easy to remember and reproduce.

2. The elements have been classified on the basis of atomic number which is more fundamental than atomic weight of the elements.

3. This periodic table is closely connected to the electronic configuration of ele-ments. Therefore, the position of an element in the periodic table can easily be justified. The electronic configuration of an element can be predicted if its position in the periodic table is known.

4. The resemblances and differences of the properties of elements in periods and groups are explained on the basis of electronic arrangement in various shell i.e., electronic configuration. Thus it reflects trends in physical and chemical properties of the elements.

Question 7.
Write the characteristics of Modern periodic table?
Answer:
Characteristics of modern periodic table:

1. This periodic table is based on the electronic configuration of elements.
2. It reflects the sequence of filling the electrons in order of sub – energy levels s, p, d an Af
3. It gives clear division of elements, transitional elements and inner transition elements.
4. Attempt has been made to separate metals from non – metals. The elements on the left – hand side of the periodic table are metals and more non – metallic elements have been placed on right side.

Question 8.
Explain, why all transition elements are d-block elements but all d – block elements are not transition elements?
Answer:
Those elements whose outer electron goes in d – orbital are known as J – block elements or transition elements. The general outer electronic configuration of these elements is
(n – 1)d^1-10ns^0-2. The electronic configuration of Zn, Cd and Hg is (n – 1 )d¹⁰nsd², but they do not show the properties of transition elements. In ground state and in general oxidation state the d – orbitals of these elements are completely filled, therefore they will not be considered as transition elements. So on the basis of properties all transition elements are d – block elements, but on the basis of electronic configuration all d – block elements are not transition elements.

Question 9.
Among the pairs whose ionization energy is less. Why?

1. Cl or F
2. Cl or S
3. K or Ar
4. Kr or Xe.

Answer:

1. Among Cl and F ionization energy of Cl is less than F because size of F is small.
2. Among Cl and S, the ionization energy of S is less as the size of S is bigger than Cl.
3. Among K and Ar the ionization energy of K is less as in the valence shell of K only one electron is present which can be easily donated and K⁺ is formed but Ar has complete octet and so stable and so more energy is required for removal of electron.
4. Among Kr and Xe, the ionization energy of Xe is less because the size of Xe is bigger than Kr.

Question 10.
What are s – block elements? Write their main properties?
Answer:
Elements in which the last electron enters into s – orbital are known as s – block elements. It includes Alkali metals of group – I and Alkaline earth metals of group – II.
General properties of s – block elements:

1. In outermost orbit the electronic configuration is ns¹ or ns².
2. These elements have definite positive oxidation number which is +1 and +2 in group 1 and group 2.
3. Except hydrogen, all are metals, ionization potentials are low. Thus, these are strong electropositive, strong reducing agent and strongly metallic in nature.
4. Elements of 1st group are alkali metals and elements of 2nd group are called alkaline earth metals.
5. Oxides of these elements are basic in nature. Oxides of 1st group dissolve in water to give alkalis.
6. These elements form electrovalent compounds.
7. These elements provide colour on heating with flame.
   
8. These elements are very reactive. Reacts with water and acids displacing their hydrogen as H₂ gas.

Question 11.
What are p – block elements? Write their main properties?
Answer:
The elements in which the last electron outers in p – block are called p – block. General characteristic of p – block elements:

1. These elements have 2 electrons in 5 sub – shell and 1 to 6 electrons in p sub-shell in outermost orbit. Only in zero group elements, outer shell is completed.
2. Definite positive or negative oxidation numbers are represented by the elements. Some of the elements show variable valencies.
3. These elements form simple ions as well as complex ions of CO₃^2-, NO₃^–.
4. These are generally non – metals and metalloids. Some of the elements are heavy elements. e,g., Pb, Bi, etc.
5. Oxides are acidic in nature. Some oxides are amphoteric, e.g., PbO, SnO etc.
6. These elements form covalent compounds with each other but with the elements of s – block form electrovalent compounds.

Question 12.
Which elements are called transition elements? Throw light on their properties?
Answer:
Transition elements:
The elements which are in between s – block and p – block are called as transition elements or elements in which d – orbitals are partially filled are called transition elements. In this, last electron goes to d – orbital of orbit inner to outer so called d – block elements. Boiling point, melting point and densities of these elements are high.
Example: Cr, Mn, Fe, Cu, etc.
Properties:

1. In this two outer orbits are incomplete
2. Electronic configuration is (n – 1) d^{1 to 10} ns^{1 to 2}
3. It has metallic properties
4. These elements show variable oxidation state
5. These form coloured ions
6. These form complex salt
7. These are good catalysts
8. These form complex compounds
9. These are generally diamagnetic and
10. These also form with non-metal compounds.

Question 13.
What are inner transition elements? Write their general properties?
Answer:
In these elements three outer orbitals are incomplete. In all these elements, the s – orbital of the last shell (n) is completely filled, the d – orbitals the the penultimate (n – 1) shell invariably contains zero or one electron but the f – orbital of the antipenultimate (n – 2) shell (being lower in energy than d – orbitals of the penultimate shell) gets progressively filled. Hence the general configuration of f – block elements is (n – 2) f^1-14 (n – 1) d^{0 – 1}ns²
Lanthanides: The last electron enters in 4f subshell.
Actinides: The last electron enters in 5f subshell.

Question 14.
Explain ionization energy and electron affinity?
Answer:
Ionization Energy:
The minimum amount of energy which is needed to remove the most loosely bound electron from a neutral isolated gaseous atom in its ground state to form a gaseous cation.
M_g + Energy → M⁺_g + e^–_g
Electron Affinity:
It is equal to the change in enthalpy when an isolated gaseous atom accepts an electron to form a monovalent anion. It is denoted by ∆_egH.
In this way, if energy is released by addition of an electron than electron affinity is positive. But if energy is required to add an electron to a negative ion than electron affinity will be negative.

Question 15.
Explain atomic radii and ionic radii?
Answer:
Atomic radius:
The size of an atom is usually expressed in terms of its radius called atomic radius. It is very important property because several physical and chemical Cation properties are related to it. If the atom is assumed to be spherical than the term atomic radius means the distance from the centre of the nucleus to the outermost shell of electrons. According to quantum mechanical model, the atomic radius is defined as, the distance from the centre of the nucleus to the point up to which the density of electron cloud (i. e., probability of finding the electron) is maximum.

Ionic radius:
The ionic radius of an ion may be defined as the distance, from its nucleus to the point up to which the nucleus has influence on the electron cloud of the ion.

Question 16.
In a periodic table how the size of the atom changes? Explain?
Answer:
The distance from the centre of the nucleus to the outermost electron is called atomic radius.
In a period:
As we move left to right in a period atomic number increases by one unit in each successive element. As the addition of electron takes place in the same principal shell, they do not screen each other from the nucleus. It means the increased nuclear charge is not neutralize by the extra valency electron, cause a decrease in the size of atom.

In a group:
In moving down the group, nuclear charge is increasing with the increase in atomic number and we expect that the size of atom should decrease. But at the same time while going from one atom to another, there is increase in the number of electron shells. The effect of increased nuclear charge is reduced by shielding effect (screening effect) of the electrons present in the inner shells. Therefore, the effect of increase in the electron shell is more pronounced than the effect of increase in nuclear charge. Consequently, the atomic size or atomic radius increases down the group.

Question 17.
What is the change in reduction and oxidation properties of elements in periodic table?
Answer:
Reducing agents:
Those elements which form positive ion by removal of electron, are called reducing agents. The reducing power of any element depends upon the tendency of it to donate electron. The ionization potential of alkali elements are less due to their large size. Therefore they can easily donate electrons, so alkali elements are strong reducing agents. On moving from left to right in a periodic table in a period the reducing power decreases and on moving top to bottom in a group reducing power increases.

Oxidizing agents:
Those elements which accept electrons will work as oxidizing agents. The oxidizing power of any element depends upon its electron accepting property. Halogen easily accept electron so they are strong oxidizing agent. On moving left to right in a period the oxidizing power increases and on moving top to bottom the oxidizing power decreases.

Question 18.
Differenctiate the Modern periodic table and Mendeleev’s periodic table?
Answer:
Differences between Modem periodic table and Mendeleev’s periodic table:
Modem Periodic Table:

1. In Modem periodic table the elements are arranged in increasing order of atomic number.
2. The elements are kept in 18 groups.
3. The metals and non – metals are separately kept.

Mendeleev’s Periodic Table:

1. In Mendeleev’s periodic table the elements are arranged in increasing order of atomic mass.
2. The elements are kept in 9 groups and 7 sub – groups.
3. The metals and non-metals are not separated.

Classification of Elements and Periodicity in Properties Long Answer Type Questions – I

Question 1.
How many types of elements are there on the basis of electronic configuration? Give example of each?
Or Describe the different types of element on the basis of electronic arrangement?
Answer:
The elements have been divided into four main classes as follows:

1. Inert gases or Noble gases or Aerogens:
The elements which belongs to the group 18 of the periodic table are known as noble gases or inert gases. They have 8 electrons in their outermost shell (ns2 np6). Therefore their combining capacity or valence is zero. Hence they are inert in nature. All the members are gaseous in nature.

2. Representative elements:
All the elements of s and p – block with exception of noble gases are called representative elements or normal elements. Representative elements includes

These elements have the outer electronic configuration from ns¹ to ns²np⁵. Elements of this type use only thier outer shell electrons in the bonding with the other atom.

3. Transition elements (d – block elements):
These are the elements in which the last shell is not completely filled. These elements have configuration (n – 1)d^1-10ns^1-2 i.e., these elements contain 1 – 9 electrons in the penultimate shell and 1 – 2 electrons in the valence shell. The elements having partially filled d – orbitals are named transition elements because these represent a transition (change) from the most electropositive elements to the most electronegative elements. Strictly speaking, elements of group 12 (Zn, Cd, Hg) cannot be included in transition elements, although these elements chemically resemble the transition elements in many respects. All these elements closely resemble each other due to the presence of the same number of electrons in the outermost shell.

4. Inner transition elements (f – block elements):
Lanthanides (₅₈Ce – ₇₁Lu) and actinides (₉₀Th – ₁₀₃Lw) are collectively known as inner transition elements. In these elements, three outermost shells are not completely filled. The last electron in those enters in the (n – 2) subshell. These elements generally have the same number of electrons in the last two shells, (n -1) and n – orbital. The properties of these elements are so close to each other that it is not easy to separate lanthanides from one another.

Question 2.
Write the applications of Mendeleev’s periodic table?
Answer:
The important contributions of Mendeleev’s periodic table to chemistry are as follows:
1. Systematic study of chemistry:
The Mendeleev’s periodic table categorised the elements for the first time in a systematic way. This helped immensely in the study of the chemistry of elements and their compounds and made the study much easier. If the properties of a group are known, one can easily guess the properties of all the elements (and their compounds) placed in that group.

2. Prediction of new elements:
At the time of Mendeleev’s 56 elements were known. While arranging these elements, he left some gaps. These gaps represented the undiscovered elements. Further Mendeleev predicted the properties of these undiscovered elements f on the basis of their positions. For example, both gallium (Ga) and germanium (Ge) were not known when Mendeleev gave the periodic table. On the basis of their expected positions, he named these elements as Eka – aluminium and Eka – silicon (from the Sanskrit word eka meaning next) because he believed that these would be similar to aluminium and silicon respectively. When these elements were actually found, their properties were the same as predicted by him.

3. Correction of atomic masses:
Mendeleev also corrected the atomic masses of certain elements with the help of their expected positions and properties. For example, be – ryllium was assigned an atomic weight of 13 – 5 on the basis of its equivalent weight (4 – 5) and valency (wrongly calculated as 3). As such, it should have been placed between carbon (atomic mass 12) and nitrogen (atomic mass 14).

But no vacant place was available in between C and N and further more properties of beryllium did not justify such a position. Therefore valency 2 was assigned to beryllium which gave it an atomic weight of 4.5 × 2 = 9, as atomic weight = equivalent weight × valency and it was placed in proper position between lithium (atomic weight 7) and boron (atomic weight 11). In a similar way atomic masses of many other elements were corrected.

4. Useful in research:
Mendeleev’s periodic table is very useful to further research and study of properties of different elements.

Question 3.
What do you mean by electronegativity of an element? How it is different from electron affinity? How electronegativity changes in periodic table?
Answer:
1. Electronegativity:
It is defined as the relactive tendency of an element to attract the shared pair of electrons in a covalent bond towards itself.

2. Electron affinity:
Electron affinity is equal to the change in enthalpy when an isolated gaseous atom accepts an electron to form a monovalent anion.
The value of first electron affinity is negative as the process is exothermic but in second electron affinity energy is absorbed because the negative ion repels the upcoming electron.

3. Difference:
Electron affinity is the property to bind extra electron whereas electro negativity is the ability of an atom of a molecule to attract electron.
Trend of Electronegativity:

4. In a period:
As we move left to right in a period electronegativity increases due to decrease in size and a corresponding increase in effective nuclear charge.

5. In a group:
While moving down a group the increased nuclear charge is neutralized by screening effect. In general, the electronegativity decreases down the group due to in-creasing size.

Question 4.
The atomic number of an element is 17. By giving the electronic configuration give its place in periodic table?
Answer:
The electronic configuration of atom having atomic number 17 = Is², 2s² 2p⁶, 3s², 3p⁵ = 2, 8, 7.
1. Its outer configuration is 3s²3p⁵, so it is a p – block elements.

2. Group:
If one orbital is vacant, than their present in outer shell show the group i.e., the element is 7th group.

3. Sub – group:
If the last electron enter in s or p-sub-shell than the element is of a sub – group.

4. Period:
No. of shells show the no. of periods. This element is member of third period. group – 7, sub – group – A, period – 3.

Question 5.
What do you mean by isoelectronic species? Write the name of any one species which is isoelectronic with following atoms and ions:

1. F^–
2. Ar
3. Mg²⁺
4. Rb⁺

Answer:
In isoelectronic species the number of electrons are same but the nuclear charge is different. In such species by increasing nuclear charge, the size of the atom increases.

1. Number of e^– in F^– = 9 + 1 = 10
2. Number of e^– in Ar = 18
3. Number of e^– in Mg⁺² = 12 – 2 = 10
4. Number of e^– in Rb⁺ = 37 – 1 = 36

N^3-, O^2-, Ne, Na⁺ and Al⁺³ species, F^– and Mg²⁺ are isoelectronic species. P^3-, S^2-, Cl^–, K⁺ and Ca²⁺ species, Ar is isoelectronic species.
Similarly Br^–, Kr and Sr²⁺ species and Rb⁺ is isoelectronic species.

Classification of Elements and Periodicity in Properties Long Answer Type Questions – II

Question 1.
What is Modern Periodic law? Give the description of periodic table based on this law?
Answer:
Modern Periodic Law:
“The physical and chemical properties of elements are the periodic functions of their atomic numbers”.

Description of Periodic table:
Characteristics of Modern Periodic table:

1. Metals and non – metals are kept separate.

2. Strongly electropositive elements (s – block elements) are kept on the left side of transitional element (d – block elements) in groups 1 and 2, transitional elements are kept in the middle in groups 3 to 12 and non-metallic elements (p – block elements) are kept on the right side of transitional element (d – block elements) in groups 13 to 17.
Thus, s – block
1 – 2 groups
d – block
3 – 12 groups
p – block
13 – 17 groups

3. On the basis of filling of electrons, elements are classified into s – block, p – block, d – block and f – block elements.

4. Transitional elements are kept apart from normal elements. These elements lie in between s – and p – block. In them the last electron enters into (n – 1) d orbital therefore, these elements show similarly in properties rather than gradation.

5. Rare earth elements (Lanthanides and Actinides) are kept away from the main table in a suitable place.

6. Sub – groups of a group are eliminated.

7. Fe, Co and Ni are kept with transitional elements which is the suitable place.

8. Hydrogen is kept in group 1.

9. This classification relates the atomic configuration of elements with their position in the periodic table due to which their study is very easy.

Question 2.
What are the defects of Mendeleev’s periodic table ? How they can be remove by Modern Periodic Law?
Answer:
Defects of Mendeleev’s Periodic table:
Inspite of remarkable contribution made to chemistry, Mendeleev’s periodic table had certain defects. These defects are as follows:

1. Position of Hydrogen:
Hydrogen is a unique element and resembles with the elements of group IA (alkali metals) as well as with those of VII A group (Halogens) in its properties. Therefore, it should have been placed in both IA and VII A groups in Mendeleev’s periodic table. Therefore, the position of hydrogen in the periodic table is anomalous or controversial.

2. Position of Isotopes:
Isotopes are the atoms of same element having same atomic number but different atomic masses. Therefore, according to Mendeleev’s classification, these should be placed at different places depending upon their atomic masses. However, isotopes have not been given separate places in the periodic table.

3. Position of Lanthanides and Actinides:
Position of lanthanides (14 elements following lanthanum, atomic number 58 – 71) and actinides (14 elements following actinium, 1 atomic number 90 – 103) is also anomalous in Mendeleev’s periodic table. In this periodic table, all these elements are supposed to be placed together in III group which is not in accordance to the periodic law.

4. Similar elements placed in different group:
The elements like silver and thallium, barium and lead, copper and mercury show similar properties, yet they are placed in . different groups in Mendeleev’s periodic table.

5. Eighth group:
This group is full of anomalies. Except osmium, no other elements of this group shows the group valency i.e., no other element is octavalent. Further they all are arranged in three triads without any justification.

6. Cause of periodicity:
Mendeleev could not explain the cause of periodicity among the elements.

Modern periodic table removes a lot of defects of Mendeleev’s periodic table like:

1. Since, this table is based on electronic configuration therefore hydrogen is placed in group 1.

2. To put element of high atomic mass before the element of low atomic mass:
In Mendeleev’s periodic table, elements of higher atomic mass precedes elements of lower atomic mass. But their position is justified in Modem periodic table because element with higher atomic mass has lower atomic number, e.g., cobalt (atomic mass 58.93, atomic number 28).

3. Position of Isotopes:
Isotopes of an element possess same atomic number, therefore, there is no necessity of giving them separate positions in the periodic table.

4. To place elements with different properties at the same place: In Mendeleev’s periodic table, elements of different properties are placed at same place. For example, elements of sub – group IA and IB. But in Modem periodic table, this defect is removed by separating the sub – groups.

5. Position of Noble gas:
Noble gases have been placed between VIIIB electromotive elements and IA electropositive elements.

6. Diagonal relationship:
It can be explained on the basis of electronic configuration and atomic radius.

Question 3.
Compare the Mendeleev’s periodic table and Modern periodic table?
Answer:
Comparison between Mendeleev’s periodic table and Modem periodic table:
Mendeleev’s periodic table:

1. Elements are arranged in order of their increasing atomic weight.
2. There are 9 horizontal blocks known as groups.
3. Zero group is added later on.
4. Elements of different properties kept in same group.
5. Every isotope don’t have different place.

Modem periodic table:

1. Elements are arranged in order of their increasing atomic number.
2. There are 18 horizontal blocks called groups.
3. Nobel gases are at the end of each period.
4. Elements of different properties kept in different groups.
5. There is no need to give different place to isotopes.

Question 4.
What is ionisation energy? Explain the factors affecting ionisation energy?
Answer:
Ionization energy:
The amount of energy which is required to separate the outermost electron from atom is called ionic energy or ionic potential i.e., to convert atom into positive ion the necessary energy required is called as ionic energy. Its unit is kJ mole^-1.
So, M_(g) + Energy → M⁺_(g) + e^–
M_(g) – Electron → M⁺_(g) + Ionisation energy.
Factors affecting ionization energy:
1. Size of atom or ion:
Greater the size of atom or ion, weaker are the forces of attra-ction and lower is the value of ionization energy.

2. Nuclear charge:
Greater the nuclear charge, more is the attraction for electrons and hence, greater is the value of ionization energy.

3. Shielding effect:
In multielectron atom with increase in atomic number, shielding effect increases due to which valence shell electron feels lesser attraction and hence, value of ionization energy is lower.

4. Penetration effect:
Simple the shape of orbitals, more is the penetration of it for the nucleus. That is it experience greater attraction. Thus, value of ionization energy is higher. It follows the order s > p > d > f

5. Electronic configuration:
Completely filled and half-filled orbitals are more stable than any other arrangement. Thus, value of ionization energy is higher for it.

6. Trend in periodic table:

(a) In period:
Ionisation energy generally increases from left to right in a period. This is due to gradual increase in nuclear charge and decrease in atomic size of the elements.

(b) In a group:
There is a gradual decrease in ionisation energy moving top to bottom. This is due to increase in the number of the main energy shell i.e., size of the atom increases.

Question 5.
What do you mean by Electron affinity? Explain the factors affecting it?
Answer:
Electron affinity:
The electron affinity of an atom is the energy released, when an electron is added to a neutral atom. It is expressed in kcal/mol. Electronegativity is a relative number on an arbitrary scale while electron affinity is expressed in the units of energy (kcal/mol).
A_g + e^– → A^–_g + E₁ (Exothermic)
A^–_g + e^– → A^2- – E₂ (Endothermic)
A^2-_g + e^– → A^3-_g – E₃ (Endothermics)
This way in the addition of an electron to neutral isolated atom energy is released and electron affinity is positive, but in an anion energy is required to add an electron because the anion opposes the intrance of an electron. Thus, electron affinity for charged ions is negative.

Factors affecting electron gain enthalpy: Some important factors affecting electron gain enthalpy are:

1. Atomic size
2. Nuclear charge
3. Electronic configuration.

1. Atomic size:
As the atomic size increases, the distance between the nucleus and the incoming electron increases. This results in lesser attraction. Consequently, electron gain enthalpy becomes less negative.

2. Nuclear charge:
Greater the nuclear charge, greater will be attraction for the incoming electron and as a result, AH becomes more negative.

3. Electronic configuration:
Atoms having stable electronic configuration have lesser tendency to accept the electron. Due to this the value of electron gain enthalpy becomes less negative.

4. Half – filled and ful – filled orbitals:
Half – filled and ful – filled orbitals are stable and in this condition they cannot easily accept the electron. So the value of electron affinity for such elements are zero.

5. Periodicity:

1. In periods: On moving left to right in a period the electron affinity increases as the nuclear charge increases.
2. In group: On moving down the group the electron affinity decreases due to increase in size of atom.

MP Board Class 11 Chemistry Important Questions

MP Board Class 12th Biology Important Questions Chapter 9 Strategies for Enhancement in Food Production

Strategies for Enhancement in Food Production Important Questions

 Strategies for Enhancement in Food Production Objective Type Questions

Question 1.
Choose the correct answer:

Question 1.
Triticum aestivum wheat is:
(a) Haploid
(b) Diploid
(c) Tetraploid
(d) Hexaploid.
Answer:
(c) Tetraploid

Question 2.
Man – made cereal is :
(a) Potato
(b) Triticale
(c) Triticum
(d) Sugarcane.
Answer:
(b) Triticale

Question 3.
In cattles, anthrax is disease is caused by :
(a) Bacteria
(b) Fungi
(c) Virus
(d) Ticks.
Answer:
(a) Bacteria

Question 4.
The causal organism of haemorrhagic septicaemia as :
(a) Brucella avartus
(b) Bacillus sp.
(c) Pasturella boviseptica
(d) Clostridium.
Answer:
(c) Pasturella boviseptica

Question 5.
Foot and Mouth disease of cattles is caused by :
(a) Fungi
(b) Bacteria
(c) Virus
(d) Mycoplasma.
Answer:
(c) Virus

Question 6.
The disease caused after rainy season is :
(a) Black fever
(b) Haemorrhagic septicaemia.
(c) Ponkni
(d) Anthrax.
Answer:
(c) Ponkni

Question 7.
The vaccination for galghontu is given to animal in :
(a) January – February
(b) March – April
(c) May – June
(d) October – Nov ember.
Answer:
(c) May – June

Question 8.
The cause of plague disease of animals is :
(a) Fungi
(b) Bacteria
(c) Virus
(d) Mycoplasma.
Answer:
(c) Virus

Question 9.
Example of cereal plant is :
(a) Wheat
(b) Rice
(c) Maize
(d) All of these.
Answer:
(d) All of these.

Question 10.
Botanical name of common wheat is :
(a) Triticum aestivum
(b) T. vulgare
(c) T. durum
(d) T. monococcum
Answer:
(b) T. vulgare

Question 11.
Wheat and rice belong to family
(a) Graminae
(b) Papillionaceae
(c) Euphorbiaceae
(d) Compositae
Answer:
(a) Graminae

Question 12.
Padma and Jaya are the improved varieties of:
(a) Wheat
(b) Rice
(c) Gram
(d) Groundnut
Answer:
(b) Rice

Question 13.
Botanical name of Ratanjot is :
(a) Pongamia pinnata
(b) Ricinus communis
(c) Jatropha curcas
(d) None of these
Answer:
(c) Jatropha curcas

Question 14.
Fertilizer elements are:
(a) Nitrogen
(b) Phosphorus
(c) Potassium
(d) All of these
Answer:
(d) All of these

Question 15.
Fertilizer that supplies least % of nitrogen is :
(a) Urea %
(b) (NH₄) SO₄
(c) (NH₄) NO₃
(d) Organic nitrogen fertilizer.
Answer:
(d) Organic nitrogen fertilizer.

Question 16.
Fertilizer that supplies both nitrogen and phosphorus to soil:
(a) Ammonium sulphate
(b) Ammonium nitrate
(c) Urea
(d) Super phosphate
Answer:
(d) Super phosphate

Question 17.
Nitrogen fixing organism is :
(a) Rhizobium
(b) Azolla
(c) Azotobacter and Azospirillum
(d) All of these
Answer:
(d) All of these

Question 18.
VAM is :
(a) Bacteria
(b) Yeast
(c) Fungi
(d) Virus.
Answer:
(c) Fungi

Question 2.
Fill in the blanks :

1. The process of separating animals with desired characters for breeding purpose is called ………………………..
2. Breeding between two genetically different animals is called ………………………..
3. Anthrax fever of cattles is caused by bacterium ………………………..
4. Ranikhet disease of fowls was first observed in ……………………….. district.
5. Fowl pox disease is caused by ………………………..
6. No. of chromosomes in Triticum vulgare is ………………………..
7. Groundnut belongs to family ………………………..
8. Botanical name of Karanj is ………………………..
9.  ……………………….. is the first genetically engineered food.
10. Rhizobium, Azolla and Anabaena are the examples of ………………………..
11. Insecticides azadirachtin is obtained from leaves of ……………………….. plants.
12. Insects harming plants are called ………………………..
13.  ……………………….. bacterium is found in the roots of leguminous plants. (MP 2015)
14. Nostoc and Anabaena are called ………………………..
15. Bacteria responsible for N₂ fixation is ……………………….. (MP 2009 Set A)

Answer:

1. Selection
2. Outbreeding
3. Bacillus anthraxis
4. Ranikhet (Kumau)
5. Virus
6. 42
7. Papillionaceae
8. Pongamiapinmta
9. Flavr – Savr Tomato
10. Biofertilizers
11. Neem
12. Pest
13. Rhizobium
14. Cyanobacteria
15. Rhizobium.

Question 3.
Match the followings :
I.

Answer:

1. (c)
2. (d)
3. (e)
4. (a)
5. (b).

II.

Answer:

1. (d)
2. (e)
3. (a)
4. (c)
5. (b).

III.

Answer:

1. (d)
2. (c)
3. (a)
4. (b)

Question 4.
Write the answer in one word/sentences:

1. Name the type of vegetative propagation in the plants having bulb.
2. Name the product of hybridization of two different species.
3. Name the first man – made crop.
4. Give one example of millet.
5. Write botanical name of coconut. (MP 2013,17)
6. What is called breeding between two closely related animals?
7. In which animal Ranikhet disease occur ? (MP 2015)
8. Name the causal organism of anthrax disease of cattles.
9. Write the name of galghontu disease of cattles.
10. Which hormone is used for production of milk in cows? (MP2016)
11. Give the botanical name of any one cereal plants.
12. Name the soil best suited for rice cropping.
13. Give the botanical name of any oil seed crop.
14. Give the botanical name of Ratanjot.
15. Name the technique by which genetically modified plants are produced.

Answer:

1. Scaling
2. Hybrid
3. Triticale
4. Rye
5. Coccus nucifera
6. Inbreeding
7. Fowls
8. Bacillus anthraxis
9. Pasturella boviseptica
10. Stilbrestol hormone,
11. Triticum aestivum (Wheat)
12. Clay loam
13. Arachis hypogea (Groundnut)
14. Jatropha curcas
15. Transgenesis.

Strategies for Enhancement in Food Production Short Answer Type Questions

Question 1.
What is meant by the term ‘breed’? What are the objective of animal breeding?
Answer:
Breed referes to the group of animals having same ancestral characters, general appearance, size, etc.

Objectives of animal breeding:

1. To increase the quantity of yield.
2. To improve the desirable qualities of the produce.

Question 2.
Name the methods employed in animal breeding. According to you which of the methods is best? Why?
Answer:
The methods employed in animal breeding are :

1. Natural methods: These can be carried out by inbreeding and outbreeding methods.
2. Artificial methods : These are carried out by artificial insemination and Multiple Ovulation Embryo Transfer (MOET).

The artificial method of animal plant breeding is best as it ensures good quality of progeny. It is also economic and time saving process to obtain the desirable progeny.

Question 3.
What is apiculture? How is it important in our lives?
Answer:
Apiculture is the practice of bee – keeping for the production of various products such as honey-bee’s wax, etc. Honey is a highly nutritious food source and is used as an indigenous system of medicines. Other commercial products obtained from honeybees include bee’s wax and bee pollen. Bee’s wax is used for making cosmetics, polishes and is even used inseveral medicinal preparations. Therefore, to meet the increasing demand of honey, people have started practicing bee – keeping on a large scale. It has become an income generating activity for farmers since, it requires a low investment and is labour intensive.

Question 4.
Discuss the role of fishery in enhancement of food production.
Answer:
Fishery is an industry which deals with catching, processing and marketing of fishes and other aquatic animals that have a high economic value. Some commercially important aquatic animals are Prawns, Crabs, Oysters, Lobsters and Octopus. Fisheries play an important role in the Indian economy. This is because a large part of the Indian population is dependent on fishes as a source of food, which is both cheap and high in animal protein. A fishery is an employment generating industry especially for people staying in the coastal areas.

Question 5.
Briefly describe various steps involved in plant breeding.
Answer:
The major steps in breeding a new genetic variety of a crop are as follows:

1. Collection of variability.
2. Evaluation and selection of parents.
3. Cross – hybridization among the selected parents.
4. Selection and testing of superior recombinants.
5. Testing, release and commercialization of new cultivars.

Question 6.
Explain what is meant by biofortification.
Answer:
Biofortification is a process of breeding crops with higher levels of vitamins, minerals, proteins and fat content. This method is employed to improve public health. Breeding of crops with improved nutritional quality is undertaken to improve the content of proteins, oil, vitamins, minerals and micro – nutrients in crops. It is also undertaken to upgrade the quality of oil and proteins. An example of this is a wheat variety known as Atlas 66, which has high protein content in comparison to the existing wheat. In addition, there are several other improved varieties of crop plants such as rice, carrots, spinach etc. which have more nutritious value and more nutrients than the existing varieties.

Question 7.
Which part of the plant is best suited for making virus free plant and why?
Answer:
The terminal bud having apical meristem are the best suited parts of plant for making virus free plant because they are not infected by virus.

Question 8.
What are the major advantages of producing plants by nticropropagation?
Answer:
Major advantages of producing plants by micropropagation are:

1. Large number of plants can be grown in short – time
2. Disease – free plants can be obtained.
3. Plants that have lost the capacity to produce seeds can be grown
4. The plants where sexual reproduction is absent, may be hybridised by tissue culture.
5. Plants produced are genetically similar to the parent and have all its characteristics.

Question 9.
Find out what are the various components of the medium used for propagation of an explant in vitro are?
Answer:
The major components of the medium for in-vitro propagation are :

1. Water
2. Agar – agar
3. Sucrose
4. Inorganic salts
5. Vitamins
6. Amino acids
7. Growth hormones like Auxin, Cytokinins.

Question 10.
Name any five hybrid varieties of crop plants which have been developed in India.
Answer:

1. Cauliflower varieties – Pusa shubhra and Pusa snowball K – 1
2. Brassica varieties – Pusa swamim (Karan rai)
3. Wheat varieties – Himgiri
4. Rice varieties – Jaya and Ratna
5. Chilli varieties – Pusa Sadabahar.

Question 11.
What is scaling? What are its importance?
Answer:
Scaling:
It is a method of vegetative propagation which is applicable for growing plants having bulbs, (example Onion, Garlic). In this method, all the scales of bulb are separated and planted in the field (Soil) having all the necessary conditions for their growth. Here scales develop to produced small bulblets. About 3 to 5 bulblets developing from one scale. This method is applicable for the plants belonging to the family Liliaceae. example Garlic, Onion, Lilium, etc.

Question 12.
What is tissue culture? What are its objectives?
Answer:
Tissue culture:
“Tissue culture is an experimental process through which a mass of cells (callus) is produced from an explant tissue and the callus produced in this way can be used directly either to regenerate plantlets or to extract to some primary and secondary metabolites.”

When appropriate culture conditions were provided, cell masses could then proceed along various developmental pathway, to regenerate shoot and root organs and eventually whole plants.

Aims of Plant Tissue Culture:

1. To develop new plants from the plant organ other than seeds.
2. To produce hybrid varieties of plants.
3. To produce disease free plants from diseased plants.
4. To reduce the period of reproductive cycle.
5. Development of haploid plants.
6. To develop stress resistance plants.

Question 13.
What is callus culture? Give its technique.
Answer:
Callus culture:
Callus is the unorganised and undifferentiated mass of tissue. The plant body of higher plants is made of multicellular, well organised differentiated structures like root, stem, leaves etc. Sometimes the cells of these differentiated structures proliferate to form large mass of unorganized and undifferentiated cells which is called as callus and this process is called callus culture. In this methods, the isolated plant cells tissues or organs are cultured in nutrient medium in glass culture tubes or in petridishes under aseptic conditions. The cultured part is called as explant. The growth responses depend upon the source of the explant, composition of the nutrient medium and the suitable growth conditions.

Technique of callus culture : Callus culture involves the following steps :

1. First it is necessary to sterilize the plant organ from which an explant is taken. Sterilizing agents commonly used are mercuric chloride solution (0.1 w/v), sodium hypochloride (1.6 available chlorine) and a solution of bromine in water (1% w/v). Explants can be taken from seedlings (cotyledon, hypocotyl or root) or mature organs or from wood stem parts.

2. Wash the explant with distilled water, cut small pieces of it and transfer it on suitable culture medium. Agar agar is used for making culture medium. The culture media was supplemented with amino acids, vitamins, kinetin or other growth factor. An auxin and usually a cytokinin promote high growth rate of callus.

Question 14.
Why aeration is essential in the process of tissue culture?
Answer:
For any living being, respiration is a must. Through respiration only it can perform various activities. Oxygen is necessary for respiration.Tissue culture also needs oxygen, then only it can grow. Aeration provides oxygen to the plant parts, thus aeration is essential in the process of tissue culture.

Question 15.
What is inbreeding ? Give its advantages.
Answer:
The mating of more closely related individuals within the same breed for 4 – 6 generation is called inbreeding. It may lead to inbreeding depression i.e., the loss of fertility, vigour and productivity of the hybrid.

Question 16.
List the components which are present in honey. Name the three species of honeybee and write the chemical compositions of honey.
Answer:
There are three species of honeybee:

1. Apis indica
2. Trigona species
3. Malinopa species.

Uses of honey:

1. In the form of medicine.
2. In the form of nutritive food material.

Chemical composition :

Fructose – 41%
Glucose – 35%
Sucrose – 1.9%
Dextrine – 1.5%
Protein – 0.18%
Mineral salts – 3.3%
Water – 17.25%

Some amount of vitamins B, B6, Coline, Vitamin C and D.

Question 17.
What precautions should be kept in the process of incubation?
Answer:
Incubatory period is 21 days in fowl, precautions of incubation of hens are as follows:

1. The eggs chosen should be of good quality.
2. Egg size should be medium.
3. Colour of egg should be white.
4. Eggs should be washed in water.
5. Eggs should not be shaken.
6. In summers, eggs should not be kept more than 30 days.
7. At night, the fowl should be fed before incubation. Incubation of egg should be done by Indian fowl.

Question 18.
Give three significance of poultry farming.
Answer:

1. Poultry provide humans with companionship, food and fiber in the form of eggs, meat and feathers.
2. Poultry rearing and poultry farming is a good source of income.
3. It provides additional income and job opportunities.

Question 19.
Give the characteristics of meat providing chickens and give two examples of these.
Answer:
Characteristics of meat providing chickens are as follows:

1. Size is big.
2. They intake large quantity of nutrition.
3. Theii feathers are loose.
4. Their growth rate is low.
   Example: Australorps, Sussex.

Question 20.
Write the examples of three freshwater and three marine water fishes and give its significance.
Answer:
Examples of three freshwater fishes :

1. Rohu
2. Catla,
3. Seenghala.

Significance of Freshwater fishes :

1. Rohu (Labio rohita) : Its brain is rich in phospho protein which improve eye sight.
2. Catla {Catla catla) : Its brain is rich in phospho protein which improve eye sight.
3. Seenghala {Mystus seenghala) : It is rich in iron and copper which is good for circulatory system.

Examples of three marine water fishes:

1. Hilsa
2. Pomfret
3. Bombayduck.

Significance of Marine water fishes :

1. Hilsa (Ilishaa species): It is rich in omega – 3 fatty acid.
2. Pomfret {Sfromatus niger): High in vitamin D
3. Bombay duck {Harpodon): It is the source of calcium.

Question 21.
Fish meat is better than other animals, why?
Answer:

1. Fish meat is better because it is rich in protein.
2. Iodine is found in it which protects from goiter disease.
3. It has low fat so, it protects our heart.
4. Fat soluble vitamin A and D are found in much quantity.
5. It is digestible. So, it is better for children.

Question 22.
Name the developed breed of cow and buffalo. Explain why buffalo milk is better than cows milk.
Answer:
Developed varieties of Cow:

1. Holstein friesian
2. Jersey
3. Ayer Shayer and
4. Brown swiss.

Developed varieties of Buffalo:

1. Murra
2. Surti
3. Bhadavari and
4. Nagpuri.

Buffalo’s milk is better than Cows milk because :

1. Buffalo gives triple qunatity of milk than cow.
2. Buffalo milk is rich in fat.
3. It has much resistance power.

Question 23.
What is the significance of sheep and goat? Give the name of three Indian species of each.
Answer:
Zoological name of sheep is Ovis aries. It gives wool, meat and leather. Its Indian species are:

1. Lohi: It gives carpet quality of wool and meat production.
2. Bakharwal.
3. Patanwadi.

Zoological name of goat is Capra aegagrus. It gives us both meat and milk. The three, species are as follows :

1. Cashmere goat.
2. Sirohi.
3. Jamunapari.

Question 24.
Name the five species of chicks.
Answer:

1. Rhode Island Red
2. New Hampshired
3. Light Sussex
4. Australorps
5. White Leghorn.

Question 25.
How foot and mouth disease of cattles spreaded? Write symptoms and control measures of this disease.
Answer:
Foot and mouth disease is a highly contagious viral disease caused by Foot and Mouth Disease Virus (FMDV). It affects clovenhoofed animals including cattle, buffalo, camels, sheep, goats, deer and pigs. Since, it is highly infectious, can be spread by infected animals through contact with contaminated animals.

Symptoms of disease:

1. High fever lasting two to five days.
2. Animals become dull, eat less due to painful lesions in the mouth.
3. Weight loss.
4. Ulcer in mouth, foot and teats and causes wound thus, parts become painful and it fails to walk properly.

Question 26.
Give characteristics of egg laying chicken.
Answer:
Characteristics of egg laying chicken are as follows:

1. Their skin is soft.
2. A gap of 3 – 4 fingers is there between pubic and keel bones.
3. Their body is heavy in weight.
4. Their vent is soft and moist.
5. Their romb is well developed, red in colour and soft.

Strategies for Enhancement in Food Production Long Answer Type Questions

Question 1.
Write the name of causal organism, symptoms of disease and control measures of ranikhet disease of fowls.
Answer:
1. Ranikhet Disease : This disease was first discovered from the hills of Ranikhet (Kumau), hence called Ranikhet disease.

2. Causal organism: Virus.

3. Symptoms:

• Difficulty in breathing.
• Diarrhoea.
• Head, neck and legs are paralyzed.
• Loss of appetite.
• Increase in the temperature of the body.
• Secretion of mucilagenous substance from the mouth and nostrils.
• The colour of the body become voilet.
• Laying of egg is inhibited and eggs become ruptured.

4. Control and Treatment:

1. Isolation.
2. Died individuals should be immediatly burned.
3. Water should be disinfected.
4. Vaccination by ranikhet vaccine :

• F strain vaccine given to 1 to 3 days old chicks.
• Freeze dried chick embryo vaccine is given to 6 to 8 months old chicks.

Question 2.
Write the method and advantages of artificial breeding in cattles.
Or
What is artificial insemination? Write its importance.
Answer:
Artificial Hybridization:
It is a method in which sperms of male are injected into the reproductive tract of female ones. Where they fertilize egg to produce individuals with new characters.

Artificial hybridisation involves the following steps:

1. Selection of Parents:
It is the first step of natural hybridization in which male and female individuals with desired characters are selected. Usually healthy animals with desired characters are selected.

2. Collection of Semen:
It is the second step of artificial hybridization. In this step male individuals are stimulated mechanically or electrically so, that they release semen. This semen is collected in vials.

3. Preservation of Semen:
Collected semen is diluted with appropriate diluting liquid and is stored in refrigerators.

4. Introduction of Semen into vagina (= Insemination):
In this step, the desired semen is injected into the vagina of female individuals when they are heated. This technique was used for the first time by Spallanzani in 1780 in dogs. In India, this technique was used for the first time by Animal Research Institute, Eta Nagar (U.P.). More than 10 – 70% species of cattles are developed by this technique.

Precaution taken during insemination:

1. Insemination should be done in appropriate period.
2. Only high quality semen should be used.
3. Correct technique of insemination should be used.
4. The animals should be healthy during insemination.

Advantages of artificial insemination:

1. Few semen of healthy males are used for inseminating many female individuals.
2. The transportation of semen in ampules is easier.
3. The problem of availability of suitable males is solved by the development of this technique.
4. Cattles with desired characters should be used.

Question 3.
How can we provide high living standards for poultry farming?
Answer:
The steps for providing high living standards are as follows:

1. Protection
2. Provide proper places
3. Necessary facility
4. Cheap and comfortable
5. Clean
6. Facility of water and light
7. Nearness from market
8. Protection from parasites and other insects.

While the construction of poultry farms see that they are made of low prices and keep in mind the following things:

1. There is no moisture left in the farm.
2. Farm should be in a place where there is proper sunlight because microorganism can not grow in this situation.
3. There should be proper aeration facility because there are no sweat glands present in fowls as they release moisture by
4. the process of breathing.
5. There should be cleanliness in farm.
6. Fowl is a feable bird who has lots of enemies this is the reason they should be defended.

Question 4.
What is aquaculture? Describe various steps of aquaculture.
Answer:
The culture of useful aquatic organisms specially animals is called as aquaculture.

Steps involved in aquaculture (Fishery):
Four types of ponds are required for the culture of fished at commercial level.

1. Hatchery tank : For fish culture first of all fish seeds are sown in hatchery tank.
2. Nursing tank : After hatching, small fishes are transferred to the nursing tank.
3. Rearing tank : When fishes attain a size of 2 – 3 inches than they are transferred into the rearing tank.
4. Storage or Stocking tank : After attaining Suitable size, these fishes are transferred into the storage tank where these fishes are stored and supplied to the market.

Question 5.
What is single cell culture? Explain paper raft technique and its application.
Answer:
Single Cell Culture :
The culturing of a single cell on suitable sterilized culture media under controlled and aseptic conditions is called single cell culture. Establishment of a single cell culture provides an excellent opportunity to investigate the properties and potentialities of plant cells. Several workers have successfully isolated single cell division and even raised complete plants from single cell cultures.

Paper raft technique of single cell culture:
1. In this technique, the single cells are isolated with the help of micropipette and transferred on to the upper surface of filter paper resting on nurse callus. These active nurse callus and the culture medium piovides growth factors to the single cells.

2. The single cells then divides and as a result of proliferation in them, the colonies develop.

3. Colonies formed in nutrient medium are transferred to the subcultured fresh nutrient media. The callus developing from such single cells are called as single cell clones.

Question 6.
There is a scope for better prospects through aquaculture in the rural areas of Chhattisgarh. Discuss.
Answer:
In the village area of Chhattisgarh ponds are developed. In all villages and towns of Chhattisgarh many ponds can be seen. Canals, dams and water reservoirs are constructed for development purpose. These all sources can be used for progress of the state by scientific way.

Production of useful aquatic organisms is known as aquaculture. Various algae and aquatic animals such as fishes, prawn, crab, oyster etc. are cultured in pond Pisciculture, Prawn culture and Pearl culture are various main culture of aquaculture. Pisciculture is rearing and management of fishes. Prawn culture is production of prawn. Pearl culture is rearing and management of oyster for pearl production. All these productions has commercial importance.

Question 7.
How can crop varieties be made disease resistant to overcome food crisis in India? Explain, Name some disease resistance variety in India. Give the method of breeding for disease resistant variety.
Answer:
Crop varieties can be made disease – resistant by conventional breeding methods or by mutation breeding. The germplasm is screened for resistance source or mutations are introduced followed by hybridization of selected parents. The resulting hybrids are evaluted and tested finally, disease resistant varieties are released.

Disease resistant variety of:

1. Wheat to leaf and stripe rust – Himgiri.
2. Brassica to white rust – Pusa swamim.

Methods to breeding for disease resistance:

1. Hybridization.
2. Selection.

These steps are involved it:

1. Selections of breed from resistant source.
2. Hybridization of selected breed.
3. Selection of Hybrid.
4. Evaluation.
5. Testing of new variety and its production.

By hybridization and selection some fungi, bacteria and viruses can be disease resistant. These varieties given below :

Table : Disease resistant variety of crops.

Question 8.
How is plant breeding helpful to provide resistance to pests?
Answer:
Plant breeding for developing resistance to insect pests:

1. The host crop plants may be resistant to insect pests due to the morphological, biochemical or physiological characteristics.

2. Some characteristics that lead to pest resistance are :

Hairy leaves in plant example resistance to Jassids in cotton and cereal leaf beetle in wheat.
Solid stem in wheat exhibits non – preference by stem sawfly.
In cotton, smooth leaf and absence of nectar repel bollworms.
In maize, high aspartic acid, low nitrogen and sugar content protects them from stem borers.

3. The steps of breeding method is same as for the other agronomic traits.

4. Some varieties developed by hybridization and selection are as follows:

Question 9.
Explain in brief the role of animal husbandry in human welfare.
Answer:
1. Animal husbandry evolves new techniques and technologies for the management of livestock like buffaloes, cows, pigs, horses, cattle, sheep, camels, goats, etc., that are useful to humans.

2. These methods can also be applied rearing animals like bees, silkworm, prawns, crabs, fishes birds, pigs, cattle, sheep and camels for their products like milk, eggs, meat, wool, silk, honey, etc.

Question 10.
If your family owned a diary farm, what measures would you undertake to improve the quality and quantity of milk production?
Answer:
Dairy farm management deals with processes which aim at improving the quality and quantity of milk production. Milk production is primarily dependent on choosing improved cattle breeds, provision of proper feed for cattle, maintaining proper shelter facilities and regular cleaning of cattle. Choosing improved cattle breeds is an important factor of cattle management. Hybrid cattle breeds are produced for improved productivity.

Therefore, it is essential that hybrid cattle breeds should have a combination of various desirable genes such, as high milk production and high resistance to diseases, Cattle should also be given healthy and nutritious food consisting of roughage, fibre concentrates and high levels of proteins and other nutrients. Cattle’s should be housed in proper cattle-houses and should be kept in well ventilated roofs to prevent them from harsh weather conditions such as heat, cold and rain. Regular baths and proper brushing should be ensured to control diseases. Also, time – to – time check – ups by a veterinary doctor for symptoms of various diseases should be undertaken.

MP Board Class 12th Biology Important Questions

MP Board Class 12th Economics Important Questions Unit 6 National Income and Related Aggregates

Micro Economics National Income and Related Aggregates Important Questions

Micro Economics National Income and Related Aggregates Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
Macro-economics is the study of:
(a) Principle or Theories of national income
(b) Consumer’s theory
(c) Production theory
(d) None of these.
Answer:
(a) Principle or Theories of national income

Question 2.
Out of the following which is not a flow:
(a) Capital
(b) Income
(c) Investment
(d) Depreciation.
Answer:
(a) Capital

Question 3.
From the following which method is used for measuring national income:
(a) Production method
(b) Income method
(c) Expenditure method
(d) All of the above.
Answer:
(d) All of the above.

Question 4.
Which of the following is included in the primary sector:
(a) Land
(b) Forest
(c) Mines
(d) All of the above.
Answer:
(d) All of the above

Question 5.
Total national income divided by total population is known as:
(a) Private income
(b) Personal income
(c) Personal spendable income
(d) Per capital income.
Answer:
(d) Per capital income

Question 6.
Production enterprises are divided in:
(a) Two sectors
(b) Three sectors
(c) Four sectors
(d) Five sectors.
Answer:
(b) Three sectors

Question 2.
Fill in the blanks:

1. Agriculture is included in sector.
2. Pigou has divided welfare into parts.
3. Chinese product is included in area of the economy.
4. National income in India is calculated by
5. The total value of all final goods and services produced with in the domestic territory of a country during an accounting year is known as
6. is an index of economic development of the country.

Answer:

1. Primary
2. Two
3. Secondary
4. Central statistical organisation
5. GDP
6. National income.

Question 3.
State true or false:

1. As compared to developed countries, India’s per capital income is quite less.
2. Black money has given birth to parallel economy in the country.
3. Major contribution in India’s national income is from the secondary sector.
4. Electricity, LPG and water supply are included in the primary sector.
5. Income from gifts are included in the national income.
6. Sale of second hand goods are not included in the national income.

Answer:

1. True
2. True
3. False
4. False
5. False
6. True.

Question 4.
Match the following:

Answer:

1. (e)
2. (a)
3. (d)
4. (c)
5. (b).

Question 5.
Answer the following in one word/sentence:

1. Which sector contributes maximum in N.I.?
2. Difference between final stock and initial stock is known as.
3. National income is studied under which economics?
4. Increase in national income indicates.
5. How many times national income is calculated in a year?
6. Money value of which goods and services are added in the GNP in a year.

Answer:

1. Tertiary
2. Change in stock
3. Macro-economics
4. Economic progress
5. One time
6. Final.

National Income and Related Aggregates Very Short Answer Type Questions

Question 1.
What is Micro-economics?
Answer:
Micro-economics studies economic actions of individuals e.g., a person, particular firm, individual household, a producer, a unit etc.

Question 2.
What is Macro-economics?
Answer:
Macro-economics is that part of economic theory which deals with the aggregate units of the economy, e.g.,all firms, all industries etc.

Question 3.
What is an Economic unit?
Answer:
Economic unit or Economic agent means those individuals or institutions which take economic decisions. They can be consumer who decide what and how much to consume. They may be producer of goods and services who decide what and how much to produce. They may be entities like the government corporation banks which also take different economic decisions like how much to spend, what interest rate to charge on the credits, how much to tax.

Question 4.
What are consumption goods?
Answer:
Objects that satisfy human needs directly and which are not used for production of other commodities are called consumption goods, e.g., milk, vegetables, wheat, rice etc.

Question 5.
What are capital goods?
Answer:
Capital goods are those goods that are used in producing other goods, rather than being bought by consumers. These goods, are used in production for a long period of time, e.g., machinery, plot, etc.

Question 6.
What are final goods?
Answer:
Final goods are those goods which are out of production line and are ready for use by the user. These goods cannot be resold and are included in estimating national income. There goods cannot be used as raw materials for production of other goods.

Question 7.
What are intermediate goods?
Answer:
Intermediate goods are those goods which are within the production line and are not ready for use by the user. These goods can be used as raw material for production of other goods, and are not included in the estimation of national income.

Question 8.
Explain the concept of Flow and Stock.
Answer:
Stock is related to a point of time. That is, the stock is a quantity measured at a certain point of time which may have accumulated in the past. Flow is an amount to be measured in a specific period of time. Flow is a price fluctuation because they are measured per unit time period, e.g., Interest on capital, Sale of rice, etc.

Question 9.
What do you understand by Gross Investment?
Answer:
Gross Investment refers to the amount invested in the purchase or construction of new capital goods. Capital stock consists of fixed assets and unsold stock. So, gross investment is the expenditure on purchase of fixed assets and unsold stock during the accounting year.

Question 10.
What is Depreciation?
Answer:
Depreciation is the permanent and continuing decrease in the quality, quantity or value of assets. Depreciation may be defined as reduction of recorded cost of a fixed asset in a systematic manner, e.g., building, office equipment, machinery, etc. In order to calculate national income depreciation is deducted from gross national product.

Question 11.
What do you mean by circular flow of income?
Answer:
Circular flow of income refers to the cycle of generation of income in the production process, its distribution among the factors of production and finally, its circulation from households to the production units in the form of consumption expenditure on goods and services produced by these units.

Question 12.
What are the principles on which circular flow of income depend?
Answer:
The circular flow of income involves two basic principles:

1. In any exchange process, the seller receives the same amount which the buyer spends.
2. Goods and services flow in one direction and the money payment to acquire them, flow in the return direction giving rise to a circular flow. Thus, product flows from the seller to the buyer is necessarily a complement of money (income) flow from the buyer to the seller.

Question 13.
What is National income?
Answer:
The national income means the total value of goods and services produced in a year in a country from all the economic activities, in terms of money. According to Prof. Marshall, “ National income is the labor and capital of a country acting on its natural resources, producing annually, a certain net aggregate of commodities, material and immaterial, including services of all kinds.” According to Prof. Pigou, “ National income is that part of the objective income of the community, including of course, income derived from abroad, which can be measured in money.”

Question 14.
What are the different methods of measuring national income?
Answer:
Different methods of measuring national income are:

1. Production method
2. Income method,
3. Expenditure method
4. Combined method,
5. Social accounting method.

National Income and Related Aggregates Short Answer Type Questions

Question 1.
Write difference between National Income and Per Capital Income.
Or
What is national Income and Per Capital Income? Write difference between them.
Answer:
National income refers to total value of goods and services produced by the people of a country in a given year. Per capital income is the average income of the normal resident of a country in a particular year.

Differences between National Income and Per Capital Income:
National Income:

1. National income means the total value of goods and services provided in a year from all the economic activities.
2. National income includes per capital income in it.
3. Active participation of various factors of production is required. .
4. National income is related to macro-economics.
5. It is an absolute concept.

Per Capital Income:

1. The income from various sources of a person is known as per capital income.
2. Per capital income is a part of national ‘income.
3. Active cooperation of the various sources of income is required.
4. Per capital income is related to micro-economics.
5. Per capital income is a relative concept.

Question 2.
Describe the four major sectors in an economy according to the macro-economics point of view.
Answer:
There are four major sectors:

1. Household : By a household we mean a single individual who takes decisions relating to her own consumption or a group of individuals for whom decision relating to consumption are jointly determined.
2. Firms : In macro – economics production units which is organized under capitalist principles are called firms.
3. Government : The role of government includes framing laws, enforcing them and delivering justice.
4. External sector : External sector means the other countries of the world which are engaged with our trade. It consists of import and export.

Question 3.
What is the difference between Micro-Economics and Macro – Economics?
Answer:

Question 4.
What do you mean by Stock and Flow? Write three differences between Stock and Flow.
Answer:
Stock means that quantity of an economic variable which is measured at a particular point of time whereas, flow is that quantity of an economic variable which is measured during a period of time.
Differences between Stock and Flow:
Stock:

1. Stock is measured at a particular point of time.
2. Stock has no dimension.
3. Stock is a static concept.

Flow:

1. Flow is measured during a period of time.
2. Flow has time dimension like how, day,month, year.
3. Flow is a dynamic concept.

Question 5.
Distinguish between National Income and National Wealth.
Answer:
Differences between National Income and National Wealth:
National Income:

1. It refers to the money value of the aggregate of goods and services produced during a particular period of time.
2. National income is measured over a period of time.
3. It is a flow variable.
4. National income is a flow because it is occurring continuously.
5. Increase and decrease of national income affect the standard of life of people.

National Wealth:

1. National wealth is the aggregate of wealth possessed by all the individuals in the country as well as collective or social wealth of the society.
2. National wealth is measured at a point of time.
3. It is a stock variable.
4. National wealth is a stock which is accumulated at a particular time.
5. Its increase and decrease affect the production capacity of goods.

Question 6.
Describe the Great depression of 1929.
Answer:
The ‘Great Depression of 1929’ and the subsequent years saw the output and employment levels in the countries of Europe and North America fall by huge amount. Demand for goods in the market was low. Many factories were lying idle, workers were thrown out of jobs. In USA from 1929 to 1933 unemployment rate rose from 3 percent to 25 percent. Over the same period aggregate output in USA fell by about 33 percent.

Question 7.
How are micro-economics and macro-economics interdependent?
Answer:
Interdependence of macro-economics and micro-economics can be studies as follows:
1. Macroeconomics depend on micro-economics:
Macro-economics and microeconomics depend on each other. Both are interdependent, macro economics contributes to the micro-economics. For example, the theory of investment belongs to micro-economics. It is derived from the behavior of the individual entrepreneur. The theory of aggregate investment function can also be derived from micro-economics theory of investment. Thus, we can say, that macro-economics depends on micro-economics.

2. Microeconomics depend on macro-economics:
Microeconomics depend upon macro-economics to a certain extent. For example, the rate of interest is a subject which belongs to micro-economics, but it is influenced by macro-economics aggregates. Thus, micro-economics depend upon macro-economics.

Conclusion:
Macro and micro-economics both are interdependent On each other. Neither is complete without the other. We must study macro-economics because it deals with average variables, such as national income and national output. We must study micro-economics because national output and national income are eventually the result of decision of millions of business firms and individuals. Thus, we can conclude that both are complementary to each other.

Question 8.
Calculate national income from the given data:

1. Salary –  Rs. 6,000
2. Rent – Rs. 2,000
3. Profit – Rs. 2,000
4. Interest – Rs. 1,000
5. Consumption – Rs. 5,000.

Solution:
N.I. = Salary + Rent + Profit + Interest
= 6,000 + 2,000 + 2,000+ 1,000
N.I. = Rs. 11,000.

Question 9.
Calculate National Income on the basis of the given data by income method: Heads Rs. (in crores)

1. Salary and wages = Rs. 18,000
2. Interest = Rs. 7,000
3. Depreciation = Rs. 4,000
4. Rent = Rs. 6,000
5. Profit = Rs. 25,000.

Solution:
National Income = Salary and wages + Interest +Rent +Profit
= Rs. 18,000 + Rs. 7,000 + Rs. 6,000 + Rs. 25,000 = Rs. 56,000.

Question 10.
On the basis of following data find out National Income by income method:

1. Salary and wages – 30,000
2. Rent – 10,000
3. Prof – 50,000
4. Interest – 10,000
5. Depreciation – 2,000
6. Gross domestic investment – 60,000.

Solution:
National income (N.I.) = Salary and Wages + Rent + Profit + Interest
N.I. = 30,000 + 10,000 + 50,000 + 10,000
N.I. = Rs. 1,00,000.

Question 11.
Calculate National Income from the following data:

1. Salary  =  Rs. 60,000
2. Rent  =  Rs. 20,000
3. Profit  =  Rs. 20,000
4. Interest  =  Rs. 10,000
5. Consumption  =  Rs. 50,000
6. Gross Domestic Product  =  Rs. 8,000.

Solution:
National Income = Salary + Rent + Interest + Profit
= Rs. 60,000 + 20,000 + 10,000 + 20,000
= Rs. 1,10,000
National Income = Salary + Rent + Interest + Profit

Question 12.
Specify the relation of gross domestic product with welfare.
Answer:
Gross domestic product refers to money value of goods and services produced within the territorial boundaries of the country in a given year. With the increase in income consumption expenditure of a person increase which in turn increases material welfare. Therefore, it is not appropriate to relate GNP with welfare or their generalization may not be correct due to. following reasons:

1. GDP shows the total goods and services produced in the country. However, it does not exhibit the structure of the product if increase in GDP is mainly due to increased production of war equipment and ammunition. Then such an increase cannot be associated with any improvement in economic welfare.

2. If increase in GDP is due to rise in prices and not due to increase in physical output, then it will not be a reliable index of economic welfare.

3. GDP does not consider the changes in population of a country. If rate of population growth is higher than the rate of growth of GDP, then it will decrease per capital availability of goods and services, which will adversely affect the economic welfare.

Question 13.
What do you mean by G.D.P.? Write any four characteristics of G.D.P.
Answer:
Meaning of G.D.P:
Gross Domestic Product is defined as “the value of all final goods and services produced by all the enterprises located within the domestic territory of a country during an accounting year. It should be noted that goods and services must be produced within the country.” G.D.P. is always money value of goods and services produced within a year.

Special features of G.D.P:

1. G.D.P. includes the value of all the goods and services produced within the country in a particular year.
2. It includes depreciation value.
3. G.D.P. is measured in terms of market price.
4. G.D.P. includes the value of new goods only i.e., it excludes the value of second hand goods.
5. It includes real capital not financial capital.
6. Consumer and capital goods are classified in durable and non-durable goods.
7. Goods may be from private sector or public sector.
8. To avoid the defect of double counting we include the value of final goods and services.

Question 14.
What precautions should be taken while calculating national income by income method?
Answer:
Precautions taken while calculating national income by income method:

1. Transfer income should not be included.
2. Income from illegal activities should not be included.
3. Imputed rent should be included as it is the part of rental income.
4. Production for self-consumption should be included.
5. Money received by sale of shares/bonds etc. should not be included.
6. Income from sale of second hand goods should not be included.
7. Death duties, wealth tax, gift tax, etc., are not included is national income.
8. Corporation tax should not be recorded separately as it is a part of profit.

Question 15.
What are the difficulties in estimating national income by income method?
Answer:
Estimation of national income by income method passes various difficulties. The major difficulties are:
(i) It is difficult to estimate mixed income. Mixed incomes are earned by an unincorporated sector and it is difficult to get reliable information from such unorganized sector.

(ii) Interest on national debt is not included in national income as per the national income convention on the assumption that government borrowings are used for consumption (unproductive) purposes. However, some economists object to this since, a part of the government borrowing is used for productive purposes.

(iii) Incomes received are generally calculated from income-tax returns. Therefore, income method is of limited used in underdeveloped countries because a very small part of the income earners are tax payers in these countries.
Income method of estimating national income is useful because it provides information about distribution of national income among various factor categories like share of wages profits etc. in national income.

Question 16.
What do you mean by G.D.P. at constant price?
Answer:
Gross Domestic Product at constant prices: Constant price means base year’s price. Base year is an average standard previous year in which major economic changes have not taken place. Goods and services produced during the year are either valued at constant price of the base year or the value of goods and services at current price is converted into the value at constant price.

Modem economies are inflationary economies where prices of goods and services are increasing at faster rates. It is therefore, advisable that the value of goods and services at current price should be converted at constant price, so that real Gross Domestic Product (G.D.P.) could be understood. Calculation at constant price should be referred as real G.D.P. Formula of conversion of G.D.P. at current price into G.D.P at constant price.

Question 17.
Will a profit maximizing firm in competitive market ever produce a positive level of output in the range where the marginal cost is falling? Give and explanation.
Answer:
A profit maximizing firm in a competitive market will produce a positive level at output in the same, where marginal cost is falling. Falling MC means that the cost of producing an additional unit of output trends to reduce. Here, price is constant as the firm is working in a competitive market in this case, the difference between firm’s total revenue and TVC (TVC = Σ MC) tends to increase. It means firm’s profit increases with the increase in the level of output. Then a competitive firm increase output when gross profit is rising.

Question 18.
From the following data, calculate Personal Income and Personal Disposable Income.
Items (₹ In cores )

• Net domestic product at factor cost 8,000
• Net factor income from abroad 200
• Disbursed profit 1,000
• Corporation tax 500
• Interest received by households 1,500
• Interest paid by households 1,200
• Transfer income 300
• Personal tax 500.

Solution:
Personal Income = (a) + (b) + (e – f) + (g) -(d)
= 8000 + 200 +(1500-1200)+ 300 – 500
= 8000 + 200 + 300 + 300 – 500
= 8800 – 500 = ₹ 8,300 Cores.
Personal Disposable Income = Personal Income – Personal Tax
= 8300 – 500 = ₹ 7,800 Croce.

Question 19.
In a single day, Raju, the barber, collects ₹ 500 from hair cuts. Over this day, his equipment depreciates in value by ₹ 50, of the remaining ₹ 450, Raju pays sales tax worth ₹ 30, takes home ₹ 200 and retains ₹ 220 for improvement and buying of new equipment He further pays 120 as income tax from his income. Based on this information, complete Raju’s contribution to the following measures of income:

(a) Gross domestic product
(b) NNP at market price
(c) NNP at factor cost
(d) Personal income
(e) Personal disposable income.

Answer:
(a) GDP = ₹500

(b) NNP_MP=GDP – DeP
₹500 – ₹ 50 = ₹450

(c) NN_fc = NNP – Sales tax
= ₹450 – ₹30 = ₹420

(d) PI = NNP_fc – Retained earnings
= ₹ 420 – ₹ 220
= ₹ 200

(e) PDI = PI – Income tax
=₹ 200 – ₹ 20
= ₹ 180.

National Income and Related Aggregates Long Answer Type Questions

Question 1.
State five points of importance of national income.
Or
Write the importance of national income.
Answer:
Importance of National Income can be explained through the following points:
1. Knowledge about the economic progress of the nation y By collecting the data of the national income of few years the economic progress of any country can be known. Increase in national income is the sign of the progress of the country. By comparing the national income estimates over a period of time, we can know whether economy is growing, or is static or declining.

2. Measure of economic welfare:
The national welfare of a country depends upon its national income. If there is an increase in national income it will bring an increase in economic welfare and a fall in national income will result in fall in economic progress.

3. Formulation of policies:
National income is helpful in the formation of the policies of the country. For example, taxation policy, employment policy etc. National income statics is very useful in formulating the plans and fixing targets.

4. Economic planning:
Economic planning can be easily done on the basis of national income. The national income helps in deciding the area for which planning has to be done. It also helps in deciding the nature of investment. i.e.,the investment should be long-term or short – term.

5. Comparative studies:
The progress of two or more countries can be compared on the basis of the data of national income. It gives the idea of savings, investments, consumption etc. of various countries. Comparative study of the economic progress of various countries can easily be made. We can compare the standards of living and the levels of economic welfare of the people.

Question 2.
Distinction between Gross Domestic Product and Gross National Product. Ans. Differences between Gross Domestic Product and Gross National Product:

Question 3.
Write difference between National Income and Private Income.
Answer:
Differences between National Income and Private Income:
National Income

1. It includes income of both the public
2. It does not include National income.
3. It is not a part of National income.
4. National income is the income of residents of india.
5. National income = Net Domestic Product at factor cost + Net factor income from abroad.

Private Income:

1. It includes the income of private sectors and private sectors. only.
2. It includes both factor income and trans-fer income.
3. It is a part of private income.
4. In private income the income of private idents of India. people are included.
5. Private income = Net Domestic Product at factor cost – Income from the domestic product accruing to public sector+ Transfer income + Net factor income from abroad.

Question 4.
What are the causes of low national income in India?
Or
Give reasons for slow growth rate of national income in India.
Answer:
The following are the causes of low national income in India:

1. Overpopulation:
   At present our population is more than 100 crores. It is the main cause of low national income.
2. Inequality in distribution of national income:
   There is a great disparity in the distribution of national income.The main reason is improper tax policy.
3. Dependence on agriculture:
   Indian economy is mainly agriculture based economy. There is always uncertainty in agricultural product. So, national income is low in India.
4. Illiteracy:
   A major part of the population in our country is uneducated. So, they are not able to understand the latest methods of production and policies. They are also not able to follow them.
5. Old method of production:
   The methods of production that are followed in our country are old and outdated due to which we are not able to utilize our resources to the full extent.

Question 5.
Write five suggestions to increase national income in India.
Or
Write suggestions to increase national income.
Answer:
1. Proper development in the agricultural fields:
Agriculture is the main source of national income in India. So, to increase the national income use of best seeds, fertilizers and tools is very important.

2. Development in the field of technical education:
An educated person can work more efficiently than uneducated one. So, education should be given to maximum number of people.

3. Proper utilization of natural resources:
If natural resources are fully and properly utilized the income of the nation can be increased.

4. Check on population:
Population must be controlled. Special efforts should be made to check population in villages which will increase per capital income.

5. Proper development of transport and communication facilities:
Development of transport and communication should be encouraged. Priority should be given to them. For this proper planning must be done. Development in transport and communication will encourage the export-import also which will increase the national income.

6. Export oriented trade policies:
Trade policies should be made in such a way that it will encourage export. Import should be discouraged so that national income will have a good effect. Five year plans and development programmers must be given stress. Export promotion should be given high priority.

Question 6.
Distinguish between Closed Economy and Open Economy.
Answer:
Differences between Closed Economy and Open Economy:
Closed Economy:

1. When a country does not have any economic relation with other country it is called closed economy.
2. In closed economy GDP and National income is equal.
3. It is an imaginary concept.
4. In this economy, capital formation is negligible.
5. In this economy consumption and investment both are equal to production.

Open Economy:

1. When a country establishes economic relation with other country it is called open economy.
2. There is a difference between GDP and National income.
3. It is a real concept.
4. In this economy, capital formation and investment both take place.
5. In this economy, the total of consumption and investment can be more or may be less than production.

Question 7.
Explain different methods of measuring national income.
Answer:
The various methods of measuring national income are:
1. Census of production method:
The gross national income is calculated by adding up the aggregate values of productions of all the industries and sectors of the economy and net income from abroad. By deducting depreciation from gross income we get national income.

2. Census of Income method:
By summing up the net incomes of all individuals and firms in a country during a year, we get the national income.

3. Expenditure method:
People don’t spend their entire income. They save a part of it as saving. By summing up all expenses and all incomes of all the people during a year, we get the national income.

4. Combined use of production and income method:
This method is also known as ‘mixed method’. In this method, both production and income methods are used together. In any country if due to certain reasons one method cannot be used, there the mixed method can be used.

5. Social accounting method:
This method was propounded by Prof. Richard Stone. In this method, the entire society was divided into various sections such as; producers, consumers, etc. The average income of some people of each section is calculated and then it is multiplied with the total number of people in each section.

Question 8.
A farmer sold cotton of Rs. 500 to cotton mill by producing himself. Cotton mill prepared garments and sold to garment factory at Rs. 600 garment factory sold it to a store on Rs.1000. Store owner sold it to consumer on Rs. 1200. Find out increased value by each.
Solution:
Following is the increased price by Farmer, Cotton mill, Ready made garments factory and store:

1. Price raised by Farmer = Sale of cotton to cotton mill = Rs. 500.
2. Price raised by cotton mill = Sale to garment factory – Sale of cotton from Farmer
   = Rs. 600 – 500 = Rs. 100.
3. By ready made garment = Sale price of dress to store – Price (Sell) of cotton from factory cotton mill
   = Rs. 1000 – 600 = Rs. 400.
4. By Store = Last sell price of consumer – Value of dress by ready made factory
   = Rs. 1200 – 1000 = Rs. 200.
5. Total price rise = Farmer+Cotton mill + Garment factory + Store value
   = Rs. 500 + 100 + 400 + 200 = Rs. 1200.

Question 9.
Write the main characteristics of capitalistic economy.
Or
What are the important features of a capitalist economy?
Answer:
Important features of a capitalist economy:
Following are important features or characteristics of a capitalist economy:

1. There is private ownership of means of production.
2. Production takes place for selling the output in the market.
3. There is sale and purchase of labor services at the price which is called the wage rate.

Question 10.
Explain in short G.D.P. at market price and G.D.P. at factor cost
Answer:
(A) Gross Domestic Product at market price:
It is also called the current price or prevailing price in the market. In order to calculate G.D.P. at current price final goods and services produced during the year are valued in terms of prevailing price of that year. To measure it we multiply the quantity of produced goods with their prices. It can be explained like this:

Here GDP _MP = P₁ (Q) + P₁ (S)
GDP_MP = Gross Domestic Products at market price
P₁ = Market price
Q = Quantity of final goods and services
S = Services

Increase in the value of Gross domestic product (G.D.P.) as compared to the value of previous year shows economic development and happy trend. It should be Carly studied whether the increase is due to increase in the quantity of goods and services produced or increase in price. If the increase has caused due to increase production, it should be taken as real increase. We can calculate per capital Gross Domestic Product (G.D.P) if we divide total G.D.P. with the population of the country.

(B) Gross Domestic Product at factor cost:
Gross Domestic Product at factor cost is the estimate of Gross Domestic Product in terms of earnings of factors of production. It is the sum total of earnings received by various factors of production in terms of wages, interest, rent, profits, etc. within the domestic territory of a country in a year.

It measures factor incomes generated with the domestic territory irrespective of whether generated by residents or non-residents. Being gross it marks no provision for the depreciation. As explained above market value of goods and services differs from the earnings of factors of production because of Net Indirect Taxes. Therefore, if we get gross domestic product at factor cost. Thus,
G.D.P. _FC = G.D.P _MP – Indirect taxes.

MP Board Class 12th Economics Important Questions

MP Board Class 12th Biology Important Questions Chapter 8 Human Health and Disease

 Human Health and Disease Important Questions

 Human Health and Disease Objective Type Questions

Question 1.
Choose the correct answer:

Question 1.
Syphilis is caused by :
(a) Tryponema
(b) Leptospira
(c) Pasturelia
(d) Vibro.
Answer:
(a) Tryponema

Question 2.
AIDS is caused by :
(a) Blood cancer
(b) H1N1
(c) Bacterium
(d)TMV.
Answer:
(b) H1N1

Question 3.
Which one is not cancer :
(a) Leukemia
(b) Glaucoma
(c) Carcinoma
(d) Sarcoma.
Answer:
(b) Glaucoma

Question 4.
First organic acid produced through the process of fermentation :
(a) Acetic acid
(b) Lactic acid
(c) Citric acid
(d) Butyric acid.
Answer:
(d) Butyric acid.

Question 5.
Vaccines produced by genetic engineering is :
(a) Hepatitis B
(b) Herpes virus
(c) Malarial vaccines
(d) Both (a) and (b).
Answer:
(d) Both (a) and (b).

Question 6.
The vitamins produced by activity of microbes are :
(a) Vitamin B₂
(b) Vitamin B₁₂
(c) Both (a) and (b)
(d) Vitamin B₂,B₁₂ and Vitamin C.
Answer:

Question 7.
Enzyme used in manufacture of detergent is :
(a) Proteases
(b) Amylases
(c) Rennet
(d) Lipase.
Answer:
(d) Lipase.

Question 8.
Common human interferons are :
(a) Leukocytic interferon – α
(b) Fibroblastic interferon – β
(c) Immune interferon – γ
(d) All of these.
Answer:
(c) Immune interferon – γ

Question 9.
Which of the following is used in genetic engineering :
(a) DNA – polymerase
(b) Nuclease
(c) Restriction endonuclease
(d) RNA – polymerase.
Answer:
(b) Nuclease

Question 10.
Yeast is used in preparation of:
(a) Acetic acid
(b) Cheese
(c) Curd
(d) Ethyl alcohol.
Answer:
(d) Ethyl alcohol.

Question 11.
Germinating barley seeds are used in the preparation of:
(a) Cheese
(b) Wine
(c) Beer
(d) Lactic acid.
Answer:
(d) Lactic acid.

Question 12.
‘Syphilis’ is a sexually transmitted disease caused by :
(a) Treponema pallidum
(b) Leptospira
(c) Pasturelia
(d) Vibrio.
Answer:
(d) Vibrio.

Question 13.
The immunity obtained after the body has recovered from a disease is :
(a) Active immunity
(b) Passive immunity
(c) Both (a) and (b)
(d) None of these.
Answer:
(b) Passive immunity

Question 14.
Vaccination used for protection from Polio, Diptheria and Tetanus : (MP 2015)
(a) BCG
(b) DPT
(c) MMR
(d) STD.
Answer:
(b) DPT

Question 15.
AIDS test is known us : (MP 2017)
(a) Australian antigen
(b) ELISA
(c) Thyroid test
(d) pH test.
Answer:
(b) ELISA

Question 2.
Fill in the blanks:

1. AIDS is an example of ………………….. transmitted disease.
2. Genes responsible for cancer are called …………………..
3.  ………………….. is known as blood cancer.
4.  ………………….. is first human made insulin by genetic engineering.
5. Hepatitis B disease is caused by …………………..
6. Asthma is a type of …………………..
7.  ………………….. is the transfer of human organs from a donor to a recipient.
8. Nutrient deficiency disease is caused by …………………..
9. Plague vaccine is discovered by …………………..
10.  ………………….. is the full name of AIDS.
11. Gonorrhea disease is caused by …………………..
12. L.S.D. is found by ………………….. fungi.
13. Typhoid is caused by …………………..
14.  ………………….. is found in Klinefelter syndrome.

Answer:

1. Sexually
2. Oncogene
3. Leukemia
4. Humulin
5. Virus
6. Allergy
7. Organ transplantation
8. Less nutrition
9. Dr. Haffkine
10. Acquired Immune Deficiency Syndrome
11. Nesseria gonorrhoeae
12. Clavicepspurpurea
13. Saltnonalatyphi,
14. One extra chromosme.

Question 3.
Match the followings:
I.

Answer:

1. (d)
2. (e)
3. (a)
4. (b)
5. (c)
6. (f)

II.

Answer:

1. (e)
2. (c)
3. (d)
4. (b)
5. (a)

Question 4.
Write answer in one word/sentences:

1. Name the vector of malarial parasite.
2. Give full name of HIV.
3. Give the name of harmful chemical compound of tobacco.
4. Give one example of sedative drugs.
5. Name the disease which is transmitted from one person to another is called.
6. When is AIDS day celebrated?
7. Who prescribed the word AIDS first time?
8. Name the branch that aims at improving the genetic quality of a human population.
9. Write the name of virus which causes cancer.
10. Give the name of one edible yeast.
11. Name the disease which is treated by chemotherapy.
12. What is the name of antiviral protein?
13. Who gave the Germ theory of disease?
14. What is the reason of syphilis?

Answer:

1. Plasmodium
2. Human Immunodeficiency Virus
3. Nicotine
4. Benzodiazopines
5. Infectious disease
6. 1 December
7. Edward Jenner
8. Eugenics
9. Oncogenic virus
10. Ashby a gossypii
11. Cancer
12. Interferon
13. Robert Koch
14. Sexual contact.

Human Health and Disease Very Short Answer Type Questions

Question 1.
What are lymphoid organs?
Answer:
Lymphoid organs are certain organs, in which lymphocytes can differentiate and proliferate.

Question 2.
What is the name of drug which converts thoughts and feelings of human and causes fear?
Answer:
Psychedelic drugs.

Question 3.
Which disease is caused by transmission of HIV?
Answer:
AIDS.

Question 4.
Name the method which is used in the diagnosis of AIDS.
Answer:
ELISA Test.

Question 5.
In different parts of the country Chikungunya is clarified. Name the carrier of this disease.
Answer:
Chikungunya is spread through bites from A. aegypti mosquitoes.

Question 6.
Name the types of Immunity.
Answer:
Immunity is two types:

Innate immunity
Acquired immunity.

Question 7.
Where is Wuchereria found?
Answer:
Filarial worms Wuchereria is found in lymph vessels.

Question 8.
Name the types of tumours.
Answer:
Tumours are of two types : Benign and Malignant.

Question 9.
What harm does AIDS cause in humans?
Answer:
Immune power of the body is decreased by AIDS.

Question 10.
When inability to open the mouth because human chewing areca nuts in betel quid or its variants (gutkha) and jaw muscles become hard. Give the name of possible disease.
Answer:
Submucous fibrasis disease.

Question 11.
Name the full form of DPT.
Answer:
Diphtheria, Pertussis and Tetanus.

Question 12.
What is the side effects of cancer treatment?
Answer:
Hair falling and Anemia.

Question 13.
What is the full form of NAC?
Answer:
National AIDS Control Organization.

Question 14.
Which plant extract is called marijuana?
Answer:
Cannabis sativa.

Question 15.
Name combine form of the poppy, morphine, heroin, pethidine and methedrine.
Answer:
Meconium.

Question 16.
What is the second name of Mary Mallon?
Answer:
The second name of Mary Mallon is Typhoid Mary.

Question 17.
Name the cells which are multiplied by HIV when it enters the human body.
Answer:
Macrophages and helper T – lymphocytes.

Question 18.
Which body organs are affected by Pneumonia?
Answer:
Lungs and Alveolies are affected.

Question 19.
What is the confirmation test of Typhoid?
Answer:
Typhoid fever can be confirmed by Widal test.

Question 20.
Write the full form of LSD.
Answer:
Lysergic Acid Diethylamide.

Question 21.
Which viruses are responsible for cancer?
Answer:
Oncogenic viruses have cancer – causing viral oncogenes.

Human Health and Disease Short Answer Type Questions

Question 1.
What are the various public health measures which you would suggest as safeguard against infectious disease ?
Answer:
The common preventive measures are as follows :

1. Education – People should be educated about communicable diseases to protect themselves from such diseases.
2. Vaccination – People should get vaccination on time to avoid infection.
3. Sanitation – The sanitation condition should be improved to avoid infection from polluted water, contaminated food, etc.
4. Eradication of vectors – The breeding places of vectors should be destroyed and adult vectors should be killed by suitable methods.
5. Sterilisation – The patient’s surroundings and articles of use should be completely sterilised so as to reduce the chances of infection.

Question 2.
Explain what is meant by metastasis?
Answer:
Metastasis is the spread of cancerous cells through migration from one tissue to other tissue and organs resulting in formation of secondary tumour. Malignant tumour is a mass of proliferating cells called neoplastic cells. They grow rapidly and invade surrounding unaffected normal cells assues. Cells get sloughed off from such tumour and migrate to distant sites through blood. A new place of infection is thus, established and a new tumour is formed. This property is called metastasis.

Question 3.
Define the following:

1. Immunity
2. Vaccine
3. Interferon
4. Vaccination.

Answer:
1. Immunity : The capacity of any organism to fight with the disease and causal organisms is known as immunity. The immunity is due to B and T cells.

2. Vaccine : The chemical substances which protect our body by disease causing organisms are called vaccines.

3. Interferon : Interferon is an antiviral protein which is produced within animal cells due to stimulus produced after viral infection and which prevents the infection and multiplication of other viruses.

4. Vaccination : Vaccination is the process by which resistance against specific disease is created in any living organism.

Question 4.
Distinguish between Inborn and Acquired immunity.
Answer:
Differences between Inborn and Acquired immunity are:

Inborn immunity:

• This immunity is present by birth.
• It is a kind of active immunity.

Acquired immunity:

• This immunity helps in the expansion of life span of organism.
• This immunity is of both type active immunity and passive immunity.

Question 5.
What is auto – immunity?
Answer:
This is an abnormality which sometimes develop in the immune system of the body. Instead of destroying foreign molecules, it starts attacking the body’s own cells leading to serious consequence. Such diseases are called autoimmune diseases. Autoimmune diseases depend on the type of self – antigen involved. If the self-antigens are R.B.Cs. then the body destroys its own R.B.Cs. resulting in chronic anaemia. When the self – antigen is a muscle cell, it results in destruction of its own muscles resulting in severe weakness, when the self-antigens are liver cells, it results in chronic hepatitis.

Question 6.
What is allergens? What cause the allergy to produce?
Answer:
Allergy is the condition of hypersensitivity of the body against certain substances or to a physical or chemical agent allergens. When antigen antibody reaction takes place in the body, it results allergy. Sufficient antibodies will not be produced in lacking of proper immune system. The allergens combine with the antibody bound mast cells, which causes the cell to burst releasing histamine. It results inflammatory responses in the body. Allergy may be caused by a medicine, cosmetics and other substances like, pollen grains, dust particles etc.

Question 7.
What is B – cells and T – cells? Explain it.
Answer:
B – lymphocytes or B – cells produce an army of protein called antibodies in blood. In response to pathogens, T – lymphocytes or T – cells help B – cells to produce antibodies, immune response are produced by these two types of lymphocytes.

Question 8.
Which types of diseases are protected by D.P.T. vaccine? Write the name of pathogens for each disease.
Answer:

Question 9.
What is eugenics?
Answer:
Eugenics:
The branch of biology which deals with the study of improvements of human race is called eugenics.

Importance:

1. Development of selective reproduction in similar species
2. Transfer of genetic materials in various organisms
3. Development of GM food and GM crops
4. Gene cloning
5. Gene therapy, etc.

Question 10.
How vaccination is important in immunity?
Answer:
Vacc, nation is the process of introduction of weakened or inactivated pathogens or proteins (vaccine) into a person so, provide protection against the disease. Vaccination provides immunisation after a time gap. Due to immunisation our body produces antibodies against the vaccine and develops the ability to neutralise pathogens during actual infection. Nowadays different types of vaccine which gives in children like polio, tetanus, deptheria, pertusis, small pox etc.

Question 11.
What is drug addiction? What are its causes?
Answer:
Addiction is most common problem of our youths because they start to take different types of drugs and alcoholic beverages due to various reasons. It makes them habitual and dependent on them. Addiction is the habitual, psychological and physiological dependence on a substance or practice which is beyond voluntary control. A person who is habituated to a substance or a practice especially harmful one, is called drug addiction.

Its causes are:

1. Curiosity
2. Fun and Stimulation
3. Will of doing more work
4. Feeling of freeding
5. Temporary escape from the life problems.

Question 12.
Write down the differences between sedative and tranquilizer.
Answer:
Differences between Sedative and Tranquilizer :

Sedative:

• These drugs depress the activities of central nervous system.
• A person sleeps more after taking excess drugs.
• Example: Barbiturates.

Tranquilizer:

• These drugs lessen tension and do not induce sleep.
• They do not sleep.
• Example: Phenothiazines.

Question 13.
Give the name of source of LSD. Give its effects also.
Answer:
LSD (Lysergic Acid Diethylamide):
It is a crystalline amidated alkaloid which is obtained from the sclerotium of ergot fungus Claviceps purpurea, pathogen of ergot disease of rye. LSD causes horrible dreams, hallucinations, chronic psychosis and damage the brain. LSD was tried as treatment for alcoholism, neurosis and cancer patients. LSD brings about chromosomal and foetal abnormalities. Pathological condition caused by LSD abuse or by eating grain affected by ergot is called ergotism.

Question 14.
Describe the effect of alcohol on human body and society.
Answer:
The effects of alcohol on human body and society are :

1. It effects the central nervous system.
2. Persons is incapable of differentiating what is right and what is wrong.
3. Taking excess of alcohol weakens heart, lungs, liver and other parts of the body.
4. Pupil of eye expands on taking excess of alcohol.
5. This increases the criminal activities in human beings.

Question 15.
Write withdrawal symptoms of addiction.
Answer:
Withdrawal symptoms from addiction:
When a drug dependent person fails to get the drug, he feels severe physical and psychological disturbances. These are called withdrawal symptoms. It includes tremors, nausea, vomiting, weakness, insomnia, anxiety run fits, decreased appetite, restlessness, elevated blood pressure, rapid heartbeat and epilepsy. These symptoms indicates that the body of addict person is unable to further use of intoxicant and they should stop it immediately.

Question 16.
Describe about the psychotropic drugs.
Answer:
These drugs effect on thinking power, mental processes, continuous use of these drugs, bring change in human behaviour, consciousness and perception. So, they are called mood altering drugs. The person becomes addict by the use of these drugs and cannot live without these drugs.

Question 17.
What are sedative? What are its types? Write its effect.
Answer:
Sedative:
Drugs which directly depress the brain and central nervous system are included in this group. They make the body free from anxiety and lethargic. The excessive use leads to sleep. Sleep causing drugs are also called Hypnotics.

It is of two types:

1. Barbiturates and
2. Benzodiazepines.

1. Barbiturates : It is a sedative and tranquilizer. It supresses brain’s activity and creates a feeling of relaxation, drowsiness and sleepiness.

2. Benzodiazepines : These drugs are commonly prescribed to help relieve anxiety in people who have anxiety disorder or another mental illness where anxiety is a symptom. They are very addictive.

Question 18.
What is interferon?
Answer:
Interferon:
Interferon is an antiviral protein which is produced within animal cells due to stimulus produced after viral infection and which prevents the infection and multiplication of other viruses.

Question 19.
How is a cancerous cell different from a normal cell?
Answer:
Cancer cell is different from normal cells in the sense that it:

1. Looses the property of contact inhibition.
2. Continues to grow and divide.
3. Produces masses of cells called tumours.

Question 20.
In which way has the study of biology helped us to control infectious diseases?
Answer:
Study of biology helps us to diagnose the pathogen in following ways:

1. The life – cycle of many pathogens studied.
2. Alternate and reservoir hosts are known.
3. The mechanisms of transmission of disease is known.
4. The protective measures are suggested against disease and pathogens based an above studies.
5. Suitable medicines against infectious disease are suggested.
6. The preparation of vaccines against many pathogens also entitle the use and study ofbiology.

Question 21.
How does the transmission of each of the following diseases take place:

1. Amoebiasis
2. Malaria
3. Ascariasis
4. Pneumonia.

Answer:

1. Amoebiasis : Through faecal-oral route.
2. Malaria : Through the bite of female Anopheles mosquito.
3. Ascariasis : Through taking contaminated food and water.
4. Pneumonia : Droplets from the sputum of the patient.

Question 22.
What measure would you take to prevent water – borne diseases?
Answer:
To prevent water borne diseases, following measures are required:

1. Drinking water should he clean, free from contamination. This could be achieved by filtration, boiling or sedimentation and chemical treatment of water.
2. Water resources/ reservoirs should be periodically de – contaminated / disinfected.
3. Water should not be allowed to stand for long to become breeding pools.
4. Standards practices of hygiene should be strictly maintained in public catering.

Question 23.
Discuss with your teacher what does ‘a suitable gene’ mean, in the context of DNA vaccines.
Answer:
The term ‘suitable gene’ refers to that specific segment of DNA which forms immunogenic protein, such genes can be cloned and then integrated with vector for introducing into an individual to be immunised for certain disorder producing a particular vaccine against the pathogens.

Question 24.
Name the primary and secondary lymphoid orgAnswer:
Answer:
Primary lymphoid organs are bone marrow and thymus. Secondarylymphoid organs are spleen, lymph nodes, tonsils, peyer’s patches of small intestine and appendix

Question 25.
The following are some well known abbreviations, which have been used in this chapter. Expand each one to its full form:

1. MALT
2. CMI
3. AIDS
4. NACO
5. HIV.

Answer:

1. MALT : Mucosa Associated Lymphoid Tissue.
2. CMI : Cell Mediated Immunity.
3. AIDS : Acquired Immune Deficiency Syndrome.
4. NACO : National AIDS Control Organisation.
5. HIV : Human Immunodeficiency Virus.

Question 26.
How are allergies related to the body’s immune system?
Answer:
Allergy is the condition of hypersensitivity of the body against certain substances or to a physical or chemical agent allergens. When antigen antibody reaction takes place in the body, it results allergy. Sufficient antibodies will not be produced in lacking of proper immune system. The allergens combine with the antibody bound mast cells, which causes the cell to burst releasing histamine. It results inflammatory responses in the body. Allergy may be caused by a medicine, cosmetics and other substances like pollen grains, dust particles, etc.

Question 27.
Differentiate the following and give examples of each:

1. Innate and Acquired immunity.
2. Active and Passive immunity.

Answer:
1. Differences between innate and acquired immunity:

Innate immunity:

• It is present from birth and is inherited from parents.
• It is non – specific.
• The various physical, physiological cellular and cytokine barriers are the basis of innate immunity.
• The innate immunity remains throughout life.

Acquired immunity:

• It is not present from the birth.
• It is pathogen specific.
• The memory cells formed by B and
• T – cells are the basis of acquired immunity.
• The aquired immunity can be short – lived or life long.

2. Differences between active and passive immunity:

Active immunity:

• It is developed due to contact with pathogen or its antigen that leads to production of antibodies in the host body.
• It has no or only few side effects.
• It is slow but long lasting.
• It takes time to develop its response.

Passive immunity:

• It is developed when readymade antibodies are injected into the body.
• It may cause a reaction.
• It is fast but lasts only for few days.
• It is used when the immune response has to be faster.

Question 28.
Draw a well – labelled diagram of an antibody molecule.
Answer:

Human Health and Disease Long Answer Type Questions

Question 1.
What is cancer? Write the names of two types of cancer and causes of cancer.
Answer:
Cancer:
When tumours are formed due to unorganized and uncontrolled division of cell, then it is called cancer.

Types of Cancer:
Cancer is not a single disease but a complex of many diseases. Today about 200 distinct types of cancer have been recognized. These are grouped into main types:

1. Carcinomas
2. Sarcomas
3. Lymphomas and
4. Leukemias.

1. Carcinomas:
The tumours which are made up of epithelial cells of ectodermal or endodermal origin are called carcinomas, example solid tumours in nerve tissues and in tissues of body surfaces or their attached glands. It includes breast, skin, cervical and brain carcinomas.

2. Sarcomas:
The tumours which are made up of connective tissue cells of mesodermal origin are called sarcomas, example solid tumours growing from connective tissues, bones, cartilages and muscles. It constitutes only about 2% of human cancers.

3. Lymphomas:
Cancers in which there is excessive production of lymphocytes by the lymph nodes and spleen are called lymphomas, example Hodgkin’s disease. It constitutes about 5% of human cancers.

4. Leukemias:
It is cancer of blood characterized by excessive number of W.B.Cs. (or leucocytes) in the blood (neoplastic growth). These cells invade into bone – marrow, lymph nodes and the spleen. It is more frequent in the children of age group 5 to 7 years but it can occur at any age. Acute leukemia causes death. It has no sure remedy. It constitute about 4% of human cancers.

Causes of Cancer:
Physical and Chemical factors which cause cancer are called as carcinogens. Main causes of cancer are as follows:

1. Smoking causes mouth and lung cancer.
2. Radiations, such as X – rays, ultraviolet rays and other ionizing radiations cause cancer.
3. Viruses may cause cancer.
4. Chemical substances such as Nicotine, caffeine, products of combustion of coal and oil, polycyclic hydrocarbons may cause cancer.

Symptoms of Cancer:
There are some symptoms of cancer which must be kept in mind:

1. Any lump or thickening in the tissue especially in breast, tongue or lip.
2. A wound that is not healing.
3. Any sudden change in mole or warts.
4. Persistent indigestion and difficulty in swallowing things.
5. Regular cough and hoarseness in sound.
6. Unusual weight loss.
7. A change in bowel habits.
8. Any ulcer that does not get well.
9. Bleeding in vagina at times other than the menstruation.
10. Non – injury bleeding from the surface of the skin, mouth or any other opening of the body.

Question 2.
What is AIDS? Write down its causes, transmission and symptoms.
Or
Write the name, two symptoms and important preventive measures of today’s dreadening disease spread through blood transfusion.
Or
Where is AIDS reported for the first time ? Describe the causes, method of transmission and control measures of this disease.
Answer:
AIDS (Acquired Immune Deficiency Syndrome) disease is discovered for the first time in America in the year 1981.

Causes of Disease:
This disease is caused by the infection of a vims known as HIV (Human Immunodeficiency Vims).

Transmission:
It is transmitted through sexual contact, homosexuality, contaminated needles, blood transfusion, dmgs, artificial insemination and organ transplantation etc.

Symptoms of Disease:
It is characterized by showing swollen lymph nodes, fever, loss of weight. The person loses the immunity against the infection. In this disease, the number of helper T-cells are reduced.

Treatment:
No suitable drug is available so far against this disease. Only anti – viral cells may increase in the number by immune stimulation method.

Control:
The following measures are advised to prevent spreading of disease:

1. Providing health education and explain the hazardous effects of AIDS.
2. Do not reutilize the used syringe. Throw it away or destroy it.
3. The blood of donor person and organs of transplantation like kidney, liver, cornea of eyes, growth hormones would be carefully examined before use.
4. Sexual contact with many people must be avoided.

Question 3.
What is the mechanism by which the AIDS virus causes deficiency in the immune system of the infected person ?
Answer:
The virus enters macrophages after getting into the body of individual where RNA forms viral DNA by reverse transcription. The viral DNA gets incorporated in the host cell’s DNA and directs the infected cells to produce viral copies. The newly produced virus particles attack helper T – cells and thus, the number of T-cells decrease. Since, the helper T-cel Is are essential for functioning of immune system, the person suffers from various diseases due to dificient immune system.

Question 4.
List the harmful effects caused by alcohol/drug abuse.
Answer:
The adverse effects of drugs and alcohol abuse are:

1. Low to moderate doses can cause reckless behaviour, vandalism and violence depression, fatigue, weight fluctuations, etc.
2. Excessive doses of drugs may lead to coma and death due to respiratory failure, heart failure or cerebral haemorrhage.
3. A combination of different drugs or alcohol mixed with drugs, results in overdosing and even death.

Question 5.
Do you think that friends can influence one to take alcohol/drugs? If yes, how may one protect himself/herself from such an influence?
Answer:
Yes, friends can influence one to take drugs and alcohol. A person can take the following steps for the prevention of themself against drug abuse:

1. By avoiding under peer pressure as everyone has their own field of interest which should be respected by there teachers and family. One should not experiment with alcohol for curiosity and fun.
2. Avoid the company of friends who take drugs.
3. Seek help from parents and peers. A child should not pushed beyond his/her threshold limits.
4. Take proper knowledge and counselling about drug abuse. Devolve your energy in other extra-curricular activities.
5. Seek immediate professional and medical help from psychologists and psychiatrists if symptoms of depression and frustration become apparent.
6. Get rid of the problem completely and lead, perfectly normal life by increasing their will power.

Question 6.
Why is that once a person starts taking alcohol or drugs, it is difficult to get rid of this habit? Discuss it with y.our teacher.
Answer:
It is difficult to get rid of this habit, because these substances are addictive and one starts having unpleasant feelings or withdrawal symptoms like nausea, vomiting, diarrhoea, shivering, muscle twitching, excessive perspiration, muscular and abdominal cramps. Mind loses control and all one can think of is taking the addictive substance. That is why resisting the temptation/pressure for the first time is the only way to avoid getting into the addictive habit and committing a slow suicide.

Question 7.
In your view what motivates youngsters to take to alcohol or drugs and how can this be avoided ? .
Answer:
Probably the ‘motivation’ comes from:

1. Curiosity to experience the effect.
2. Foolishness to try to prove oneself in front of the peers.
3. Wrongly taking it as an excuse to escape from reality.
4. Wrong thinking that one time ‘try’ is not going to do any harm.

But youngsters who are strong willed, who understand its ill effects and who are satisfied with their academic and other achievements and who don’t want to waste their precious life, don’t fall for this kind of ‘Motivation’.

Question 8.
What is immune system? Describe various components of immune system of man and its role.
Answer:
The Immune System or Immunity (A Specific Defence Mechanism):
The ability of an organism to resist the pathogen Or development of disease resistance is known as immunity and the study of immunity is called immunology, while the infected person with no disease is called immune. The most peculiar characteristic of immune system is that it can differentiate the self (body’s own cells) and non-self (foreign microbes).

Cells of the Immune System:
Lymphocytes are the type of W.B.Cs. or Leucocytes which are chief cells of immune system of body. There are two types of lymphocytes that promote cellular immunity and humoral immunity. Both of these types of lymphocytes are derived from lymphocyte stem cells in the bone – marrow in the embryo.

1. T – cells of lymphocytes:
These cells eventually migrate to the lymphoid tissue. Before doing so, the lymphocytes first migrate to thymus gland and are processed in the gland, hence called T – lymphocytes or T – cells. These are responsible for cellular immunity. There are following types of T – cells :

(i) Killer T – cells:
Killer T – cells or KT – cells directly attack and destroy antigen. In doing so, they move to the site of invasion and produce some chemical that attracts and stimulate phagocytes to feed more voraciously on antigen.

(ii) Helper T – cells:
Helper T – cells or HT – cells stimulate B – cells to produce more antibody.

(iii) Suppressor T – cells:
Suppressor T – cells or ST – cells keep entire immune system to attack on the own body cell.

Mode of action of T – cells to antigens:
T – cells are antigen specific (each T – cell recognizes a specific antigen and different types of T – cells are stimulated by different types of antigens). When a T – cell is stimulated by specific antigen, T – lymphocytes divide rapidly to form a clone of T – cells called lymphoblasts. T – cells live for 4 – 5 years or even longer. T – cells of a clone are morphologically similar but they perform different functions. According to their functions, their are three classes of T – cells, i.e., killer T – cells, helper T – cells and suppressor T – cells.

2. B – cells of lymphocytes:
The other population of lymphocytes which produces antibodies are processed in some unknown area, possibly liver or spleen. This population was firstly discovered in birds in which processing occurs in the bursa of fabricus, a structure not found in mammals. For this reason they are called as B – cells or B – lymphocytes. They are responsible for humoral immunity.

Mode of action B – cells to antigens:
Once a B – cells is activated by the antigen, it multiplies very fast and forms a clone of plasma cells. Most of these produce antibody at a tremendous rate of 2,000 molecules per second. These antibodies circulate in the lymph to fight the antigen. So, forming humoral immune system. B – cells are short lived and are replaced by new cells from the bone – marrow after every few days.

The capacity of B – cells to produce specific antibodies is acquired during its development and maturation.

Question 9.
Describe the harmful effects of tobacco smoking.
Answer:
Effect of chewing and smoking tobacco:
The chewing and smoking of tobacco affects us in the following ways:

1. It affects the route of the transfer of nerve impulse and central nervous system. In low concentration nicotine stimulates conduction of nerve impulse but long – term use reduces the activity of nervous system.

2. Nicotine stimulates the release of adrenaline leading to high blood pressure. Increased blood pressure due to smoking enhances the risk of heart diseases.

3. It retards foetal growth in pregnant women.

4. The smoke of tobacco contains aromatic hydrocarbons and tar along with carbon monoxide (CO). Carbon monoxide reduces oxygen carrying capacity of the blood. Hydrocarbons induces cancer. Due to these reasons tobacco chewing person suffer from mouth cancer and smokers suffer from throat and lung cancers.

5. The use of tobacco in any form stimulates the secretion of saliva and gastric juices due to which acidity is increased in stomach. It may cause ulcers in the wall of stomach. The absorption capacity of mucous membrane of stomach also decreases. Thus, person get suffered from hyponutrition, loss of appetite and constipation.

6. Smoking also affects the activity of kidneys.

7. Nicotin relaxes the muscular and skeletal tissues due to which person becomes weak.

8. Long – term smoking may also cause diseases like bronchitis and emphysema.

9. Smoking reduces immunity of the body.

10. Lips of smokers may become dark coloured. Teeth and fingers get stained. The breath becomes foul.

MP Board Class 12th Biology Important Questions

MP Board Class 11th Chemistry Solutions Chapter 13 हाइड्रोकार्बन

हाइड्रोकार्बन NCERT अभ्यास प्रश्न

प्रश्न 1.
मेथेन के क्लोरीनीकरण के दौरान ऐथेन कैसे बनती है ? आप इसे कैसे समझाएँगे?
उत्तर:
मेथेन का क्लोरीनीकरण मुक्त मूलक क्रियाविधि द्वारा होता है। मेथिल मुक्त मूलक (CH₃ ) श्रृंखला समापन पद के दौरान ऐथेन में रूपान्तरित हो जाते हैं।

प्रश्न 2.
निम्नलिखित यौगिकों के IUPAC नाम लिखिए –
(i) CH₃ CH = C(CH₃)₂
(ii) CH₃ = CH – C ≡ C – CH₃

उत्तर:

प्रश्न 3.
निम्नलिखित यौगिकों, जिनमें द्विआबन्ध तथा त्रिआबन्ध की संख्या दर्शायी गई है, के सभी सम्भावित स्थिति समावयवों के संरचना-सूत्र एवं IUPAC नाम दीजिए –
(a) C₄H₈ (एक द्विआबन्ध)
(b) C₅H₈ (एक त्रिआबन्ध)।
उत्तर:
(a) C₄H₈ के समावयवी जो द्विआबंध रखते हैं –

(b) C₅H₈ के समावयवी जो त्रिआबंध रखते हैं –

प्रश्न 4.
निम्नलिखित यौगिकों के ओजोनी-अपघटन के पश्चात् बनने वाले उत्पादों के नाम लिखिए –
(1) पेन्ट-2-ईन
(ii) 3, 4-डाइमेथिलहेप्ट-3-ईन
(iii) 2- एथिलब्यूट-1-ईन
(iv) 1-फेनिलब्यूट-1-ईन।
उत्तर:

प्रश्न 5.
एक ऐल्कीन ‘A’ के ओजोनी अपघटन से पेन्टेन-3-ओन तथा ऐथेनल का मिश्रण प्राप्त होता है। A का IUPAC नाम तथा संरचना दीजिए।
उत्तर:
ओजोनी अपघटन के फलस्वरूप बने उत्पादों की संरचना इस प्रकार लिखते हैं जिससे उनके ऑक्सीजन परमाणु एक दूसरे की ओर इंगित रहे। दोनों ऑक्सीजन परमाणु को निकालने के पश्चात् दोनों सिरों की द्विआबंध से जोड़कर, एल्कीन ‘A’ की संरचना प्राप्त करते है।

प्रश्न 6.
एक ऐल्कीन A में तीन C – C, आठ C – H सिग्मा आबन्ध तथा एक C – C पाई आबन्ध है। A ओजोनी अपघटन से दो अणु ऐल्डिहाइड, जिनका मोलर द्रव्यमान 44 है, देता है। A का आई.यू.मी.ए.सी. नाम लिखिए।
उत्तर:
मोलर द्रव्यमान 44u वाला ऐल्डिहाइड, ऐथेनल (CH₃CHO) है। अतः इसके दो अणु की संरचनाओं से –

अत: एल्कीन ‘A’ अर्थात् ब्यूट-2-ईन में तीन C-C, आठ C- HO – आबंध तथा एक C – C  2-आबंध उपस्थित है। जो संख्या प्रश्नों में दी गई है।

प्रश्न 7.
एक एल्कीन, जिसके ओजोनी अपघटन से प्रोपेनल (Propanal) तथा पेन्टेन-3-ओन प्राप्त होते हैं, का संरचनात्मक सूत्र क्या है ?
उत्तर:
प्रोपेनल तथा पेन्टेन-3-ओन में से ऑक्सीजन अलग होकर ये द्वि-बंध द्वारा जुड़ जाते हैं।

प्रश्न 8.
निम्नलिखित हाइड्रोकार्बनों के दहन की रासायनिक अभिक्रिया लिखिए –
(i) ब्यूटेन
(ii) पेन्टीन
(iii) हेक्साइन
(iv) टॉलुईन।
उत्तर:
सभी हाइड्रोकार्बन पूर्ण दहन पर CO₂ और H₂O देते है।

प्रश्न 9.
हेक्स-2-ईन की समपक्ष (सिस) तथा विपक्ष (ट्रान्स ) संरचनायें बनाइए। इनमें से कौनसे समावयव का क्वथनांक उच्च होता है और क्यों ?
उत्तर:
हेक्स-2-ईन (CH₃CH₂CH₂CH = CHCH₃) की समपक्ष तथा विपक्ष समावयव की संरचनाएँ निम्न हैं –

सिस समावयवी में क्वथनांक अपेक्षाकृत उच्च होगा क्योंकि इसके द्विध्रुव-द्विध्रुव अन्योन्य क्रिया का परिणाम, ट्रान्स समावयवी की अपेक्षा अधिक होता है।

प्रश्न 10.
बेंजीन में तीन द्वि-आबन्ध होते हैं, फिर भी यह अत्यधिक स्थायी है, क्यों?
उत्तर:
अनुनाद तथा इलेक्ट्रॉनों के विस्थानीकरण के कारण बेन्जीन अणु अत्यधिक स्थायी होता है।

संकरित संरचना संकरित संरचना में बिन्दु वृत्त, बेन्जीन वलय के छ: कार्बन परमाणु पर विस्थानीकृत छ: इलेक्ट्रॉनों को दर्शाता है। अतः विस्थानीकृत छः इलेक्ट्रॉनों की उपस्थिति के कारण बेन्जीन अत्यधिक स्थायी होता है।

प्रश्न 11.
किसी निकाय द्वारा ऐरोमैटिकता प्रदर्शित करने के लिए आवश्यक शर्ते क्या हैं ?
उत्तर:
किसी निकाय का ऐरोमैटिक गुण प्रदर्शित निम्न शर्तों पर निर्भर करता है –

• यौगिक संरचना समतलीय होनी चाहिये।
• यौगिक अनुनादी संरचनायें प्रदर्शित करें।
• यौगिक हकल नियम का पालन करें।
• यौगिक इलेक्ट्रॉन स्नेही अभिक्रियाएँ प्रदर्शित करें

प्रश्न 12.
इनमें से कौन-से निकाय ऐरोमैटिक नहीं है ? कारण स्पष्ट कीजिए –

उत्तर:

(a) यह संरचना समतलीय नहीं है क्योंकि इसमें एक C परमाणु sp’ संकरित अवस्था में उपस्थित है।
(b) यह संरचना इलेक्ट्रॉन स्नेही प्रतिस्थापी अभिक्रियाएँ प्रदर्शित नहीं करती।

(ii)
यह संरचना ऐरोमैटिक गुण प्रदर्शित नहीं करता क्योंकि
(a) इसकी संरचना समतलीय नहीं है (इसमें एक C परमाणु का संकरण अवस्था sp’ है।)
(b) यह हकल नियम का पालन नहीं करता।
(c) यह अनुनादी संरचनायें भी प्रदर्शित नहीं करता।
(d) यह इलेक्ट्रॉन स्नेही प्रतिस्थापी अभिक्रियाएँ नहीं देती।

(ii)
यह संरचना ऐरोमैटिक गुण प्रदर्शित नहीं करता क्योंकि
(a) इसकी संरचना समतलीय नहीं है।
(b) यह संरचना हकल नियम का पालन नहीं करती।।
(c) यह इलेक्ट्रॉन स्नेही प्रतिस्थापी अभिक्रियाएँ प्रदर्शित नहीं करती।

प्रश्न 13.
बेंजीन को निम्नलिखित में कैसे परिवर्तित करेंगे –

1. p – नाइट्रोब्रोमोबेंजीन
2. m – नाइट्रोक्लोरोबेंजीन
3. p – नाइट्रोटॉलुईन
4. ऐसीटोफिनोन।

उत्तर:
ये रूपान्तरण इस तथ्य पर आधारित होते हैं कि –

• क्लोरीन की प्रकृति ऑर्थों और पैरा निर्देशी होती है।
• नाइट्रो समूह की प्रकृति मेटा निर्देशी होती है।

1. बेंजीन से p – नाइट्रोनोमोबेंजीन –

2. बेंजीन से m – क्लोरोनाइट्रोबेंजीन –

3. बेंजीन से p – नाइट्रोटॉलुईन –

4. बेंजीन से p – एसीटोफिनोन –

प्रश्न 14.
ऐल्केन H₃C – CH₂ – C(CH₃)₂ – CH₂– CH(CH₃)₂ में 1,2° तथा 3° कार्बन परमाणुओं की पहचान कीजिए तथा प्रत्येक कार्बन से आबन्धित कुल हाइड्रोजन परमाणुओं की संख्या भी बताइए।
उत्तर:

प्रश्न 15.
क्वथनांक पर ऐल्केन की श्रृंखला के शाखन (Branch) का क्या प्रभाव पड़ता है ?
उत्तर:
श्रृंखला में शाखन में वृद्धि के फलस्वरूप पृष्ठ सतह घटता है। अतः एल्केन की श्रृंखला के शाखन में वृद्धि के फलस्वरूप वाण्डर वाल्स आकर्षण बलों में कमी के कारण, क्वथनांक घटता है।

प्रश्न 16.
प्रोपीन पर HBr के संकलन से 2-ब्रोमोप्रोपेन बनता है, जबकि बेन्जॉयल परॉक्साइड की उपस्थिति में यह अभिक्रिया 1-ब्रोमोप्रोपेन देती है। क्रियाविधि की सहायता से इसका कारण स्पष्ट कीजिए।
उत्तर:
प्रोपीन (असममित ऐल्कीन) पर HBr योग मार्कोनीकॉफ नियम के अनुसार धनायनिक क्रियाविधि से संपादित होती है। HBr इलेक्ट्रॉन स्नेही, H’ उत्पन्न करता है जो कार्बधनायन से द्विबंध पर आक्रमण करता है।
(i) H – Br → H⁺ + Br^–

इस -2° कार्बधनायन पर Br आयन आक्रमण करके उत्पाद बनाता है।

ब्रोमो प्रोपेन (मुख्य उत्पाद) बेन्जॉयल परॉक्साइड की उपस्थिति में प्रोपीन पर HBr का योग मार्कोनीकॉफ नियम के विपरीत होता है। यह मुक्त मूलक की क्रिया से संपादित होता है। इस अभिक्रिया को प्रति मार्कोनीकॉफ योग या परॉक्साइड प्रभाव या खराश प्रभाव कहते हैं। यह केवल HBr के साथ होता है, HCl तथा HI के साथ नहीं। क्रियाविधि निम्न हैं –

प्रश्न 17.
1, 2-डाइमेथिलबेंजीन (o – जाइलीन) के ओजोनी अपघटन के फलस्वरूप निर्मित उत्पादों को लिखिए। यह परिणाम बेंजीन की केकुले संरचना की पुष्टि किस प्रकार करता है ?
उत्तर:

इसी प्रकार,

ये तीनों उत्पाद दोनों कैकुले संरचनाओं में से किसी एक द्वारा ही नहीं प्राप्त किए जा सकते है। इससे प्रदर्शित होता है कि o-जाइलीन, वास्तव में दो कैकुले संरचनाओं ग्लाइऑक्सल (I तथा II) का अनुनादी रूप है।

प्रश्न 18.
बेंजीन, n – हेक्सेन तथा एथाइन को घटते हुए अम्लीय व्यवहार के क्रम में व्यवस्थित कीजिए और इस व्यवहार का कारण बताइए।
उत्तर:
अम्लीय सामर्थ्य का घटता हुआ क्रम है –

अम्लीय अभिलक्षण S-अभिलक्षण की प्रतिशतता से सम्बन्धित होता है। 5-अभिलक्षण जितना अधिक होता है, कार्बन परमाणु की वैद्युत ऋणात्मकता उतनी ही अधिक होती है तथा उसका अम्लीय अभिलक्षण भी उतना ही अधिक होगा।

प्रश्न 19.
बेंजीन इलेक्ट्रॉनस्नेही प्रतिस्थापन अभिक्रियाएँ सरलतापूर्वक क्यों प्रदर्शित करती है, जबकि उसमें नाभिकस्नेही प्रतिस्थापन कठिन होता है ?
उत्तर:
बेंजीन में द्विआबन्धों को प्रदर्शित करने वाले तीन T – इलेक्ट्रॉनों युग्मों के कारण इलेक्ट्रॉन घनत्व उच्च होता है। यद्यपि इलेक्ट्रॉन आवेश अनुनाद के कारण बहुत अधिक विस्थानीकृत हो जाता है, तथापि इसमें इलेक्ट्रॉनस्नेही प्रतिस्थापन कराने वाला इलेक्ट्रॉन-स्नेही आक्रमण सम्भव होता है। किन्तु, बेंजीन नाभिकस्नेही प्रतिस्थापन के प्रति अनुक्रियाशील नहीं होता है क्योंकि नाभिकस्नेही प्राथमिकता के तौर पर कम इलेक्ट्रॉन घनत्व के केन्द्र पर आक्रमण करता है।

प्रश्न 20.
आप निम्नलिखित यौगिकों को बेंजीन में कैसे परिवर्तित करेंगे –

1. एथाइन
2. एथीन
3. हेक्सेन।

उत्तर:
1. एथाइन से बेंजीन –

2. एथीन से बेंजीन –

3. हेक्सेन से बेंजीन –

प्रश्न 21.
उन सभी एल्कीनों की संरचनाएँ लिखिए, जो हाइड्रोजनीकरण करने पर 2-मेथिलब्यूटेन देती हैं।
उत्तर:
उपर्युक्त प्रश्न को हम निम्न प्रकार से मालूम करेंगे –
2-मेथिलब्यूटेन प्राप्त करने के लिये कौन-सी एल्कीन लेनी होगी –

उपर्युक्त संरचना को हमें एल्कीन से प्राप्त करनी है। उपर्युक्त संरचना में पास-पास वाले C परमाणुओं से H परमाणु हटा कर द्विबन्ध जोड़ दें।

प्रश्न 22.
निम्नलिखित यौगिकों को उनकी इलेक्ट्रॉनस्नेही (E’) के प्रति घटती सापेक्षिक अभिक्रियाशीलता के क्रम में व्यवस्थित कीजिए –
1. क्लोरोबेंजीन, 2-4-डाइनाइट्रोक्लोरोबेंजीन, p-नाइट्रो-क्लोरोबेंजीन
2. टॉलुईन, P – H₃C – C₆H₄ – NO₂, P – O₂N – C₆H₄ – NO₂
उत्तर:
1. इलेक्ट्रॉनस्नेही प्रतिस्थापन के प्रति अभिक्रियाशीलता का घटता हुआ सही क्रम है –
क्लोरोबेंजीन >p-नाइट्रोक्लोरोबेंजीन >2,4-डाईनाइट्रोक्लोरोबेंजीन
नाइट्रो समूह (NO₂) एक विसक्रियकारी समूह है। बेंजीन वलय पर इसकी उपस्थिति इसे इलेक्ट्रॉनस्नेही आक्रमण के प्रति विसक्रियित करेगी, क्योंकि इलेक्ट्रॉनस्नेही उच्च इलेक्ट्रॉन घनत्व के केन्द्र की खोज करता है। अतः नाइट्रो समूहों की संख्या जितनी ही अधिक होगी, इलेक्ट्रॉनस्नेही प्रतिस्थापन के प्रति यौगिकों की अभिक्रियाशीलता उतनी ही कम होगी।

2. घटती हुई अभिक्रियाशीलता का सही क्रम है – .
टॉलुईन > p – नाइट्रोटॉलुईन > p – डाईनाइट्रोबेंजीन
मेथिल समूह एक सक्रियकारी समूह है, जबकि नाइट्रो समूह की प्रकृति विसक्रियकारी होती है। इस तथ्य के प्रकाश में इलेक्ट्रॉनस्नेही आक्रमण के प्रति अभिक्रियाशीलता का घटता हुआ यह क्रम तर्कसंगत सिद्ध होता है –
टॉलुईन > बेंजीन > m-डाईनाइट्रोबेंजीन

प्रश्न 23.
बेंजीन, m – डाइनाइट्रोबेंजीन और टॉलुईन में से किसका नाइट्रीकरण आसानी से होता है। और क्यों ?
उत्तर:
बेंजीन के नाइट्रीकरण में वलय पर \(\mathrm{NO}_{2}^{\ominus}\) (नाइट्रोनियम आयन) का इलेक्ट्रॉनस्नेही आक्रमण होता है। चूंकि CH₃ समूह में +I प्रभाव होता है, इसलिए यह वलय को सक्रिय कर देता है और इसका इलेक्ट्रॉनस्नेही प्रतिस्थापन आसानी से होता है। दूसरी ओर, नाइट्रो समूह की विसक्रियकारी प्रकृति के कारण यह m-डाइनाइट्रोबेंजीन में सबसे कठिनाई से होता है। इस प्रकार टॉलुईन का नाइट्रीकरण सबसे आसानी से होगा। टॉलुईन > बेंजीन > m – डाईनाइट्रोबेंजीन

प्रश्न 24.
बेंजीन के एथिलीकरण में निर्जल ऐल्युमिनियम क्लोराइड के स्थान पर कोई दूसरा लुईस अम्ल सुझाइए।
उत्तर;
निर्जल फेरिक क्लोराइड (FeCl₅) वह अन्य लुईस अम्ल है जिसे प्रयुक्त कर सकते हैं। यह इलेक्ट्रॉनस्नेही (C₂H₅ई) पैदा करने में सहायक होता है। स्टेनिक क्लोराइड (SnCl₄) एवं बोरॉन ट्राइफ्लुओराइड (BF₃) . का भी प्रयोग किया जा सकता है।

प्रश्न 25.
क्या कारण है कि वुर्ट्ज अभिक्रिया से विषम संख्या कार्बन परमाणु वाले विशुद्ध ऐल्केन बनाने के लिए प्रयुक्त नहीं की जाती? एक उदाहरण देकर स्पष्ट कीजिए।
उत्तर:
कार्बन परमाणुओं की विषम संख्या वाले ऐल्केन के निर्माण में दो भिन्न-भिन्न हैलोऐल्केन आवश्यक होते हैं, जिनमें से एक में कार्बन परमाणुओं की विषम संख्या हो और दूसरे में सम संख्या हो। उदाहरण के लिए ब्रोमोएथेन और 1-ब्रोमोप्रोपेन इस अभिक्रिया के फलस्वरूप पेन्टेन देंगे।

परन्तु जब इस अभिक्रिया में भाग लेने वाले सदस्य अलग-अलग अभिक्रिया करेंगे तो पार्श्व उत्पाद भी बनेंगे। उदाहरण के लिए, ब्रोमोएथेन, ब्यूटेन देता है और 1- ब्रोमोप्रोपेन, हेक्सेन देता हैं।

इस प्रकार ब्यूटेन, पेन्टेन और हेक्सेन का मिश्रण बनेगा। इस मिश्रण से इनके घटकों को पृथक् करना काफी कठिन होगा।

हाइड्रोकार्बन अन्य महत्वपूर्ण प्रश्न

हाइड्रोकार्बन वस्तुनिष्ठ प्रश्न

प्रश्न 1.
सही विकल्प चुनकर लिखिए –

प्रश्न 1.
मेथेन में H – C – H बन्ध कोण है –
(a) 100°5′
(b) 109°
(c) 109°28′
(d) 180°
उत्तर:
(c) 109°28′

प्रश्न 2.
C = C में है –
(a) 30 बन्ध
(b) एक सिग्मा और तीन पाई बन्ध
(c) 37 बन्ध
(d) एक सिग्मा और दो पाई बन्ध
उत्तर:
(d) एक सिग्मा और दो पाई बन्ध

प्रश्न 3.
एथीन में है –
(a) पाँच सिग्मा और एक पाई बन्ध
(b) छ: सिग्मा बन्ध
(c) चार सिग्मा और दो पाई बन्ध
(d) पाँच सिग्मा बन्ध।
उत्तर:
(a) पाँच सिग्मा और एक पाई बन्ध

प्रश्न 4.
किसकी क्रियाशीलता सर्वाधिक है –
(a) C₂H₂
(b) CH₄
(c) C₂H₄
(d) C₂H₆.
उत्तर:
(a) C₂H₂

प्रश्न 5.
ज्यामितीय समावयवता प्रदर्शित करता है –
(a) ब्यूट-2-ईन
(b) ब्यूट-2-आइन
(c) ब्यूटेन-2-ऑल
(d) ब्यूटेनल।
उत्तर:
(a) ब्यूट-2-ईन

प्रश्न 6.
बेंजीन में कार्बन द्वारा उपयोग में लाई गई प्रसंकरित ऑर्बिटल (कक्षक) होती है –
(a) sp³
(b) sp²
(c) sp
(d) dsp³
उत्तर:
(b) sp²

प्रश्न 7.
HC ≡ C – CH = CH, के C – C एक आबन्ध के कार्बन परमाणुओं का संकरण है –
(a) sp³ – sp³
(b) sp² – sp³
(c) sp³ – sp
(d) sp – sp²
उत्तर:
(d) sp – sp²

प्रश्न 8.
ब्यूट-1-इन में सिग्मा बन्धों की संख्या है –
(a) 8
(b) 10
(c) 11
(d) 12.
उत्तर:
(c) 11

प्रश्न 9.
एथिलीन में उपस्थित दो परमाणुओं के मध्य विद्यमान द्विबन्ध होता है –
(a) लम्बवत् दो सिग्मा-बन्ध
(b) एक सिग्मा (σ) तथा एक पाई (π) बन्ध
(c) लम्बवत् दो पाई-बन्ध
(d) 60 अंश का कोण बनाते हुए दो पाई-बन्ध।
उत्तर:
(b) एक सिग्मा (σ) तथा एक पाई (π) बन्ध

प्रश्न 10.
निम्न में से कौन-सा अभिकर्मक एथिलीन और ऐसीटिलीन में विभेद करता है –
(a) जलीय क्षारीय KMnO₄
(b) CCl₄ में Cl₂ विलेय
(c) अमोनियामय Cu₂ Cl₂
(d) सान्द्र H₂SO₄
उत्तर:
(c) अमोनियामय Cu₂Cl₂

प्रश्न 11.
इंजन में अपस्फोटी ध्वनि उत्पन्न होती है, जब ईंधन –
(a) धीरे जलता है
(b) तेजी से जलता है
(c) पानी होता है
(d) मशीन तेल मिश्रित होता है।
उत्तर:
(b) तेजी से जलता है

प्रश्न 12.
ईंधन का अपस्फोटक गुण बढ़ाने के लिये मिलाया जाता है –
(a) PbBr₂
(b) ZnBr₂
(c) Pbo
(d) TEL (Tetraethyl lead).
उत्तर:
(d) TEL (Tetraethyl lead).

प्रश्न 13.
मेथेन बनाने के लिए निम्न में से किस विधि का उपयोग किया जा सकता है –
(a) वु अभिक्रिया
(b) कोल्बे अभिक्रिया
(c) ऐल्किल हैलाइड का अपचयन
(d) ऐल्कीन का हाइड्रोजनीकरण।
उत्तर:
(c) ऐल्किल हैलाइड का अपचयन

प्रश्न 14.
जब ऐसीटिलीन HCl की उपस्थिति में HgCl₂ से अभिक्रिया करती है, तो बनता है
(a) मेथिल क्लोराइड
(b) ऐसीटैल्डिहाइड
(c) वाइनिल क्लोराइड
(d) फॉर्मेल्डिहाइड।
उत्तर:
(b) ऐसीटैल्डिहाइड

प्रश्न 15.
जब प्रोपाइन को HgSO₄ की उपस्थिति में जलीय H₂ SO₄ से प्रतिकृत किया जाता है, तो मुख्य उत्पाद बनता है –
(a) प्रोपेनल
(b) प्रोपिल हाइड्रोजन सल्फेट
(c) ऐसीटोन
(d) प्रोपेनॉल।
उत्तर:
(c) ऐसीटोन

प्रश्न 16.
प्रोपीन तथा प्रोपाइन में विभेद करने के लिए प्रयुक्त अभिकर्मक है –
(a) ब्रोमीन
(b) क्षारीय KMnO₄
(c) अमोनियामय AgNO₃
(d) ओजोन।
उत्तर:
(b) क्षारीय KMnO₄

प्रश्न 17.

(a) वुज अभिक्रिया
(b) कोल्बे अभिक्रिया
(c) साबात्ये सेण्डेरेन्स अभिक्रिया
(d) कार्बिल-ऐमीन अभिक्रिया
उत्तर:
(c) साबात्ये सेण्डेरेन्स अभिक्रिया

प्रश्न 18.
अमोनियाकृत सिल्वर नाइट्रेट विलयन से अभिक्रिया करके C₂ H₂ बनाता है –
(a) सिल्वर दर्पण
(b) सिल्वर ऑक्साइड
(c) सिल्वर फॉर्मेट
(d) सिल्वर ऐसीटिलाइड।
उत्तर:
(d) सिल्वर ऐसीटिलाइड।

प्रश्न 19.
एक अज्ञात यौगिक A का अणु सूत्र C₄ H₆ है । जब Aकी ब्रोमीन की अधिक मात्रा से अभि क्रिया करायी जाती है, एक नया पदार्थ B बनता है जिसका अणुसूत्र C₄ H₆ Br₄ है। A अमोनिया युक्त AgNO₃ के साथ सफेद अवक्षेप देता है। A हो सकता है –
(a) ब्यूट-1-आइन
(b) ब्यूट-2-आइन
(c) ब्यूट-1-ईन
(d) ब्यूट-2-ईन।
उत्तर:
(b) ब्यूट-2-आइन

प्रश्न 20.
क्रियाशीलता बढ़ाने वाले समूह होते हैं –
(a) o-,p-निर्देशकारी समूह
(b) m-निर्देशकारी समूह
(0) NO₂
(d) इनमें से कोई नहीं।
उत्तर:
(a) o-,p-निर्देशकारी समूह

प्रश्न 21.
निम्नलिखित में से कौन-सा एल्केन, वु अभिक्रिया द्वारा प्राप्त नहीं होता है –
(a) CH₄
(b) C₂H₆
(c) C₃H₈
(d) C₄H₁₀
उत्तर:
(a) CH₄

प्रश्न 22.
निम्न में प्रति ऐरोमैटिक है –
(a) बेंजीन
(b) साइक्लोऑक्टाडाईन
(c) ट्रोपोलियम धनायन
(d) साइक्लोपेन्टाडाइनील धनायन।
उत्तर:
(d) साइक्लोपेन्टाडाइनील धनायन।

प्रश्न 2.
रिक्त स्थानों की पूर्ति कीजिये –

1. कैरोसीन तेल …………. का मिश्रण है।
2. ………… में कार्बन-कार्बन बन्ध लम्बाई न्यूनतम होती है।
3. प्रोपीन तथा प्रोपाइन में विभेद करने के लिए ………… अभिकर्मक प्रयुक्त किया जाता है।
4. टेफ्लॉन …………. का बहुलक है।
5. एथेनॉल के निर्जलीकरण से ………… बनता है।
6. बेंजीन H₂ से योग करके …………. बनाता है।
7. ज्यामितीय समावयवता ……………… में पायी जाती है।
8. सर्वाधिक स्थायी संरूपी …………… रूप होता है।
9. विपक्ष समावयवी, समरूप समावयवी से …………. स्थायी होता है।
10. ऐल्युमीनियम कार्बाइड की जल से अभिक्रिया कराने पर …………. प्राप्त होता है।

उत्तर:

1. एल्केन
2. एथाइन
3. बेयर अभिकर्मक (क्षारीय KMnO₄)
4. टेट्रा फ्लोरो एथिलीन
5. एथीन
6. साइक्लोहेक्सेन
7. ऐल्कीन
8. सांतरित
9. अधिक
10. CH₄

प्रश्न 3.
उचित संबंध जोडिए –

उत्तर:

1. (b) कोल्बे अभिक्रिया
2. (d) वु अभिक्रिया से
3. (e) मेथेन।
4. (a) इलेक्ट्रॉन स्नेही प्रतिस्थापन अभिक्रिया
5. (c) sp – संकरण

उत्तर:

1. (e) पार्श्व अतिव्यापन
2. (a) इलेक्ट्रॉन स्नेही प्रतिस्थापन
3. (1) 0, p समूह
4. (b) असंतृप्त हाइड्रोकार्बन
5. (c) द्रवीभूत पेट्रोलियम गैस
6. (g) कम्प्रेस्ड नेचुरल गैस
7. (d) समपक्ष-विपक्ष समावयवी

प्रश्न 4.
एक शब्द / वाक्य में उत्तर दीजिए –
1. T.E.L. का पूरा नाम है।
2. एथिलीन डाइ ब्रोमाइड को Zn चूर्ण के साथ गर्म करने पर क्या बनता है?
3. L.P.G. में दुर्गन्ध पैदा करने वाले पदार्थ का नाम बताइये।
4. पोटैशियम एसीटेट के जलीय विलयन के विद्युत् अपघटन से एथेन बनता है, इस विधि का नाम बताइए।
5.
6.

प्रश्न 7.
एल्किल हैलाइड व सोडियम से ऐल्केन बनाने के लिए प्रयुक्त अभिक्रिया का नाम लिखिए।
उत्तर:
1. टेट्रा एथिल लेड
2. एथिलीन
3. एथिल मर्केप्टेन
4. कोल्बे अभिक्रिया
5. साबात्ये सेण्डरेन्स अपचयन अभिक्रिया
6. (A) CH = CH, (B) CH₃ – CHO, (C) CH₃– CH₂– OH
7. वु फिटिग अभिक्रिया।

हाइड्रोकार्बन अति लघु उत्तरीय प्रश्न

प्रश्न 1.
ऐल्काइन के द्रव अमोनिया में सोडियम द्वारा अपचयन के फलस्वरूप विपक्ष ऐल्कीन बनती है। क्या 2-ब्यूटाइन के इस प्रकार हुए अपचयन के फलस्वरूप ब्यूटीन ज्यामितीय समावयवता प्रदर्शित करेगी?
उत्तर:

2-ब्यूटाइन के अपचयन से प्राप्त विपक्ष-2-ब्यूटीन ज्यामितीय समावयवता प्रदर्शित करती है।

प्रश्न 2.
-1 प्रभाव के बावजूद, हैलोजन, हैलोएरीन यौगिकों में 0 – (ऑर्थो) तथा p – (पैरा) निर्देशी होती है। कारण स्पष्ट कीजिए।
उत्तर:
हैलोजन अत्यधिक निष्क्रिय समूह है। इनके प्रबल – I प्रभाव के कारण बेन्जीन वलय पर इलेक्ट्रॉन घनत्व घटता है। परन्तु अनुनाद के कारण o – तथा p – स्थानों पर इलेक्ट्रॉन घनत्व m – स्थान की अपेक्षा अधिक होता है। जिसके कारण ये o – तथा p – निर्देशी समूह होते हैं।

प्रश्न 3.
एल्केनों से एल्कीन की अधिक क्रियाशीलता का क्या कारण है ?
उत्तर:
एल्केनों में C – C के मध्य केवल आबन्ध होता है। जबकि एल्कीन में C = C के मध्य एक – आबन्ध और एक आबंध होता है। पार्वीय अतिव्यापन के कारण π बंध, σ बंध से दुर्बल होता है। इस कारण ऐल्कीन, ऐल्केनों से अधिक क्रियाशील है। 1 आबंध की आबन्ध ऊर्जा (251 kJ/mol) σ आबंध की आबंध ऊर्जा (347kJ/mol) से कम होने के कारण भी इनकी क्रियाशीलता ऐल्केन से अधिक होती है।

प्रश्न 4.
असममित कार्बन किसे कहते हैं ?
उत्तर:
वह कार्बन परमाणु जिससे चार भिन्न समूह या परमाणु जुड़े रहते हैं। असममित कार्बन परमाणु कहलाता है। इस असममित कार्बन की उपस्थिति के कारण यौगिक असममिति दर्शाता है तथा प्रकाश घूर्णकता का गुण दर्शाता है।

प्रश्न 5.
ब्यूटेन के ग्रसित तथा सांतरित संरूपों का न्यूमैन प्रक्षेप आरेख दीजिए।
उत्तर:
ब्यूटेन का संरचना सूत्र –

प्रश्न 6.
किरेलता से क्या समझते हो?
उत्तर:
वे अणु जो अपने दर्पण प्रतिबिम्ब पर अध्यारोपित नहीं होते हैं किरेल अणु कहलाते हैं तथा इस गुण को किरेलता कहते हैं। किरेल अणु ध्रुवण घूर्णक होते हैं। अणु में उपस्थित किरेलता असममित कार्बन परमाणु की उपस्थिति के कारण होती है। जिन अणुओं में किरेलता होती है वे ध्रुवण घूर्णक होते हैं लेकिन असममित कार्बन परमाणु युक्त अणु में ध्रुवण घूर्णकता हो यह जरूरी नहीं है। वे ध्रुवण घूर्णक हो भी सकते हैं और नहीं भी।

प्रश्न 7.
ऐल्केन किसे कहते हैं ? तथा इनमें किस प्रकार के बंध होते हैं ?
उत्तर:
ऐल्केन संतृप्त हाइड्रोकार्बन हैं। इन्हें पैराफिन भी कहते हैं। ये अत्यन्त कम क्रियाशील होते हैं तथा अधिक स्थायी होते हैं। इनका सामान्य सूत्र – C_nH_2n+2होता है। ऐल्केन में कार्बन – कार्बन के मध्य एकल बंध व 6 बंध होता है तथा कार्बन-हाइड्रोजन बंध भी बंध होता है। ऐल्केन में प्रत्येक कार्बन sp3 संकरित अवस्था में होता है।
उदाहरण – मेथेन CH₄एथेन C₂H₆

प्रश्न 8.
ऐल्कीन किसे कहते हैं ? इनमें कार्बन किस संकरित अवस्था में होता है ?
उत्तर:
ऐल्कीन असंतृप्त हाइड्रोकार्बन होते हैं। इन्हें ओलीफिन भी कहते हैं। ये ऐल्केन की तुलना में अधिक क्रियाशील होते हैं तथा इनका स्थायित्व ऐल्केन की तुलना में कम होता है। ये सरलता से योगात्मक अभिक्रिया देते हैं। इनका सामान्य सूत्र C_nH_{2n – 2} होता है। ऐल्कीन में कार्बन-कार्बन के बीच द्विबंध होता है तथा कार्बन sp संकरित अवस्था में होता है। उदाहरण – एथिलीन CH₂ = CH₂ प्रोपीलीन CH₃ – CH = CH₂

प्रश्न 9.
ऐल्काइन किसे कहते हैं ? तथा इनमें किस प्रकार के बंध होते हैं
उत्तर:
ऐल्काइन असंतृप्त हाइड्रोकार्बन होते हैं। ये अत्यधिक क्रियाशील होते हैं तथा अत्यधिक अस्थायी होते हैं। इनका सामान्य सूत्र C_nH_2n+1 होता है।
कार्बन – कार्बन के मध्य त्रिबंध होता है। जिसमें एक बंध व दो 7 बंध होते हैं तथा दोनों कार्बन sp संकरित अवस्था में होते हैं।
उदाहरण – एसीटिलीन CH = CH, प्रोपाईन CH₃ – C ≡ CH₂

प्रश्न 10.
समपक्ष-विपक्ष समावयवता क्या होती है ? उदाहरण सहित समझाइये।
उत्तर:
समपक्ष-विपक्ष समावयवता को ज्यामितीय समावयवता भी कहते हैं, जो युग्म बंध युक्त ऐसे यौगिकों के द्वारा दर्शायी जाती है, जिनमें युग्म बन्धित कार्बन परमाणु दो भिन्न परमाणुओं या समूहों द्वारा जुड़े रहते हैं। जब समान समूह या हाइड्रोजन परमाणु द्विबंध के एक ही ओर स्थित होते हैं तो प्राप्त यौगिक समपक्ष समावयवयी तथा जब विपरीत ओर स्थित होते हैं, तो प्राप्त यौगिक विपक्ष समावयवयी कहलाता है।
उदाहरण – CH₃ CH = CH – CH₃

प्रश्न 11.
ऐसीटिलीन से नाइट्रोबेन्जीन आप किस प्रकार प्राप्त करोगे?
उत्तर:

प्रश्न 12.
इलेक्ट्रॉन स्नेही तथा नाभिक स्नेही क्रमशः इलेक्ट्रॉन न्यून तथा इलेक्ट्रॉन समृद्ध अभिक्रिया मध्यवर्ती है। अतः इनकी प्रवृत्ति क्रमशः इलेक्ट्रॉन समृद्ध तथा इलेक्ट्रॉन न्यून नाभिकों पर आक्रमण करने की होती है। निम्नलिखित स्पीशीज को इलेक्ट्रॉन स्नेही तथा नाभिक स्नेही के रूप में वर्गीकृत कीजिए –
(i) H₃CO^–
(iii) Cl
(iv) Cl₂C:
(v) (CH₃)₃C⁺
(vi) Br^–
(vii) CH₃OH,
(viii) R – NH – R
उत्तर:
इलेक्ट्रॉन स्नेही, इलेक्ट्रॉन न्यून स्पीशीज होते हैं। ये उदासीन या धनावेशित हो सकते हैं।
(iii) Cl,
(iv) Cl₂C:
(v) (CH₃)₃C
नाभिक स्नेही, इलेक्ट्रॉन समृद्ध स्पीशीज होते है। ये उदासीन या ऋणावेशित हो सकते हैं।
(i) CH₃O

प्रश्न 13.
साइक्लोहेक्सेन की तुलना में साइक्लोप्रोपेन अधिक क्रियाशील होता है, क्यों ?
उत्तर:
साइक्लोप्रोपेन में C – C – C बंध कोण 60° का होता है, जिसके कारण वलय तनाव में होता है इसलिये इसका स्थायित्व कम तथा क्रियाशीलता अधिक होती है। जबकि साइक्लोहेक्सेन में C – C – C बंध कोण 109°28 के पास होता है, जिसके कारण वलय का तनाव कम होता है, जिसके कारण इसका स्थायित्व अधिक और क्रियाशीलता कम होती है।

प्रश्न 14.
क्रियात्मक समावयवता को उदाहरण सहित समझाइये।
उत्तर:
जब दो या दो से अधिक यौगिकों में अलग-अलग क्रियात्मक समूह उपस्थित हों पर उनका अणुसूत्र एक ही हो तो इस प्रकार उत्पन्न समावयवता को क्रियात्मक समावयवता कहते हैं।
उदाहरण – C₂H₆O
CH₃ – O – CH₂ ⇔ C₂H₅ – OH.

प्रश्न 15.
वियोजन क्या है ?
उत्तर:
उपयुक्त विधियों द्वारा रेसेमिक मिश्रण को d या ! प्रतिबिम्ब समावयवयी में पृथक् करने की विधि को वियोजन कहते हैं। इसके लिये यौगिक, जीव रासायनिक एवं रासायनिक विधियों द्वारा वियोजन किया जा सकता है।

प्रश्न 16.
एरीन में कौन-सी समावयवता पायी जाती है ? उदाहरण सहित स्पष्ट कीजिए।
उत्तर:
एरीन में स्थिति समावयवता पायी जाती है। टॉलुईन के अतिरिक्त सभी बेंजीन के यौगिकों में स्थिति समावयवता होती है।
उदाहरण – C₈H₁₀ चार समावयवयी रूपों में मिलता है

प्रश्न 17.
ऐल्काइन की अम्लीय प्रकृति को दर्शाने के लिये एक अभिक्रिया लिखिए।
उत्तर:
वे ऐल्काइन जिनके अणु के अंतिम छोर में त्रिबंध होता है, वे दुर्बल अम्ल की तरह कार्य करते हैं । ऐसे ऐल्काइन की अभिक्रिया Na, Ca जैसी क्रियाशील धातुओं से कराने पर ये हाइड्रोजन मुक्त करते हैं तथा इनके व्युत्पन्न प्राप्त होते हैं, जिन्हें एसीटिलाइड कहते हैं।

प्रश्न 18.
बेयर अभिकर्मक क्या है, तथा इससे असंतृप्तता का परीक्षण कैसे करते हैं ?
उत्तर:
क्षारीय KMnO₄ को बेयर अभिकर्मक कहते हैं। असंतृप्त हाइड्रोकार्बन की अभिक्रिया बेयर अभिकर्मक से कराने पर क्षारीय KMnO₄ का रंग उड़ जाता है। इसलिये इसका उपयोग यौगिक की असंतृप्तता के परीक्षण के लिये करते हैं।

प्रश्न 19.
ऐल्कीन पर बेयर अभिकर्मक की अभिक्रिया को समीकरण सहित स्पष्ट कीजिए।
उत्तर:
एथिलीन कमरे के ताप पर 1% क्षारीय KMnO₄ अर्थात् बेयर अभिकर्मक के साथ अभिक्रिया कराने पर एथिलीन ग्लाइकॉल बनाता है तथा इस योगात्मक अभिक्रिया के कारण KMnO₄ का गुलाबी रंग उड़ जाता है।

प्रश्न 20.
परॉक्साइड प्रभाव क्या है ? एक उदाहरण दीजिए।
उत्तर:
यदि कार्बनिक परॉक्साइड जैसे बेंजॉयल परॉक्साइड की उपस्थिति में असममित एल्कीन या एल्काइन पर असममित अभिकर्मक का योग कराया जाता है तो अभिक्रिया मार्कोनीकॉफ नियम के विपरीत होती है। इस अभिक्रिया को प्रति मार्कोनीकॉफ नियम या परॉक्साइड प्रभाव या खराश प्रभाव कहते हैं।

प्रश्न 21.
एथेन, एथिलीन तथा एसीटिलीन में विभेद कैसे करते हैं ? परीक्षण सहित समझाइए।
उत्तर:
एथेन, एथिलीन तथा एसीटिलीन में विभेद –

प्रश्न 22.
बर्थलोट संश्लेषण क्या है ?
उत्तर:
दो कार्बन इलेक्ट्रोड के बीच विद्युत् आर्क में से हाइड्रोजन गैस की धारा प्रवाहित करने पर एसीटिलीन प्राप्त होता है। इसे बर्थलोट संश्लेषण कहते हैं।

प्रश्न 23.
वेस्ट्रॉन तथा वेस्ट्रॉसोल क्या है ?
उत्तर:
(1) ऐसीटिलीन पर CCl₄, विलायक की उपस्थिति में हैलोजन की योगात्मक अभिक्रिया से बना .. यौगिक वेस्ट्रॉन कहलाता है।

(2) वेस्ट्रॉन को ऐल्कोहॉलिक KOH के साथ गर्म किया जाता है तो विहाइड्रो – हैलोजनीकरण के कारण वेस्ट्रॉसोल प्राप्त होता है।

प्रश्न 24.
प्रोटोट्रॉफी किसे कहते हैं ?
उत्तर:
प्रोपाइन पर जलयोजन होने पर इनॉल व कीटो रूप प्राप्त होते हैं। यह चलावयवता समावयवता को प्रदर्शित करते हैं तथा इस प्रकार की समावयवता उन यौगिकों में होती है, जिनमें कम-से-कम एक हाइड्रोजन होता है तथा एक स्थिति से दूसरे तक प्रोटॉन के स्थानांतरण के कारण उत्पन्न होती है इसे प्रोटोट्रॉफी कहते हैं।

प्रश्न 25.
संरूपण समावयवता किसे कहते हैं ?
उत्तर:
कार्बन-कार्बन एकल बंध के मध्य घूर्णन के कारण जो विभिन्न आकाशीय व्यवस्थाएँ उत्पन्न होती हैं वे संरूपी कहलाती हैं तथा संरूपियों से सम्बन्धित आण्विक ज्यामिति को संरूपण समावयवता कहते हैं।

प्रश्न 26.
बहुलीकरण अभिक्रिया को उदाहरण सहित समझाइये।
उत्तर:
वह रासायनिक अभिक्रिया जिसमें दो या दो से अधिक सरल इकाई जिन्हें एकलक कहते हैं। परस्पर संयोजन कर एक जटिल अणु का निर्माण करते हैं बहुलक कहलाते हैं तथा इस अभिक्रिया को बहुलीकरण कहते हैं।
उदाहरण – एथिलीन अणुओं के बहुलीकरण से पॉलीएथिलीन बनता है।

प्रश्न 27.
एल्कीन इलेक्ट्रॉन स्नेही योगात्मक अभिक्रियाएँ प्रदर्शित करती है, जबकि ऐरीन इलेक्ट्रॉनस्नेही प्रतिस्थापन अभिक्रियाएँ प्रदर्शित करती है। कारण स्पष्ट कीजिए।
उत्तर:
एल्कीन ढीले बँधे π – इलेक्ट्रॉनों के धनी स्रोत होते है, जिसके कारण ये इलेक्ट्रॉनस्नेही योगात्मक अभिक्रियाएँ प्रदर्शित करता है। ऐल्कीनों की इलेक्ट्रॉन स्नेही योगात्मक अभिक्रियाओं में ऊर्जा में अत्यधिक बदलाव आता है। जिसके कारण ये इलेक्ट्रॉन स्नेही प्रतिस्थापन अभिक्रियाओं की अपेक्षा ऊर्जात्मक रूप से अधिक प्रभावी होती है। एरीन में इलेक्ट्रॉन स्नेही योगात्मक अभिक्रिया के दौरान बेंजीन वलय की ऐरोमैटिक प्रकृति नष्ट हो जाती है जबकि इलेक्ट्रॉन स्नेही प्रतिस्थापन अभिक्रिया में यह स्थिर रहती है। ऐरीन की इलेक्ट्रॉन स्नेही प्रतिस्थापन अभिक्रियाएँ ऊर्जात्मक रूप से इलेक्ट्रॉन स्नेही योगात्मक अभिक्रियाओं की अपेक्षा अधिक प्रभावी होती है।

प्रश्न 28.
ज्यामितीय समावयवता की आवश्यक शर्ते क्या हैं ?
उत्तर:
ज्यामितीय समावयवता के लिये निम्नलिखित शर्ते आवश्यक हैं –

• इसमें कम-से-कम एक कार्बन-कार्बन द्विबंध होना चाहिए।
• द्विबंधित कार्बन परमाणु से जुड़े परमाणु या समूह भिन्न-भिन्न होने चाहिए।

प्रश्न 29.
सेटजेफ नियम क्या है ? उदाहरण सहित समझाइये।
उत्तर:
यदि ऐल्किल हैलाइड में से हाइड्रोजन हैलाइड का विलोपन किया जाता है तो यह भिन्न-भिन्न प्रकार से हो सकता है तथा ऐल्कीन प्राप्त होता है। इस नियम के अनुसार उस ऐल्कीन के बनने की संभावना अधिक होगी, जिसमें द्विबंध से जुड़े कार्बन परमाणु अधिक ऐल्किलीकृत होते हैं। अर्थात् हाइड्रोजन का विलोपन उस कार्बन से होता है जहाँ हाइड्रोजन की संख्या कम होती है।

प्रश्न 30.
ऑक्टेन संख्या से आप क्या समझते हैं ?
उत्तर:
विभिन्न ईंधनों के तुलनात्मक अपस्फोटरोधी गुण को व्यक्त करने के लिए एडगर ने सन् 1927 में ऑक्टेन अंक शब्द प्रयुक्त किया, जिसके अनुसार किसी ईंधन की ऑक्टेन संख्या आवश्यकतानुसार आइसो ऑक्टेन के मिश्रण में उपस्थित होती है, जिसका किसी मानक (Standard) इंजन में अपस्फोटन दिये हुए ईंधन के अपस्फोटन के बराबर होता है, अर्थात् किसी ईंधन की ऑक्टेन संख्या, हेप्टेन तथा आइसो ऑक्टेन के मिश्रण में आइसो ऑक्टेन का प्रतिशत होती है।

प्रश्न 31.
पैराफीन्स, ओलिफीन्स एवं ऐसीटिलीन की निम्न बिन्दुओं में तुलना कीजिए –
1. IUPAC नाम
2. सामान्य सूत्र
3. क्रियाशीलता
4. ब्रोमीन जल से क्रिया।
उत्तर:

हाइड्रोकार्बन लघु उत्तरीय प्रश्न

प्रश्न 1.
बेन्जीन, n – हेक्सेन तथा एथाइन को घटते हुए अम्लीय व्यवहार के क्रम में व्यवस्थित कीजिए और इस व्यवहार का कारण बताइए।
उत्तर:
दिये गये यौगिकों में कार्बन की संकरण अवस्था निम्न है –

अम्लीय व्यवहार, कक्षक के S – गुण में वृद्धि के साथ-साथ बढ़ता है। अतः बेन्जीन, n-हेक्सेन तथा एथाइन के अम्लीय व्यवहार का घटता हुआ क्रम निम्न है –
ऐथाइन > बेन्जीन > n – हेक्सेन

प्रश्न 2.
किसी निकाय द्वारा ऐरोमैटिकता प्रदर्शित करने के लिए आवश्यक शर्ते क्या हैं ?
उत्तर:
किसी निकाय द्वारा ऐरोमैटिकता प्रदर्शित करने के लिए आवश्यक शर्ते निम्न हैं –

• अणु समतलीय होना चाहिए।
• अणु चक्रीय होना चाहिए जिसमें एकान्तर क्रम में एकल तथा द्विबंध होना चाहिए अर्थात् वलय में T – इलेक्ट्रॉनों का संपूर्ण विस्थानीकरण होना चाहिए।
• अणु के वलय (ring) में (4n + 2) π इलेक्ट्रॉन होने चाहिए। जहाँ n = 0,1,2,3 …….. (ह्यूकेल नियम)। यदि कोई अणु उपरोक्त में से किसी एक अथवा अधिक दशाओं को संतुष्ट नहीं कर पाता है, तो उसे अ-ऐरोमैटिक कहते हैं।

प्रश्न 3.
मध्यावयवता समावयवता क्या है ? उदाहरण सहित समझाइये।
उत्तर:
जब दो या दो से अधिक यौगिकों के अणुसूत्र समान हो और उनमें उपस्थित क्रियात्मक समूह भी समान हो लेकिन उनसे जुड़े एल्किल मूलक में भिन्नता हो तो इस प्रकार उत्पन्न समावयवता को मध्यावयवता कहते हैं।
उदाहरण –

प्रश्न 4.
चलावयवता समावयवता क्या है ? उदाहरण सहित समझाइये।
उत्तर:
यह एक विशिष्ट प्रकार की क्रियात्मक समावयवता है, जिसमें दोनों समावयवयी साम्य अवस्था में होते हैं तथा सरलता से एक-दूसरे में परिवर्तित हो सकते हैं। इस प्रकार की समावयवता तब उत्पन्न होती है, जब हाइड्रोजन या कोई भी अन्य समूह द्विबंध या त्रिबंध के दोनों तरफ दोलन करता है।
यह दो प्रकार की होती है –
1. द्विक प्रणाली – इस प्रणाली में हाइड्रोजन का दोलन दो बहु-संयोजकीय परमाणुओं के बीच होता है।
उदाहरण – H – C = N – H – N – C
2. त्रिक प्रणाली – इस प्रणाली में हाइड्रोजन का दोलन तीन बहु-संयोजकीय परमाणुओं के बीच होता है।

इनॉल रूप इसे कीटो-इनॉल समावयवता भी कहते हैं।

प्रश्न 5.
न्यूमैन प्रक्षेपण सूत्र क्या है ?
उत्तर:
यदि दो कार्बन परमाणु के मध्य एकल बंध उपस्थित हो और दोनों कार्बन को एक वृत्त के रूप में दर्शाया जाये तथा इनसे जुड़े हाइड्रोजन को C – H बंध द्वारा उनके केन्द्र से जुड़ा हुआ दर्शाया जाये। यदि दोनों कार्बन एक-दूसरे के पीछे व्यवस्थित हो तो उनमें से केवल सामने वाला कार्बन दिखाई देता है तथा उससे जुड़े हुए तीनों हाइड्रोजन उसके केन्द्र से जुड़े दिखाई देते हैं तथा पीछे वाले कार्बन के हाइड्रोजन पहले कार्बन की परिधि पर जुड़े हुए दिखाई देते हैं।

प्रश्न 6.
मार्कोनीकॉफ नियम क्या है ? उदाहरण सहित समझाइये।
उत्तर:
जब सममित हाइड्रोकार्बन पर असममित अभिकर्मक का योग होता है तो आक्रमणकारी समूह का एक भाग द्विबंध या त्रिबंध वाले एक कार्बन परमाणु पर तथा दूसरा भाग दूसरे कार्बन परमाणु पर जुड़ता है।

लेकिन जब असममित ऐल्कीन पर असममित अभिकर्मक का योग होता है तो सामान्यतः अभिक्रिया मार्कोनीकॉफ नियम के अनुसार होती है। इस नियम के अनुसार युग्म बंध पर जुड़ने वाले आक्रमणकारी समूह का ऋणात्मक भाग द्विबंध से जुड़े उस कार्बन परमाणु पर जुड़ता है जिस पर हाइड्रोजन की संख्या न्यूनतम होती है।

प्रश्न 7.
रेसेमिक मिश्रण को उदाहरण सहित समझाइये।
उत्तर:
दो प्रतिबिम्ब समावयवी की समान मात्राओं का मिश्रण ध्रुवण घूर्णकता नहीं दर्शाता क्योंकि मिश्रण में उपस्थित दोनों प्रतिबिम्ब समावयवी की ध्रुवण घूर्णकता बराबर किन्तु विपरीत दिशा में होती है तथा एक – दूसरे के कारण उत्पन्न ध्रुवण घूर्णकता को विनष्ट कर देती है। ऐसे मिश्रण को रेसेमिक मिश्रण कहते हैं तथा इसे dl या ± चिन्ह द्वारा दर्शाते हैं। उदाहरण – रेसेमिक लेक्टिक अम्ल – यह d तथा l रूप का समअणुक मिश्रण है। इसमें 50% d रूप तथा 50% l रूप होता है। यह रूप ध्रुवण अघूर्णक होता है तथा इसे d तथा l रूप में वियोजित किया जा सकता है। इसे dl या ± द्वारा दर्शाते हैं।

प्रश्न 8.
ऐल्केन की प्रतिस्थापन अभिक्रिया को उदाहरण सहित समझाइये।
उत्तर:
वह अभिक्रिया जिसमें किसी यौगिक में उपस्थित परमाणु किसी अन्य परमाणु या मूलक से इस प्रकार प्रतिस्थापित होता है कि यौगिक की आंतरिक संरचना में कोई परिवर्तन नहीं आता प्रतिस्थापन अभिक्रिया कहलाती है। ऐल्केन में होने वाली हैलोजनीकरण, नाइट्रीकरण, सल्फोनीकरण अभिक्रिया इसके उदाहरण हैं। हैलोजनीकरण अभिक्रिया – ऐल्केन की अभिक्रिया क्लोरीन के साथ सूर्य प्रकाश की उपस्थिति में कराने पर ऐल्केन में उपस्थित हाइड्रोजन का प्रतिस्थापन क्लोरीन द्वारा होता है तथा क्रमशः मोनो, डाई, ट्राई तथा टेट्रा हैलोएल्केन का मिश्रण प्राप्त होता है।

प्रश्न 9.
B.H.C. क्या है ? इसका उपयोग बताइये।
उत्तर:
बेंजीन की अभिक्रिया सूर्य प्रकाश अथवा पराबैंगनी प्रकाश की उपस्थिति में क्लोरीन से कराने पर बेंजीन हेक्साक्लोराइड प्राप्त होता है।
यह आठ त्रिविम समावयवयी रूपों में मिलता है। लेकिन इसके केवल चार समावयवयी रूप α β γ या δ रूप को शुद्ध अवस्था में प्राप्त किया जा सकता है। इसके विभिन्न समावयवयी रूप हाइड्रोजन तथा क्लोरीन की विभिन्न व्यवस्थाओं के कारण उत्पन्न होते हैं। इसका γ समावयवयी रूप सबसे अधिक स्थायी तथा प्रबल कीटनाशी है। इसको लिण्डेन या गैमेक्सेन या 666 के नाम से भी जाना जाता है। इसका उपयोग कीटाणुनाशक के रूप में होता है।

प्रश्न 10.
निम्नलिखित परिवर्तन कैसे करोगे केवल समीकरण दीजिए –

1. मेथेन से एथेन
2. एथेन से मेथेन
3. ऐसीटिलीन से बेंजीन।

उत्तर:
1. मेथेन से एथेन –

2. एथेन से मेथेन –

3. ऐसीटिलीन से बेंजीन –

प्रश्न 11.
कैसे प्राप्त करोगे (केवल समीकरण दीजिए) –

1. बेंजीन से B.H.C.
2. बेंजीन से ऐसीटोफिनोन
3. क्लोरोएथीन से पी.वी.सी.
4. टेट्राफ्लोरो एथीन से टेफ्लॉन।

उत्तर:
1. बेंजीन से B.H.C –

2. बेंजीन से ऐसीटोफिनोन –

3. क्लोरोएथीन से –

4. टेट्राफ्लोरो एथीन से टेफ्लॉन

प्रश्न 12.
ज्यामितीय समावयवता किस प्रकार के यौगिकों में पायी जाती है ? उदाहरण सहित समझाइये।
उत्तर:
यह एक प्रकार की त्रिविम समावयवता है। जो युग्म बंध युक्त ऐसे यौगिकों द्वारा प्रदर्शित की जाती है, जिनमें युग्म बंधित कार्बन परमाणु से जुड़े दो परमाणु या समूह भिन्न-भिन्न प्रकार के हो सकते हैं। जब समान परमाणु या समूह द्विबंध के एक ओर स्थित होते हैं तो प्राप्त यौगिक समपक्ष समावयवयी कहलाता है तथा जब विपरीत परमाणु या समूह द्विबंध के एक ओर स्थित हो तो प्राप्त यौगिक विपक्ष समावयवयी कहलाता है। इसलिये इसे समपक्ष-विपक्ष समावयवता भी कहते हैं।

उदाहरण – 2 – butene

प्रश्न 13.
ह्यूकेल का नियम क्या है ?
उत्तर:
ह्यूकेल ने अनेक ऐरोमैटिक यौगिकों का अध्ययन करने के पश्चात् एक नियम प्रतिपादित किया जिसे ह्यूकेल का नियम कहते हैं। इस नियम के अनुसार वे सभी समतलीय चक्रीय यौगिक ऐरोमैटिक गुण प्रदर्शित करते हैं। जिनके चक्र में (4n + 2) π इलेक्ट्रॉन होते हैं, यहाँ n पूर्णांक है जिसका मान 0, 1, 2 ………. होता है। अत: जिन चक्रीय यौगिक में 6(n = 1), 10 (n = 2), 14(n=3) इलेक्ट्रॉन होते हैं, उनमें ऐरोमैटिक गुण होता – है। ऐरोमैटिक यौगिक दो प्रकार के होते हैं –
1. बेंजीनोइड्स – वे यौगिक जो एक या अधिक बेंजीन वलय युक्त होते हैं, बेंजीनोइड्स कहलाते हैं।

2. नॉन – बेन्जीनोइड्स – ऐसे यौगिक जिनमें बेंजीन रिंग नहीं होती है।

प्रश्न 14.
ऐल्कीन सरलता से योगात्मक अभिक्रिया प्रदर्शित करता है, क्यों ?
उत्तर:
ऐल्कीन एक असंतृप्त हाइड्रोकार्बन है। इसमें कार्बन – कार्बन के बीच द्विबंध होता है तथा इस द्विबंध में एक σ बंध एक π बंध होता है। बंध – बंध की तुलना में दुर्बल होता है। इस π बंध की उपस्थिति के कारण एल्कीन सरलता से योगात्मक अभिक्रिया दर्शाता है। इस योगात्मक अभिक्रिया के दौरान एक π बंध टूटता है तो दो नये σ बंध का निर्माण होता है।
CH₂ = CH₂ + HCl → CH₃ – CH₂Cl

प्रश्न 15.
फ्रीडल क्राफ्ट्स अभिक्रिया को समीकरण सहित दर्शाइये।
उत्तर:
एल्किलीकरण:
बेंजीन की अभिक्रिया निर्जल AlCl₃ की उपस्थिति में CH₃Cl के साथ कराने पर टॉलुईन प्राप्त होता है। इस अभिक्रिया के दौरान बेंजीन में से हाइड्रोजन का प्रतिस्थापन एल्किल समूह द्वारा होता है इसलिये इसे एल्किलीकरण कहते हैं।

एसिलीकरण – बेंजीन की अभिक्रिया निर्जल AlCl₃ की उपस्थिति में एसीटिल क्लोराइड

के साथ कराने पर एसीटोफिनोन प्राप्त होता है। इस अभिक्रिया के दौरान बेंजीन में से हाइड्रोजन का प्रतिस्थापन एसीटिल या एसिल समूह द्वारा होता है। इसलिये इसे एसिटलीकरण या एसिलीकरण अभिक्रिया कहते हैं।

प्रश्न 16.
ज्यामितीय समावयवियों के नामकरण हेतु E व z संकेत क्या है ?
उत्तर:
जब द्विबंधित कार्बन परमाणु पर सभी चारों समूह अलग – अलग हों तो ज्यामितीय समावयवियों को E व Z संकेत से दर्शाते हैं। ये निम्न अनुक्रम नियम पर आधारित हैं –

नियम I:
सभी परमाणु और समूह जो द्विबंधित कार्बन परमाणु से जुड़े होते हैं। उनके प्रथम परमाणु के परमाणु क्रमांक के बढ़ते क्रम के आधार पर उनकी प्राथमिकता निर्भर करते हैं। कम परमाणु क्रमांक वाले परमाणु या समूह को निम्नतम प्राथमिकता देते हैं तथा अधिक परमाणु क्रमांक वाले परमाणु या समूह को उच्चतम प्राथमिकता देते हैं । यदि इन समूह के प्रथम परमाणु समान हों तो द्वितीय परमाणु अथवा तृतीय परमाणु के परमाणु क्रमांक द्वारा प्राथमिकता का अनुक्रम निर्धारित करते हैं।

नियम II:
जब द्विबंध से बँधे दोनों कार्बन परमाणु पर उच्च प्राथमिकता वाले परमाणु या समूह विपरीत ओर एक ही दिशा में हो तो इस विन्यास को E रूप से दर्शाते हैं। जब यदि द्विबंध से बँधे दोनों कार्बन परमाणु पर उच्च प्राथमिकता वाले परमाणु या समूह एक ही दिशा में हो तो इस विन्यास को Z रूप से दर्शाते हैं।
उदाहरण –

प्रश्न 17.
डाइईन्स किसे कहते हैं ? डाइईन्स कितने प्रकार के होते हैं ? उदाहरण सहित समझाइये।
उत्तर:
डाइईन्स असंतृप्त हाइड्रोकार्बन है, इनमें कार्बन श्रृंखला में कार्बन – कार्बन के मध्य दो द्विबंध होते हैं तथा द्विबंधों की सापेक्षिक स्थिति के आधार पर डाइईन्स तीन प्रकार के होते हैं –
1. विलगित डाइईन्स:
ऐसे डाइईन्स जिसमें दो द्विबंध परस्पर एक से अधिक एकल बंधों द्वारा अलग होते हैं।
CH₂ = CH – CH₂ – CH = CH₂

2. संयुग्मित डाइईन्स – ऐसे डाइईन्स में दो द्विबंध संयुग्मित या एकान्तर स्थिति पर होते हैं।

3. संचयी डाइईन्स – इन डाइईन्स में दो द्विबंध समीपस्थ स्थिति पर होते हैं।
CH₂ = C = CH – CH₃
CH₃ – CH = C = CH₂

प्रश्न 18.
डील्स एल्डर अभिक्रिया को समीकरण सहित लिखिए।
उत्तर:
जब संयुग्मित डाइईन्स को किसी एल्कीन या प्रतिस्थापित एल्कीन के साथ गर्म करते हैं तो एक छः सदस्यीय चक्रीय यौगिक बनता है इसलिये इस अभिक्रिया को चक्रीय संकलन अभिक्रिया भी कहते हैं। इसमें एक 47 इलेक्ट्रॉन निकाय से जुड़ता है। इस तरह की अभिक्रिया को डील्स एल्डर अभिक्रिया कहते हैं।

प्रश्न 19.
लिण्डलार उत्प्रेरक क्या है ? तथा इसके उपयोग लिखिए।
उत्तर:
बेरियम सल्फेट या कैल्सियम कार्बोनेट पर निक्षेपित पैलेडियम उत्प्रेरक का मिश्रण लिण्डलार उत्प्रेरक कहलाता है। यहाँ सल्फर या क्विनोलीन उत्प्रेरक विष का कार्य करता है और केवल एल्कीन अवस्था तक ही एल्काइन का अपचयन करता है।
उपयोग – एल्काइन का अपचयन हाइड्रोजन द्वारा लिण्डलार उत्प्रेरक की उपस्थिति में कराने पर एल्कीन प्राप्त होता है। यह उत्प्रेरक आगे एल्कीन को एल्केन में अपचयित नहीं होने देता।

प्रश्न 20.
बेंजीन की संरचना के लिये कैकुले सूत्र के पक्ष में चार प्रमाण दीजिए।
उत्तर:
बेंजीन की संरचना के लिये कैकुले सूत्र के पक्ष में प्रमाण –
1. बेंजीन तीन अणु हाइड्रोजन के साथ संयोग कर चक्रीय यौगिक साइक्लोहेक्सेन बनाता है, जिससे बेंजीन में तीन युग्म बंध की पुष्टि होती है।

2. बेंजीन तीन अणु क्लोरीन से संयोग कर B.H.C. बनाता है। अतः यह भी तीन युग्म बंध की पुष्टि करता है।

3. बेंजीन ओजोन के साथ संयोग कर ट्राइ ओजोनाइड बनाता है जो जल अपघटित होकर ग्लाईऑक्सेल के तीन अणु बनाता है।

4. एसीटिलीन के तीन अणु बहुलीकरण के द्वारा बेंजीन का निर्माण करते हैं। ..

प्रश्न 21.
कारण दीजिए –
1. शाखायुक्त यौगिकों के क्वथनांक सीधी श्रृंखला युक्त यौगिकों की अपेक्षा कम होते हैं, क्यों ?
2. विषम संख्या कार्बन परमाणु वाले यौगिक के गलनांक सम संख्या कार्बन परमाणु वाले यौगिकों से कम होते हैं, क्यों?
उत्तर:
1. रेखीय शृंखला वाले कार्बनिक यौगिकों का पृष्ठीय क्षेत्रफल अधिक होता है और इनमें अंतरअणुक आकर्षण बल अधिक होता है जबकि कार्बन परमाणु की श्रृंखला में शाखायुक्त हो जाने पर अणु में स्थित विभिन्न परमाणु पास-पास आ जाते हैं, जिससे उनके बीच अंतर-अणुक आकर्षण बल कम होता है इसलिये श्रृंखला वाले यौगिकों का क्वथनांक शाखायुक्त यौगिकों से अधिक होता है।

2. कार्बन परमाणु की विषम संख्या युक्त ऐल्केन कार्बन श्रृंखला के सिरों पर स्थित कार्बन परमाणु समान पक्ष में होते हैं। जबकि कार्बन परमाणु की सम संख्या वाले ऐल्केन में कार्बन शृंखला के सिरों पर स्थित कार्बन विपरीत पक्ष में होते हैं। सम संख्या वाले यौगिकों के विषम कार्बन संख्या वाले यौगिकों की तुलना में पैकिंग अधिक सघन होती है। इसलिए सम कार्बन संख्या वाले यौगिकों के क्वथनांक अधिक होते हैं।

प्रश्न 22.
निम्नलिखित पर टिप्पणी लिखिए –

1. सबात्ये और सेण्डरेन्स अभिक्रिया
2. बुर्दज अभिक्रिया
3. इयमा अभिक्रिया
4. स्वार्ट अभिक्रिया।

उत्तर:
1. सबात्ये और सेण्डरेन्स अभिक्रिया – ऐल्कीन की अभिक्रिया Ni या Pt की उपस्थिति में हाइड्रोजन के साथ कराने पर हाइड्रोजनीकरण के पश्चात् ऐल्केन प्राप्त होता है।

2. बुर्दज अभिक्रिया – दो अणु ऐल्किल हैलाइड की अभिक्रिया सोडियम के साथ शुष्क ईथर की उपस्थिति में कराने पर ऐल्केन प्राप्त होता है। इस प्रकार प्राप्त ऐल्केन में ऐल्किल हैलाइड की तुलना में दो गुना ज्यादा कार्बन होते हैं।

3. ड्यूमा अभिक्रिया – मोनोकार्बोक्सिलिक अम्ल के सोडियम लवण की अभिक्रिया सोडालाइम के साथ कराने पर विकार्बोक्सीकरण के पश्चात् एल्केन प्राप्त होता है।

4. स्वार्ट अभिक्रिया – जब एल्किल हैलाइड की अभिक्रिया मरक्यूरिक फ्लोराइड के साथ कराने पर फ्लोरो एल्केन प्राप्त होता है। इस अभिक्रिया के दौरान एल्किल हैलाइड के हैलोजन का प्रतिस्थापन फ्लोरीन द्वारा होता है।
2C₂H₅ – I + HgF₂ → 2CH₃ → 2C₂H₅ + F + HgI₂
प्रश्न 23.
कोल्बे की वैद्युत अपघटन अभिक्रिया को समीकरण सहित लिखिए।
उत्तर:
मोनो कार्बोक्सिलिक अम्ल के सोडियम या पोटैशियम लवण के सान्द्र जलीय विलयन का वैद्युत अपघटन करने पर एनोड पर एल्केन प्राप्त होता है।

एनोड पर – एसीटेट आयन इलेक्ट्रॉन त्यागकर उदासीन हो जाता है और विघटित होकर एल्केन देता है।
2CH₃COO^– – 2e^– → 2CH₃ COO → C₂H₆ + 2CO₂

कैथोड पर – हाइड्रोजन आयन इलेक्ट्रॉन ग्रहण कर हाइड्रोजन देता है।
2Na⁺ + 2HOH + 2e^– → 2NaOH + H₂

प्रश्न 24.
निम्नलिखित अभिक्रियाओं के केवल समीकरण दीजिए –

1. कैल्सियम कार्बाइड की जल से।
2. एथिलीन पर ब्रोमीन जल की अभिक्रिया।
3. एथिलीन को क्षारीय KMnO₄के साथ गर्म करने पर।
4. बेंजीन को सान्द्र HNOJ तथा सान्द्र H2SO, के साथ गर्म करने पर।
5. बेंजीन को मेथिल क्लोराइड के साथ निर्जल AICI, की उपस्थिति में गर्म करने पर।

उत्तर:
1. कैल्सियम कार्बाइड की जल के साथ अभिक्रिया –
CaC₂ + 2HOH → CH = CH + Ca(OH)₂
2. एथिलीन पर ब्रोमीन जल की अभिक्रिया –

3. एथिलीन को क्षारीय KMnO, के साथ गर्म करने पर

4. बेंजीन को सान्द्र HNOJ तथा सान्द्र H,SO, के साथ गर्म करने पर –

5. बेंजीन को CHICI के साथ निर्जल AICI की उपस्थिति में गर्म करने पर

प्रश्न 25.
निम्नलिखित को कैसे प्राप्त करोगे

1. एसीटिलीन से एसिटैल्डिहाइड
2. एथिलीन से मस्टर्ड गैस
3. ग्रिगनार्ड अभिकर्मक से एथेन
4. एसीटिलीन से क्यूप्रस एसीटिलाइड
5. ऐल्युमिनियम कार्बाइड से मेथेन।

उत्तर:
1. एसीटिलीन से एसिटैल्डिहाइड –

2. एथिलीन से मस्टर्ड गैस –

3. ग्रिगनार्ड अभिकर्मक से एथेन –

4. एसीटिलीन से क्यूप्रस एसीटिलाइड –
CH ≡ CH + Cu₂Cl₂ + 2NH₄OH D Cu – C ≡ C – Cu + 2NH₄Cl + 2H₂O
5. ऐल्युमिनियम कार्बाइड से मेथेन –
Al₄C₃ + 12H₂ O → 3CH₄ + 4Al(OH)₂

प्रश्न 26.
किसी प्राथमिक ऐल्किल हैलाइड की वु अभिक्रिया कराने पर एकमात्र उत्पाद के रूप में C₈H₁₈ प्राप्त होता है। इस ऐल्केन का मोनोब्रोमीकरण करने पर तृतीयक ब्रोमाइड का एकल समावयव प्राप्त होता है। ऐल्केन तथा तृतीयक ब्रोमाइड की पहचान लिखिए।
उत्तर:
चूँकि ऐल्केन C₈H₁₈ मोनोब्रोमीकरण के पश्चात् तृतीयक ब्रोमाइड का एक समावयव बनाता है अतः ऐल्केन में तृतीयक हाइड्रोजन उपस्थित होनी चाहिए। यह तभी सम्भव है जबकि प्राथमिक ऐल्किल हैलाइड (जो वु अभिक्रिया में भाग लेता है) के पास तृतीयक हाइड्रोजन हो।

प्रश्न 27.
2 – मेथिल प्रोपेन के मोनो क्लोरीनीकरण में बनने वाले मध्यवर्ती हाइड्रोकार्बन मूलकों को लिखिए। इनमें से कौन-सा अधिक स्थायी होगा। कारण भी दीजिए।
उत्तर:
2-मेथिल प्रोपेन निम्न दो प्रकार के मूलक देता है, जो निम्न है –

मूलक (I) अधिक स्थायी है क्योंकि यह 3° मुक्त मूलक है तथा नौ अति संयुग्मित संरचनाओं को स्थायी करता है (क्योंकि इसमें 9a -हाइड्रोजन है।)
मूलक (II) कम स्थायी है क्योंकि यह 1° मुक्त मूलक है तथा यह केवल एक अति संयुग्मित संरचना को स्थायी करता है। (क्योंकि इसमें केवल 1a- हाइड्रोजन है।)

प्रश्न 28.
विहाइड्रोहैलोजनीकरण तथा विहैलोजनीकरण अभिक्रिया को उदाहरण सहित समझाइये।
उत्तर:
विहाइड्रोहैलोजनीकरण – किसी कार्बनिक यौगिक में हाइड्रोजन हैलाइड के अणु का विलोपन विहाइड्रोहैलोजनीकरण कहलाता है। इस अभिक्रिया के दौरान β स्थिति से हाइड्रोजन का विलोपन होता है। इसलिये इसे β विलोपन अभिक्रिया भी कहते हैं।

उदाहरण – नॉर्मल प्रोपिल क्लोराइड को एल्कोहॉलिक KOH के साथ गर्म करने पर एल्कीन प्राप्त होता है।
CH₃ – CH₂ – CH₂ – Cl + KOH → CH₃ – CH = CH₂ + KCl + H₂O

विहैलोजनीकरण – बिस डाइहैलाइड को Zn चूर्ण के साथ मेथिल एल्कोहॉल की उपस्थिति में गर्म करने पर एल्कीन प्राप्त होता है, इस अभिक्रिया के दौरान केवल हैलोजन का विलोपन होता है इसलिए इसे विहैलोजनीकरण अभिक्रिया कहते हैं।

प्रश्न 29.
क्या होता है जब

1. सोडियम एसीटेट को सोडालाइम के साथ गर्म करने पर।
2. 2 – प्रोपेनॉल को एलुमिना के साथ 300°C ताप पर गर्म करने पर।
3. एसीटिलीन को अमोनियामय AgNO₃ के विलयन में प्रवाहित करने पर।
4. एथिल आयोडाइड को सोडियम के साथ गर्म करने पर।
5. एथिलीन पर हाइपोक्लोरस अम्ल की अभिक्रिया कराने पर।

उत्तर:
1. सोडियम एसीटेट को सोडालाइम के साथ गर्म करने पर –

2. 2-प्रोपेनॉल को एलुमिना के साथ 300°C ताप पर गर्म करने पर –

3. एसीटिलीन को अमोनियामय AgNOJ के साथ गर्म करने पर –
CH ≡ CH + 2AgNO₃ + 2NH₄OH → Ag – C ≡ C – Ag + 2NH₄NO₃ + 2H₂O
4. एथिल आयोडाइड को सोडियम के साथ गर्म करने पर –

5. एथिलीन पर हाइपोक्लोरस अम्ल की अभिक्रिया कराने पर –

प्रश्न 30.
निम्नलिखित पर टिप्पणी लिखिए –
1. हाइड्रोबोरोनीकरण
2. एपॉक्सीकरण।
उत्तर:
1. हाइड्रोबोरोनीकरण – एल्कीन पर जब डाइबोरेन से अभिक्रिया करायी जाती है तब एल्कीन के द्विबंध पर योगात्मक क्रिया होती है एवं ट्राइऐल्किल बोरेन बनता है, जो जल अपघटन पर एल्कोहॉल देता है यह हाइड्रोबोरोनीकरण अभिक्रिया कहलाती है।

2. एपॉक्सीकरण – एल्कीन ऑक्साइड को एपॉक्साइड कहते हैं। एल्कीन के ऑक्सीकरण से एपॉक्साइड बनने की क्रिया एपॉक्सीकरण कहलाती है।
उदाहरण – निम्नतर एल्कीन 200 – 400°C ताप पर सिल्वर उत्प्रेरक की उपस्थिति में ऑक्सीजन से संयोग करके एपॉक्साइड बनते हैं।

प्रश्न 31.
वुज अभिक्रिया को विषम कार्बन संख्या वाले ऐल्केन बनाने के लिये क्यों उपयुक्त नहीं माना जाता है ?
उत्तर:
एल्किल हैलाइड के दो अणु सोडियम के साथ शुष्क ईथर की उपस्थिति में गर्म करने पर ऐल्केन प्राप्त होता है।

इस अभिक्रिया द्वारा विषम कार्बन संख्या वाले ऐल्केन का निर्माण नहीं किया जा सकता है। क्योंकि इसके लिये दो अलग-अलग एल्किल हैलाइड को सोडियम के साथ गर्म करने पर ऐल्केनों का मिश्रण प्राप्त होता है जिन्हें पृथक् करना बहुत कठिन होता है। उदाहरण के लिये यदि मेथिल ब्रोमाइड तथा एथिल ब्रोमाइड को शुष्क ईथर की उपस्थिति में सोडियम के साथ गर्म करने पर एथेन, प्रोपेन तथा ब्यूटेन का मिश्रण प्राप्त होता है और इसमें से प्रोपेन को पृथक् करना अत्यन्त कठिन होता है।

प्रश्न 32.
HI, HBr तथा HCl की प्रोपीन के साथ क्रिया में बना मध्यवर्ती कार्बधनायन समान रहता है। HCl, HBr तथा Hl की आबंध ऊर्जाएँ क्रमशः 430.5 kJmol^– 363.7 kJmol^– तथा 296.8 kJmol^– होती है। इन हैलोजन अम्लों की क्रियाशीलता का क्रम क्या होगा?
उत्तर:
हैलोजन अम्लों का ऐल्कीन के साथ योग एक इलेक्ट्रॉन स्नेही योगात्मक अभिक्रिया है।

चूँकि प्रथम पद मंद है अतः यह दर निर्धारक पद है। इस पद की दर, प्रोटॉन की उपलब्धता पर निर्भर करती है। जो पुनः H – X अणुओं की आबंध वियोजन ऊर्जा पर निर्भर करती है। H – X अणु की आबंध वियोजन ऊर्जा जितनी कम होती है, हैलोजन अम्ल की क्रियाशीलता उतनी ही अधिक होती है। अतः हैलोजन अम्लों की क्रियाशीलता का घटता हुआ क्रम निम्न है
HI(296.8kJ) > HBr(363.7kJ) > HCl(430.5kJ)

प्रश्न 33.
भंजन से क्या समझते हैं ? भंजन तथा इसके उपयोग पर टिप्पणी लिखिए।
उत्तर:
उच्च ताप के द्वारा या उत्प्रेरक की उपस्थिति में उच्चतर और जटिल हाइड्रोकार्बन का सरल हाइड्रोकार्बन में होने वाला अपघटन भंजन कहलाता है। दूसरे शब्दों में, कम वाष्पशील तथा उच्च हाइड्रोकार्बन का अधिक वाष्पशील तथा निम्न हाइड्रोकार्बन में तापीय अपघटन भंजन कहलाता है।

भंजन दो प्रकार का होता है –
1. ताप भंजन – जब भंजन उच्च ताप व दाब की परिस्थिति में उत्प्रेरक की अनुपस्थिति में कराया जाता है, तो इसे तापीय भंजन कहते हैं।
2. उत्प्रेरक भंजन – जब उत्प्रेरक की उपस्थिति में भंजन कराया जाता है, तो उसे उत्प्रेरक भंजन कहते हैं। उत्प्रेरक की उपस्थिति में भंजन तापीय भंजन की तुलना में कम ताप तथा कम दाब पर कराया जाता है।

उपयोग –

• मिट्टी के तेल से गैस बनाना।
• पेट्रोल के भंजन से पेट्रोलियम गैस बनाना।

प्रश्न 34.
एक हाइड्रोकार्बन A वाष्प घनत्व (14) बेयर अभिकर्मक को रंगहीन कर निम्नानुसार रासायनिक क्रिया करता है –

प्राप्त उत्पादों A, B, C और D के नाम और सूत्र लिखिये।
उत्तर:

(A) एथीलीन, (B) 1, 2 डाई ब्रोमो एथेन या एथीलीन ब्रोमाइड ,(C) एसीटिलीन, (D) एसीटेल्डिहाइड।

हाइड्रोकार्बन दीर्घ उत्तरीय प्रश्न

प्रश्न 1.
एल्कीन बनाने की प्रयोगशाला विधि का चित्र सहित वर्णन कीजिए।
उत्तर:
प्राथमिक एल्कोहॉल को सान्द्र H₂SO₄ के आधिक्य के साथ 170°C ताप पर गर्म करने पर एल्कोहॉल में से एक जल का अणु निकल जाता है और निर्जलीकरण के पश्चात् एल्कीन प्राप्त होता है।

एक गोल पेंदी वाले फ्लास्क में एल्कोहॉल तथा सान्द्र H2SO लेते हैं। इस मिश्रण में निर्जल Al(SOA)3 तथा रेत मिलाते हैं। AICSO), तथा रेत का मिश्रण झाग उत्पन्न होने नहीं देता तथा अभिक्रिया 140°C ताप पर ही सम्पन्न हो जाती है। आसवन फ्लास्क में या गोल पेंदी वाले फ्लास्क में एक थर्मामीटर, बिन्दुपाती कीप तथा निकास नली लगाते हैं। निकास नली का दूसरा सिरा दो वाष्प बोतलों से जुड़ा रहता है।

जिसमें सान्द्र H SoA तथा KOH भरा रहता है। बिन्दुपाती कीप की सहायता से एल्कोहॉल तथा सान्द्र H2SOA के मिश्रण को गिराते हैं। इसे बालू उष्मक पर 150°C ताप पर गर्म करते हैं । बनने वाली एथिलीन गैस में SO, तथा CO, की अशुद्धि भी होती है जो क्रमशः H,SO, तथा KOH में अवशोषित हो जाती है और शुद्ध एथिलीन गैस को गैस जार में जल के ऊपर एकत्रित कर लेते हैं।

प्रश्न 2.
एसीटिलीन बनाने की प्रयोगशाला विधि का चित्र सहित वर्णन कीजिए।
अथवा
एसीटिलीन बनाने की प्रयोगशाला विधि का वर्णन निम्नांकित बिन्दुओं के आधार पर कीजिए

1. विधि एवं रासायनिक समीकरण
2. नामांकित चित्र।

उत्तर:
प्रयोगशाला में एसीटिलीन गैस को CaC₂पर जल की अभिक्रिया द्वारा बनाया जाता है। इस विधि से प्राप्त एसीटिलीन में NH₃ तथा PH₃ की अशुद्धि होती है जिन्हें दूर करने के लिये इसे अम्लीय CuSO₄ में प्रवाहित करते हैं।
CaC₂ + 2H₂O → CH == CH + Ca(OH)₂

एक कोनिकल फ्लास्क में थोड़ी – सी रेत लेकर उसके ऊपर CaC₂ के टुकड़े रखते हैं तथा फ्लास्क में उपस्थित वायु को तेल गैस प्रवाहित कर विस्थापित कर देते हैं। कोनिकल फ्लास्क में बिन्दुपाती कीप तथा निकास नली लगी होती है। बिन्दुपाती कीप की सहायता से CaC₂ पर धीरे-धीरे H₂O की बूंदें डालते हैं जिससे एसीटिलीन गैस प्राप्त होती है। जिसे अम्लीय CuSO₄ विलयन में प्रवाहित कर – एसीटिलीन विरंजक चूर्ण के निलंबन में प्रवाहित करते ram हैं तथा एसीटिलीन गैस को गैस जार में जल के ऊपर एकत्रित कर लेते हैं।

सावधानी:

• प्रयोग के पूर्व बालू फ्लास्क की वायु को तेल गैस द्वारा विस्थापित कर देते हैं क्योंकि एसीटिलीन अम्लीकृत विरंजक चूर्ण Cuson का निलंबन वायु के साथ विस्फोटक मिश्रण बनाती है।
• CaC₂ के ऊपर धीरे-धीरे जल डाला जाता है क्योंकि अभिक्रिया बहुत तीव्र गति से होती है।
• फ्लास्क की तली में पहले रेत रखकर CaC₂ के टुकड़ों को रखा जाता है क्योंकि अभिक्रिया में बहुत अधिक मात्रा में ऊष्मा प्राप्त होती है।

प्रश्न 3.
मेथेन बनाने की प्रयोगशाला विधि का सचित्र वर्णन कीजिए।
उत्तर:
वसीय अम्लों के सोडियम लवणों को सोडा लाइम के साथ 630°K ताप पर गर्म करने पर एल्केन प्राप्त होता है। कॉस्टिक सोडा NaOH तथा अनबुझा चूना Cao के मिश्रण को सोडा लाइम कहते हैं। यहाँ अभिक्रिया में केवल NaOH भाग लेता है Cao, NaOH को शुष्क रखता है और NaOH की तीव्रता को कम करता है जिससे काँच पर अभिक्रिया नहीं हो पाती।

एक कठोर काँच की नली में कडे काँच की नली सोडियम एसीटेट व सोडालाइम का मिश्रण लेते हैं तथा कॉर्क की सहायता साड से इसमें निकास नली लगाते हैं। जिसका सोडालाइम दूसरा सिरा जल से भरे गैस जार में लगा रहता है। सोडियम एसीटेट व सोडा लाइम के मिश्रण को परखनली में बुन्सन बर्नर पर गर्म करते हैं तथा बनने वाली मेथेन गैस को जल से भरे गैस जार में जल के ऊपर एकत्रित कर लेते हैं।

प्रश्न 4.
एक असंतृप्त हाइड्रोकार्बन ‘A’ दो अणु H, को जोड़ता है तथा अपचयित ओजोनीकरण के पश्चात् ब्यूटेन-1,4 डाइअल, एथेनल तथा प्रोपेनोन देता है। यौगिक ‘A’ की संरचना तथा IUPAC नाम लिखिए। प्रयुक्त अभिक्रियाओं को समझाइए।
उत्तर:
हाइड्रोकार्बन ‘A’ में दो अणु H₂ का योग हो सकता है। अतः ‘A’ एल्केन, डाइईन या ऐल्काइन होना चाहिए। अपचयित ओजोनीकरण के पश्चात् ‘A’ तीन स्पीशीज देता है जिनमें से एक डाइऐल्डिहाइड है। इसका अर्थ है कि अणु दोनों सिरों से टूटता है। अतः ‘A’ में दो द्विआबंध होने चाहिए। यह निम्नलिखित तीन स्पीशीज देता है।

अतः यौगिक ‘A’ की संरचना निम्न है –

प्रश्न 5.
एसीटिलीन की अम्लीय प्रकृति को उदाहरण सहित समझाइये।
उत्तर:
ऐसे एल्काइन जिनके अणु के अंतिम छोर में = बंध होता है वे दुर्बल अम्लीय प्रकृति दर्शाते हैं। इनकी अम्लीय प्रकृति को संकरण के आधार पर समझाया जा सकता है। ऽ कक्षक में उपस्थित इलेक्ट्रॉन pad कक्षक में उपस्थित इलेक्ट्रॉन की तुलना में नाभिक से अधिक दृढ़ता से बँधे होते हैं। क्योंकि ऽ कक्षक, p व d कक्षक की तुलना में नाभिक के अधिक पास स्थित होता है। दूसरे शब्दों में sp संकरित कक्षक में 5 गुण (50%), sp² (33:3%) तथा sp³ संकरित कक्षक (25%) की तुलना में अधिक होता है।

जिसके कारण sp संकरित कार्बन परमाणु sp²तथा sp³ संकरित कार्बन की तुलना में अधिक ऋणविद्युती होता है। जिसके कारण C – Hबंध के इलेक्ट्रॉन कार्बन की ओर विस्थापित होने लगता है। जिसके फलस्वरूप कार्बन पर आंशिक ऋणावेश व हाइड्रोजन पर आंशिक धनावेश आ जाता है और इस प्रकार यह आयनित होकर धनावेशित H⁺ को प्रोटॉन के रूप में दान कर सकता है। इसलिये यह दुर्बल अम्ल के रूप में कार्य करता है।
उदाहरण –

(1) AgNO₃ से अभिक्रिया – एसीटिलीन गैस को अमोनियामय सिल्वर नाइट्रेट के विलयन में प्रवाहित करने पर सिल्वर एसीटीलाइड का श्वेत अवक्षेप प्राप्त होता है। H – C ≡ C – H + 2NH₄OH + 2AgNO₃ → Ag – C = C – Ag + 2NH₄NO₃ + 2H₂O

(2) अमोनियामय कॉपर क्लोराइड के साथ अभिक्रिया-एसीटिलीन गैस को अमोनियामय क्यूप्रस क्लोराइड के विलयन में प्रवाहित करने पर लाल रंग का क्यूप्रस एसीटीलाइड का अवक्षेप प्राप्त होता है। H – C ≡ C – H + Cu₂Cl₂ + 2NH₄ OH ≡ Cu – C ≡ C – Cu + 2NH₄Cl + 2H₂O

प्रश्न 6.
संरूपण से आप क्या समझते हैं ? एथेन के संरूपण का विस्तारपूर्वक वर्णन कीजिए।
उत्तर:
कार्बन-कार्बन एकल बंध के मध्य घूर्णन के कारण जो विभिन्न आकाशीय व्यवस्थाएँ उत्पन्न होती हैं, जिन्हें संरूपी कहते हैं तथा संरूपियों से संबंधित आण्विक ज्यामिति को संरूपण समावयवता कहते हैं। एथेन में संरूपण समावयवता-एथेन में दो कार्बन परमाणु एकल बंध की सहायता से जुड़े रहते हैं तथा प्रत्येक कार्बन पर तीन हाइड्रोजन परमाणु द्वारा जुड़े रहते हैं। अर्थात् एथेन अणु में दो मेथिल समूह एकल बंध की सहायता से जुड़े रहते हैं।

यदि इसमें से एक कार्बन को स्थिर रखते हुए दूसरे कार्बन परमाणु को एकल बंध के चारों तरफ मुक्त घूर्णन करने दिया जाये तो विभिन्न त्रिविम व्यवस्थाएँ संभव हैं। सामान्यतः यदि एक कार्बन को स्थिर रखते हुये दूसरे कार्बन को एकल बंध के चारों तरफ 60° के कोण से मुक्त घूर्णन करने दिया जाये तो मुख्यतः 6 त्रिविम व्यवस्थाएं संभव हैं, जिनमें से 1, 3 और 5 संरचनाएँ समान हैं। इसलिये इनकी ऊर्जा तथा स्थायित्व भी समान होगा। इसी प्रकार 2, 4 और 6 वीं संरचना समान है इसलिये इनकी ऊर्जा तथा स्थायित्व भी समान होगा।

1. सांतरित रूप:
सांतरित रूप में दोनों कार्बन परमाणुओं पर H परमाणु इस प्रकार व्यवस्थित रहते हैं कि उनके बीच दूरी अधिकतम है जिसके कारण इनके बीच लगने वाला प्रतिकर्षण बल न्यूनतम रहता है जिसके फलस्वरूप इनकी ऊर्जा कम तथा स्थायित्व अधिक रहता है।

2. ग्रसित रूप:
ग्रसित रूप में दोनों कार्बन परमाणु इस प्रकार व्यवस्थित रहते हैं कि उनसे जुड़े हाइड्रोजन परमाणु के मध्य न्यूनतम दूरी है जिसके कारण इनके बीच लगने वाला प्रतिकर्षण बल अधिकतम होता है जिसके फलस्वरूप इनकी ऊर्जा अधिकतम तथा स्थायित्व न्यूनतम होता है। एथेन में सांतरित संरूपीय ग्रसित संरूपीय की अपेक्षा 12.6 kJ/mo ऊर्जा से अधिक स्थायी है। यह ऊर्जा का अंतर बहुत कम होने के कारण एथेन में से दोनों संरूपों को पृथक् करना कठिन होता है।

प्रश्न 7.
परॉक्साइड की उपस्थिति में, प्रोपीन में HBr का योग प्रतिमार्कोनीकॉफ नियमानुसार होता है, परन्तु HCl तथा Hl परॉक्साइड प्रभाव प्रदर्शित नहीं करते हैं, क्यों?
उत्तर:
प्रोपीन में HCI तथा HI के योग में परॉक्साइड प्रभाव प्रदर्शित नहीं होता है। इसका कारण है कि H – Cl आबंध (430.5 kJ moll^-1), H – Br आबंध (363.7 kJ moll^-1) की अपेक्षा प्रबल होने के कारण मुक्त मूलक द्वारा विदलित नहीं हो पाता है। दूसरी ओर H – I आबंध (296-8 kJ mol^-1) दुर्बल होता है तथा आयोडीन मुक्त मूलक द्विआबंध में जुड़ने की अपेक्षा आयोडीन अणु से संयुक्त होता है। इसकी ऊष्मागतिकीय आँकड़ों की सहायता से भी व्याख्या की जा सकती है। हाइड्रोजन हैलाइड की मुक्त मूलक योगात्मक अभिक्रियाओं में प्रयुक्त चरणों में एन्थैल्पी परिवर्तन निम्न प्रकार है –

उपरोक्त आँकड़ों से स्पष्ट है कि HBr के योग के दोनों चरण ऊष्माक्षेपी है जो कि अभिक्रिया होने की अनुकूल दशा है। परन्तु HCl तथा HI की दशा में एक चरण ऊष्माशोषी है, जो कि किसी भी रासायनिक अभिक्रिया के होने के लिए ऊष्मागतिकी की दृष्टि से अनुकूलतम स्थिति नहीं है।

प्रश्न 8.
साइक्लोहेक्सेन में संरूपण समावयवता को समझाइये।
उत्तर:
खुली श्रृंखला वाले एल्केनों के अतिरिक्त बंद श्रृंखला वाले साइक्लोएल्केन भी संरूपण समावयवता दर्शाते हैं। साइक्लोप्रोपेन तथा साइक्लोब्यूटेन में बंध कोण क्रमश: 60° तथा 90° का होता है। जिनके कारण ये वलय तनाव में होते हैं तथा इनकी क्रियाशीलता अधिकतम होती है।

साइक्लोपेंटेन में बंध कोण 108° होता है जो कि सामान्य चतुष्फलकीय बंध कोण के निकटतम है। साइक्लोहेक्सेन में बंध कोण 109°28′ होता है। जिसके कारण वलय तनावरहित तथा अधिक स्थायी होती है। इसलिये इसमें संरूपण समावयवता दर्शायी जा सकती है। त्रिविम में विभिन्न व्यवस्थाओं के कारण यह दो समावयवी रूपों में पाया जाता है।

1. कुर्सी संरूपण – यह साइक्लोहेक्सेन का अत्यधिक स्थायी संरूपी है जिसमें सभी बंध कोण चतुष्फलकीय बंध कोण 109°28 के बराबर है। लेकिन समीपवर्ती कार्बन परमाणु के हाइड्रोजन सांतरित स्थिति में है। इसलिये यह वलय तनाव से मुक्त है और इसका स्थायित्व अधिकतम है।

2. नाव संरूपण – यह साइक्लोहेक्सेन का कम स्थायी समावयवी रूप है। इसमें भी सभी बंध कोण चतुष्फलकीय बंध कोण के बराबर है। लेकिन समीपवर्ती कार्बन परमाणु के हाइड्रोजन ग्रसित रूप में है जिसके कारण वलय तनाव में है तथा इसका स्थायित्व कुर्सी रूप की तुलना में कम है। कुर्सी रूप तथा नाव रूप में ऊर्जा का अंतर 44 kJ/mol^-1 है।
नाव संरूपण –

कुर्सी संरूपण –

प्रश्न 9.
ऐथेन के ग्रस्त तथा सांतरित रूपों के न्यूमैन तथा साँहार्स प्रक्षेप लिखिए। इनमें से कौन-सा प्रक्षेप अधिक स्थायी होगा तथा क्यों?
उत्तर:

ऐथेन का सांतरित रूप, ग्रस्त रूप की अपेक्षा लगभग 12.5 kJmol^-1 ऊर्जा द्वारा अधिक स्थायी होता है। इसका कारण है कि सांतरित रूप में कोई भी दो हाइड्रोजन परमाणु समीपवर्ती कार्बन परमाणुओं से अधिकतम दूरी पर स्थित होते हैं जबकि ग्रस्त अवस्था में ये अत्यधिक पास-पास (कभी-कभी अध्यारोपित भी हो जाते हैं) आ जाते हैं। अतः सांतरित रूप में, इनमें न्यूनतम प्रतिकर्षण बल, न्यूनतम ऊर्जा तथा अधिकतम स्थायित्व होता है।

प्रश्न 10.
ब्यूटेन में संरूपण समावयवता को समझाइये।
उत्तर:
n ब्यूटेन को एथेन का डाइ मेथिल व्युत्पन्न माना जा सकता है जिसमें प्रत्येक कार्बन का एकएक हाइड्रोजन परमाणु मेथिल समूह से प्रतिस्थापित हो गया है। ऐथेन के समान ब्यूटेन में यदि C₂ को स्थिर रखकर C₃ को घुमाया जाता है तब 360° से घुमाने पर अणु पुनः मूल स्थिति में आ जाता है। जब दोनों कार्बन परमाणु के मेथिल समूह एक-दूसरे से अधिकतम दूरी पर स्थित होते हैं तो इनमें न्यूनतम प्रतिकर्षण होता है तथा सबसे स्थायी रूप है इसे पूर्णतः सांतरित रूप (I) कहते हैं।

पूर्ण सांतरित रूप को घूमाने पर क्रमशः 120° व 240° पर III व V रूप प्राप्त होता है इसमें एक कार्बन का मेथिल समूह दूसरे कार्बन के मेथिल व हाइड्रोजन परमाणु के मध्य होता है। इसे गॉश रूप कहते हैं, यह कम स्थायी होता है। रूप I को 60° व 300° पर घुमाने से क्रमशः II व VI रूप प्राप्त होते हैं ।

ये ग्रसित रूप कहलाता है तथा 180° पर रूप IV प्राप्त होता है जो पूर्णतः ग्रसित रूप है। रूप IV सबसे कम स्थायी है। इसमें दोनों मेथिल समूह की दूरी न्यूनतम होती है। अतः प्रतिकर्षण अधिकतम होता है। पूर्णतः ग्रसित रूप IV की अपेक्षा ग्रसित रूप II व III का स्थायित्व थोड़ा अधिक होता है।

प्रश्न 11.
बेंजीन के अनुनाद सूत्र को समझाइये।
उत्तर:
बेंजीन में प्रत्येक C – Cबंध लंबाई 1.40 A होती है जो कि एकल बंध 154 A और युग्म बंध 134 A के मध्यवर्ती है। अत: बेंजीन में C – C बंध एकल बंध या युग्म बंध से न जुड़े होकर आंशिक युग्म बंध तथा आंशिक एकल बंध से जुड़े होते हैं। अर्थात् कुछ समय पश्चात् द्वि-बंध एकल बंध में तथा एकल बंध द्विबंध में परिवर्तित होते रहते हैं। ऐसे बंधों की कल्पना तो की जा सकती है। लेकिन इन्हें कागजों पर नहीं दर्शाया जा सकता है। इसलिये ऐसा माना जाता है कि बेंजीन निम्नलिखित संरचनाओं का अनुनादी सूत्र है।

उपर्युक्त संरचनाओं में पहली तथा दूसरी संरचना Kekule संरचना है तथा तीसरी, चौथी तथा पाँचवीं संरचना Dewar संरचना है। Dewar संरचना की ऊर्जा अधिक होती है Para बंध की उपस्थिति के कारण। इसलिये अनुनाद में इनका योगदान केवल 20% होता है। जबकि Kekule सूत्र समतुल्य है और अन्य सूत्र की अपेक्षा अधिक स्थायी है।

इसलिये अनुनाद में इनका योगदान 80% होता है। इसी कारण बेंजीन को इन दो संरचनाओं Kekule सूत्र का ही अनुनादी संकर माना जाता है। सामान्यतः अनुनादी संकर सूत्र को अनेक सूत्र के स्थान पर केवल एक पार्श्व सूत्र द्वारा प्रदर्शित करते हैं जिसमें खंडित वृत्त असंतृप्तता को दर्शाता है।

प्रश्न 12.
एल्केन में होने वाली हैलोजनीकरण अभिक्रिया की मुक्त मूलक क्रियाविधि को समझाइये।
उत्तर:
एल्केन में हैलोजनीकरण अभिक्रिया मुक्त मूलक क्रियाविधि द्वारा सम्पन्न होती है।
1. श्रृंखला का समारम्भ पद – उच्च ताप या प्रकाश के पराबैंगनी विकिरण की ऊर्जा से क्लोरीन के अणु का समांश विखण्डन होता है एवं क्लोरीन का मुक्त मूलक प्राप्त होता है।

2. श्रृंखला संचरण पद – उक्त पद में क्लोरीन मुक्त मूलक एल्केन अणु में हाइड्रोजन को विस्थापित कर एक एल्किल मुक्त मूलक प्राप्त होता है।

यह मुक्त मेथिल मूलक क्लोरीन अणु से क्रिया कर एल्किल हैलाइड तथा क्लोरीन मुक्त मूलक देता है।

यह मुक्त क्लोरीन मूलक पुनः एल्केन से अभिक्रिया कर मेथिल मूलक देता है। इस प्रकार अभिक्रिया की पुनरावृत्ति होती रहती है।

3. श्रृंखला का समापन पद – अंत में दोनों मुक्त मूलक परस्पर क्रिया करके श्रृंखला अभिक्रिया को समाप्त कर देते हैं।

हैलोजन का मुक्त मूलक एल्किल हैलाइड पर आक्रमण कर नया मुक्त मूलक बनाता है।

यह मुक्त मूलक हैलोजन के साथ क्रिया कर डाइ हैलोएल्केन देता है। यह प्रक्रिया धीरे – धीरे तब तक चलती रहती है जब तक सभी हाइड्रोजन परमाणु क्लोरीन द्वारा प्रतिस्थापित नहीं हो जाते हैं।

प्रश्न 13.
समूहों के दिशात्मक प्रभाव का इलेक्ट्रॉनिक स्पष्टीकरण दीजिए।
उत्तर:
यदि बेंजीन रिंग पर एक प्रतिस्थापी समूह पहले से उपस्थित है तो प्रतिस्थापन अभिक्रिया के फलस्वरूप नया समूह रिंग के किस स्थान पर प्रवेश करेगा इसका निर्धारण पहले से उपस्थित प्रतिस्थापी समूह की प्रकृति के आधार पर होता है इसे उस समूह का दैशिक प्रभाव कहते हैं।

इलेक्ट्रॉनिक सिद्धान्त के आधार पर समूह के निर्देशक प्रभाव की व्याख्या –
1. ऑर्थों व पैरा निर्देशकारी समूह – ये वे समूह होते हैं जो बेंजीन वलय पर पहले से उपस्थित होने पर नये समूह को ऑर्थो व पैरा स्थान पर निर्देशित करते हैं।
उदाहरण – OH, – OCH₃, – CH₃, – NH₂
ये समूह अपनी इलेक्ट्रॉन मुक्तकारी क्षमता के कारण बेंजीन में ऑर्थो व पैरा स्थिति में इलेक्ट्रॉन घनत्व बढ़ा देते हैं। इलेक्ट्रॉन घनत्व बढ़ जाने की वजह से बेंजीन नाभिक की क्रियाशीलता बढ़ जाती है तथा इलेक्ट्रॉन स्नेही अभिकर्मक इस स्थिति में उच्च इलेक्ट्रॉन घनत्व होने के कारण इन्हीं स्थानों पर प्रवेश करता है। .

2. मेटा निर्देशकारी प्रभाव – ये वे समूह हैं जो बेंजीन वलय पर पहले से उपस्थित होने पर नये समूह को मेटा स्थान पर निर्देशित करते हैं।
उदाहरण- – NO₂ – COOH, – SO₃H, – CN
जब ये समूह बेंजीन वलय पर जुड़े होते हैं तो मेसोमेरिक प्रभाव के कारण बेंजीन वलय से इलेक्ट्रॉन खींच लेते हैं जिसके फलस्वरूप वलय का इलेक्ट्रॉन घनत्व कम हो जाता है तथा इलेक्ट्रॉन घनत्व मुख्यतः ऑर्थो तथा पैरा स्थिति पर घटता है जबकि मेटा स्थिति अप्रभावित रहती है अर्थात् मेटा स्थिति पर इलेक्ट्रॉन घनत्व उच्च रहता है। इसलिये इलेक्ट्रॉन स्नेही अभिकर्मक मेटा स्थिति पर प्रवेश करता है।

प्रश्न 14.
क्लोरीनीकरण के प्रति 1°,2°,3° हैलोजनों की आपेक्षिक क्रियाशीलता 1:3.8:5 है। 2 – मेथिल ब्यूटेन के सभी मोनोक्लोरीनीकृत उत्पादों की प्रतिशतता ज्ञात कीजिए।

मोनो क्लोरीनीकृत उत्पादों की आपेक्षिक मात्रा = हाइड्रोजन की मात्रा × आपेक्षिक क्रियाशीलता –
(1°) मोनो क्लोरीनीकृत उत्पाद के लिए = 9 × 1 = 9
(2°) मोनो क्लोरीनीकृत उत्पाद के लिए = 2 × 3.8 = 7.6
(3°) मोनो क्लोरीनीकृत उत्पाद के लिए = 1 × 5 = 5
मोनो क्लोरीनीकृत यौगिकों की कुल संख्या = 9 + 7.6 + 5 = 21.6
1° मोनो क्लोरीनीकृत उत्पाद की % मात्रा = \(\frac { 9 × 100 }{ 21.6 }\) = 41.67%
2° मोनो क्लोरीनीकृत उत्पाद की % मात्रा = \(\frac { 7.6 × 100 }{ 21.6 }\) = 35.18%
3° मोनो क्लोरीनीकृत उत्पाद की % मात्रा =\(\frac {5 × 100 }{ 21.6 }\) = 23.15 %

प्रश्न 15.
निम्नलिखित अभिक्रिया के फलस्वरूप कौन-सा उत्पाद प्राप्त होगा तथा क्यों ?

जब फ्रीडल – क्राफ्ट ऐल्कीकरण उच्च ऐल्किल हैलाइड जैसे n – प्रोपिल क्लोराइड के साथ होता है, तो इलेक्ट्रॉन स्नेही, n – प्रोपिल कार्बधनायन (1° कार्बधनायन) पुनर्व्यवस्थित होकर अधिक स्थायी आइसो-प्रोपिल कार्बधनायन (2° कार्बधनायन) में बदल जाता है तथा अभिक्रिया के परिणामस्वरूप मुख्य उत्पाद आइसो-प्रोपिल बेन्जीन प्राप्त होता है।

प्रश्न 16.
निम्नलिखित यौगिकों को इलेक्ट्रॉन स्नेही अभिकर्मक के प्रति उनकी घटती हुई आपेक्षिक क्रियाशीलता के क्रम में व्यवस्थित कीजिए।

उत्तर:
OCH₃ (मेथॉक्सी समूह) इलेक्ट्रॉन निर्मुक्त करने वाला समूह है। यह अनुनाद प्रभाव (+R प्रभाव) के कारण बेन्जीन नाभिक पर इलेक्ट्रॉन घनत्व बढ़ाता है। इसके कारण एनीसॉल, इलेक्ट्रॉन स्नेही अभिकर्मकों के प्रति, बेन्जीन की अपेक्षा अधिक क्रियाशील है। ऐरिल हैलाइडों की दशा में, हैलोजन अपने प्रबल – I प्रभाव के कारण अत्यधिक निष्क्रिय होते हैं जिससे बेन्जीन वलय में कुल इलेक्ट्रॉन घनत्व घट जाता है। इसके कारण पुनः प्रतिस्थापन घट जाता है।

– NO₂ समूह इलेक्ट्रॉन आकर्षित करने वाला समूह है। यह प्रबल – प्रभाव के कारण बेन्जीन नाभिक में इलेक्ट्रॉन घनत्व घटाता है। जिसके कारण नाइट्रोबेन्जीन कम क्रियाशील हो जाती है। अतः इन यौगिकों की इलेक्ट्रॉन स्नेही अभिकर्मकों के प्रति कियाशीलता का क्रम निम्न होगा –

MP Board Class 11th Chemistry Solutions

MP Board Class 12th Hindi Swati Solutions गद्य Chapter 11 गीता और स्वधर्म (निबंध, आचार्य विनोबा भावे)

गीता और स्वधर्म अभ्यास

गीता और स्वधर्म अति लघु उत्तरीय प्रश्न

प्रश्न 1.
अर्जुन के स्वभाव में कौन-सी वृत्ति विद्यमान थी?
उत्तर:
कृत-निश्चय होकर और कर्तव्य भाव से समर-भूमि में खड़े अर्जुन के स्वभाव में क्षात्रवृत्ति विद्यमान थी।

प्रश्न 2.
किस सजा से अपराधी के सुधरने की आशा नष्ट हो जाती है?
उत्तर:
फाँसी की सजा अमानुषी होने के कारण मनुष्य को शोभा नहीं देती क्योंकि इससे अपराधी के सुधरने की आशा नष्ट हो जाती है।

प्रश्न 3.
लेखक किस सागर में डुबकी लगाकर बैठ जाता है?
उत्तर:
लेखक विनोबा भावे जब अकेले होते हैं तब गीता के अमृत सागर में गहरी डुबकी लगाकर बैठ जाते हैं।

प्रश्न 4.
किसने श्रीकृष्ण से अपना सारथ्य स्वीकार कराया? (2016)
उत्तर:
दुर्योधन के द्वारा संधि प्रस्ताव ठुकराने पर अर्जुन ने अनेक देशों के राजाओं को एकत्र करके श्रीकृष्ण से अपना सारथ्य स्वीकार कराया।

प्रश्न 5.
युद्ध में आप्त स्वजन सम्बन्धियों की कितनी पीढ़ियाँ एकत्र हुई थी?
उत्तर:
युद्ध भूमि के मध्य खड़े होकर अर्जुन ने देखा कि दादा, बाप, बेटे, पोते, आप्त-स्वजन सम्बन्धियों की चार पीढ़ियाँ एकत्र थीं।

प्रश्न 6.
अर्जुन के मन में कौन-सा भाव उत्पन्न हो गया था?
उत्तर:
युद्ध के लिए तत्पर स्वजन समूह को देखकर सदैव विजयी रहने वाले अर्जुन के मन में अहिंसा का भाव उत्पन्न हो गया था।

गीता और स्वधर्म लघु उत्तरीय प्रश्न

प्रश्न 1.
गीता के गगन में लेखक किन उपकरणों से उड़ान भरता है?
उत्तर:
जिस प्रकार एक पक्षी अपने दो पंखों की सहायता से नीले खुले गगन में स्वछन्द होकर यथाशक्ति दूर तक उड़ान भरता है। ठीक उसी प्रकार लेखक तर्क को त्यागकर श्रद्धा और प्रयोग,इन दो उपकरणों से गीता के गगन में यथाशक्ति उड़ान भरता रहता है।

प्रश्न 2.
अर्जुन ने अकेले ही किन-किन के दाँत खट्टे कर दिए थे? (2017)
उत्तर:
जिस समय पांडव अज्ञातवास में थे उस समय कौरवों की सेना ने उत्तर कुमार की गायों का हरण करने का प्रयास किया तब अर्जुन ने उत्तर कुमार का सारथी बनकर अकेले ही धीर भीष्म पितामह, आचार्य द्रोण और सूर्यपुत्र कर्ण के दाँत खट्टे कर दिए थे।

प्रश्न 3.
युद्ध टालने के लिए कौन-कौन सी दोनों बातें बेकार हो चुकी थीं?
उत्तर:
अर्जुन के स्वभाव में क्षात्रवृत्ति थी। वह कृत निश्चय होकर और कर्त्तव्य भाव से समर-भूमि में खड़ा था। लेकिन युद्ध के विनाशकारी परिणामों का उसे आभास था। अत: युद्ध को टालने के लिए अर्जुन ने पहली, कौरवों के पास कम से कम माँग का प्रस्ताव भेजा-दूसरी, कृष्ण को मध्यस्थ बना कर भेजा। लेकिन विनाशकारी बुद्धि वाले दुर्योधन ने एक भी बात को स्वीकार नहीं किया।

प्रश्न 4.
लेखक के अनुसार गीता के जन्म का उद्देश्य क्या था?
उत्तर:
युद्धभूमि में अर्जुन धर्म-सम्मूढ़ हो गया था, इस कारण उसके मन में स्वधर्म के विषय में मोह पैदा हो गया था। इस मोह को अर्जुन स्वयं स्वीकार करता है। अतः स्पष्ट है कि गीता का जन्म स्वधर्म में बाधक जो मोह है, उसके निवारणार्थ हुआ है। गीता के जन्म का प्रधान उद्देश्य यही था। गीता सुनने के बाद अर्जुन कृष्ण से कहता है-भगवन्, मेरा मोह नष्ट हो गया है, मुझे स्वधर्म का भान हो गया है।

प्रश्न 5.
लेखक के अनुसार गीता का मुख्य काम क्या-क्या है?
उत्तर:
यदि गीता के उपक्रम और उपसंहार को मिलाकर देखें तो स्वधर्म में बाधक मोह-ममत्व तथा स्वजनासक्ति दूर करना गीता का मुख्य काम है,मोह का निवारण करना ही गीता का काम है। गीता ही नहीं,सम्पूर्ण महाभारत का काम लोक हृदय के मोहावरण को दूर करना है। यही काम गीता ने किया जिसके परिणामस्वरूप अर्जुन का मोह नष्ट हो गया और उसे क्षात्रधर्म का ज्ञान हो गया।

गीता और स्वधर्म दीर्घ उत्तरीय प्रश्न

प्रश्न 1.
विनोबा जी का गीता के साथ किस प्रकार का सम्बन्ध था?
उत्तर:
विनोबा जी का गीता के साथ जो सम्बन्ध था उसे बताना कठिन है क्योंकि वह अलौकिक था जिसे तर्क द्वारा नहीं बताया जा सकता है। विनोबा जी कहते हैं कि उनके शरीर का निर्माण तो माँ के दूध से हुआ किन्तु उनके हृदय और बुद्धि का पोषण गीता के दूध अर्थात् गीता के संदेशों से हुआ। इस सम्बन्ध को हम हार्दिक सम्बन्ध कह सकते हैं। हार्दिक सम्बन्धों में तर्क बहस,दलील या चर्चा का कोई महत्व नहीं होता। तर्क के स्थान पर श्रद्धा और प्रयोग इन दो बातों के आधार पर गीता को समझने का प्रयास किया जाता है।

गीता उनका प्राणतत्व है, आत्मा है। जब वह गीता के मोह निवारण पर चर्चा करते हैं तो मानो, वह गीता रूपी सागर पर तैर रहे होते हैं अर्थात् गीता के श्लोकों का शब्दार्थ कर रहे हैं परन्तु जब वह एकाकी होकर मोह निवारण का माप श्रद्धा व प्रयोग के आधार पर हृदय में मनन करते हैं तो उन्हें ऐसा लगता है, मानो वे अमृत-सागर में डुबकी (गोता) लगा रहे हैं जिससे उनकी आत्मा को परम सुख की प्राप्ति होती है। इसी आत्मा के परम सुख की प्राप्ति के रूप में ही विनोबा जी का सम्बन्ध गीता से है। यह सम्बन्ध अलौकिक होने के साथ-साथ हृदय के तारों से मधुर ईश्वरीय संगीत को सुनाने वाला है।

प्रश्न 2.
अर्जुन को महावीर क्यों कहा गया?
उत्तर:
विनोबा जी ने अर्जुन को महावीर कहा है, उनका यह कथन बिल्कुल सत्य है, क्योंकि अर्जुन में अठारह अक्षौहिणी सेना से अधिक शक्ति थी। वह सैकड़ों लड़ाइयों में अपना जौहर दिखा चुका था। उत्तर-गो ग्रहण के समय उसने अकेले ही भीष्म, द्रोण और कर्ण के दाँत खट्टे कर दिए थे। वह सदा विजय प्राप्त करने वाला और सब नरों में एक ही सच्चा नर था। वीरवृत्ति उसके रोम-रोम में भरी थी। उसके विचार कृत-निश्चय और कर्त्तव्य भाव से पूर्ण थे। क्षात्रवृत्ति उसके स्वभाव में थी। वीरवृत्ति का उत्साह उसकी प्रेरणा थी। युद्ध क्षेत्र में उसने असंख्य वीरों का संहार किया था।

उसका गांडीव हाथ से कभी नहीं गिरा था। उसके शरीर में कभी कम्पन नहीं हुआ था न आँखें गीली हुई थीं। वह सदैव युद्ध-प्रवृत्त ही था। युद्ध उसकी दृष्टि से उसका स्वभाव प्राप्त और अपरिहार्य रूप से निश्चित कर्त्तव्य था। पलभर के लिए उसके मन में परिवार के प्रति आसक्ति तथा मोह जाग्रत हुआ था। परन्तु कृष्ण ने उसके इस मोह को गीता सुनाकर नष्ट कर दिया था। गीता कर्मयोग तथा युद्धयोग दोनों का प्रतिपादन करती है जिसे अर्जुन ने पूर्ण रूप से अपनाया था। इन्हीं सब कारणों से अर्जुन को महावीर कहा गया।

प्रश्न 3.
युद्ध क्षेत्र में स्वजनों को देखकर अर्जुन के मन में कौन-कौन से भाव उत्पन्न होते है? (2014)
उत्तर:
पाण्डवों ने महाभारत के युद्ध को टालने के लिए दुर्योधन के पास कम-से-कम माँग का प्रस्ताव और श्रीकृष्ण जैसे मध्यस्थ को भेजा परन्तु दुर्योधन नहीं माना तो अर्जुन कृष्ण को अपना सारथी बनाकर रणांगन में पहुँचा और अपने रथ को दोनों सेनाओं के बीच खड़ा करने को कहा। सेनाओं के बीच खड़े होकर उसने सारे स्वजन समूह को देखा तो उसके हृदय में उथल-पुथल मच गई। उसे बहुत बुरा लगा। अर्जुन के मन में भाव उठे कि दादा, बाप, बेटे, पोते-आप्त,स्वजन-सम्बन्धियों की चार पीढ़ियाँ मरने-मारने के अन्तिम निश्चय से वहाँ एकत्र हुई हैं। इस प्रत्यक्ष दर्शन का उसके हृदय पर हृदय को विचलित कर देने वाला प्रभाव पड़ा।

आज तक उसने अनेक युद्धों में असंख्य वीरों का संहार किया है, परन्तु उस समय उसे बुरा नहीं लगा था। उसका गांडीव हाथ से नहीं गिरा था। शरीर में कंपन नहीं हुआ था, उसकी आँखें गीली नहीं हुई थीं। तो इसी समय ऐसा क्यों हुआ? उसके मन में स्वजनासक्ति के भाव उत्पन्न हुए। कर्त्तव्यविमुख होने के भावों के साथ तत्व ज्ञान (दर्शन) के भाव जाग्रत हुए। वह युद्ध को व्यर्थ समझकर पाप समझने लगा। युद्ध से कुल क्षय होगा, धर्म का लोप होगा। स्वैराचार मचेगा, व्यभिचार फैलेगा, अकाल आ पड़ेगा,समाज पर तरह-तरह के संकट आयेंगे। इस प्रकार के अनेक भाव अर्जुन के मन में उत्पन्न होते हैं।

प्रश्न 4.
न्यायाधीश के उदाहरण से लेखक क्या सीख देना चाहता है?
उत्तर:
एक न्यायाधीश ने सैकड़ों अपराधियों को फाँसी की सजा दी थी। परन्तु जब अपने पुत्र को खून के जुर्म में मृत्युदण्ड देने का समय आया तो पुत्र-स्नेह के कारण वह हिचकने लगा तथा बुद्धिवाद बघारने लगा-फाँसी की सजा बड़ी अमानुषी है, लज्जा की बात है, बड़ा कलंक है। उसकी यह बात आंतरिक नहीं थी। वह आसक्ति-जनित थी। इस प्रकार महावीर अर्जुन भी स्वजन आसक्ति में आकर अहिंसावादी तथा बुद्धिवादी बन गया और युद्ध में दोष बताने लगा। अतः लेखक बताना चाहता था कि यह अर्जुन का तत्व ज्ञान नहीं कोरा प्रज्ञावाद था। मनुष्य परिजनों के स्नेह में पड़कर कर्त्तव्य को भूल जाता है, वह मोह में पड़ जाता है। इसी मोह को दूर करना गीता का धर्म है। मनुष्य को मोह में न पड़कर अपना कर्तव्य पालन करना चाहिए। मोह मनुष्य को नीचे गिरा देता है। अर्जुन की गति न्यायाधीश जैसी हो गई थी।

प्रश्न 5.
श्रीकृष्ण ने अर्जुन की जिज्ञासाओं का कैसे समाधान किया?
उत्तर:
श्रीकृष्ण द्वारा मध्यस्थता करने तथा कम-से-कम मांग के प्रस्ताव को दुर्योधन ने स्वीकार नहीं किया तो युद्ध अनिवार्य हो गया। दोनों पक्षों की सेनाएँ युद्धभूमि में खड़ी थीं। तब अर्जुन के मन में अचानक जिज्ञासा जागी कि वह दोनों सेनाओं के चेहरे देखे। अर्जुन ने कृष्ण को अपनी जिज्ञासा बताई, कृष्ण ने अर्जुन का रथ दोनों सेनाओं के मध्य खड़ा कर दिया। अर्जुन ने अपनी चार पीढ़ियों को देखा और मोहग्रस्त हो युद्ध से विरक्त हो गया। इसी प्रकार स्वधर्म के विषय में उनके मन में मोह पैदा हो गया था। श्रीकृष्ण ने अर्जुन की जिज्ञासा व मोह को दूर किया। इसके लिए श्री कृष्ण ने अर्जुन को गीता सुनाई जो गीता महाभारत के मध्यभाग में एक ऊँचे दीपक के समान है तथा समस्त जिज्ञासाओं को हल करने में पूर्णतः सक्षम है।

प्रश्न 6.
गीता का निष्कर्ष क्या है?
उत्तर:
गीता की योजना महाभारत में की गई थी जो महाभारत के मध्य भाग में एक ऊँचे दीपक की तरह पूर्ण महाभारत को प्रकाशित करती है। गीता का निष्कर्ष केवल कर्म-योग ही नहीं, बल्कि युद्ध-योग का भी प्रतिपादन करता है। युद्ध-भूमि के मध्य खड़ा अर्जुन स्वजन आसक्ति के कारण क्षात्रवृत्ति से विमुख होकर युद्ध के दुष्परिणाम बघारने लगा क्योंकि सारे जन समूह को देखकर उसके हृदय में उथल-पुथल मच गई थी। कृष्ण अर्जुन के आसक्तिजनित मोह को जानते थे, इसलिए उन्होंने अर्जुन के मोह-पाश का उपाय शुरू किया। स्वधर्म में बाधक जो मोह है उसका निवारण करना ही गीता का उद्देश्य है। मोह, ममत्व, आसक्ति को दूर करके स्वधर्म का भान कराना ही गीता का निष्कर्ष है। गीता ही नहीं सम्पूर्ण महाभारत में लोक हृदय के मोहावरण को दूर करने के लिए यह इतिहास-प्रदीप जलाया गया है। मुख्य निष्कर्ष मोह निरसन ही है।

गीता और स्वधर्म भाषा-अध्ययन

प्रश्न 1.
दिए गए मुहावरों का वाक्यों में प्रयोग कीजिए

1. दाँत खट्टे कर देना
2. उथल-पुथल मचाना
3. आँखें गीली होना
4. जौहर दिखाना
5. उड़ान भरना
6.  डुबकी लगाना
7. जुनून उतर जाना।

उत्तर:

1. दाँत खट्टे करना – भारतीय सैनिकों ने 1971 के युद्ध में पाकिस्तानी सैनिकों के दाँत खट्टे कर दिए थे।
2. उथल-पुथल मचना – कलिंग युद्ध के मैदान में अनेक सैनिकों की कराहट को सुनकर सम्राट अशोक के हृदय में उथल-पुथल मच गई।
3. आँखें गीली होना – रेल दुर्घटना के वीभत्स दृश्य को देखकर उपस्थित जनसमूह की आँखें गीली हो गईं।
4. जौहर दिखाना – झाँसी वाली रानी ने अकेले ही ब्रिटिश सैनिकों के बीच जौहर दिखाया।
5. उड़ान भरना – जीवन में सफलता पाने के लिए कल्पना की उड़ान भरने के साथ परिश्रम करना भी आवश्यक है।
6. डुबकी लगाना – श्री विनोबा भावे ने गीता के अमृत सागर में डुबकी लगाकर जीवन। का लक्ष्य प्राप्त कर लिया।
7. जुनून उतर जाना – स्वजनों के मोह का जूनून उतरने पर ही अर्जुन महाभारत के युद्ध को जीत सका।

प्रश्न 2.
निम्नलिखित वाक्यों का भाव-विस्तार कीजिए-
(अ) जहाँ हार्दिक सम्बन्ध होता है, वहाँ तर्क की गुंजाइश नहीं होती। (2017)
उत्तर:
भाव विस्तार :
‘गीता और स्वधर्म’ शीर्षक में ‘श्री विनोबा भावे’ने बताया है कि गीता के साथ उनका हार्दिक सम्बन्ध है। इस कारण इस सम्बन्ध को साबित करने के लिए किसी भी प्रकार की दलील नहीं दी जा सकती और न ही बहस की जा सकती है। हार्दिक सम्बन्ध भावना से जुड़े होते हैं जिन्हें अनुभव किया जाता है, परन्तु दलीलों द्वारा नहीं बताया जा सकता। साथ ही यह सम्बन्ध सूक्ष्म होता है। इस सम्बन्ध में बड़ी शक्ति होती है,जो पाषाण हृदय को भी कोमल बना देती है। इस सम्बन्ध के द्वारा आत्मिक प्रसन्नता व शान्ति मिलती है।

(ब) इस आसक्ति जनित मोह ने उसकी कर्त्तव्य निष्ठा को ग्रस लिया और तब उसे तत्त्व ज्ञान याद आया।
उत्तर:
भाव विस्तार :
‘श्री विनोबा भावे’ जी ने अपने निबन्ध ‘गीता और स्वधर्म’ में अर्जुन के मोह व कृष्ण की गीता के विषय में बताया है। अर्जुन युद्धभूमि के मध्य रथ पर सवार था,तब उसने स्वजन समूह को देखा तो उसके हृदय में उथल-पुथल मच गई। उसके हृदय में परिजनों के प्रति मोह उत्पन्न हुआ, इस कारण वह अपने क्षात्रधर्म अर्थात् युद्ध कर्म को भूल कर प्रज्ञावादी बन गया। युद्ध को पाप व मानव जाति का कलंक कहने लगा। जो अर्जुन युद्ध प्रवृत्त था, युद्ध करना उसका स्वभाव था, अपरिहार्य रूप से उसका कर्त्तव्य था, उस कर्त्तव्य को अर्जुन भूल गया। युद्ध के दुष्परिणामों को बताने लगा यद्यपि जो सत्य थे परन्तु अर्जुन के मुख से सुशोभित नहीं हो रहे थे क्योंकि अर्जुन का कर्तव्य युद्ध में निहित था। उसका तत्व ज्ञान आत्मिक न होकर बौद्धिक था। कहीं न कहीं उस तत्त्व ज्ञान की जड़ में मोह था जिसने अर्जुन को कर्तव्य से गिरा दिया था।

गीता और स्वधर्म पाठ का सारांश

भूदान आन्दोलन के प्रणेता तथा किसानों के मसीहा ‘आचार्य विनोबा भावे’ द्वारा लिखित प्रस्तुत निबन्ध ‘गीता और स्वधर्म’ में आचार्य जी ने गीता के माध्यम से मनुष्य को अपनी बुद्धि के आधार पर न्यायपूर्ण कार्य करने का संदेश दिया है।

लेखक का गीता के साथ तर्कपूर्ण नहीं, आत्मिक रिश्ता है। उनके हृदय और बुद्धि का पोषण गीता के दूध से हुआ है। गीता पर उनकी अपार श्रद्धा है। गीता उनके लिए अमृत का सागर है। यह गीता श्रीकृष्ण ने युद्ध स्थल में युद्ध से विमुख हुए अर्जुन को कर्तव्य का ज्ञान कराने के लिए सुनाई थी। इसीलिए गीता महाभारत में दीपक के समान प्रकाश देती है।

माना जाता है कि कृष्ण ने अर्जुन को गीता दो कारणों से सुनाई होगी। एक, अर्जुन की नपुंसकता को दूर करने तथा दूसरी अर्जुन की अहिंसा-वृत्ति को दूर करने के लिए। लेकिन ये दोनों बातें ही ठीक नहीं हैं.क्योंकि अर्जन ‘महावीर’ थे,उन्होंने उत्तर-गो ग्रहण के समय अकेले ही भीष्म, द्रोण और कर्ण को पराजित किया था। वीर-वृत्ति उनके रोम-रोम में बसी थी। क्षात्रवृत्ति उनके स्वभाव में थी। युद्ध को टालने के लिए कम से कम माँग का प्रस्ताव और कृष्ण ने मध्यस्थता की थी परन्तु दुर्योधन सहमत नहीं था। इस कारण कृष्ण को अपना सारथी बनाकर वीर अर्जुन कुरुक्षेत्र में पहुँचे। वहाँ दोनों पक्षों की सेनाओं के मध्य अपने रथ में बैठे अपनी चार पीढ़ियों के मरण का उत्साह देखकर वह स्वजनाशक्ति में आ गए थे। वीरता का शौर्य दिखाने वाले उस महावीर अर्जुन का गांडीव कभी झुका नहीं था,न शरीर में कम्पन हुआ था और न कभी आँखें गीली हुई थीं।

वहीं अर्जुन जिसमें कभी अहिंसा-वृत्ति ने जन्म नहीं लिया था, उसके आसक्ति जनित मोह ने कर्तव्य को त्याग कर तत्व ज्ञान की शरण ली। कहने लगे कि युद्ध मानव जाति के विनाश का कारण होगा। उस समय अर्जुन की दशा उस न्यायाधीश जैसी थी जो अनेकों को मृत्यु दण्ड दे चुका था परन्तु जब अपने बेटे को खून के जुर्म में मृत्यु दण्ड देने का समय आया तो कहने लगा कि मृत्यु दण्ड अमानुषी सजा है, बड़ा कलंक है। यह कथन आसक्ति जनित है। अर्जुन के इस तत्व ज्ञान को कृष्ण जानते थे इसलिए अर्जुन के मोहपाश को नष्ट करने का उपाय किया और गीता में अर्जुन के इसी मोहपाश पर गदा प्रहार किया है।

अतः गीता का जन्म,स्वधर्म में बाधक जो मोह है,उसके निवारणार्थ हुआ है। गीता सुनाने के बाद कृष्ण ने अर्जुन से पूछा कि अर्जुन तेरा मोह गया? तब अर्जुन ने उत्तर दिया-हाँ भगवन! मेरा मोह नष्ट हो गया, मुझे स्वधर्म का भान हो गया। गीता ही नहीं सम्पूर्ण महाभारत का यही उद्देश्य है। व्यास जी ने महाभारत के आरम्भ में कहा है कि लोक हृदय के मोहावरण को दूर करने के लिए मैं यह इतिहास प्रदीप जला रहा हूँ।

गीता और स्वधर्म कठिन शब्दार्थ

तर्क = दलील। क्लैष्य = नपुंसकता। प्रवृत्त = संलग्न। परावृत्त = दूर भागना। जौहर = वीरता। ख्याति = यश। समर-भूमि = युद्ध-भूमि। क्षात्रवृत्ति = क्षत्रिय धर्म। रणांगण = युद्ध भूमि। स्वजनासक्ति = पारिवारिक जनों के प्रति मोह। प्रतिपादन = सिद्ध करना। क्षय = नष्ट। स्वैराचार = स्वेच्छाचार। नौबत = अवसर। अमानुषी = जंगलीपन। जुनून = धुन। आसक्ति = मोह। प्रज्ञावेद = बुद्धिवाद। अपरिहार्य = जो छोड़ा न जा सके। प्रहार = चोट। निरसन = निराकरण। सारथ्य = सारथी का कार्य। कर्त्तव्यच्युति = अपने कर्त्तव्य से विमुख। अवान्तर = अन्य।

गीता और स्वधर्म संदर्भ-प्रसंग सहित व्याख्या

(1) गीता का और मेरा सम्बन्ध तर्क से परे है। मेरा शरीर माँ के दूध पर जितना पला है, उससे कहीं अधिक मेरे हृदय और बुद्धि का पोषण गीता के दूध पर हुआ है। जहाँ हार्दिक सम्बन्ध होता है, वहाँ तर्क की गुंजाइश नहीं रहती। तर्क को काटकर श्रद्धा और प्रयोग, इन दो पंखों से ही मैं गीता-गगन में यथाशक्ति उड़ान भरता रहता हूँ।

संदर्भ :
प्रस्तुत गद्य अवतरण हमारी पाठ्य-पुस्तक के निबन्ध ‘गीता और स्वधर्म’ नामक पाठ से अवतरित है। इसके लेखक ‘आचार्य विनोबा भावे’ हैं।

प्रसंग :
इन पंक्तियों में गीता तथा विनोबा भावे के सम्बन्ध को तर्कहीन बताकर गीता के प्रति उनकी अपार श्रद्धा को व्यक्त किया गया है।

व्याख्या :
विनोबा भावे गीता पर प्रवचन देते हुए कहते हैं कि उनका और गीता का सम्बन्ध अलौकिक है जिसे शब्दों के द्वारा नहीं बताया जा सकता, न उस सम्बन्ध के विषय में कोई दलील या बहस की जा सकती है। गीता के साथ अपने सम्बन्ध को स्पष्ट करते हुए वे कहते हैं कि माँ के दूध व वात्सल्य से उनके शरीर का निर्माण हुआ परन्तु उनके हृदय व बुद्धि का विकास गीता के ज्ञान से हुआ। गीता के रहस्य ने ही उनके हृदय को पवित्र तथा बुद्धि को परिष्कृत किया है। जब किसी से हार्दिक सम्बन्ध हो जाते हैं तो वहाँ बहस या दलील व्यर्थ हो जाती है।

हृदय दलीलों को नहीं मानता, वह तो सत्य व कोमलता को स्वीकार करता है। जिस प्रकार एक पक्षी अपने दोनों पंखों की सहायता से स्वछन्द नीले आकाश में अपनी पूर्ण शक्ति के साथ उड़ान भरता हुआ प्रसन्न होता है ठीक उसी प्रकार विनोबा जी भी गीता में श्रद्धा रखते हुए तथा उसे अपने जीवन में साक्षात प्रयोग करते हुए गीता के अर्थ को या उसके रहस्य को समझते हैं और सुख का अनुभव करते हैं। श्रद्धा और प्रयोग उनके गहन अध्ययन के दो आधार रूपी पंख हैं।

विशेष :

1. विनोबा जी की गीता के प्रति श्रद्धा अभिव्यक्त की गई है।
2. संस्कृतनिष्ठ शुद्ध साहित्यिक खड़ी बोली का प्रयोग है।
3. गीता-गगन में रूपक अलंकार का प्रयोग है।
4. उदाहरण व गवेषणात्मक शैली का प्रयोग है।

(2) मैं प्राय: गीता के ही वातावरण में रहता हूँ। गीता मेरा प्राणतत्व है। जब मैं गीता के सम्बन्ध में किसी से बात करता हूँ, तब गीता-सागर पर तैरता हूँ और जब अकेला रहता हूँ तब उस अमृत-सागर में गहरी डुबकी लगाकर बैठ जाता हूँ।

सन्दर्भ :
पूर्ववत्।

प्रसंग :
प्रस्तुत अंश में विनोबा जी गीता के प्रति अपनी श्रद्धा का वर्णन करते हैं। गीता के प्रति उनकी श्रद्धा तर्करहित हार्दिक है। उनके जीवन का हर पल गीता के मूल से जुड़ा है।

व्याख्या :
विनोबा भावे, आसक्ति रहित कर्म करने का संदेश देने वाली गीता से, आजीवन जुड़े रहे। गीता ने उन्हें जीवन प्रदान किया। गीता उनके प्राण-आत्मा थी। गीता की चर्चा करते समय वह उसके बाह्य रूप के सम्पर्क में रहते थे लेकिन एकान्त की अवस्था में वह उसके गूढ़ रहस्य को समझने में लगे रहते थे। परन्तु प्रतिपल वे गीता के सम्पर्क में रहते थे। एकाकी अवस्था में उन्होंने गीता रूपी सागर के निष्काम कर्म रूपी अमृत को पीया। गीता-सागर में डुबकी लगाने अर्थात् उसका गहन अध्ययन करने पर उन्हें सुख मिलता था। जैसे अमृत पीकर मनुष्य अमर हो जाते हैं, उसी प्रकार गीता के रहस्य को समझने पर वे अमर हो गये या कहें कि वे सुख-दुःख से परे हो गए। इस प्रकार गीता व विनोबा जी दो अलग रूप होते हुए एक हो गए थे। गीता ने उन्हें आनन्दपूर्ण जीवन प्रदान किया।

विशेष :

1. गीता के द्वारा ही मनुष्य मोक्ष पा सकता है।
2. प्राणतत्व जैसे गूढ़ शब्दों के कारण भाव कठिन हो गए हैं।
3. अलंकारिक व मुहावरेदार भाषा।
4. संस्कृत शब्दावली का प्रयोग।
5. साहित्यिक खड़ी बोली।

(3) अर्जुन, तो लड़ाई से परावृत्त हो रहा था, सो भय के कारण नहीं। सैकड़ों लड़ाइयों में अपना जौहर दिखाने वाला वह महावीर था। उत्तर-गो ग्रहण के समय उसने अकेले ही भीष्म, द्रोण और कर्ण के दाँत खट्टे कर दिये थे। सदा विजय प्राप्त करने वाला और सब नरों में एक ही सच्चा नर, ऐसी उसकी ख्याति थी। वीरवृत्ति उसके रोम-रोम में भरी थी।

सन्दर्भ :
पूर्ववत्।

प्रसंग :
प्रस्तुत पंक्तियों में बताया गया है कि जब अर्जुन कुरुक्षेत्र की युद्ध-भूमि में खड़ी अट्ठारह अक्षोहिणी सेना के मध्य अपनी चार पीढ़ियों को खड़ा देखते हैं तो उनके मन में स्वजनासक्ति आ जाती है और वह युद्ध न करने की बात कृष्ण से कहते हैं। तब कृष्ण गीता के माध्यम से क्षात्रधर्म का सन्देश देकर उनमें उत्साह का संचार करते हैं।

व्याख्या :
श्री विनोबा जी बताते हैं कि अर्जुन ने युद्ध करना अस्वीकार किया। इसका कारण विशाल सेना की शक्ति को देखकर वह भयभीत नहीं था। अर्जुन महावीर था, उसने अनेक युद्धों में अपनी वीरता दिखाई थी तथा वह अनेक लड़ाइयाँ जीत चुका था। जिस समय पाण्डव अज्ञातवास में थे तब कौरव सेना, उत्तर कुमार की गायों का अपहरण करने आई थी। जिनमें भीष्म, द्रोण और सूर्यपुत्र कर्ण जैसे अजेय वीर थे, उस समय अर्जुन ने उत्तर कुमार का सारथी बनकर कौरवों की सेना को पराजित किया था।

यह अर्जुन की वीरता और निडरता का उदाहरण है। अत: अर्जुन शत्रु की सेना की शक्ति से नहीं डरा था। अर्जुन की प्रत्येक लड़ाई में विजय हुई थी, वह नर-श्रेष्ठ था। उसकी वीरता का यश दसों दिशाओं में फैला था। अर्जुन के सम्पूर्ण शरीर व रोम-रोम में वीरता की भावना भरी हुई थी। लेखक ने अर्जुन द्वारा युद्ध न किए जाने का कारण स्वजनासक्ति बताया है। उस आसक्ति को कृष्ण ने गीता सुना कर समाप्त किया था।

विशेष :

1. शुद्ध खड़ी बोली का प्रयोग।
2. ‘दाँत खट्टे करना’ तथा ‘रोम-रोम में भरा’ जैसे मुहावरों का प्रयोग।
3. उद्धरण शैली का प्रयोग।
4. ‘परावृत्त’ जैसे संस्कृत शब्दों का प्रयोग हुआ है।
5. अर्जुन की वीरता का परिचय दिया गया है।

(4) क्या अशोक की तरह उसके मन में अहिंसा-वृत्ति का उदय हुआ था? नहीं, यह तो केवल स्वजनासक्ति थी। इस समय भी यदि गुरु बंधु और आप्त सामने न होते, तो उसने शत्रुओं के मुण्ड गेंद की तरह उड़ा दिये होते। परन्तु इस आसक्ति जनित मोह ने उसकी कर्त्तव्यनिष्ठा को ग्रस लिया और तब उसे तत्वज्ञान याद आया।

सन्दर्भ :
पूर्ववत्।

प्रसंग :
विनोबा जी ने बताया है कि युद्धभूमि में अपने परिजनों को देखकर अर्जुन मोह में पड़ गया, इस कारण वह अपने क्षात्रधर्म को भूल गया।

व्याख्या :
कुरुक्षेत्र के मैदान में अपने स्वजन समूह को देखकर अर्जुन के हृदय में हलचल मच गई। वह अचानक अहिंसावादी बन गया । अर्जुन की अहिंसा अशोक जैसी अहिंसा नहीं थी, उसकी अहिंसा का कारण परिवार के प्रति मोह था। अशोक युद्ध के वीभत्स परिणामों के कारण अहिंसावादी बना था। अशोक और अर्जुन की अहिंसा में अन्तर था। अर्जुन के सामने यदि उसके गुरु,भाईबन्धु, मित्र आदि न होकर शत्रु पक्ष की सेना होती तो वह विपक्ष को नष्ट कर देता। इस समय परिजनों के प्रति आसक्ति ने उसे मोह में डुबो दिया जिसका परिणाम था कि वह अपने क्षात्रधर्म अर्थात् कर्त्तव्य को भूल गया। वह अहिंसा को श्रेष्ठ मानने लगा तथा अपना तत्त्व-ज्ञान अर्थात् दर्शन बघारने लगा कि युद्ध पाप है,समाज का कलंक है, धर्म का नाश है, व्यभिचार की जड़ है, आदि। इसी मोह को नष्ट करने व क्षात्रधर्म याद कराने के लिए कृष्ण ने अर्जुन को युद्धभूमि में गीता सुनाई थी।

विशेष :

1. अर्जुन मोहवश अपने कर्तव्य-युद्ध को भूल गया।
2. शुद्ध साहित्यिक खड़ी बोली का प्रयोग है।
3. संस्कृत शब्दों की अधिकता है।
4. अशोक और अर्जुन की अहिंसा में अन्तर बताया है।
5. शैली में संक्षिप्तता तथा क्लिष्टता है।

(5) परन्तु सारी गीता में इस मुद्दे का कहीं भी जवाब नहीं दिया है, फिर भी अर्जुन का समाधान हुआ है। यह सब कहने का अर्थ इतना ही है कि अर्जुन में अहिंसा-वृत्ति नहीं थी, वह युद्ध प्रवृत्त ही था। युद्ध उसकी दृष्टि से उसका स्वभावप्राप्त और अपरिहार्य रूप से निश्चित कर्त्तव्य था। उसे वह मोह के वश होकर टालना चाहता था। और गीता का मुख्यत: इस मोह पर ही गदा प्रहार है।

सन्दर्भ :
पूर्ववत्।

प्रसंग :
निबन्ध की अन्तिम पंक्तियों में बताया गया है कि युद्ध न करना अर्जुन का दर्शन नहीं बुद्धिवाद था। अतः कृष्ण ने अर्जुन के बुद्धिवाद पर ध्यान न देकर अर्जुन के मोह को तोड़ा।

व्याख्या :
कृष्ण अर्जुन की परिवार में निहित आसक्ति को जानते थे, वह यह भी जानते थे कि अर्जुन अहिंसावादी नहीं है, उसका स्वभाव युद्ध है, लेकिन इन तथ्यों को गीता में नहीं बताया गया है। कृष्ण ने तो केवल अर्जुन के मोह को नष्ट किया है, उसके कर्त्तव्य की याद दिलाई है। कृष्ण ने ऐसा इसलिए किया क्योंकि वे जानते थे कि अर्जुन क्षत्रिय है, युद्ध करना उसका स्वभाव है और एक क्षत्रिय अहिंसा को कभी नहीं अपनाता। युद्ध एक क्षत्रिय का कभी न त्यागने वाला कर्त्तव्य होता है। अर्जुन सच्चे अर्थों में एक वीर योद्धा था। युद्ध के परिणामों को जानते हुए भी वह युद्ध को नहीं त्याग सकता था। लेकिन परिवार के मोह ने उसे युद्ध से विमुख कर दिया था। इसी मोह को श्रीकृष्ण ने गीता के सन्देश के द्वारा नष्ट कर दिया। अन्त में, अर्जुन ने कहा कि उसका भ्रम अर्थात् मोह नष्ट हो गया है और वह अपने धर्म के लिए तैयार है।

विशेष :

1. कृष्ण के द्वारा अर्जुन का मोह भंग हुआ है।
2. संस्कृत के शब्दों के प्रयोग के साथ भावों की सरलता है।
3. लघु वाक्यों ने विचारों को स्पष्ट किया है।
4. शुद्ध साहित्यिक खड़ी बोली।
5. ‘मुद्दे’ व ‘जवाब’ जैसे उर्दू के शब्दों का प्रयोग।

MP Board Class 12th Hindi Solutions

MP Board Class 12th Biology Important Questions Chapter 7 Evolution

Evolution Important Questions

Evolution Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
Atmosphere of earth just before the origin of life consisted of:
(a) Water vapour, CH₄, NH₃and O₂
(b) CO₂, NH₃and CH₄
(c) CH₄, NH₃, H₂ and water vapour
(d) CH₄ O₃, O₂ and water vapour.
Answer:
(a) Water vapour, CH₄, NH₃and O₂

Question 2.
Primitive atmosphere is made up of mixture of these gases :
(a) CH₄
(b) NH₃
(C) Water vapour
(d) None of these.
Answer:
(d) None of these.

Question 3.
What is the meaning of Abiogenesis :
(a) Life is originated from non – living things
(b) Life is originated from living things
(c) Origin of virus and microorganisms
(d) None of these.
Answer:
(a) Life is originated from non – living things

Question 4.
Primitive atmosphere of earth did not posses :
(a) CH₄
(b) NH₃
(C) H₂
(d) O₂
Answer:
(a) CH₄

Question 5.
Which of the following was formed in Miller’s experiment:
(a) Microspheres
(b) Nucleic acid
(c) Amino acid
(d) UV – radiation.
Answer:
(d) UV – radiation.

Question 6.
What is the unit of evolution :
(a) Community
(b) Genus
(c) Order
(d) Species.
Answer:
(a) Community

Question 7.
Whith of the following has not life :
(a) Azoic era
(b) Mesozoic era
(c) Paleozoic era
(d) Cenozoic era.
Answer:
(a) Azoic era

Question 8.
Which of the following are not an analogous organ :
(a) Wings of birds and butterfly
(b) Eye of octopus and mammals
(c) Thom of Baugainvilla and tendril of Cucurbita
(d) Tuberous roots of sweet potato and tuber of potato.
Answer:
(d) Tuberous roots of sweet potato and tuber of potato.

Question 9.
The earliest era is :
(a) Cenozoic
(b) Mesozoic
(c) Paleozoic
(d) Precambrian.
Answer:
(c) Paleozoic

Question 10.
Which of the following is analogous organ :
(a) Which has structural symmetry
(b) Which has functional and structural symmetry
(c) Similar in functional structure
(d) Mostly inactive.
Answer:
(c) Similar in functional structure

Question 11.
Who gave the exact proof of evolution :
(a) Fossils
(b) Vestigeal organ
(c) Embryo
(d) Morphology.
Answer:
(a) Fossils

Question 12.
Which era is called of mammals and angiosperm’s era :
(a) Mesozoic
(b) Cenozoic
(c) Paleozoic
(d) Archaeozoic.
Answer:
(b) Cenozoic

Question 13.
Whose dental structure is similar to human :
(a) Homo erectus erectus
(b) Homo erectus pekinensis
(c) Homo habillis
(d) Homo sapiens neanderthalensis.
Answer:
(c) Homo habillis

Question 14.
Which of these cells are immortal:
(a) Germ cells
(b) Liver cells
(c) Kidney cells
(d) Neurons.
Answer:
(a) Germ cells

Question 2.
Fill in the blanks:

1. Earth is a member of ……………….
2. The great explosion that resulted into the formation of universe is ……………….
3. ‘Philosophic Zoologique’ is written by ……………….
4. ………………. is a link between reptiles and birds.
5. ………………. is the ancient ancestor of modem horses.
6. At present marsupiales (kangaroos) are found only in ……………….
7. ………………. is the first photosynthetic organism that originate on the earth.
8. ………………. is the process by which changes in the genetic composition of organism.
9. ………………. constructed geological time scale.
10. ………………. is the first prehistoric human.
11. ………………. was among the first fossils to be recognized as belonging to Homo sapiens.
12. ………………. is found since the 19th century in the Siwalik Hills of the Indian sub – continent.
13. Discoveries related to the genetic code and its function in protein synthesis is given by ……………….
14. ………………. was the father of the Paleontology.
15. ………………. is the name of Darwin’s ship.

Answer:

1. Solar system
2. Big bang
3. Lamarck
4. Archaeopteryx
5. Eohippus
6. Australia
7. Cyanobacteria
8. Organic evolution
9. Geovani Abduna
10. Homo habilis
11. Cro – magnon
12. Ramapithecus
13. Dr. Hargovind khorana
14. Leonardo da Vinci
15. Beagle.

Question 3.
Match the followings :
I.

Answer:

1. (d)
2. (e)
3. (b)
4. (c)
5. (a)

II.

Answer:

1. (d)
2. (a)
3. (e)
4. (c)
5. (b)

Question 4.
Write the answer in one word/sentences:

1. The matter which is a link between acellular and cellular system.
2. The island at which Darwin studies the organisms for his theory of evolution.
3. When the earth is originate?
4. Which is known as the link between living and non – living?
5. Where are originate the first animal on the earth?
6. Name the scientist who disapproved Lamarkism.
7. The whole process of the development at changes from embryo to adult organism.
8. Other name of natural selection.
9. Who proposed the Mutaion Theory of Evolution?
10. The organs which are different in their origin but have similar function.
11. Who proposed the theory of inheritance of acquired characters?
12. Who proposed the theory of natural selection ?
13. The remains of ancient organisms.

Answer:

1. Coacervates
2. Galapagos
3. 4.6 million years ago
4. Virus
5. In water
6. Weismann
7. Ontogeny
8. Darwinism
9. Hugo de Vries
10. Homologous organ
11. Lamarck
12. Darwin
13. Fossils.

Evolution Very Short Answer Type Questions

Question 1.
Who proposed the theory of natural selection?
Answer:
Darwin.

Question 2.
Who proposed the Recapitulation theory or Biogenetic law?
Answer:
Haeckel.

Question 3.
Astronomical distance measured in?
Answer:
Astronomical distance measured in Light years.

Question 4.
Name the theory by which earth is said to originate.
Answer;
The big – bang theory.

Question 5.
What is fossil?
Answer:
Fossils are the remains or impressions of ancient organisms preserved in sedimentary rocks or other media.

Question 6.
What is mutation?
Answer:
New species originate due to changes of hereditary characters are called mutation.

Question 7.
Name the scientist who tell the spontaneous theory is wrong.
Answer:
Louis Pasteurs.

Question 8.
Which era is called golden period of Dinosaurs?
Answer:
Mesozoic period is billed golden period of Dinosaurs.

Question 9.
In which ship Darwin studied the nature?
Answer:
Beagle.

Question 10.
Name any two vertibrates body organ which are homologus organs of human forelimb.
Answer:

1. Flipper of whale
2. Wing of birds.

Question 11.
What is the scientific name of modern man?
Answer:
Homo sapiens.

Question 12.
Who is the early man of the modern human?
Answer:
Cro – Magnon peoples are early human of modem human.

Question 13.
Who are the early human and sub – human.
Answer:
Ramapithecus is early human and Australopithecus is early human.

Question 14.
Which human form first started to walk on two legs?
Answer:
Australopithecus form first started to walk on two legs.

Question 15.
Which type of human was ‘Cro – Magnon’ on the basis of food intake?
Answer:
Cro – Magnon was carnivorous.

Question 16.
On the basis of evolution which human had brain size of 1400cc?
Answer:
Neanderthal.

Question 17.
Give the name of ape-like ancestors of humans.
Answer:
Ape – like ancestors of human’s are Dryopithecus.

Question 18.
Differenciate between Dryopithecus and Ramapithecus.
Answer:
Dryopithecus were apelike but Ramapithecus were mostly human like.

Evolution Short Answer Type Questions

Question 1.
Explain antibiotic resistance observed in bacteria in light of Darwinism selection theory.
Answer:
Darwinism theory of natural selection states that environment selects organisms with favourable variations and these organisms thus, survive and reproduce. It is observed when bacterial populations are exposed to certain antibiotic, the sensitive bacteria could not tolerate and hence, died due to the adverse environment. Whereas some bacteria that devel¬oped mutation became resistant to the particular antibiotic and survived.

As a result such resistant bacteria survive and multiply quickly as compared to other sensitive bacteria. So, the whole population is regained by multiplication of resistant variety and antibiotic resistant gene becomes widespread in the bacterial population.

Question 2.
Find out from newspapers and popular science articles any new fossil dis – coveries or controversies about evolution.
Answer:
Fossils of dinosaurs have revealed the evolution of reptiles in Jurassic period. As a result of this evolution of other animals such as birds and mammals has also been discovered. However, two unusual fossils recently unearthed in China have ignited a controversy over the evolution of birds confuciusomis is one such genus of primitive birds that were crow sized and lived during the Cretaceous period in China.

Question 3.
Attempt giving a clear definition of the term species.
Answer:
A species generally includes similar organism. Members of this group can show interbreeding. Similar group of genes are found in the members of same species and this group has capacity to produce new species. Every species has some cause of isolation which intruped the interbreeding with nearest reactional species which is refer as reproduptively isolated.

Question 4.
What is virus? Why is it treated as a link between living and non – iiving ?
Answer:
Viruses are simplest organism,of the earth, which consist of nucleic acid (DNA or RNA) surrounded by protein cover. It shows characteristics of living as well as non – living organisms.

(A) Living characters of virus:

1. Virus shows structural differentiations.
2. They contain hereditary material.
3. They exhibit mutation.
4. They spread plant and animal diseases.
5. Growth and development present.
6. They exhibit adaptaion.
7. They possess sensitivity.

(B) Non – living characters of virus:

1. Lack protoplasm and cell organelles.
2. Can be crystallized.
3. No metabolic activities seen.
4. Cannot reproduce outside living cells.
5. They lack enzymes.
6. Due to above reason, viruses are considered as link between living and non-living organisms, thus, it is the first life
7. originated in the earth.

Question 5.
What is oxygen revolution? Explain.
Answer:
Oxygen revolution:
Evolution of O₂ in photosynthesis during primitive environmental conditions is very important because, it is required in the evolution of organism and conversion of reducing environment into oxidizing environment hence, it is called oxygen revolution. Oxygen evolution should cause the following changes in the environment:

1. Oxygen evolution should cause the conversion of reducing envronment into oxidizing environment.
2. Ozone layer is formed 15 miles above from the earth which absorbs the ultraviolet light of the sunlight and thus, prevents
3. the entry of uv light in the atmosphere.
4. O₂ present in the environment dissociates methane (CH₄) into CO₂ and O₂. This CO₂ is used in photosynthesis.
5. NH₃ of the primitive environment is dissociated into H₂O and nitrogen.
   CH₄ + 2O₂ → CO₂ + 2H₂O
   4NH₃ + 3O₂ → 2N₂ + 6H₂O.

Question 6.
Explain the origin of the earth.
Answer:
Origin of the earth:

1. Earth was formed 4 – 5 billion years back.
2. Initially, the surface was covered with water vapour, methane, CO₂ and NH₃.
3. The UV rays of the sun broke water into hydrogen and oxygen.
4. Hydrogen escaped and oxygen combined with NH₃ and CH₄ to form water, CO₂ and other gases, also forming the ozone layer.
5. Cooling of water vapour led to rain which filled the depressions on earth’s surface, forming water bodies.

Question 7.
Mention the names of discoveries and principles given by the following scientists:

1. Louis Pasteur
2. A. I. Oparin
3. Urey and Miller
4. Francesco Redi
5. Faux.

Answer:

1. Louis Pasteur – He proved that air contains spores of microorganism and Biogenesis theory was supported by him.
2. A. I. Oparin – He presented the biochemical explanation of origin of life in his book “The Origin of Life on Earth”.
3. Urey and Miller – They supported the evidence of Oparin – Haldane theory of Origin of life.
4. Francesco Redi – He by conducting experiments proved that abiogenesis cannot exist but bioginesis theory can exist i.e., Life arises from pre – existing life.
5. Faux – He has been experimentally supporting the organic substances as described by Oparin.

Question 8.
What are homologous organs?
Or
What is homology?
Answer:
Organs which are similar in structure and origin but different in appearance and functions are called homologous organs and the phenomenon is called homology.

Examples:
Forelimbs of bat, wings of bat, hands of man, forelimbs of horse. These are the examples of homologous organs because, they are made up of similar bones, humerus, radius – ulna, carpals, metacarpals and fingers.

Question 9.
What do you mean by analogous?
Answer:
Analogous organs:
Organs which are different in origin and structure but performing similar functions are known as analogous organs and the phenomenon is called as analogy. Analogous organs do not indicate phylogeny.

Examples:
Wings of butterflies are made up of chitin, wings of birds made by produc¬tion of feathers on forelimbs and skin present between the fingers of bat are the examples of analogous orgAnswer:

Question 10.
What is the difference between homologous and analogous organs ? Give two examples of each of them.
Answer:
Differences between Homologous and Analogous organs :

Homologous organ:

• Organs which are similar in structure and origin but different in function are known as homologous organs.
• These structures indicate that organisms bearing them are evolutionary related.
• These organs are differ in outlook.
• They exhibit similarity in internal structure.
  Example: Forelimbs of frog, hand of human, wings of bat and forelimb of horse.

Analogous organ:

• Organs which are differing in structure and origin but similar in function are known as analogous organs.
• These structures indicate that organisms bearing them are evolutionary different.
• These organs are similar in outlook.
• They do not exhibit similarity in internal structure.
  Example: Wings of butterflies, bats and birds.

Question 11.
What do you mean by vestigial organs?
Or
Write the two names of vestigial organs of man.
Or
What are vestigial organs? Explain. Write four vestigial organs of the human body.
Answer:
Vestigial organs:
Organs that are reduced and have become functionless in an organism but were functional in their ancestors are called as vestigial organs.
Examples:

1. Vermiform appendix.
2. Coccygial vertebrae.
3. Nictitating membrane in the eyes of human.
4. Muscles of external ear (Pinna).

Question 12.
Write down the demerits of Darwinism.
Answer:
Some of the demerits of Darwinism are:

1. Darwinism stresses upon small fluctuating variations which has no role in evolution.
2. Does not satisfactorily explain effect of use and disused and presence of vestigial organs.
3. It did not differentiate somatic and germinal variations.
4. It explains survival of the fittest but not arrival of the fittest.

Question 13.
Differentiate between lamarckism and darwinism.
Answer:
Differences between Lamarckism and Darwinism:

Lamarckism:

• It is based on the theory of inheritance of acquired characters.
• According to this theory the length of neck of Giraffe increased only to facilitate it in eating leaves of higher trees.
• Increase in length of neck of Giraffe resulted in evolution of Giraffe with long necks.
• The theory is based on the use or misuse of the organs.

Darwinism:

• It is based on the theory of natural selection.
• Ancestors of Giraffe were both with long and short necks.
• Giraffe with long neck only could survive in struggle for existence.
• This theory is based on the inheritance of the characters in next generation.

Question 14.
Explain Lamarckism in short.
Or
Explain Lamarckism of organic evolution in brief.
Answer:
Lamarckism:
In 1809, Lamarck has proposed a theory to explain organic evolution, which is known, as the “Theory of inheritance of acquired characters.” According to Lamarck, organisms acquire certain characters during their lifetime due to changes in environment and these acquired characters are heritable. According to this theory, new species are originated as follows:

1. New requirements and wills are produced in the organisms due to the effect of changed environment.
2. New requirements and wills of organisms resulting in the production of new habits.
3. Changes in the habit bringing about modifications of the organ.
4. New habits resulting in the use or disuse of the organs.
5. Use of organ resulting in the development of acquired characters.
6. These acquired characters are heritable.
7. Inheritance of acquired characters resulting in the development of new species.

Question 15.
Write two incidences which influenced Darwin to set out theory of evolution.
Answer:
Two incidences which influenced Darwin are:

1. During the voyage of Beagle Darwin noticed distribution of a kind of bird called as finches and other organisms by looking at his observation of Galapagos island. He found variation in the beaks of finches adapted according to the environment.

2. Pegion keepers kills weak varieties of pegion generation after generation to obtain better variety of pegion.

3. Above two incidences influenced Darwin to set out theory of evolution (Natural selection).

Evolution Long Answer Type Questions

Question 1.
Draw a well – labelled diagram of Miller and Urey’s experiment.
Answer:

Experimental evidence of Chemical evolution or Miller’s experiment:

1. Experiment was performed by S.L. Miller and H.C. Urey in 1953.

2. Experimental set – up:
In a closed flask containing CH₄, H₂, NH₃and water vapour at 800°C, electric discharge was created. The conditions were similar to those in primitive atmosphere.

3. Observations:
After a week, they observed presence of amino acids and complex molecules like sugars, nitrogen bases, pigments and fats in the flask.

4. Conclusions:

• It provides experimental evidence for the theory of chemical origin.
• It showed that the first non-cellular form of life was created about 3 billion years ago.
• It showed that non-cellular biomolecules exist in the form of DNA, RNA, polysaccharides and protein.

Question 2.
Write an essay on modern concepts of origin of life.
Or
Explain the role of non – living in origin of life.
Answer:
Modern concept of origin of life:
The modem concept of origin of life was postulated by a Russian biochemist A.I. Oparin in 1936. According to this theory, after the formation of earth various chemicals played important role in the formation of atmosphere. Life originated and first organism came into existence from certain molecules when atmospheric conditions became suitable. According to Oparin, life originated in the following steps:

1. Formation of earth and its atmosphere:
Earth is believed to be originated some 4,500 million years ago by the condensation and cooling of the clouds of cosmic dust and gases called ylem. The heavier elements collected at the core and lighter elements around the core. Outermost layer contains H, C, O and N. Oxygen was found only in combination of other elements. These four elements reacted with each other forming H₂, H₂O, CH₄, NH₃, CO₂ and HCN.

2. Formation of small organic molecules:
The mixture of methane, ammonia, water and hydrogen comes in contact of solar energy. Cosmic rays and electric discharge could produce some simple organic compounds. These simple organic compounds formed in such a way and accumulated in primitive atmosphere and oceans were responsible for synthesis of complex micro-molecules as follows :

1. CH₄, H₂O → Sugars
→ Fatty acids
→ Glycerine

2. CH₄, H₂O, NH₃ → Amino acids

3. CH₄, HCN, H₂O, NH₃ → Nitrogenous bases (Purines and Pyrimidines)

3. Formation of polymers:
It is clearly understood from the above description that a large number of micro molecules such as hydrocarbons, amino acids, fatty acids, purine and pyrimidines and simple sugars accumulated in the oceans. When atmospheric water condensed on further cooling, the inorganic precursors collided, reacted and aggregated to form new molecules of increasing size and complexity. Thus, by polymerization macromolecules were formed. The chemical reactions for the formation of macro – molecules can be summarized as follows:

• Sugar + Sugar → Polysaccharides
• Fatty acid + Glycerine → Lipids
• Amino acid + Amino acid → Protein
• Nitrogenous base (Adenine) + Sugar + Phosphate → Adenosine phosphate
• Nitrogenous base + Sugar → Nucleoside
• Nucleoside + Phosphate → Nucleotide
• Nucleotide + Nucleotide → Nucleic acid.

4. Formation of molecular aggregates and primitive cells:
Over a vast of time, these molecules became associated with one temporary complex. Ultimately, it leads to the formation of a coacervate. A coacervate is a solution of high molecular weight of chemicals, i.e., proteins and carbohydrates, which become bounded by lipid membrane, which is selectively permeable.

The coacervate grows by absorbing molecules from their environment. The substances which got accumulated in the coacervates underwent reactions and resulted in the molecular reorganization of some proteins into enzymes. A coacervate having nucleoprotein surrounded by various nutritive organic substances and covered by surface membrane is considered to be the precell, which got later transformed into first living cell. The coacervate can reproduce by budding.

5. Evolution of complex biochemical reactions:
Primitive organism utilize chemical substances present in the environment as food hence, they are :

(a) Heterotrophic, chemosynthetic organisms appeared due to mutation and natural selection in heterotrophs.

(b) Blue – green algae evolved from chemosynthetic organisms by mutation and natural selection.

(c) The liberation of free oxygen into the atmosphere produced by the blue – green algae due to the process of photosynthesis. It finally changed the reducing atmosphere into an oxidizing one and therefore, all possibilities of further chemical evolution were finished.

Free living eukaryotes originated in the ocean from blue – green algae.

6. The origin of well – developed organisms:
From the simple eukaryotes which were like unicellular organisms of today various forms of life evolved during passage of time.

Question 3.
Write the process of formation of organic molecules in sea water on earth with the help of Miller and Urey’s experiment.
Answer:
The work of A.I. Oparin (1938 – 1965), H.Urey and Stanley Miller (1959) provided evidences in the favour of biochemical origin of life. They had prepared the atmosphere like that of primitive earth and as described by Oparin, they made the synthesis of organic compounds by the following methods:

1. Four elements H, C, O (not free O₂) and N react with each other to form H₂O, CH₄, NH₃, CO₂ and HCN on primitive earth.

2. From these four elements following organic molecules were formed in sea water of earth:
(i)

(ii) CH₄, H₂O, NH₃ → Amino acids.

(iii) CH₄, HCN, H₂O, NH₃ → Nitrogenous bases.

3. Macro – molecules of organic compounds were synthesized by these above prepared organic compounds.

• Sugar + Sugar → Polysaccharides (Carbohydrate).
• Fatty acids + Glycerol → Fats.
• Amino acid + Amino acid → Protein.
• Nitrogenous base + Sugar → Nucleoside.
• Nucleoside + Phosphoric acid → Nucleotide.
• Nucleotide + Nucleotide → Nucleic acid.
• Nitrogenous base (Adenine) + Sugar + Phosphate → Adenosine phosphate.

4. The above organic compounds and salts together constituted the first living being.

Question 4.
Name connecting link of reptiles and birds. Also write their characters.
Answer:
Archaeopteryx is the connecting link of birds and reptiles. Archaeopteryx was a bird. It is regarded as the connecting link between reptiles and birds, which suggests the path of evolution of the latter from the former. It is found as fossils. They are found during Jurassic period 140 million years. Archaeopteryx exhibits both reptiles and birds like characters.

1. Reptiles like characters:

• Bones were similar to that of reptiles in which air sacs were absent.
• Tail bearing vertebra.
• It had teeth in jaws, scales were present on the body.
• Metacarpals were free.
• Pelvic girdle recombines with the pelvic girdle of reptiles.

2. Birds like characters:

• Presence of feathers on body.
• Forelimbs were modified in wings.
• Skull large and monocondylar.
• Jaws were modified into beak.
• Hallux was backwarded and pointed.

Question 5.
Give a detailed account of theory of natural selection.
Or
Describe the Darwin’s opinion about the origin of new species of organisms.
Answer:
Charles Darwin (1809 – 1882) explained the theory of evolution in his book “Origin of species by natural selection.” Darwin undertook a long voyage for five years in the capacity of a naturalist on a British warship ‘Beagle’. He travelled to islands of Galapagos and collected evidences to explain evolution.

To explain origin of species he gave theory of natural selection as a mechanism for evolution.

The main points of Darwinism are given below:

1. Over production of offsprings:
Every living being has an inherent tendency to produce more offspring than that can survive.

2. Struggle for existence:
Though the offsprings are produced in large number yet their production remain almost constant. This is because of struggle for existence. There is struggle for food, space, breeding, etc. Moreover death of individuals due to diseases and predators, population are kept under control.

3. Survival of the fittest:
Darwin believed that any individual is successful in struggle for existence if it survives long enough to produces offsprings. Individuals who are fit in a particular environment can only survive.

4. Variation:
Due to constant struggle, the organisms change themselves in accordance with the new needs.

5. Natural selection:
In the struggle, for existence organisms having variations favourable to the environment would have more chance to survive and reproduce their own kind. Those which do not possess favourable variations would die or fail to reproduce.

6. Origin of species:
Any changes in environmental conditions cause natural selection to act upon the population and select the well adapted individuals. It results in changes of characters of the populations. By the inheritance of these changes in successive generations, new species are formed.

Question 6.
Organic Evolution is a continuous process, explain it. And giving any three evidences.
Answer:
Evolution is a complex phenomenon accounting for the present day diversity among organisms. But it has clearly maintained the basic unity among them since it occurred over a period of millions of years, no one would have seen/recorded evolution and hence scientists have provided various evidences to prove evolution. Some of the evidences of organic evolution are described below:

I. Evidences from Embryology:
Important activities that occur various animals are:

1. For the survival, all animals get energy and various substances from environment.
2. In all organisms energy is produced from ATP.
3. In all organisms, the duplication of DNA is similar.
4. In all organisms, protein synthesis is same and it is produced from ribosomes.
5. In all organisms respiration and steps of respiration is same.
6. All organisms multiplicate and reproduce, due to which they have basic similarities.
7. All organisms conduct hereditary characters on similar principles.

II. Evidence from Anatomy:
Anatomy of living organisms will be explained with different examples:

1. Homologous organs : Organs which are similar in structure and origin but different in function and appearance is known as homologous organs.

2. Analogous organs : Organs which are different in origin and structure but performing similar functions are known as analogous organs.

3. Vestigial organs : Organs that are reduced and have become functionless in an organism, but were functional in their ancestors are called vestigial organ.

III. Evidences from vestigial organs:
Organs of the body which are non – functional but they are functional in some other organisms are called vestigial organs: Morphological evidence of evolution is provided by the presence of vestigial organs of body which are often undesired, degenerated and non-functional. These might have been large and functional in some other animals or in ancestors of those which now possess it in rudimentary forms, example vermiform appendix in man, muscles of external ear (pinna) in man, nictitating membrane or plica, semilunaris in human eye, wisdom teeth (third pair of molars) tail bone (coccyx) in man, wings of ostrich, hindlimbs in snakes, etc.

Question 7.
What do you mean by organic evolution? How do fossils exhibit evidence to prove organic evolution?
Answer:
Descent with modification in organism is known as organic evolution.

Evidences of organic evolution from fossils record:
Fossils are treated as significant evidence of organic evolution. Fossils are the remains or impressions of ancient organisms preserved in the layers of rock and soil. Fossils only do not prove the theory of organic evolution, yet it evidently prove that gradually complexity increased in body organization. The complexity in the body of organization can be noticed as we study the upper layers. Thus, it can be concluded from above observations :

1. The crust of the earth and the organisms living on it underwent change in the course of time.
2. The organisms with simple structural organization originated earlier than the complex ones.
3. Some of the organisms lived on the earth for short time and became extinct. This was a result of drastic changes in the climate on the earth.

Hence, forth fossils produce bonafide record of such plants and animals which had shown their existence once upon a time and now are extinct or not present exactly in the same form, thus, producing strong evidence in favour of organic evolution.

Question 8.
Try to trace the various components of human evolution (Hint: Brain size and function, skeletal structure, dietary preference, etc.)
Answer:
The various components of human evolution are as follows:

1. Brain capacity.
2. Posture.
3. Food/Dietary preference and other important features.

Name, brain capacity, posture and food features:

1. Dryopithecus Africans:
Knuckle walker, walked similar to Gorillas and Chimpanzees (was more apelike), soft fruit and leaves; canines large, arm and legs are of equal size.

2. Ramapithecus:
Semi – erect (more manlike) ate seeds and nuts, canines were small while molars were large.

3. Australopithecus africanus:
Brain capacity 450 cm³, full erect prosture, height 1.05m, herbivorous (ate fruits), hunted with stone weapons, lived as trees, canines and incisors were small.

4. Homo habilus:
Brain capacity 735 cm³, fully erect posture, height, 1.5m, carnivorous, canines were small. They were first tool makers.

5. Homo erectus:
Brain capacity 800 – 1100 cm³, fully erect posture, height 1.5 – 1.8m, omnivorous. They used stone and bone tools for hunting games.

6. Homo neanderthalensis :
Brain capacity 1300 – 1600 cm³, fully erect posture, height 1.5 – 1.6m, omnivorous cave dwellers, used hiles to protect their bodies and buried their dead.

7. Homo sapiens fossils:
Brain capacity 1650 cm3, fully erect posture with height 1.8m, omnivorous. They had strong jaw with teeth close together. They were cave dwellers, made painting and carvings in the caves. They developed a culture and were called first modern man.

8. Homo sapiens sapiens:
Brain capacity 1200 – 1600 cm³, fully erect posture, height 1.5 – 1.8m, omnivorous. They are the living modem men with high intelligence. They developed art, culture, language, speech, etc. They cultivated crops and domesticated animals.

Question 9.
Find out through internet and popular science articles whether animals other than man has self – consciousness.
Answer:
There are many animals other than humans, which have self – consciousness. An example of an animal being self-conscious is dolphins. They are highly intelligent. They have a sense of self and, they also recognize others among themselves and others. They communicate with each other by whistles, tail – slapping, and other body movements. Not dolphins, there are certain other animals such as Crow, Parrot, Chimpanzee, Gorilla, Orangutan, etc., which exhibit self – consciousness.

Question 10.
List 10 modern day animals and using the internet resources link it to a corresponding ancient fossil. Name both.
Answer:
Modern and Ancient corresponding animals:

Question 11.
Practise drawing various animals and plants.
Answer:

Question 12.
Using various resources such as your school Library or the internet and discussions with your teacher, trace the evolutionary stages of any one animal, say horse.
Answer:
The evolution of horse started with Eohippus during Eocene period. It involved the following evolutionary stages:

1. Gradual increase in body size.
2. Elongation of head and neck region.
3. Increase in the length of limbs and feet.
4. Gradual reduction of lateral digits.
5. Enlargement of third functional toe.
6. Strengthening of the back.
7. Development of brain and sensory organs.
8. Increase in the complexity of teeth for feeding on grass.

1. Eohippus:
It had a short head and neck. It had four functional toes and a splint of 1 and 5 on each hind limb and a splint of 1 and 3 in each forelimb. The molars were short crowned that were adapted for grinding the plant diet.

2. Mesohippus:
It was slightly taller than Eohippus. It had three toes in each foot.

3. Merychippus:
It had the size of approximately 100 cm. Although it still had three toes in each foot, but it could run on one toe. The side toe did not touch the ground. The molars were adapted for chewing the grass.

4. Pliohippus:
It resembled the modern horse and was around 108 cm tall. It had a single functional toe with splint of 2nd and 4th in each limb.

Equus:
Pliohippus gave rise to Equus or the modern horse with one toe in each foot. They have incisors for cutting grass and molars for grinding food.

Question 13.
How far inter relationship among? The living organisms is helpful to understand the process of evolution?
Answer:
Organisms which are externally different shows some similarities. This is known as interrelationship. It proves that they might have evolved from the same ancestor. Inter relationship among the living organisms can be understood by following example:

1. All living organisms obtain energy and various materials from the environment.
2. All living organisms multiply and reproduce.
3. All living organisms show transmission of genetic information according to same principle.
4. All living organisms synthesize protein in the ribosome and steps of protein synthesis are same in all living organisms.
5. All organisms respire and steps of respiration in them are same.
6. In all organism method of DNA replication are same.
7. In all living organisms flow of information occurs by the help of nucleic acids present in the nucleus.
8. In all living organisms energy is obtained from ATP.

MP Board Class 12th Biology Important Questions