Category: Class 12

MP Board Class 12th Special Hindi सहायक वाचन Solutions Chapter 7 भारतीय गायिकाओं में बेजोड़ लता मंगेशकर (लेख, कुमार गंधर्व)

भारतीय गायिकाओं में बेजोड़ लता मंगेशकर अभ्यास प्रश्न

प्रश्न 1.
लता के गायन की विशेषताएँ लिखिए। (2016)
अथवा
भारतीय गायिकाओं में बेजोड़ लता मंगेशकर के गायन की विशेषताएँ लिखिए तथा बताइए कि लताजी की लोकप्रियता का मुख्य मर्म क्या है? (2009)
उत्तर:
लेखक का स्पष्ट मत है कि लता के जोड़ की गायिका हुई ही नहीं है। लता के कारण चित्रपट संगीत को और मनोरंजन की दुनिया को विलक्षण लोकप्रियता प्राप्त हुई है, यही नहीं लोगों का शास्त्रीय संगीत की ओर देखने का दृष्टिकोण भी बदला है। लता के गाने की मुख्य विशेषताएँ उसका ‘गानपन’ है। लता के गाने की एक और विशेषता है, उसके स्वरों की निर्मलता। लता के स्वरों में कोमलता और मुग्धता है। ऐसा अनुभव होता है कि लता का जीवन की ओर देखने का जो दृष्टिकोण है वही उसके गायन की निर्मलता में झलक रहा है। लता के गाने की एक और महत्त्वपूर्ण विशेषता है उसका ‘नादमय उच्चार’। उसके गीत के किन्हीं दो शब्दों का अन्तर स्वरों के आलाप द्वारा बड़ी सुन्दर रीति से भरा रहता है और ऐसा प्रतीत होता है कि वे दोनों शब्द विलीन होते-होते एक-दूसरे में मिल जाते हैं। यद्यपि गाने में यह बात पैदा करना बहुत कठिन है, परन्तु लता के साथ यह अत्यन्त सहज और स्वाभाविक ही बैठी है। वास्तव में,चित्रपट संगीत के क्षेत्र की लता साम्राज्ञी हैं।

प्रश्न 2.
“लता ने करुण रस के साथ उतना न्याय नहीं किया है। बजाए इसके, मुग्ध श्रृंगार की अभिव्यक्ति करने वाले गाने लता ने बड़ी उत्कटता से गाए हैं।” इस कथन से आप कहाँ तक सहमत हैं?
उत्तर:
लता द्वारा चित्रपट :
संगीत के क्षेत्र में गाये गये गीतों पर यदि दृष्टि डाली जाये तो एक पल को यह कथन उचित ही प्रतीत होता है कि “लता ने करुण रस के साथ उतना न्याय नहीं किया है। बजाए इसके, मुग्ध श्रृंगार की अभिव्यक्ति करने वाले गाने लता ने बड़ी उत्कटता से गाए हैं”,किन्तु हमें यह नहीं भूलना चाहिए कि चित्रपट-संगीत की दुनिया में यह अधिकार गायक अथवा गायिका के पास नहीं होता कि उसे किस प्रकार के गाने गाने को मिलें, अपितु संगीत दिग्दर्शक अपनी पसन्द से गायक-गायिकाओं को गाने गाने के लिए चुनकर देते हैं। अतः, इसे लता की व्यावसायिक मजबूरी अथवा सीमा से उत्पन्न स्थिति ही कहा जाये तो बेहतर होगा कि स्वर कोकिला को करुण रस को व्यक्त करने वाले गाने उतनी संख्या में नहीं मिल सके कि वह इस रस में भी अपने कौशल का प्रभावशाली प्रदर्शन कर पातीं, तथापि उन्हें जब-जब भी अवसर मिला उन्होंने करुण रस के साथ भी पूरा न्याय किया है।

उपर्युक्त चर्चा से स्पष्ट है कि गायकी के क्षेत्र में लता की विविधताएँ असीमित हैं और उनके कौशल का लोहा संगीत प्रेमी भली प्रकार मानते हैं। यह मात्र संयोग ही है कि जिन भी संगीत दिग्दर्शकों के साथ उन्होंने कार्य किया है,वे लता को करुण रस की अभिव्यक्ति वाले गाने पर्याप्त मात्रा में गाने को नहीं दे सके।

प्रश्न 3.
शास्त्रीय संगीत और चित्रपट संगीत में अन्तर बतलाइए। (2012)
उत्तर:
लेखक के अनुसार शास्त्रीय संगीत और चित्रपट संगीत के मध्य किसी भी प्रकार की तुलना करना बेमानी है। उसका कारण यह है कि शास्त्रीय संगीत और चित्रपट संगीत में तुलना हो ही नहीं सकती। जहाँ गंभीरता शास्त्रीय संगीत का स्थायी भाव है वहीं द्रुत लय और चपलता चित्रपट संगीत का मुख्य गुणधर्म है। चित्रपट संगीत का ताल प्राथमिक अवस्था का ताल होता है, जबकि शास्त्रीय संगीत में ताल अपने परिष्कृत रूप में पाया जाता है। चित्रपट संगीत में आधे तालों का उपयोग किया जाता है। उसकी लयकारी बिल्कुल भिन्न होती है, आसान होती है। यहाँ गीत और आघात को अधिक महत्त्व दिया जाता है तथा सुलभता और लोच को अग्र स्थान पर रखा जाता है। चित्रपट संगीत द्वारा लोगों की अभिजात्य संगीत से जान-पहचान होती है। वास्तव में,चित्रपट संगीत का तंत्र ही अलग है। यहाँ नवनिर्मित की बहुत गुंजाइश है।

प्रश्न 4.
“चित्रपट संगीत ने लोगों के कान बिगाड़ दिए हैं।” आप इस कथन से कहाँ तक सहमत हैं?
उत्तर:
यदि यह बात कही जाये तो कोई अतिशयोक्ति न होगी कि 70-80वें दशक तक का चित्रपट संगीत, शास्त्रीय संगीत की दृष्टि से भी उच्च कोटि का था, किन्तु उसके बाद के चित्रपट संगीत में हास का दौर प्रारम्भ हुआ जो आज तक जारी है। बीच-बीच में कुछेक फिल्मों के संगीत में अवश्य ही पुराने दौर के गीत-संगीत की झलक दिखाई पड़ी,किन्तु कमोबेश स्थिति बद-से-बदतर होती चली गयी। नये दौर के चित्रपट संगीत में न तो पहले जैसी कर्णप्रिय धुनें थीं और न ही संगीत दिग्दर्शकों की व्यक्तिगत सोच ही परिलक्षित होती थी। नित्य नये विकसित वाद्ययंत्रों उच्चकोटि की लाजवाब प्रौद्योगिकी के बाद भी आज के दौर का चित्रपट संगीत अपनी गहरी और लम्बी छाप नहीं छोड़ सका है।

वर्तमान में,चित्रपट संगीत का आलम यह है कि कोई गाना आज बनता, कल सुना जाता है और परसों तक लोग उसे भूल जाते हैं। इस दौर का संगीत कानफाडू वाद्य यन्त्रों की सहायता से श्रोता के शरीर को तो हो सकता उत्तेजित कर सका हो,किन्तु किसी भी अर्थों में वह सुनने वालों के मन-मस्तिष्क में नहीं उतर सका है। इस स्थिति का एक बड़ा दुष्परिणाम यह भी हुआ है कि आजकल का श्रोता इस कानफाड़ चित्रपट संगीत को सुन-सुनकर अच्छे संगीत की समझ खो चुका है।

उपर्युक्त चर्चा से स्पष्ट है कि चित्रपट संगीत ने लोगों के कान बिगाड़ दिए हैं और उन्हें शास्त्रीय संगीत नीरस और उबाऊ प्रतीत होने लगा है।

प्रश्न 5.
संगीत के क्षेत्र को विस्तीर्ण क्यों कहा गया है?
उत्तर:
लेखक ने संगीत के क्षेत्र को विस्तीर्ण कहा है, क्योंकि उसके अनुसार संगीत के क्षेत्र में अब तक अलक्षित, असंशोधित और अदृष्टिपूर्ण ऐसा बहुत बड़ा प्रान्त है जिसकी खोज अथवा जिस पर कार्य होना अभी बाकी है। वास्तव में,संगीत एक ऐसी विधा है, जिसमें असीम सम्भावनाएँ हैं, करने के लिए काफी कुछ है। प्रयोगधर्मियों के लिए संगीत जैसा विस्तीर्ण क्षेत्र कोई दूसरा नहीं है। संगीत के क्षेत्र में होने वाले नित नए प्रयोग और कार्य इसे और भी सम्भावनाओं वाला क्षेत्र बनाते हैं।

प्रश्न 6.
स्वर साम्राज्ञी लता मंगेशकर’ पर एक लघु निबन्ध लिखिए।
उत्तर:
वैसे तो भारतीय भूमि पर एक से बढ़कर एक कलाकारों,साहित्यकारों, वैज्ञानिकों और राजनेताओं ने जन्म लिया है, परन्तु इनमें से कुछेक ऐसे भी होते हैं, जो अपने कौशल के कारण जीवित किवदन्ती बन जाते हैं। ऐसी ही एक जीवित किवदन्ती हैं-स्वर साम्राज्ञी, स्वर कोकिला-लता मंगेशकर।

सुप्रसिद्ध गायक दीनानाथ मंगेशकर की सुपुत्री लताजी को यदि भारतीय चित्रपट संगीत का पर्याय कहा जाये तो कोई अतिशयोक्ति न होगी। उन्होंने अपने कोकिल कण्ठ के मीठे व कोमल स्वरों से आम जनमानस को आनन्दित करने का जो भागीरथ कार्य किया है उसकी जितनी भी प्रशंसा की जाये कम ही होगी।

यूँ तो लताजी के चित्रपट संगीत की दुनिया में कदम रखने से पूर्व और पश्चात् सैकड़ों गायिकाओं ने अपनी-अपनी आवाजों का जादू बिखेरा, किन्तु लताजी के गाये गीतों का नशा हर भारतीय के सिर चढ़कर बोला। सच कहा जाये तो भारतीय गायिकाओं में लता जी के जोड़ की दूसरी कोई गायिका हुई ही नहीं। लताजी के कारण चित्रपट संगीत और मनोरंजन की दुनिया को विलक्षण लोकप्रियता प्राप्त हुई है, यही नहीं लोगों का शास्त्रीय संगीत की ओर देखने का दृष्टिकोण भी पूरी तरह बदला है। उनकी अभिप्रेरणा से देश के कोने-कोने यहाँ तक कि विदेशों में भी बच्चे-बड़े स्वर में गाने गुनगुनाते रहे हैं। सुरों से सजे गाने सुनकर लताजी के श्रोता उनका अनुकरण करने का प्रयास करते रहे हैं।

लता मंगेशकर की लोकप्रियता का मुख्य मर्म उनके गायन में मौजूद ‘गानपन’ है। लताजी के स्वरों में कोमलता और मुग्धता है। उनके गले की हरकतें’ सामान्य से गाने को भी असाधारण रूप में परिवर्तित करने में सक्षम हैं। शास्त्रीय संगीत का गहरा ज्ञान लताजी को अपना सर्वश्रेष्ठ देने के योग्य बनाता है। उनके गाने की एक और विशेषता है, उनके स्वरों की निर्मलता। उनके गायन में एक अजब-सी मिठास है, जो श्रोता को बाँधे रखती है। लताजी की एक बड़ी विशेषता और है और वह है उनका ‘नादमय उच्चार’।

चित्रपट संगीत के क्षेत्र की लताजी निर्विवाद साम्राज्ञी हैं। उनकी लोकप्रियता के शिखर का स्थान अचल है। नयी पीढ़ी के संगीत को संस्कारित करने और सामान्य मनुष्य में संगीत विषयक अभिरुचि पैदा करने में उनका उल्लेखनीय योगदान रहा है। संगीत की लोकप्रियता, उसके प्रसार और अभिरुचि के विकास का श्रेय लताजी को जाता है। हम सभी वास्तव में बहुत सौभाग्यशाली हैं कि हम इस कालजयी कलाकार को देख-सुन पा रहे हैं।

प्रश्न 7.
पाठ में विभिन्न प्रदेशों के विविध लोकगीतों की चर्चा की गई है। आप भी अपनी क्षेत्रीय बोली का कोई लोकगीत लिखिए तथा उसका मातृभाषा में अनुवाद कीजिए।
उत्तर:
विद्यार्थी स्वयं लिखें।

भारतीय गायिकाओं में बेजोड़ लता मंगेशकर अति लघु उत्तरीय प्रश्न

प्रश्न 1.
लता मंगेशकर के पिताजी का नाम क्या था? वह क्या थे?
उत्तर:
लता मंगेशकर के पिताजी का नाम दीनानाथ मंगेशकर था। वह अपने जमाने के सुप्रसिद्ध गायक थे।

प्रश्न 2.
शास्त्रीय गायकी से आप क्या समझते हैं?
उत्तर:
शास्त्रीय गायकी गायन की एक ऐसी विधा है जिसमें गायन को कुछ निर्धारित नियमों के अन्दर ही गाया बजाया जाता है। ख्याल, ध्रुपद, धमार आदि शास्त्रीय गायकी के अन्तर्गत ही आते हैं।

भारतीय गायिकाओं में बेजोड़ लता मंगेशकर पाठ का सारांश

‘कुमार गंधर्व’ द्वारा लिखित प्रस्तुत लेख, भारतीय गायिकाओं में बेजोड़ लता मंगेशकर’ में स्वर साम्राज्ञी, लता मंगेशकर’ की प्रशंसा बहुत ही सुन्दर एवं विश्लेषणात्मक ढंग से की गई है।

लेखक के अनुसार भारत-भूमि पर अब तक सैकड़ों प्रतिभाशाली एवं सुरीले कण्ठ वाली गायिकाएँ पैदा हुई हैं, जिन्होंने अपने गायन से जन-जन को आनन्दित एवं प्रभावित किया है, किन्तु इन सब में से लता मंगेशकर का स्थान निर्विवादित रूप से सर्वोच्च है। लताजी का गायन व्यक्ति के तन से होता हुआ मन तक पहुँचता है और अन्तस को एक पारलौकिक अनुभूति प्रदान करता है। सुप्रसिद्ध गायक दीनानाथ मंगेशकर की सुपुत्री लता मंगेशकर की आवाज जितनी कोमल है, उतनी ही उसमें मिठास भी है। लताजी का गायन सुप्रसिद्ध चित्रपट-गायिका नूरजहाँ से भी कहीं बेहतर और मर्म को छू लेने वाला है।

लेखक के अनुसार लताजी के कारण चित्रपट संगीत और मनोरंजन की दुनिया को विलक्षण लोकप्रियता प्राप्त हुई है, साथ ही, लोगों का शास्त्रीय संगीत की ओर देखने का दृष्टिकोण भी एकदम बदला है। ये लताजी के कण्ठ का ही जादू है जो साधारण प्रकार के लोगों को भी संगीत के सुर-ताल और लय की सक्ष्मता समझ में आने लगी है। वास्तव में संगीत की लोकप्रियता, उसके प्रसार और अभिरुचि के विकास का श्रेय लताजी को ही देना पड़ेगा।

लताजी की लोकप्रियता का मुख्य मर्म उनका ‘गानपन’ है। उनके गाने की एक और विशेषता है, उसके स्वरों की निर्मलता। लताजी के स्वरों में कोमलता और मुग्धता है। साथ ही, लताजी के गाने में ‘नादमय उच्चार’ का भी अपना महत्त्व है।

लेखक के अनुसार शास्त्रीय संगीत और चित्रपट संगीत की तुलना बेमानी है। जहाँ गंभीरता शास्त्रीय संगीत का स्थायी भाव है वहीं द्रुतलय और चपलता चित्रपट संगीत का मुख्य गुणधर्म है। यह ठीक है कि चित्रपट संगीत से जुड़े व्यक्ति के लिए शास्त्रीय संगीत का ज्ञान होना परमावश्यक है और वह ज्ञान लताजी के पास नि:संशय भरपूर है। लताजी चित्रपट संगीत के क्षेत्र की सर्वमान्य साम्राज्ञी हैं। उनकी लोकप्रियता दुनिया के कोने-कोने में है। लताजी जैसा कलाकार शताब्दियों में एकाध ही पैदा होता है। यह हमारा सौभाग्य है कि हम शताब्दियों के इस कलाकार को यूँ जीता-जागता, घूमता-फिरता देख पा रहे हैं।

MP Board Class 12th Hindi Solutions

MP Board Class 12th Economics Important Questions Unit 2 Consumer Behavior and Demand

Micro Economics Consumer Behaviour and Demand Important Questions

Micro Economics Consumer Behavior and Demand Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
Consumer is in equilibrium when:
(a) MU_x = PU_x
(b) MU_x> PU_x
(c) MU_x < P_x
(d) MU_x ÷ P_x
Answer:
(a) MU_x = PU_x

Question 2.
Marshall has given the law of Equimarginal utility related:
(a) Related to goods
(b) Related to money
(c) In relation to both
(d) None of these.
Answer:
(a) Related to goods

Question 3.
How many tremendous curves can touch the budget line:
(a) One
(b) Two
(c) Several
(d) Depends on the basis of indifference maps.
Answer:
(a) One

Question 4.
Indifference curves were first introduced by the English economist in 1881 by:
(a) Edge worth
(b) Pareto
(c) Myers
(d) Hicks.
Answer:
(a) Edge worth

Question 5.
Any statement about the demand of an object is considered complete when it is mentioned in the following:
(a) Price of good
(b) Demand of good
(c) Time period
(d) All of the above.
Answer:
(d) All of the above.

Question 6.
If price of goods ‘X’ falls leading to increase in demand of goods ‘ Y’ then both the goods are:
(a) Substitute goods
(b) Complementary goods
(c) Not related
(d) Competitor.
Answer:
(b) Complementary goods

Question 7
According to total outlay method, the demand of a good is sinelastic when:
(a) Price will fall with the increase in amount spent
(b) When price of good decreases and money spent decreases
(c) Expenditure remains the same, even if price falls
(d) Expenditure decreases with the increase in price.
Answer:
(b) When price of good decreases and money spent decreases

Question 2.
Fill in the blanks:

1. Consumer is a …………. human being.
2. If the price of substitute goods increases then the demand curve shifts to the ………….
3. …………. propounded the law of Diminishing Returns.
4. According to Marshall utility can be measured in terms of ………….
5. An indifference curve gives …………. level of satisfaction to the consumers.
6. Car and Petrol are goods ………….
7. There is …………. relation between price and demand.

Answer:

1. Rational
2. Right
3. Gossen
4. Money
5. Equal
6. Substitute
7. inverse.

Question 3.
State true or false:

1. Utility is an intensive assumption.
2. The proportion of the cost of two goods measures the slope of budget line.
3. Demand curve is generally negative sloped.
4. Budget set is a collection of all bundles that a consumer purchases from their income at market prices.
5. The elasticity of the demand of the object and the expenditure on the object is closely related.

Answer:

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

Question 4.
Match the following:

Answer:

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

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

1. Which curve is convex to the origin?
2. After which stage marginal utility and Total utility starts decreasing?
3. The point where a consumer derives maximum satisfaction is known as?
4. The elasticity of demand of luxurious goods is.
5. What is the demand for means of productions?

Answer:

1. Indifference curve
2. At zero point
3. Consumer’s equilibrium
4. Highly elastic
5. Derived demand.

Consumer Behavior and Demand Very Short Answer Type Questions

Question 1.
What is the law of demand?
Answer:
The law of demand states that other things remaining the same, quantity demanded increases with the fall in price and quantity demanded decreases with rise in price.

Question 2.
What are complementary goods?
Answer:
Those goods which are jointly required to satisfy a particular want are known as complementary goods, e.g., bread and butter, car and petrol, pen and ink. These are also known as joint demand.

Question 3.
What is elasticity of demand?
Answer:
When we measure the proportionate change in the quantity demanded of a commodity due to change in its price, is known as elasticity of demand.

Question 4.
What do you mean by Relatively elastic demand?
Answer:
Demand is said to be relatively elastic when percentage change in demand is greater than percentage change in price.

Question 5.
What is perfectly inelastic demand?
Answer:
The change of price does not affect the demand of certain commodities. The demand for these commodities remain almost constant. The demand of these commodities are known as perfectly inelastic demand (Ep = 0).

Question 6.
Write the differences between the demand and want
Answer:
Differences between the Demand and Want:
Demand:

1. Demand is created by want.
2. Demand goes on changing.

Want:

1. Desire gives rise to want.
2. Wants are more or less permanent.

Question 7.
What is cross elasticity of demand?
Answer:
Cross elasticity of Demand :
Cross elasticity of demand refers to a change in demand for a goods as a result of change in the price of another goods. Following formula for the cross elasticity of demand :

Cross elasticity of demand arises in case of interrelated goods such as substitutes and complementary goods.

Question 8.
What are substitute goods?
Answer:
Commodities which can be used in place of other goods are known as substitute goods. Fall in price of one commodity leads to rise in demand for other commodity.
Example : Tea and coffee, complain and bournvita.

Question 9.
What do you mean by consumer’s equilibrium?
Answer:
It refers to a situation under which a consumer spends his given income on purchase of a commodity in such a way which gives him maximum satisfaction and there is no tendency to change.

Question 10.
What is the effect of increase or decrease in the level of income on elasticity of demand?
Answer:
With the increase in income demand increases and with the decrease in income demand falls.

Question 11.
What do you mean by the budget set of a consumer?
Answer:
The budget set is the collection of all bundles of goods that a consumer can buy with his income at a prevailing market price.

Question 12.
What is budget line?
Answer:
The budget line represents all bundles which cost the consumers his entire income. The budget line is negatively sloping. If the consumer wants to consume an extra unit of goods 1, he will have to give up some amount of goods 2.

Question 13.
What do you mean by indifference curve?
Answer:
An indifference curve is the curve which represents all the combinations of two goods which gives the same level of satisfaction to a consumer.

Question 14.
What do you mean by market demand curve?
Answer:
Market demand curve represents the total of quantities of a commodity demanded by all the consumers in the market at different prices.

Question 15.
What do you mean by zero elasticity of demand or perfectly inelastic demand?
Answer:
A perfectly inelastic demand is one in which a change in a price causes no change in the quantity demanded.

Question 16.
What do you mean by market demand?
Answer:
Market demand means the total quantity of a good that all its buyers are willing to purchase at different prices over a given period of time.

Question 17.
What do you mean by Giffen goods?
or
What do you mean by inferior goods?
Answer:
Giffen goods may be defined as those goods whose price effect is positive and income effect is negative. In it the demand falls with the fall in price and rises with an increase in price.

Question 18.
What do you mean by price effect?
Answer:
When the price of a commodity falls the real income of the consumer goes up and thus demand of the commodity increases. This effect is called the price effect.

Question 19.
Write the assumptions of the demand curve.
Answer:
Following are the assumptions of demand curve:

1. There should not be any change in income and interest of consumer.
2. It is assumed that there is small and continuous change in price and demand relationship.
3. Goods can be divided into small units.
4. Perfect completion is found in the market.

Question 20.
What do you mean by normal goods?
Answer:
Normal goods:
Normal goods are those goods for which the demand increases with the increases in income of the consumer and decreases with fall in income.
For example :
Demand for such goods like car, refrigerators, televisions, etc. increases with the increase in income and their demand decreases with the decrease in income.

Question 21.
Explain the meaning of complementary goods. Explain with example.
Answer:
Complementary goods are those goods which are complementary to one another. In other words, they are used jointly or consumed together. For example: Ink and Pen, Car and Petrol. An increase or decrease in price of petrol will affect the use of car. If the price for petrol decreases, the demand for car will increase along with demand for car. On the other hand, if the prices of petrol increase the demand for petrol will decreases along with the demand for car.

Question 22.
Consider the demand curve D_p = 10 – 3_x. What is the elasticity at price
\(\frac{5}{3}\)?
Solution:
Given ; q = a – bp
q = 10 – 3p
a = 10, b = 3, p =\(\frac{5}{3}\)
e_D=-\(\frac{bp}{a-bp}\)
=(3 x \(\frac{5}{3}\)) ÷ (10 – 3 x \(\frac{5}{3}\))
= – (5) ÷ (10 – 5) = – 5 – 5 – 5 = -1
Price elasticity is (Ed) = -1
Price elasticity = -1.

Question 23.
Write the difference between Law of Demand and Elasticity of Demand.
Answer:
Differences between Law of Demand and Elasticity of Demand:
Law of Demand:

1. The Law of demand is only a qualitative statement.
2. It indicates direction of change in demand in response to the change in its price.
3. It does not specify the quantity of change in demand in response to the change in price.

Elasticity of Demand:

1. It is a quantitative statement.
2. It indicates quantitative change in the demand for a commodity in response to a change in its price.
3. Elasticity of demand is a measure of rate of change in demand in response price. to a change in the price of a commodity.

Question 24.
What do you mean by income demand?
Answer:
The income demand refers to various quantities of goods and services which would be purchased by the consumer at various levels of income. We assume that the price of the commodity or service as well as the price related goods the taste and desire of the consumer do not change. The income demand shows relationship between the income and quantities demanded. If the income increases the demand for a particular good will be increased and vice versa.

Question 25.
What do you mean by income elasticity of demand? Give one definition.
Answer:
The income and demand of goods has direct relation. The income elasticity of demand means the change .in demand which occurs as a result of change in income. Here, price remains constant.

Definition of Watson:
“Income elasticity of demand in the ratio between percentage of change in income and % of change in quantity demanded.”

Question 26.
Define price elasticity of demand.
Answer:
It is a measure of degree of responsiveness of demand for a commodity to change in its price or it is the ratio of percentage change in quantity demanded in response to a percentage change in price.

Consumer Behavior and Demand Short Answer Type Questions

Question 1.
What do you mean by utility? Give definition of it.
Answer:

1. The power or capacity which satisfies human wants is called utility.
2. According to Prof. Waugh, “Utility is the capacity to satisfy human wants”.

Question 2.
Explain the characteristics of utility. Give definition of it.
Answer:
1. Utility is a psychological word :
Utility is a formless thing which is concerned with human sentiments. It can only be experienced because it has no form. Therefore, utility is supposed to be a psychological word and that the utility of one commodity may be different for different persons. It is an abstract noun. .

2. Utility is an individual characteristic:
The second characteristic of utility is that it is personal. The same utility is found to be different for different individuals. The utility of a commodity for one individual depends on his desire, taste, fashion, habit, environment and such other circumstances.

3. Utility depends on intensity of want:
The utility of a commodity depends on the intensity of its want. A person will obtain utility of a commodity depending upon the intensity of the utility of the commodity to the individual. This is the reason why a man gets maximum utility from food when he is very hungry. But the utility becomes zero when his hunger is satisfied.

Question 3.
Explain the types of utility.
Answer:
There are three types of utility:

1. Total utility
2. Marginal utility
3. Average utility.

1. Total utility:
When a consumer uses more than one unit of a commodity, the sum total of the utility derived from all the units is called total utility. In other words, the utility derived from all the units of a commodity is called total utility.

2. Marginal utility:
The utility obtained from the last unit of a commodity is called marginal utility.“The marginal utility is the utility derived from the last unit of commodity consumed”.

3. Average utility:
When total utility of an article is divided with the total units of an article. The sum received is called average utility.

Question 4.
What are the factors which affect the marginal utility?
Answer:
Following are the factors which affect the marginal utility:

1. Quantity of goods:
   When the supply of a commodity is in surplus its marginal
   utility declines on the other hand if there is scarcity of goods, the marginal utility will increase. .
2. Substitute goods:
   If there are more substitutes available of a commodity, the marginal utility of that commodity declines and vice-versa.
3. Income of a person:
   With the in the income of a person, the marginal utility of a commodity increases, while on the other hand it may decrease.

Question 5.
Write the assumptions of consumer’s equilibrium.
Answer:
Following are the assumptions of the consumer’s equilibrium:

1. Maximum satisfaction :
   The first assumption on of the consumer equilibrium is that consumer is a rational human being and by purchasing two goods, he can achieve maxi-mum satisfaction.
2. No change in taste and habit of the consumer during analysis:
   It is assumed that during the time of analysis of consumer equilibrium, there is no changes in taste, habit and liking of the consumer.
3. Perfect competition:
   There is perfect competition in the market from where he purchases his goods.
4. Consumer has an indifference map:
   Consumer has an indifference map showing his scale of preference for various combinations of the two goods (Apples and Mangoes). This scale of preference remains the same through out the analysis.
5. No change in the price of the commodity:
   Prices of the goods in the market are given and they are constant during consumer’s equilibrium. Each goods is homogeneous and divisible
6. 6. Constant amount of money:
   Consumer is given a constant amount of money to spend on the goods and if he does not spend on one good he must spend it on other.

Question 6.
Write three importance of law of diminishing marginal utility.
Answer:
Following three importance of the law of diminishing marginal utility is of great use to man in almost every walk of life:

1. Basis of production:
The law of diminishing marginal utility helps the producers to produce their articles and goods they know that,the consumer gets the diminishing utility by consuming successive units of a commodity. So, various types of articles are produced by him instead of same articles.

2. Basis of consumer’s surplus:
The law helps us to study consumer’s behavior. We know that by each successive unit gives less and less utility to the consumer, though the price of the commodity is the same. The consumer thus stops consuming the commodity at the points of satisfaction.

3. Law of demand:
The law of diminishing marginal utility is the basis of the ‘Law of demand. It is this law which explains to us why the demand curve slopes downwards. The diminishing tendency is utility with increase in supply shows the points cut by the price and amount demanded in.

Question 7.
Write defects of law of diminishing marginal utility.
Answer:
The law of diminishing marginal utility is not free from the defects.

1. Utility cannot be measured cardinally:
According to Marshall, utility analysis is based on the hypothesis that utility is cardinally measured in utils or units and that utility can be added and subtracted.

2. Marginal utility of money is not constant:
The utility analysis assumes the marginal utility of money to be constant. Critics point out that marginal utility of money never remain constant. So it may affect consumer’s preferences.

3. The law depends on the supply of the substitutes and complements:
The law does not depend upon the supply of the commodity a consumer consumes but also on its substitutes and complements. If the green coconuts are available in plenty the utility of sarabat will decrease rapidly.

4. Rationality:
The theory assumes that the consumer is rational. However, various factors such as advertisement and ignorance can influence the consumer’s decision.

5. In-applicability in case of indivisible goods:
The application of this law to an indivisible bulky commodity seems to be absurd because no one would normally but at a time more than one unit of goods like TV set, Scooter, House etc.

Question 8.
Write the essential elements of demand.
Answer:
Following are the essential elements of demand:

1. Desire for goods: For demand desire of any good is essential. If a person does not have desire for anything, then it cannot be turned into demand.
2. Sufficient means or Wealth to purchase:
   A person should have sufficient wealth and means to get the goods, otherwise he/she cannot fulfill his wants.
3. Eagerness to spend:
   A person should be willing to use means or wealth to fulfill his demand. Otherwise it will remain only desire not the demand.
4. Fixed price:
   Demand is always expressed at a fixed price. If it is not expressed in terms of price, we cannot call it demand.
5. Fixed Time:
   Demand is always expressed at a particular time. In a specific time only quantity of good is demanded.

Question 9.
Distinguish between Marginal Utility and Total Utility.
Answer:
Differences between Marginal Utility and Total Utility:

Question 10.
Explain, why the budget line is downward sloping?
Answer:
A budget line is the line showing different possible combinations of two goods i.e., goods x and goods y, which a consumer can buy, given his budget and the prices of two goods. Now, when the consumer can purchase two goods only with the given income and the prices, it is but obvious that the consumer can buy more of goods x only when he buys less of goods y. So, the budget line will be downward sloping indicating an inverse relationship between the consumption of two goods.

Question 11.
Write the exceptions of law of demand.
Answer:
Following are the exceptions of the law of demand:

1. Articles of Distinction:
This exception was first of all discussed by Veblen. According to him, articles of distinction have more demand only if their prices are sufficiently high. Diamond, jewelry, costly carpets etc. have more demand because their prices are abnormally high. It is so because distinction is bestowed on diamond, jewelry, etc. by the society because of their being costly. Accordingly, their demand is also high. If their prices falls, they will no longer be considered as articles of distinction and so their demand will decrease.

2. Giffen Goods:
In other words, Giffen goods are those inferior goods in the case of which income effect is negative and stronger than the substitution effect of a change in price. As a result, when price of such commodities falls, their demand also shrinks. Both in case of inferior good and Giffen goods income effect is negative. But in case of Giffen goods, negative income effect is always stronger than the substitution effect.

While in case of inferior goods, it may or may not be so. Law of demand fails only if negative income effect is stronger than the substitution effect. So, that while law of demand may or may not fail in case of inferior goods, it must always fail in case of Giffen goods. Therefore, at higher price the quantity demand of diamonds by rich consumers may increase.

3. Expectation regarding future prices:
If price of a commodity is rising today and it is likely tor rise more in the future, people will buy more even at the existing higher price and store it up. They will do this order to avoid the pinch of higher price in future. Similarly, when the consumers anticipate a large fall in the price of a commodity in future, they will postpone their purchase even when price falls today so as to purchase this commodity at a still lower price in future.

4. Emergencies:
Law of demand may not hold good emergencies like war, famines, etc. At such times consumers behave in an abnormal way. If they expect shortage of goods, they would buy and hoard goods even at high prices during such periods. On the other hand, during depression they will buy less even at low prices.

Question 12.
A consumer wants to consume two goods the prices of two goods are Rs. 4 and Rs. 5, respectively. The consumer incomes is Rs. 20. Find out the following:

1. Write down the equation of the budget line.
2. How much of goods 1 can the consumer consume if he/she spends entire income on that goods?
3. How much of goods 2 Can a consumer consume if he/she spends her entire income on that goods?
4. What is the sole of the budget line?

Answer:
Equation of budget line is:
1. P_x Q_x + P_y Q_y < Y, 4 Q_y ≤ 20.

2. If he/she spends entire on goods 1 then his consumption on 1 will be,
= Total income of consumer =\(\frac{Rs.20}{Rs.4}\)
= Price of one goods.
= 5 units.

3. If the consumer consumes his full income on goods 2 then he will consume goods 2 in this quantity.
= Total incomes of consumer =\(\frac{Rs.20}{Rs.4}\)
=4 units.

Question 13.
How does the budget line change if the consumer’s income increases to ₹40 but the prices remain unchanged? (NCERT)
Answer:
An increase in consumer’s income implies that the consumer can purchase increased quantities of both the commodities at the prevailing market price. As a result the consumer will face a new budget line. The new budget line will shift-rightwards parallel to the original budget line. It can be explained with the following

In the above figure if the income of consumers is increased from ₹ 20 to ₹ 40 the budget line shift/upward) right side. Now the consumer can consume more quantity of goods than before because there is no change in price of goods. The new budget line is parallel to the original budget line.

Question 14.
How does the budget line change if the price of good 2 decreases by a rupee but the price of good 1 and the consumer’s income remain unchanged?
Answer:
If the price of goods 2 decreases by ₹1 and there is no change in income and price the budget line will change because the consumer can buy more of goods 2. It is clear form the following

Question 15.
Suppose a consumer can afford to buy 6 units of goods 1 and 8 units of goods 2 if he spends his entire income. The prices of two goods are ₹6 and ₹8 respectively. How much in the consumer’s income?
Answer:
Price of good 1= ₹6.
Quantity of good = ₹6.
Price of good 2 = ₹8.
Quantity of good 2 = ₹8.
Budget set;
or C₁ X₁ + C₁ X₂ = I
or 6 x 6 + 8 x 8 = I
or 36 + 64 = 1
100 = 1
So, income of consumer.

Question 16.
Consider the demand curve for a good. At price ₹ 4 the demand for the good is ₹ 25. Suppose the price of the good increases to₹ 5 and as a result the command for the falls to 20 unit Find out the price elasticity.
Solution:

=\(\frac { \frac { { q }_{ 1 }-{ q }_{ 0 } }{ { q }_{ 0 } } }{ \frac { p_{ 1 }-{ p }_{ 0 } }{ { p }_{ 0 } } }
\)
According to question, q₀ = 25, p₀ = 4, q₀ = 20, p₁ = 5
\({ e }_{ D }=\frac { \frac { 20-25 }{ 25 } }{ \frac { 5-4 }{ 4 } } =\frac { \frac { -5 }{ 25 } }{ \frac { 1 }{ 4 } } \)
\({ e }_{ D }=\frac { -5 }{ 25 } x\frac { 4 }{ 1 } =\frac { -20 }{ 25 } =-0.8\)

Question 17.
Write the assumptions of the law of marginal utility.
Answer:

1. Units of the commodity must be similar:
   Each successive unit of the commodity must be similar in quantity and quality.
2. Consumption should be continuous:
   The law will operate only when the consumption of unit is continuous without interval.
3. Interest nature of the consumer should not change:
   If in the period of consumer interest and nature of the consumer changes then the law will not be applicable.
4. Income should not change:
   The income of the consumer should not be changed. As soon as income changes man’s need changes.

Question 18.
Suppose the price elasticity of demand for a good is 0.2. If there is a 5% increase in the price of the good, by what percentage will the demand for the good go down?
Answer:

Substituting the value, we get

or, percentage change in quantity demanded
= 0.2 x 5 = 1
Demand of good will be reduced by 1 %.

Consumer Behavior and Demand Long Answer Type Questions

Question 1.
Write any six causes of the implication of the law of demand.
Or
Why demand curve slopes downwards to the right?
Answer:
It is a general law that the demand curve slopes downwards to the right. It shows the inverse relationship between the price and demand i.e., when price rises demand falls and vice – versa. This is why, it is also known as negative slope of the demand curve.

Following are the causes responsible for the downward sloping of the demand curve:

1. Law of diminishing marginal utility:
According to this law, consumption of a commodity increases, the utility from each successive unit goes on diminishing. Accordingly for every additional unit to be purchased, the consumer is willing to pay less price.

2. Income effect change:
Change in own price of a commodity causes a change in real income of the consumer, with a fall in price, real income increases. Accordingly, demand for the commodity expands.

3. Substitution effect:
It refers to substitution of one commodity for the other when it becomes relatively cheaper due in relative prices.

4. Size of consumer group:
When price of a commodity falls, it attracts new buyers who can afford to buy it, hence, quantity demanded rises.

5. Different uses:
Many goods have alternative uses e.g., Milk is used for making Curd, cheese and butter. If price of milk reduces, it will be put into different uses. Accordingly, demand for milk expands.

6. Tendency to satisfy the unsatisfied wants:
Each person has some unsatisfied wants. When the price of the goods falls, he wants to satisfy his unsatisfied wants which leads him to increase its demand. Because of this tendency of human beings, the demand curve slopes downwards to the right.

Question 2.
Write any five exceptions to the law of demand.
Answer:
The law of demand i.e., more demand of the commodity at lower price and lesser demand at higher price does not apply in every case and situation. The exceptions to the law of demand are as follows :
1. Necessaries of life:
Certain commodities represent necessaries of life and so the consumer is forced to buy them even at high price. As such, the demand curve may go upward or the law of demand may not operate.

2. Social status symbol:
There are certain goods which constitute social status symbol and the consumer has to buy them for maintaining his prestige in the society. He is, therefore, compelled to purchase such goods inspire of an increase in their prices. The law of demand will not operate as such.

3. Precious stores:
The law of demand does not operate in the case of precious stones like diamond etc. People do purchase them inspire of an increase in their price in order to distinguish their recognition.

4. Ignorance and psychology of consumer:
If the consumer is not aware of the competitive price of a commodity prevailing in the market, he may buy it in more quantity at higher price. It may be a psychological phenomenon that high price represents high quality. The law of demand may not operate as such.

5. Change in fashion, habits, interest and preference:
The law of demand does not operate when there is a change in consumer’s taste, habit, interest, fashion and preference. A commodity of new fashion will be purchased more even if the price is increased and so also is the case of change in habit, interest, taste and preference.

Question 3.
Write any five factors affecting elasticity of demand.
Answer:
The elasticity of demand is affected by the following factors:
1. Nature of commodities:
Demand for necessity is inelastic whereas the demand for luxuries is elastic. Here too, we have to note the possibility that substitution plays an important role. Demand for necessities like bread and potatoes is inelastic because there are no close substitutes for them within the same price range and not merely because they are necessaries”. Hanson further sates that “The demand for some expensive luxury goods may be very inelastic not because they are luxuries but rather because they lack close substitutes.”

2. Consumer’s income:
Elasticity is closely related to person’s income. The demand of rich for all commodities may be quite unaffected by any changes of price. But this is not the case with the majority of the people as they have limited income and have to make a choice between this or that commodity. They cannot purchase all commodities.

3. Proportion of income spent on commodity:
The demand for a commodity is quite elastic over which consumer’s spend a large part of their income. It is so because even a small rise in price is likely to reduce substantially their ability to buy this item and so result in sharp percentage declines in the quantity demanded.

4. The possibility of substitution:
The most important influence on elasticity of demand is the degree of closeness of the substitute for the goods. The closer the substitute, the higher the elasticity of demand.

5. Possibility of postponement of the use of commodity:
If the consumption of a commodity can be postponed for further, the demand for such commodity will be elastic as the consumer does not feel its urgency. On the other hand if the consumption of a commodity cannot be postponed for future or which is very urgent, the demand for it will be inelastic.

Question 4.
Explain the factors affecting demand.
Answer:
Following are the factors affecting demand:

1. Income:
   When consumer’s income increases, he or she usually buys more goods which increases the demand.
2. Price of substitute goods:
   When the price of substitute goods increases, a consumer normally gives up at least some of its consumption and as a result the demand in-creases. (e.g., pineapple).
3. Prices of complementary goods:
   When the price of complementary good in-creases, a consumer normally gives up some of its consumption as a result demand decreases (e.g. sugar).
4. Number of consumer:
   When the number of consumers increases there are more people who buy the goods and as a result demand increases.
5. Consumer’s taste:
   When a consumer likes the goods more he or she buys it more and the demand increases.

Question 5.
Explain the types of price elasticity of demand.
Or
Explain the degree of price elasticity of demand.
Answer:
Following are the types of price elasticity of demand:

1. Perfectly elastic demand:
Let us take one extreme case of elasticity of demand, when it is infinite or perfect elasticity of demand is infinity when even a negligible fall in the price of commodity leads to an infinite extension in the demand for it. Even when the price remains the same, the demand goes on changing.

2. Perfectly inelastic demand:
It means however great the rise or fall in the price of the commodity, its demand remains absolutely unchanged. In
other words, the elasticity of demand is zero. No amount of change in price induces a change in demand.  In other words, the change in price does not at all affect the quantity demanded. It is a case of perfectly inelastic demand.

3. Unitary elastic demand:
Demand for a commodity will be said to be unitary elastic, if the percentage change in the quantity demanded equals to the percentage change in the price. In other words, when the demand changes in the same proportion as in the price of the commodity, the elasticity of demand is equal to one.

4. Inelastic demand or Less than unit elastic demand:
When a considerable change in price does not lead to much change in the demand, the demand is said to be less elastic or inelastic. Here, the elasticity of demand is said to be less than unity. The slope of demand curve is more inclined towards Y axis.

5. Elastic demand or More than unit elastic demand :
When a small change in price leads to a greater change in demand, the demand is said to be elastic or more elastic. Here, the elasticity of demand is said to be greater than unity. In this case, proportionate change in demand will be more than proportionate change in price.

Question 6.
Explain the law of demand with the help of table and graph.
Answer:
The law of demand explains the relationship between price of a commodity and its quantity demanded in the market. It says that there is inverse relationship between price and the quantity demanded. The law states that other things remaining same, the consumer will demand lesser quantity of goods at higher price and more quantity of goods at lower price. Thus, consumer’s equilibrium is the basis of law of demand.
Example:

The above table show that when the price of oranges is ₹ 1 per unit 80 units are demanded. If the price increases to ₹ 5 the quantity demand decreases it is 40 units.

This can be further explained with the help of figure:
From the figure it is clear that DD demand curve is a downward slopping curve. Which indicates that when the price of a good increases demand falls and when price reduces there is increase in demand. This shows inverse relation between price and demand. Demand

Question 7.
Explain the law of diminishing marginal utility with example.
Answer:
Definition of Law of Diminishing Marginal Utility:

1. Prof. Alfred Marshall:
“The additional benefit which a person derives from a given increase in his stock of a thing diminishes with every increase in the stock that he already has.”

The law of diminishing marginal utility has great importance in the study of economics. This law was firstly introduced by the French economist Herman Henrick Gosen. So, it is known as ‘Gosen’s first-law, Afterwards Prof. Marshall presented it scientifically in a systematic manner. This law explains the relation between the units of a commodity and it marginal utility.

The law is the most logical exposition of a consumer behavior. As we go on consuming more of anything in succession, the satisfaction derived by its successive units goes on decreasing. It is a matter of common observation that the more we have the commodity, the less urgently we want its subsequent units.

Explanation: We may take an example to illustrate this law. We are very hungry and we want food. We start eating bread. The first bread, that we eat is of utmost importance to us. The utility of this bread is say 40. Then we eat the second bread, but the utility of this bread is not as great as that of the first. Its utility is say 30, because our hunger has been slightly satisfied. The next bread that we eat have lesser and lesser of utility. The utility of the third and fourth bread is say 20 and 10 respectively.

Suppose after eating 5 units of bread his hunger is satisfied. Now we won’t like to eat the sixth bread. There will be no intensity to eat the sixth bread, therefore no utility of the sixth bread will be there. Still if we eat the sixth bread, we may get displeasure or dissatisfaction. This is the negative utility.Here we get zero utility. The seventh bread will give him negative utility because he has spend money on it without getting any satisfaction. Because of the consumption of the additional unit he might feel uneasy.

We may summarize it in this manner :

1. As long as we have intensity for a thing, there will be utility for that.
2. With the consumption of each unit of any commodity, the intensity for that commodity will be lesser and lesser, hence its utility will also diminish.
3.  If there is no intensity for a commodity, there will be no utility.
4.  In spite of no intensity if we keep on consuming a thing, there will be negative
   utility.

In the above example, we see that after consuming number of 5 breads, our hunger is satisfied, therefore the utility of bread will be up to 5 breads only. This utility is in the decreasing order because with the consumption of every bread his hunger also decreases. At the consumption of the sixth bread, the utility received is zero because the hunger has been fully satisfied. There is no need of the seventh bread, but still if he eats, there will be negative utility.

Question 8.
What is Giffcn paradox?
Answer:
In economics Giffen goods is a good that is in greater demand as its price increases and falls when the price decreases. A Giffen goods is typically an inferior product that does not have easily available substitutes. There is a positive relationship between the price and the quantity demanded.

This situation is also known as Giffen paradox. The demand for inferior goods such as coarse grain, coarse cloth, inferior meat etc., will not increase even with the fall of their price, because consumers of there commodities will start consuming more of a superior commodity. As a result, the demand for Giffen commodity will fall.

Question 9.
Explain the concept of consumer’s equilibrium with the help of suitable example.
Answer:
Consumers equilibrium refers to a situation, in which a consumer derives maximum satisfaction, with no intention to change it and subject to given prices and given income. The point of maximum satisfaction is achieved. The consumer equilibrium under indifference curve must meet the following conditions:

The three conditions must be satisfied for a consumer to attain equilibrium:

1. The price line should be tangent to an indifference curve or MRS of one commodity for another should be equal to their relative prices.

AB is the price line and IC₁, IC₂ and IC₃ are the indifference curves. This curve shows the combination of goods X and Y. IC₃ and IC₂ indifference curve which lie above and below the price line. In other words a rational consumer with limited income cannot do the expenditure and curve IC₁ shows less satisfaction, but IC₂ curve touches the price line at ‘P’ which is a point at which consumer maximizes his satisfaction.

2. In the given figure, slope of price line and indifferent curve is same or equal at point ‘P.’

3. At the point of equilibrium an indifference curve must be convex to the origin. Thus, the point of consumer equilibrium or maximum satisfaction may be defined by the condition that the marginal rate of substitution between any pair of two commodity will be equal to the ratio of their prices, or the marginal rate of substitution of money for any commodity is equal to the price of the commodity.

Question 10.
What is indifference curve? Write its features.
Answer:
An indifference curve is the curve, which represents all those combinations of two commodity which give same level of satisfaction.

Main features are :

1. The indifference curve must slopes downwards to the right.
2. Higher indifference curve represents higher level of satisfaction.
3. Indifference curves are convex to the origin.
4. Indifference curve cannot intersect each other.
5. Indifference curve do not touch the horizontal or vertical axis.
6. The consumer acts rationally so as to maximize satisfaction.
7. There are two goods X and Y.
8. The consumer possesses complete information about the prices of the goods in the market.

Question 11.
What is indifference map?
Answer:
A set of indifference curves is called indifference map. An indifference map depicts complete figure of consumer’s tastes and preference. The indifference map shows the preference of the consumer, he definitely prefer’s the combination lying on the higher indifference curve to the combination lying on a lower indifference curve because a higher indifference curve represents a higher level of satisfaction.

Question 12.
What do you mean by extension of demand and contraction of demand?
Answer:
1. Extension of demand :
When the quantity demanded of a commodity rises due to fall in its price, other things remaining the same, it is called ‘rise in quantity demanded or extension of demand. For example, as shown in when the price of apples falls ₹ 30 per Kg to ₹ 25 per Kg. A consumers purchase of apples rises from 1 Kg to 2 Kg per week. This is extension of demand.

2. Contraction of demand:
Contraction of demand or fall in quantity demanded refers to a fall in quantity demanded of a commodity as a result of rise in its price, other things remaining the same.” When the price of apples rises from ₹15 a Kg. to ₹ 20 a Kg. a consumer buys less apples, 4 Kg. instead of 6 Kg. In this case, there is contraction of demand or decrease in quantity demanded.

Any point on a demand curve represents a particular quantity being bought at a specified price. Different points on a demand curve represent quantities demanded at different prices. Therefore, a change in quantity demanded is indicated by a movement along a particular demand curve. A movement down a demand curve is called a “rise in quantity demanded” or “extension of demand.”

On the other hand, a movement up the demand curve is called a‘ fall in quantity demanded of ‘contraction of demand.’ Thus, a change in the quantity demanded as a result of change in price of a commodity alone does not involve the drawing of a new demand curve, but is represented by the movement up or down on a given demand curve. This is illustrated in.

It will be seen in fig. that when the price is OP₁ quantity demanded is OQ₁. Now, if the price of the commodity falls to OP₂, the quantity demanded rises to QO₂. This movement from A₁ to A₂ in the downward direction (as indicated by an arrow) on the given demand curve DD is the extension of demand.

On the other hand, if the price of the commodity rises from OP₁ to OP₃, the quantity demanded of the good falls to OQ₃. This movement from A₁ to A₃ in the upward direction (as indicated by the arrow) on the given demand curve is the contraction of demand.

Extension in demand results from
a fall in the price, other things remaining the same.

Contraction in Demand results from
a rise in the price, other things remaining the same.

MP Board Class 12th Economics Important Questions

MP Board Class 12th Special Hindi सहायक वाचन Solutions Chapter 6 उनको पुकारता हूँ (कविता, आनन्द मिश्र)

उनको पुकारता हूँ अभ्यास प्रश्न

प्रश्न 1.
‘लहू के पानी होने’ से कवि का क्या तात्पर्य है? (2015)
उत्तर:
प्रस्तुत कविता में ‘लहू के पानी होने से कवि का तात्पर्य ऐसे शौर्यवान और पराक्रमी लोगों से है, जिनके शरीर की धमनियों में बहता रक्त अपनी मातृभूमि को गुलामी की बेड़ियों से मुक्त कराने के लिए सदैव उबलता रहता है। उनके रक्त के ताप की अनुभूति युद्ध के मैदान में उनकी वीरता को देखकर सहज ही की जा सकती है। सच्चे अर्थों में ऐसे वीर युवाओं का रक्त-ही-रक्त है अन्यथा आपातकाल में भी जिस रक्त में उबाल न आये, उसे निरा पानी कहना ही न्यायसंगत होगा।

प्रश्न 2.
‘मिटकर अजर-अमर जो’ कहकर कवि किन लोगों की ओर संकेत कर रहा है?
उत्तर:
प्रस्तुत कविता में वाक्यांश-‘मिटकर अजर-अमर जो’ से कवि देश के उन महान् शहीदों को अपने श्रद्धा सुमन अर्पित करना चाहता है, जिन्होंने अपनी मातृभूमि के आन-मान सम्मान के लिए अपना सर्वस्व न्यौछावर कर दिया। इस पंक्ति के माध्यम से कवि आज की युवा पीढ़ी को यह समझाना चाहता है कि संकट के समय संघर्ष करते हुए जिन लोगों ने देश-हित में अपने प्राण तक न्यौछावर कर दिये,वे मरकर भी अजर-अमर हैं। आने वाली संततियाँ उनके नाम से स्वयं को जोड़कर गौरव का अनुभव करेंगी।

प्रश्न 3.
विजय से भाँवर भरने की क्षमता किसमें होती है?
उत्तर:
कवि के अनुसार युद्ध के मैदान में जो रण-बाँकुरे अपने शौर्य और वीरता से शत्र के छक्के छुड़ा देते हैं तथा जो आवश्यकता पड़ने पर स्वतन्त्रता के यज्ञ में सफलता पाने हेतु अपने प्राणों तक की आहुति देने से भी नहीं हिचकते,वास्तव में, विजयश्री’ के साथ भाँवर भरने अथवा उसका ‘वरण’ करने का अधिकार भी उन्हीं को होता है। ऐसे वीर पुरुष अपने व्यक्तिगत हितों को त्यागकर निःस्वार्थ भावना से राष्ट्र की सेवा में स्वयं को पूरी तरह झोंक देते हैं और समूचा राष्ट्र अपने इन लाड़लों के कृत्यों से निहाल हो उठता है।

प्रश्न 4.
‘पावक’ से श्रृंगार कौन करता है?
उत्तर:
कवि के अनुसार देश-सेवा के लिए सिर्फ वही व्यक्ति उपयुक्त हैं जो महलों की ऐशो-आराम की जिन्दगी को त्यागकर कठिन एवं प्रतिकूल परिस्थितियों में भी संघर्ष करते हैं। ऐसे श्रम-साधकों को अपने श्रृंगार हेतु किसी भी प्रकार के सौन्दर्य प्रसाधनों अथवा पुष्पात्यादि की आवश्यकता नहीं होती, बल्कि तपती आग के सम्पर्क में आकर इनके चेहरे का ओज और भी चमक उठता है। ऐसे मतवालों का प्रथम प्यार होता है,देश की स्वतन्त्रता और उसे पाने के लिए वे सदैव अपना सर्वस्व न्यौछावर करने के लिए तत्पर रहते हैं।

प्रश्न 5.
कवि किन सपूतों को जागरण का संदेश देना चाह रहा है? (2014)
उत्तर:
प्रस्तुत कविता के माध्यम से कवि माँ भारती के उन सभी सपूतों का आह्वान करना चाहता है, जिनका रक्त का उबाल अभी तक ठण्डा नहीं हुआ है तथा जिनके पराक्रम एवं शौर्य का संसार में दूसरा कोई उदाहरण नहीं मिलता। देश-सेवा हेतु आह्वान करते हुए कवि ऐसे रण-बांकुरों को आवाज देता है,जो वीरता से लड़ते-लड़ते युद्ध-स्थल पर वीरगति को प्राप्त होकर भी अजर-अमर हैं, जिनकी गर्जना सुनकर समूची सृष्टि दहल जाये तथा जिनके प्रलयंकारी प्रहार से एकबारगी विशाल पर्वत तक चूर-चूर हो जायें। कवि ऐसे शेर-सपूतों को आन्दोलित करना चाहता है, जिनका प्रथम प्यार राष्ट्र है और जिनका श्रृंगार स्वयं अग्निदेव किया करते हैं। ऐसे वीर पुरुषों को पुकारते हुए कवि उन्हें मुक्ति-दूत की संज्ञा देता है और चाहता है कि संग्राम-संघर्ष के इस काल में वे सभी स्वाभिमानी राष्ट्रवासी देश-सेवा हेतु आगे आयें जिनका मान अभी तक मिटा नहीं है अर्थात् जो राष्ट्र के आन-मान-सम्मान की रक्षार्थ अपना सर्वस्व त्यागने को सदैव तत्पर रहते हैं।

प्रश्न 6.
‘मुक्ति-दूत’ से कवि का क्या तात्पर्य है? स्पष्ट कीजिए।
उत्तर:
प्रस्तुत कविता में ‘मुक्ति-दूत’ से कवि का तात्पर्य उन वीरों से है,जो अपने अदम्य साहस और अनूठे पराक्रम के बलबूते पर परतन्त्रता की बेड़ियाँ काटने की क्षमता रखते हैं। ऐसे निःस्वार्थी लोग अपने कार्यों से देश के लिए उन मुक्ति के दूतों के समान ही तो हैं,जो राष्ट्र को स्वतन्त्रता की मीठी सुगन्ध से परिचित कराने हेतु अपना सर्वस्य न्यौछावर करने को सदैव तत्पर रहते हैं। ऐसे वीर, संकटकाल में माँ भारती के सम्मानार्थ संघर्ष करते हैं और उसे हर संकट से मुक्ति प्रदान करवाने में प्राण-प्रण से प्रयास करते हैं।

प्रश्न 7.
‘सोया न मान जिनका, चेरा विहान जिनका’ इस पंक्ति का भावार्थ लिखिए।
उत्तर:
सोया न मान जिनका, चेरा विहान जिनका’ इस पंक्ति के माध्यम से कवि उन राष्ट्रभक्तों को राष्ट्र-रक्षा हेतु आवाज देना चाहता है, जिनका स्वाभिमान अभी तक जीवित है और जो देश के आन-मान-सम्मान और स्वाभिमान की रक्षा के लिए बड़े-से-बड़ा त्याग करने को भी सदैव आकुल रहते हैं। साथ ही, कवि माँ भारती के उन वीर सपूतों का भी आह्वान करता है जो प्राण-पण से संकट एवं संघर्ष के समय देश-रक्षा के अभियान में जुट जायें, जिनके पराक्रम और साहस को प्रकृति भी स्वीकार करती हो तथा आशाओं भरा प्रभातकाल चाकर (नौकर) बनकर जिनके सम्मुख खड़ा रहता हो।

प्रश्न 8.
‘उनको पुकारता हूँ’ कविता का केन्द्रीय भाव लिखिए।
उत्तर:
इस प्रश्न के उत्तर हेतु कृपया पाठ के प्रारम्भ में दिए गये ‘पाठ का सारांश’ का अवलोकन करें।

उनको पुकारता हूँ अति लघु उत्तरीय प्रश्न

प्रश्न 1.
‘उनको पुकारता हूँ’ में कवि ने देश-हित हेतु किसका आह्वान किया है?
उत्तर:
उक्त कविता में कवि ने देश-हित हेतु अपना सर्वस्व न्यौछावर करने के लिए स्वाभिमानी युवाओं का आह्वान किया है।

प्रश्न 2.
कवि आनन्द मिश्र के अनुसार सच्चे देशभक्त को परतन्त्रता की बेडियाँ कैसी लगती हैं?
उत्तर:
कवि के अनुसार सच्चे राष्ट्रभक्तों को परतन्त्रता की बेडियाँ नरक की यातना के समान लगती हैं।

उनको पुकारता हूँ पाठ का सारांश

कुशल कवि ‘आनन्द मिश्र’ द्वारा लिखित प्रस्तुत कविता, ‘उनको पुकारता है’ में कवि ने देश-हित हेतु अपना सर्वस्व न्यौछावर करने के लिए स्वाभिमानी युवाओं का आह्वान किया है।

कवि आपातकाल में देश-सेवा हेतु माँ भारती के उन रण-बाँकुरों को आवाज देता है, जिनका स्वाभिमान जीवित है तथा संसार में जिनकी वीरता और त्याग का दूसरा कोई उदाहरण नहीं मिलता,जो आवश्यकता पड़ने पर अपने प्राणों की बाजी लगाने से भी नहीं हिचकते तथा जो वीरगति को प्राप्त होकर भी सदा के लिए. अमर हो गये हैं। जिनकी हंकार से विशाल पर्वत भी दहल जायें, जिनका आघात अत्यन्त प्रलयंकारी हो तथा जो अपने पराक्रम एवं शौर्य से युद्ध के मैदान में ‘विजयश्री’ का वरण’ करते हैं। कवि ऐसे वीरों का आह्वान करता है जिन्हें परतन्त्रता की बेड़ियाँ नरक की यातना के सदृश लगती हैं और जो अपने प्राणों की आहुति देकर भी स्वतन्त्रता का दीप-गान गाते हैं। युद्ध-काल के समय कवि ऐसे युवाओं को पुकारता है, जिनका मान सोया नहीं है तथा प्रभातकाल जिनके आदेश का पालन करने को सदैव तत्पर रहता है।

MP Board Class 12th Hindi Solutions

MP Board Class 12th Special Hindi सहायक वाचन Solutions Chapter 5 नैनो टेक्नोलॉजी (वैज्ञानिक निबंध, संकलित)

नैनो टेक्नोलॉजी अभ्यास प्रश्न

प्रश्न 1.
नैनो टेक्नोलॉजी क्या है? इसके क्षेत्र-विस्तार के बारे में सम्भावनाएँ बतलाइए। (2011, 14)
उत्तर:
नैनो टेक्नोलॉजी एक अतिसूक्ष्म दुनिया है, जिसका दायरा एक मीटर के अरबवें हिस्से अथवा उससे भी छोटा है। वास्तव में नैनो’ शब्द की उत्पत्ति ग्रीक भाषा के शब्द नैनों से हुई है, जिसका शाब्दिक अर्थ है-बौना अथवा सूक्ष्म। यह नाम जापान के वैज्ञानिक नौरिया तानीगूगूची ने 1976 में दिया। नैनो टेक्नोलॉजी एक इकाई है जो एक मीटर के अरबवें हिस्से के बराबर होती है। आश्चर्यजनक बात यह है कि यह टेक्नोलॉजी जितनी अधिक सूक्ष्म है,उतनी ही विशाल सम्भावनाएँ यह अपने आप में समेटे हुए है। वर्तमान में नैनो टेक्नोलॉजी चिकित्सा के क्षेत्र से लेकर उद्योगों तक में अपनी उपयोगिता सिद्ध कर रही है। यद्यपि भारतीय बाजारों में नैनो उत्पादों की संख्या अत्यन्त कम है,मगर वह दिन दूर नहीं जब भारत में भी नैनो टेक्नोलॉजी जनित उत्पादों का बोलबाला होगा। वर्तमान में भारतीय विशेषज्ञ भी इस क्षेत्र में शोध करने में रत हैं। स्पष्ट है कि भविष्य में नैनो टेक्नोलॉजी के क्षेत्र विस्तार की सम्भावनाएँ असीम हैं।

प्रश्न 2.
‘नैनोडोमेन’ की निर्माण प्रक्रिया समझाते हुए उसके आश्चर्यजनक परिणाम लिखिए। (2009)
उत्तर:
नैनो टेक्नोलॉजी एक इकाई है जिसका मान 1 मीटर के अरबवें हिस्से के बराबर होता है। एक से लेकर सौ नैनोमीटर को ‘नैनोडोमेन’ कहा जाता है। नैनो टेक्नोलॉजी के तहत मेटेरियल का आकार छोटा करके उसे नैनोडोमेन’ बना लिया जाता है। ऐसा करने पर उस पदार्थ के विभिन्न गुण; जैसे-इलेक्ट्रिकल, मैकेनिकल,थर्मल व ऑप्टीकल इत्यादि हर स्तर पर बदलना शुरू हो जाते हैं। यह एक नवीन विज्ञान है जो बेहद आश्चर्यचकित परिणाम प्रदान करता है। जब अणु और परमाणु नैनो क्षेत्र को प्रभावित करते हैं तो इनमें नवीन परिवर्तन होना प्रारम्भ हो जाते हैं। ये परिवर्तन अद्भुत होते हैं, जिसमें वस्तु के मूल गुण तक बदल जाते हैं।

प्रश्न 3.
नैनो मेटेरियल किसे कहते हैं? नैनो मेटेरियल तैयार करने की दो पद्धतियाँ कौन-कौन सी हैं? (2015)
उत्तर:
नैनो टेक्नोलॉजी के तहत मेटेरियल के आकार को छोटा करके उसे नैनोडोमेन में बदल लिया जाता है। इस प्रक्रिया में मेटेरियल के विभिन्न गुण; जैसे-इलेक्ट्रिकल,मैकेनिकल, थर्मल व ऑप्टीकल इत्यादि हर स्तर पर बदलने लगते हैं। इन परिवर्तनों से अत्यन्त आश्चर्यजनक परिणाम प्राप्त होते हैं। जैसे-जैसे परमाणु का आकार छोटा होता जाता है, उसके अन्दर दूसरी धातुओं व पदार्थों से आपसी प्रतिक्रिया की क्षमता बढ़ती जाती है। इस विशेषता का उपयोग करके नैनो मेटेरियल से एकदम नया उत्पाद सरलता से तैयार किया जा सकता है।

नैनो मेटेरियल को तैयार करने के लिए सदैव दो पद्धतियों को उपयोग में लाया जाता है-प्रथम, बड़े से छोटा करने की पद्धति और द्वितीय, छोटे से बड़ा करने की पद्धति। इन पद्धतियों से एक आश्चर्यचकित कर देने वाला नैनो मेटेरियल तैयार किया जा सकता है।

प्रश्न 4.
चिकित्सा क्षेत्र में नैनो टेक्नोलॉजी की उपयोगिता बताइए। (2009)
उत्तर:
वर्तमान में नैनो टेक्नोलॉजी दुनिया भर में अपनी विशेषताओं और उपयोगिताओं के कारण अत्यन्त तेजी से लोकप्रिय हो रही है। वैसे तो नैनो टेक्नोलॉजी की उपयोगिताओं का क्षेत्र प्रसार अनन्त एवं असीम है, किन्तु वर्तमान में इसका सर्वाधिक प्रभाव चिकित्सा के क्षेत्र में ही देखने को मिल रहा है। वैज्ञानिक इस प्रौद्योगिकी का उपयोग कर ‘गोल्ड पार्टिकल बैक्टीरिया ट्यूमर सेल्स’ का निर्माण कर रहे हैं,जो कैंसर की संमूची प्रक्रिया को ही परिवर्तित करने में सक्षम होंगे। इससे ट्यूमर के खतरनाक तत्व को समाप्त कर दिया जाता है। इसके अतिरिक्त विशेषज्ञ कलाई में पहन सकने योग्य एक ऐसी कलाई घड़ी के रूप में नैनो टेक्नोलॉजी आधारित युक्ति का विकास करने में प्रयत्नशील हैं, जिसके माध्यम से व्यक्ति अपने शरीर की कई बीमारियों का समय रहते पता लगा पायेंगे।

प्रश्न 5.
“सुपर कम्प्यूटर नैनो टेक्नोलॉजी का ही परिणाम है।” समझाइए।
उत्तर:
वर्तमान युग प्रौद्योगिकी एवं कम्प्यूटर का युग है। आज कम्प्यूटर हमारे दिन-प्रतिदिन के जीवन के मध्य इतना घुल-मिल गये हैं कि इनके बिना अब जीवन की कल्पना करना भी आसान नहीं है। कम्प्यूटर की चर्चा चलते ही एक बड़े से घनाभाकार डिब्बे की आकृति मानस-पटल पर अंकित हो उठती है। एक समय था जब कम्प्यूटर अपनी शैशवावस्था में था। उसका आकार काफी बड़ा और उसकी क्षमता सीमित थी। किन्तु नैनो टेक्नोलॉजी के आगमन ने कम्प्यूटर की तो मानो काया ही पलट कर रख दी है। नैनो टेक्नोलॉजी के उपयोग से जहाँ कम्प्यूटर के आकार को छोटा किया जाना सम्भव हो सका है, वहीं उसकी तमाम क्षमताओं में आश्चर्यजनक बढ़ोत्तरी की जा सकती है। कम्प्यूटर के क्षेत्र में नैनो टेक्नोलॉजी के प्रभावी दखल का सबसे ज्वलंत उदाहरण है-‘सुपर कम्प्यूटर’ वास्तव में,सुपर कम्प्यूटर इस नैनो टेक्नोलॉजी का ही परिणाम है। पलभर में अरबों गणनाएँ त्रुटिरहित सम्पन्न कर देना, मैमोरी इतनी विशाल कि असंख्य आँकड़े समा जायें इत्यादि विशेषताएँ सुपर कम्प्यूटर में नैनो टेक्नोलॉजी के उपयोग से ही सम्भव हो सकी हैं।

प्रश्न 6.
निम्नलिखित क्षेत्रों में नैनो टेक्नोलॉजी की उपयोगिता बतलाइए
(1) पेंट
(2) कपड़ा
(3) जल-शोधन,
(4) टी. वी डिस्प्ले।
उत्तर:
जीवन से जुड़े विभिन्न क्षेत्रों में नैनो टेक्नोलॉजी की उपयोगिता अब सर्वविदित है। कुछ विशिष्ट क्षेत्रों में इस नवीन क्रान्तिकारी प्रौद्योगिकी के उपयोग की चर्चा निम्नवत् की जा सकती है-
(1) पेंट उद्योग में :
पेंट उद्योग के क्षेत्र में नैनो टेक्नोलॉजी अपनी पैठ बनाती जा रही है, जैसे-टिटेनियम डाइ-ऑक्साइड पेंट। यदि इस पेंट को नैनो मेटेरियल बनाकर अन्य पेंट में मिला दिया जाये तो उसकी चमक और अन्य गुण बढ़ जाते हैं। इस प्रकार निर्मित पेंट का जीवन अन्य सामान्य पेंट की तुलना में काफी अधिक होता है।

(2) कपड़ा उद्योग में :
कपड़ा उद्योग में भी नैनो टेक्नोलॉजी अपना प्रभाव एवं उपयोगिता सिद्ध कर रही है। इस चमत्कारी प्रौद्योगिकी का उपयोग करके ‘नैनोबेस्ड क्लॉथ’ बनाए जा रहे हैं,जो व्यक्ति के पसीने को सरलता से सोख लेते हैं। साथ ही, इस तकनीक से बना कपड़ा उपलब्ध अन्य कपड़ों की तुलना में अधिक टिकाऊ होता है।

(3) जल-शोधन में :
नैनो टेक्नोलॉजी रूपी वरदान का उपयोग जल-शोधन के क्षेत्र में भी किया जा सकता है। भारत जैसे विकासशील देश में जहाँ तीन-चौथाई जनसंख्या को शुद्ध पेयजल तक उपलब्ध नहीं है, इस प्रौद्योगिकी का उपयोग किसी ‘देव-वरदान’ से कम सिद्ध नहीं होगा। इस नवीन प्रौद्योगिकी के माध्यम से जल में मौजूद एवं स्वास्थ्य के लिए अत्यन्त हानिकारक ऑर्सेनिक तत्त्व को समाप्त कर दिया जाता है अथवा एकत्र कर जल से पृथक् कर दिया जाता है। इस प्रक्रिया में नैनो मिनरल, नैनो गोल्ड, नैनो सिल्वर व नाइट्रेट इत्यादि नैनो उत्पादों का प्रयोग किया जाता है।

(4) टी. वी. डिस्ले में :
नैनो टेक्नोलॉजी के आम जनजीवन में उपयोग का सबसे सुन्दर उदाहरण है टी.वी. डिस्प्ले का क्षेत्र। टेलीविजन पर दिखाई देने वाली तस्वीर की ‘ब्राइटनेस’ व ‘कंट्रास्ट’ को बेहतर बनाने के लिए इस प्रौद्योगिकी का उपयोग किया जाता है। इस प्रक्रिया में नैनो फास्टर मेटेरियल का उपयोग किया जाता है, जिससे टी.वी. की ‘पिक्चर क्वालिटी काफी उन्नत हो जाती है। वास्तव में, नैनो टेक्नोलॉजी एक ऐसी प्रौद्योगिकी है जिसे एक नये युग का सूत्रपात माना जा सकता है।

प्रश्न 7.
भारत में नैनो टेक्नोलॉजी के शिक्षण-प्रशिक्षण की उपलब्धता पर प्रकाश डालिए।
उत्तर:
यदि वर्तमान में भारत में नैनो टेक्नोलॉजी के प्रचार-प्रसार और उपयोग की बात की जाये तो नैनो टेक्नोलॉजी के शिक्षण-प्रशिक्षण में अभी बहुत कम निजी व सरकारी संस्थान आगे आए हैं। वर्तमान में, इस प्रौद्योगिकी से सम्बन्धित मात्र एम. टेक. नैनो टेक्नोलॉजी पाठ्यक्रम ही देश में उपलब्ध है, जिसके लिए निर्धारित योग्यता इंजीनियरिंग की डिग्री अथवा भौतिक विज्ञान, रसायन विज्ञान या जैव प्रौद्योगिकी के साथ स्नातकोत्तर डिग्री अनिवार्य है। एम. टेक.के इस कोर्स की कुल अवधि दो वर्ष है, जिसमें प्रशिक्षुओं को छ: माह का प्रशिक्षण उपलब्ध कराया जाता है।

आशा है कि जिस प्रकार यह प्रौद्योगिकी दनिया-भर में तेजी से अपने पैर पसार रही है. भारत में भी जल्दी ही विश्वविद्यालयों एवं संस्थानों में इससे सम्बन्धित अनेक पाठ्यक्रम पढ़ाए जाने लगेंगे।

नैनो टेक्नोलॉजी अति लघु उत्तरीय प्रश्न

प्रश्न 1.
किस वैज्ञानिक युक्ति की सहायता से वैज्ञानिक पहली बार अणु व परमाणु को देख पाए?
उत्तर:
जर्मन वैज्ञानिक गार्ड विनिग व स्विट्जरलैंड के हैनरिच रारेर के संयुक्त प्रयास से तैयार ‘स्कैनिंग टानलिंग माइक्रोस्कोप’ की सहायता से वैज्ञानिक पहली बार अणु व परमाणु को देख पाए।

प्रश्न 2.
एक नैनो मीटर मानव बाल के कौन-से हिस्से के बराबर होता है?
उत्तर:
एक नैनो मीटर का आकार ‘मानव बाल के 50 हजारवें’ हिस्से के बराबर होता है।

नैनो टेक्नोलॉजी पाठ का सारांश

संकलित वैज्ञानिक निबन्ध, ‘नैनो टेक्नोलॉजी’ में वर्तमान में चल रहे वैज्ञानिक युग में एक नये एवं क्रान्तिकारी युग के सूत्रपात की अवधारणा और सम्भावना की बात कही गई है।

‘नैनो’ शब्द की उत्पत्ति ग्रीक भाषा के शब्द ‘नैनों’ से हुई है, जिसका अर्थ है-‘बौना’ या ‘सूक्ष्म’। यह नाम जापान के वैज्ञानिक नौरिया तानीगूगूची ने वर्ष 1976 में दिया था । वास्तव में, नैनो टेक्नोलॉजी एक इकाई है जो एक मीटर के अरब हिस्से के बराबर होती है। एक से लेकर सौ नैनोमीटर को ‘नैनोडोमेन’ कहा जाता है।

प्रौद्योगिकी के क्षेत्र में नैनो टेक्नोलॉजी को एक नए युग के सूत्रपात के रूप में देखा जा रहा है। नैनो टेक्नोलॉजी की दुनिया अति सूक्ष्म है। अद्भुत बात यह है कि जितनी अधिक यह सूक्ष्म है उतनी ही अधिक सम्भावनाएँ इसमें निहित हैं। नैनो टेक्नोलॉजी के तहत मेटेरियल का आकार छोटा करके उसे ‘नैनोडोमेन’ बना लिया जाता है। ऐसा करने पर उस पदार्थ के विभिन्न गुण; जैसे-इलेक्ट्रिकल, मैकेनिकल, थर्मल व ऑप्टीकल, हर स्तर पर बदल जाते हैं। नैनो उत्पाद बेहद हल्के,छोटे,मजबूत,पारदर्शी एवं अपने मूल मेटेरियल से पूरी तरह से भिन्न होते हैं।

वर्तमान प्रौद्योगिकी के इस युग में नैनो टेक्नोलॉजी का क्षेत्र असीम है और इसके विस्तार की सम्भावनाएँ भी अनन्त हैं। आज नैनो टेक्नोलॉजी चिकित्सा क्षेत्र से लेकर उद्योगों तक कहीं-न-कहीं अपनी महत्वपूर्ण भूमिका अदा कर रही है। भारत में भी इसका उपयोग और विस्तार अत्यन्त तेजी से हो रहा है।

MP Board Class 12th Hindi Solutions

MP Board Class 12th Special Hindi सहायक वाचन Solutions Chapter 4 मेरे जीवन के कुछ चित्र (आत्मकथा, डॉ. रामकुमार वर्मा)

मेरे जीवन के कुछ चित्र अभ्यास प्रश्न

प्रश्न 1.
डॉ. रामकुमार वर्मा सबसे पहले अपनी माता का स्मरण क्यों करते हैं? उनकी माता की दिनचर्या लिखिए।
उत्तर:
अपने अतीत के झरोखों में झाँकते समय डॉ.रामकुमार वर्मा के मन-मस्तिष्क में जो सबसे पहली तस्वीर उभरती है वह है उनकी पूज्यनीय एवं प्रातः स्मरणीय माताजी राजरानी देवी की डॉ. वर्मा अपनी माताजी का बहुत आदर और सम्मान करते थे। उनकी माँ एक उच्च कोटि की संगीतज्ञ एवं काव्य-ज्ञान से परिपूर्ण थीं। उन्हीं की प्रेरणा,स्नेह,मार्गदर्शन और आशीर्वाद से वे कविता-लेखन के क्षेत्र में कदम रख सके थे, अत: डॉ.वर्मा अपनी माँ में न सिर्फ करुणामयी माँ का रूप देखते थे, अपितु एक गुरु का बिम्ब भी उन्हें अपनी माँ में दिखाई देता था। अत: डॉ. रामकुमार वर्मा सवसे पहले अपनी माता का स्मरण किया करते थे।

डॉ.रामकुमार वर्मा की माँ एक कुशल संगीतज्ञ एवं कला प्रेमी महिला थीं। उनके कण्ठ में अद्भुत मिठास थी। वे सुबह-सवेरे जल्दी उठकर शौच इत्यादि से निवृत्त हो राग विभास के स्वरों ‘भोर भयो जागह रघुनन्दन’ का तन्मयता से गान करती थीं। परिवार के अन्य सभी लोग उनके कोकिल कण्ठ को सुनने के लिए उनके पास एकत्रित हो जाते थे। ये नियम उनका प्रतिदिन का था। प्रातःकाल गान के पश्चात् ही वे अन्य आवश्यक कार्यों को सम्पादित किया करती थीं।”

प्रश्न 2.
बचपन में लेखक किस पात्र के अभिनय के विशेषज्ञ थे? इस अभिनय का प्रभाव उन पर कितने समय तक बना रहा?
उत्तर:
बचपन से ही लेखक को कुश्ती लड़ने,नाटक करने, अभिनय करने और पढ़ने का बहुत शौक था। वैसे तो लेखक ने नाटकों में कई पात्रों का अभिनय किया था, किन्तु ‘श्रीकृष्ण’ का अभिनय करने में उन्हें दक्षता प्राप्त थी और वे उसके विशेषज्ञ माने जाते थे। ‘श्रीकृष्ण’ का अभिनय करने के लिए उनके गुरुजन उन्हें शहर के बाहर भी लेकर जाते थे। कई लोग तो उन्हें ‘श्रीकृष्ण’ कहकर ही पुकारने लगे थे।

श्रीकृष्ण’ के अभिनय का लेखक पर प्रभाव पूरे बचपन भर बना रहा। इस पात्र के अतिरिक्त उन्हें किसी अन्य चरित्र का अभिनय करने में आनन्द प्राप्त नहीं होता था। जैसे-जैसे लेखक ने बाल्यावस्था से किशोरावस्था में प्रवेश किया ‘श्रीकृष्ण’ का अभिनय छूटता गया, क्योंकि अब वे बड़े हो गये थे।

प्रश्न 3.
नागपंचमी के दिन घटित अखाड़े की घटना का वर्णन अपने शब्दों में लिखिए।
उत्तर:
बचपन से ही लेखक को कुश्ती लड़ने, नाटक करने, अभिनय करने और पढ़ने इत्यादि का बहुत शौक था। साथ ही,लेखक इनकी प्रतियोगिताओं में भी भाग लेने के लिए सदैव ही उत्सुक रहते थे। एक बार बचपन में लेखक अपने पिताजी के साथ तमाशा देखने के लिए गये। वह नागपंचमी का दिन था। अखाड़े में कुश्ती की प्रतियोगिता चल रही थी। दूर-दूर से कई पहलवान कुश्ती के मैदान में अपना-अपना भाग्य परखने के लिए डटे थे। प्रतियोगिता के दौरान एक पहलवान सबको ‘चित्त’ करता गया और ‘फुल्लम’ (सर्व विजयी) घोषित हुआ। दम्भ के मारे वह पहलवान अखाड़े की मिट्टी को शरीर पर मलते हुए ताल ठोंककर किसी को भी उसका मुकाबला करने के लिए खुली चुनौती देने लगा। लेखक अपने पिताजी के साथ ये सब देख रहे थे।

उनसे यूँ चुनौती से दूर भाग जाना गवारा न हुआ। उन्होंने आव देखा न ताव और उस ‘फुल्लम’ की चुनौती को स्वीकार करते हुए कुश्ती के लिए ललकार दिया। दोनों पहलवानों ने अखाड़े की मिट्टी में अपने-अपने हाथ मले और बोल बजरंग’ के उद्घोष के साथ भिड़ गये। मात्र 5 मिनट से भी कम समय में वह ‘फुल्लम’ पहलवान ‘फुस्स’ हो धरती की धूल चाट रहा था और लेखक के चेहरे पर विजयी आभा तैर रही थी। तालियों की करतल ध्वनि के मध्य लेखक को शेरवानी और नकद पुरस्कार उपहारस्वरूप दिये गये जो लेखक ने प्राप्त करके उदारता के साथ उसी ‘फुल्लम’ पहलवान को प्रदान कर दिये।

प्रश्न 4.
माँ ने रामकुमार वर्मा को पढ़ाई के सम्बन्ध में क्या निर्देश दिए थे? (2010)
उत्तर:
डॉ. रामकुमार वर्मा की माँ एक सुशिक्षित एवं सुसंस्कृत महिला थीं। वे अपने बच्चों में भी शिक्षा के उच्च संस्कार प्रदान करना चाहती थीं। यह उन्हीं के मार्गदर्शन और सीख का फल था कि डॉ.रामकुमार वर्मा कभी अनुत्तीर्ण नहीं हुए, बल्कि वे सदैव ‘डिवीजन’ से उत्तीर्ण होते रहे। पढ़ाई के सम्बन्ध में निर्देशित करते हुए उनकी माँ ने उनसे कहा था कि पढ़ाई में उन्हें पहले दर्जे का ध्यान रखना चाहिए। अपने लक्ष्य के प्रति उसी एकाग्रता एवं समर्पण के साथ प्रयत्नशील रहना चाहिए जिस प्रकार महाभारत काल में अर्जुन ने चिड़िया की केवल आँख पर अपना ध्यान रखा था।

प्रश्न 5.
लेखक ने स्कूल जाना क्यों छोड़ा?
उत्तर:
लेखक जब अपनी किशोरावस्था से युवावस्था में प्रवेश कर रहे थे तब देश में स्वतन्त्रता के लिए संघर्ष अपने चरम पर था। महात्मा गाँधीजी के आह्वान पर देशभर में असहयोग आन्दोलन चलाया जा रहा था। लेखक ने भी इस असहयोग आन्दोलन में भाग लिया। सन् 1921 में जब नागपुर में आयोजित कांग्रेस के सम्मेलन में असहयोग-आन्दोलन का प्रस्ताव पारित हुआ तो लेखक ने मन-ही-मन स्कूल छोड़ने का प्रण कर लिया। लेखक नरसिंहपुर में रहते थे और उनके पिताजी मंडला (सी.पी) में ‘ऐक्स्ट्रा असिस्टेंट कमिश्नर’ थे। उस समय लेखक कक्षा 10 में पढ़ते थे और उन्हें 6 रुपये का वजीफा भी मिलता था। अपने प्रण को पूरा करते हुए लेखक ने स्कूल छोड़ दिया। यह समाचार सुनकर उनके पिताजी ने उन्हें भविष्य के स्वप्न दिखाते हुए पुनः स्कूल जाने के लिए कहा,किन्तु लेखक नहीं माने। पिताजी उनसे रुष्ट हो गये और बेंत से उन्हें दण्ड भी दिया। लेखक ने 72 घण्टे तक उपवास रखा और अपने स्कूल न जाने के निर्णय पर अडिग रहे।

प्रश्न 6.
लेखक ने ‘देश-सेवा’ कविता किन परिस्थितियों में लिखी और उसका क्या परिणाम हुआ? (2016)
उत्तर:
उन दिनों देश-भर में असहयोग आन्दोलन की गूंज थी। बच्चे, बड़े, स्त्री-पुरुष सभी बढ़-चढ़कर उस आन्दोलन में भाग ले रहे थे। गाँधीजी के नेतृत्व में समूचा राष्ट्र मानो एक साथ उठ खड़ा हुआ था। उन दिनों जुलूस राष्ट्रीय झण्डे को लेकर निकलते थे और गाने के लिए नए-नए गीतों की आवश्यकता पड़ती थी। उसी समय देश-सेवा’ कविता के लिए कानपुर के श्री बेनीमाधव खन्ना की 51 रुपये के नकद पुरस्कार वाली घोषणा निकली। लेखक के पिताजी ने लेखक से कहलवाया; “छोटे गाँधीजी से कहो देश-सेवा पर कविता लिखें।” लेखक ने पिताजी की आज्ञा को चुनौती के रूप में स्वीकार करते हुए कविता लिखने की ठान ली। उन्होंने बिना किसी को बतलाए कविता लिखकर भेज दी। तीन माह बाद सूचना मिली कि लेखक की भेजी गई कविता को सर्वोत्तम आँका गया है और उन्हें 51 रुपये का पुरस्कार प्रेषित किया जा रहा है। यूँ कविता चयन की बात सुनकर प्रसन्न माताजी ने लेखक पर अभिमान जताते हुए कहा था, “मुझे गर्व है कि मेरा एक बेटा देश-सेवा में तन-मन से काम कर रहा है” और लेखक के पिताजी ने प्रसन्न होकर लेखक के लिए एक कोट बनवाया था।

मेरे जीवन के कुछ चित्र अति लघु उत्तरीय प्रश्न

प्रश्न 1.
लेखक डॉ. रामकुमार वर्मा के लिए ‘देव पुरस्कार’ से भी अधिक मूल्यवान क्या था?
उत्तर:
लेखक की माताजी संगीतज्ञ एवं काव्य-ज्ञान से पूर्ण थीं। वे उषा-काल में उठकर ‘भोर भयो जागहु रघुनन्दन’ गातीं और लेखक से भी गाने के लिए कहतीं। ठीक गाने पर लेखक को एक जलेबी अधिक का पुरस्कार मिलता था जो लेखक के लिए किसी ‘देव पुरस्कार’ से भी अधिक मूल्यवान था।

प्रश्न 2.
बचपन में लेखक डॉ. रामकुमार वर्मा की विशेष रुचि क्या थीं?
उत्तर:
लेखक को बचपन से ही ‘प्रतियोगिता’ विशेष प्रिय रही। कुश्ती लड़ने, नाटक करने, अभिनय करने और पढ़ने में लेखक की विशेष रुचि रही।

मेरे जीवन के कुछ चित्र पाठ का सारांश

सुप्रसिद्ध कहानीकार ‘डॉ. रामकुमार वर्मा द्वारा लिखित प्रस्तुत आत्मकथा ‘मेरे जीवन के कुछ चित्र’ में लेखक ने अपने बचपन एवं प्रियजनों से सम्बन्धित अतीत की कुछ घटनाओं का सुन्दर एवं सजीव वर्णन किया है।

लेखक के अनुसार उनके जीवन में उनकी माँ का स्थान सर्वोपरि है। उनकी माता का नाम राजरानी देवी था। वे एक उच्च कोटि की संगीतज्ञ थीं और उन्हें काव्य-ज्ञान भी खूब था। वे प्रात:काल जल्दी उठकर राग विभास में गान करतीं और परिवार के सभी लोग सुध-बुध खोकर तन्मयता से उनके गान को सुना करते थे। उन्हीं की प्रेरणा एवं प्रभाव से लेखक कविता-लेखन के क्षेत्र में प्रविष्ट हुए। बचपन से ही लेखक को कुश्ती लड़ने, नाटक खेलने, अभिनय करने और पढ़ने इत्यादि में गहन रुचि थी। किशोरावस्था में एक बार लेखक ने अपने से कहीं अधिक बलशाली प्रतिद्वन्द्वी को कुश्ती में हराकर पुरस्कार जीता था। अभिनय की यदि बात की जाये तो लेखक श्रीकृष्ण’ के अभिनय के विशेषज्ञ थे। श्रीकृष्ण के अभिनय में उन्होंने बहुत-से पुरस्कार अर्जित किये थे।

लेखक पढ़ने में भी काफी होशियार थे। वे सदैव ‘डिवीजन’ में ही उत्तीर्ण हुआ करते थे। माँ की प्रेरणा पर वे सदैव लक्ष्य पर ही अपना ध्यान केन्द्रित करते और उसे पाकर ही साँस लेते थे। लेखक ने अपने जीवन की प्रथम कविता स्वयं-प्रेरणा से एक छोटी-सी तुकबन्दी के रूप में लिखी थी। युवावस्था में लेखक ने असहयोग आन्दोलन में भाग लिया और विरोधस्वरूप स्कूल छोड़ दिया। एक बार पिताजी के कहने पर लेखक ने देश-सेवा पर एक कविता लिखी और 51 रुपये का नकद पुरस्कार अर्जित कर अपने माता-पिता को गौरवान्वित किया। समाचार के साथ-साथ अपने बचपन की यादों से जुड़ी ये कहानियाँ अब लेखक के मस्तिष्क से निकलती जा रही हैं।

MP Board Class 12th Hindi Solutions

MP Board Class 12th Biology Important Questions Chapter 4 Reproductive Health

Reproductive Health Important Questions

Reproductive Health Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
The gestation period in human female is :
(a) 30 days
(b) 200 days
(c) 250 days
(d) 270-280 days.
Answer:
(d) 270-280 days.

Question 2.
In population growth curve the early phase is also called as :
(a) Exponential phase
(b) Stationary phase
(c) Lag period
(d) None of these.
Answer:
(c) Lag period

Question 3.
Removal of fallopian tube in human female is called :
(a) Vesectomy
(b) Tubectomy
(c) Ovaritectomy
(d) Castration.
Answer:
(b) Tubectomy

Question 4.
The cause of population explosion in large cities is : (MP 2009 Set A)
(a) Chances of education
(b) Available facilities
(c) Sources of income
(d) All of these.
Answer:
(d) All of these.

Question 5.
Population density is more in : (MP 2009 Set B)
(a) USA
(b) India
(c) China
(d) Japan.
Answer:
(b) India

Question 6.
Ratio of death rate and birth rate percentage is called : (MP 2016)
(a) Organic index
(b) Demography
(c) Population density
(d) Total population.
Answer:
(a) Organic index

Question 7.
Which of the following is the best solution of population problem in India :
(a) Conservation of natural resources
(b) Growth of medicinal fascility
(c) Decreasing in birth rate
(d) Increasing in food product.
Answer:
(c) Decreasing in birth rate

Question 8.
In which state has less population density :
(a) Manipur
(b) Rajasthan
(c) Meghalaya
(d) Arunachal pradesh.
Answer:
(d) Arunachal pradesh.

Question 9.
Meaning of test tube-baby, when child :
(a) Produce from unfertilized egg
(b) Developed in test-tube
(c) Developed by tissue culture
(d) Fertilization of ovum to out side the body then transplant in uterus.
Answer:
(d) Fertilization of ovum to out side the body then transplant in uterus.

Question 10.
Study of human population growth is :
(a) Anthropology
(b) Sociology
(c) Demography
(d) Geography.
Answer:
(c) Demography

Question 11.
Amniocentesis is used for determining :
(a) Heart disease
(b) Brain disease
(c) Hereditary disease of embryo
(d) All of these.
Answer:
(c) Hereditary disease of embryo

Question 12.
Amniocentesis is the withdrawal of amniotic fluid in :
(a) Menopause
(b) Lactation
(c) Gastation
(d) Pregnancy.
Answer:
(d) Pregnancy.

Question 2.
Fill in the blanks :

1. Statisitical study of population is called ………………
2. According to Malthus population grows ……………… whereas the means of its subsistinance grows ………………
3. According to census 2001, the population of India was ………………
4. The entry and exit of member in any population is called ………………
5. Cutting and ligating ends of segments of vas deferense is called ………………
6. The testing of sex of embryo is done by ………………
7. Immigration ……………… the population.
8. Study of differences in foetus is called ………………
9. Theory of population growth was given by ………………

Answer:

1. Demography
2. Geometrically Arithmatically
3. 1,02,70,15,247
4. Migration
5. Vasectomy
6. Amniocentesis
7. Increases
8. Teratology
9. Malthus.

Question 3.
Match the followings :
I.

Answer:

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

II.

Answer:

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

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

1. Give the full name of IUCD.
2. Write a disease which is transmitted by sexual contact.
3. Write the full name of ZIFT.
4. Name the method in which cutting and binding of spermatic duct in male.
5. What is the name of the study of population?
6. World population day celebrated on.
7. Name the process in which implantation of embryo in fallopian tube.
8. Name the stage of life which is called puberty.
9. Name the disease caused by HIV.
10. Who gave the human population growth theory?
11. Write the name of technique in which testing of amniotic fluid to find out the sex and disorders of the foetus.
12. Name the technique by which found the AIDS.
13. Write the lull name of GIFT.
14. Name the technique in which removal of a segment of oviduct.

Answer:

1. Intrauterine Contraceptive Device
2. Gonorrhoea
3. Zygote Intrafallopian Transfer
4. Vasectomy
5. Demography
6. 11 July
7. Actopic pregnancy
8. 13 to 18 years
9. AIDS
10. T.R.Malthus
11. Amniocentesis
12. ELISA test
13. Gamete Intrafaillopian Transfer
14. Tubectomy.

Reproductive Health Important Questions Very Short Answer Type Questions

Question 1.
Write one benefit of condom.
Answer:
Condom provides protection from Sexually Transmitted Diseases (STDs).

Question 2.
What is the name of contraceptive pill which is taken only in once in a week?
Answer:
“Saheli.”

Question 3.
Write the full form of IUCD.
Answer:
Intra Uterine Contraceptive Device.

Question 4.
Write the full form of STDs.
Answer:
Sexually Transmitted Diseases.

Question 5.
What is the legal age for marriage of male and female in India?
Answer:
For male 21 Years and for female 18 years.

Question 6.
Write the name of two STDs which are spread through infected blood.
Answer:
AIDS, Hepatitis – B.

Question 7.
Write the name of two diseases which are caused by sexual contact.
Answer:
Gonorrhoea, Syphilis.

Question 8.
Write the full form of HIV and AIDS.
Answer:
HIV : Human Immunodeficiency Virus.
AIDS : Acquired Immune Deficiency Syndrome.

Question 9.
Write the full form of ZIFT.
Answer:
Zygote Intrafallopian Transfer.

Question 10.
What is the process for surgical sterilization in males called?
Answer:
Vasectomy.

Reproductive Health Short Answer Type Questions

Question 1.
Explain the following :

1. Tubectomy
2. Vasectomy.

Answer:
1. Tubectomy:
The surgical removal of a segment of oviduct and then ligating the cut end is called tubectomy. It is applied in females to check the pregnancy.

2. Vasectomy:
Surgical cutting and ligating ends of segments of vas deferens is called vasectomy.

Question 2.
What is amniocentesis? Write its effects and two advantages.
Answer:
Amniocentesis:
It is prenatal diagnostic technique in which amniotic fluid of uterus is isolated by a surgical needle and foetus cells are cultured on a culture medium and chromosomes are examined.

This technique is used to understand the following things or Advantages:

1. Chromosomal abnormalities like that of Down’s syndrome, Philadelphia syndrome and Edward’s syndrome.
2. Metabolic disorders like that of PKV, Cretinism, Alkaptonuria, etc.
3. Sex of the embryo can be examined by this technique.

Effects of amniocentesis:
Due to this type of test, the female embryos are being eradicated. This leads into the decrease in number of females which may cause a serious problem.

Question 3.
Explain the social causes of human population growth.
Answer:
Social causes of human population growth rate are:

1. Illiteracy in society.
2. Low level of society.
3. Various orthodox tradition like son leads to progeny.
4. Social barriers.
5. Early child marriage presuming that after mid-age marriage reproductive capacity degenerates.
6. Social backwardness.
7. Social set – up that “Putra Ratan se Moksh milta hai”.

Question 4.
What do you think about the significance of reproductive health in a society?
Answer:
Significance of reproductive health in a society are:

1. Control over the transmission of STDs.
2. Less death due to reproduction related diseases, like AIDS, cancer of reproductive tract.
3. Control in population explosion.
4. Not only this reproductive health of men and women affectsthe health of the next generation.

Question 5.
Suggest the aspects of reproductive health which need to be given special attention in the present scenario.
Answer:
Special attention need to be given to the following aspects:

1. Introduction of sex education in school that to helps in eradicating myths and misconceptions regarding sex – related aspects.
2. Proper information about reproductive organs, safe and hygienic sexual practices and Sexually Transmitted Diseases.
3. Awareness of problems due to uncontrolled population growth, social evils like sex abuse and sex – related crimes etc.
4. Strong infrastructural facilities, professional expertise and material support to provide medical assistance and care to people in reproduction related problems.
5. Educating people about available birth control options, care of pregnant mothers, postnatal care of mother and child, importance of breast feeding, equal opportunities for the male and female child.

Question 6.
Is sex education necessary in schools. Why?
Answer:
Yes, sex education is necessary in schools because:

1. It will provide proper information about reproductive organs, adolescence, safe, hygienic sexual practices and Sexually Transmitted Diseases (STDs).
2. It will provide right information to avoid myths and misconceptions about sex related queries.

Question 7.
Do you think that reproductive health in our country has improved in the past 50 years? If yes, mention some such areas of improvement.
Answer:
Yes, reproductive health in our country has improved in the last 50 years.

Some areas of improvement are:

1. Better awareness about sex-related matters.
2. Increased number of medically assisted deliveries and better post-natal care of child and mother leading to decreased maternal and infant mortality rates.
3. Increased number of couples with small families.
4. Better direction and cure of STDs and overall increased medical facilities for all sex – related problems.

Question 8.
What are the suggested reasons of population explosion?
Answer:
The situation where population exceeds productive capacity is known as popu-lation explosion. In nature, the amount of resources are limited hence, if the population increases in the present rate and increasing beyond the limit, they (Resources) would get exhausted.

Reasons of population explosion : Following are the reasons of population explosion:

1. Increasing birth rate.
2. Decreasing death rate.
3. Higher rate of reproduction.
4. Medical services have brought down mortality due to fatal diseases and epidemics.
5. Lack of predator in the civilized world today, the only predator of man is man himself.

Question 9.
Is the use of contraceptives justified? Give reasons.
Answer:
Yes, use of contraceptive is justified because it helps to control the rapid growth of human population. It will also help in preventing unwanted pregnancies and STDs. Contraceptive also help in controlling the population growth rate.

Question 10.
Removal of gonads can not be considered as a contraceptive option, why?
Answer:
Removal of gonads not only stops the production of gametes but will also stop the secretions of various important hormones, which are important for bodily func¬tions. This method is irreversible and thus, can not be considered as a contraceptive method.

Question 11.
Amniocentesis for sex determination is banned in our country. Is this ban necessary? Comment.
Answer:
Yes, the ban is necessary because amniocentesis is misused for determining the sex of the foetus and then aborting the child if it is a female. This process is illegal as it causes harm to the foetus as well as mother it can also disturb the sex ratio.

Question 12.
What is test – tube baby?
Answer:
In some cases, a woman is unable to have a normal fertilization to bear the child. In such cases, test – tube technique may be successful. In this technique, the unfertilized eggs of such woman is isolated in aseptic condition and fertilized it in test – tube by the sperms of her husband. The fertilized egg or blastocyst can be maintained in vitro till it gets 32 celled stage. It can be implanted in the uterus of the female. The female remains under the supervision of doctor till completion of gestation period of 280 days. The baby produced in such a way is called a test – tube baby.

Question 13.
What is GIFT? Explain in brief.
Answer:
GIFT (Gametes Intrafallopian Transfer): It is a latest technique to produce a child. In this technique, the gametes are kept separately in a catheter and injected directly into the fallopian tube of the woman using laproscopy. Thus, in this case, fertilization occurs inside the body of woman. Prior to injection of gametes, the mother would be given hormones for about a week to stimulate follicle formation. This causes development of several eggs i.e., super ovulation. The first GIFT in India was done in Mumbai and twins were born in August, 1990.

Reproductive Health Long Answer Type Questions

Question 1.
Suggest some methods to assist infertile couples to have children.
Answer:
If the couples are enable birth the children and corrections are not possible, the couples could be assisted to have children through certain special techniques, com¬monly known as Assisted Reproductive Technologies (ART). Some methods are given as:

(1) In Vitro Fertilization (IVF):
In this method, ova from the female and the sperm from the male are collected and induced to form zygote under stimulated conditions in the laboratory. This process is called In Vitro Fertilization (IVF). Some method given as follows:

1. Zygote Intrafallopian Transfer (ZIFT):
The zygote or early embryo with up to 8 blastomeres is transferred into the fallopian tube.

2. Intra Uterine Transfer (IUT):
Embryo with more than 8 blastomeres is trans – ferred into the uterus in females who cannot conceive embryos formed by fusion of gametes in another female are transfered.

3. Test – tube baby:
In this method, ova from the donor (female) and sperm from the donor (male) are collected and are induced to form zygote under stimulated conditions in the laboratory. The zygote could then be transferred into the fallopian tube and embryos transferred intc the uterus, to complete its further development. The child bom from this method is called test-tube baby.

(2) Gamete Intrafallopian Transfer (GIFT):
It is the transfer of an ovum collected from a donor into the fallopian tube of another female who cannot produce one, but can provide suitable environment for fertilization and further development of the embryo.

(3) Intra Cytoplasmic Sperm Injection (ICSI):
It is a procedure to form an embryo in the laboratory by directly injecting the sperm into an ovum.

(4) Artificial Insemination (AI):
In this method, the semen collected either from the husband or a healthy donor is artificially introduced into the vegina or into the uterus (Intra Uterine Insemination, IUI). This technique is used in cases where the male is unable to inseminate sperms in the female reproductive tract or due to very low sperm counts in the ejaculation.

(5) Host Mothering:
In this process, the embryo is transferred from the biological mother to a surrogate mother. The embryo then develops till it is fully developed or partially developed. It is then transferred to the biological mother or into any other. This technique is useful for females in which embryo forms but is not able to develop.

Question 2.
What are the measures one has to take to prevent from contracting STDs?
Answer:
STDs can be prevented by the following methods:

1. Avoid sex with unknown partners/multiple partners.
2. Always use condoms during coitus.
3. Always contact a qualified doctor for any doubt in early stage of infection and get complete treatment if diagnosed with disease.

Question 3.
State True/False with explanation.

Question (a)
Abortion could happen spontaneously too. (True/False)
Answer:
False, Abortion does not happen under normal conditions. It happens accidently or under the will of Parents.

Question (b)
Infertility is defined as the inability to produce a viable offspring and is always due to abnormalities/defects in the female partner. (True/False)
Answer:
False, Sterility always does not occur due to female. Sometimes males are also responsible for this.

Question (c)
Complete lactation could help as a natural method of contraception. (True/False)
Answer:
True, Menstrual cycle does not occur after parturition which can act as natural contraception but this method is functional for a period of six months from parturition.

Question (d)
Creating awareness about sex related aspects is an effective method to im-prove reproductive health of the people. (True/False)
Answer:
True, this creates better reproductive health among people.

Question 4.
Correct the following statements:

Question (a)
Surgical methods of contraception prevent gamete formation.
Answer:
It prevents the transportation of gametes not their formation.

Question (b)
All sexually transmitted diseases are completely curable.
Answer:
Hepatitis – B and AIDS are not curable.

Question (c)
Oral pills are very popular contraceptives among the rural women.
Answer:
Oral pills are not popular among rural women. They require sex education.

Question (d)
In E.T. techniques, embryos are always transferred into the uterus.
Answer:
In E.T. techniques, 8 – celled blastomere is transferred into the fallopian tube. While more than 8 – celled blastomere is transferred into the uterus.

MP Board Class 12th Biology Important Questions

MP Board Class 12th Biology Important Questions Chapter 3 Human Reproduction

Human Reproduction Important Questions

Human Reproduction Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
The number of chromosome in human cell will be :
(a) 23
(b) 46
(c) 92
(d) 22
Answer:
(b) 46

Question 2.
The hormone estrogen is secreted by :
(a) Corpus luteum
(b) Graafian follicle
(c) Uterus
(d) Vagina.
Answer:
(b) Graafian follicle

Question 3.
The copulatory organ in female human being is :
(a) Fallopian tube
(b) Uterus
(c) Clitoris
(d) Vagina.
Answer:
(c) Clitoris

Question 4.
The gestation period in rabbit is about :
(a) 27 days
(b) 22 – 30 days
(c) 45 days
(d) 28 days.
Answer:
(b) 22 – 30 days

Question 5.
Hormone secreted during delivery is:
(a) Progesterone
(b) Thyroxine
(c) Relaxin
(d) Glucocorticoid.
Answer:
(c) Relaxin

Question 6.
Blastopore is formed in :
(a) Gastrula
(b) Blastula
(c) Morula
(d) Nurmula
Answer:
(a) Gastrula

Question 7.
Number of parents involved in asexual reproduction is :
(a) Many
(b) Three
(c) Two
(d) One
Answer:
(d) One

Question 8.
Sertoli cells are found in :
(a) Kidney
(b) Ovary
(c) Liver
(d) Testis.
Answer:
(d) Testis.

Question 9.
Which two are found in human semen in more quantity :
(a) Ribos and potassium
(b) Fructose and calcium
(c) Glucose and calcium
(d) DNA and testosteron.
Answer:
(b) Fructose and calcium

Question 10.
Which part of the fallopian tube is nearest to ovary :
(a) Ampula
(b) Isthmus
(c) Infundibulum
(d) DNA and testosteron.
Answer:
(c) Infundibulum

Question 11.
In ovarian cycle of human ovulation is starts from :
(a) 1st day
(b) 5th day
(c) 14th day
(d) 28th day.
Answer:
(c) 14th day

Question 12.
Which hormone controls the sperm formation :
(a) ADH
(b) FSH
(c) LH
(d) STH.
Answer:
(b) FSH

Question 13.
Which is responsible for movement of sperm :
(a) Cilia
(b) Flagella
(c) Basal body
(d) Nucleosome.
Answer:
(b) Flagella

Question 14.
Sperms are mature in :
(a) In oviduct
(b) In epididymis
(c) In vagina
(d) All of the above
Answer:
(b) In epididymis

Question 15.
Seminiferous tubules are found in :
(a) In testis
(b) In ovary
(c) In kidney
(d) In lungs.
Answer:
(a) In testis

Question 2.
Fill in the blanks :

1. The nature of semen is ………………
2. The male sex hormone testosterone is produced by ……………… in testis.
3. The structure between placenta and foetus is called ………………
4. Human being are ……………… breeders.
5. The site of fertilization and implantation in human female is ……………… and ………………
6. After ……………… year growth does not occur in girls.
7. ……………… hormone is secreted during child birth.
8. Segments of testis is consist of ……………… tubules.
9. Testis starts the secretion of ……………… hormone at puberty.
10. The process of fertilization is occurs in ……………… tube.
11. ……………… provides the nutrition to embryo.
12. ……………… hormones are secreted by graafian follicle.

Answer:

1. Alkaline
2. Leyding cells
3. Umblical cord
4. Continuous
5. Oviducts, uterus
6. 14
7. Relaxin
8. Seminiferous tubules
9. Testosteron
10. Follopean tube
11. Placenta
12. Estrogen and Progesteron.

Question 3.
Match the followings:
I.

Answer:

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

II.

Answer:

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

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

1. How many sperms will be produced from 24 spermatocytes during spermatogenesis?
2. Where does fertilization takes place in mammals?
3. How many polar bodies are formed during the formation of one gamete?
4. How many polar bodies are formed during the formation of ovum during oogenesis?
5. Write the name of three layers of gastrula.
6. Spermatogenesis is the example of.
7. How many germ layers are found in gastrula stage?
8. Write the duration of gastation period in human cases.
9. How many autosomes are found in human sperm?
10. Name the process in which formation and maturation of ova.
11. Name the main store house of sperms.
12. Skeletal muscle is originated by these layer.
13. Name the process in which zygote starts dividing by specific mitotic divisions.
14. In which month body hair developed in embryo.

Answer:

1. 1.96
2. Fallopian tube
3. 2
4. 3
5. Ectoderm, Mesoderm and Endoderm
6. Male gamete formation
7. Three
8. 280 days
9. 22
10. Oogenesis
11. Epididymis
12. Ectoderm
13. Cleavage
14. Fourth month.

Human Reproduction Very Short Answer Type Questions

Question 1.
After fertilization, how many days are needed for the birth of human child?
Answer:
280 days (9 months and 10 days).

Question 2.
To produce the new organisms of their own kind is called by a term, name it.
Answer:
Reproduction.

Question 3.
By which name, the reproduction happens by means of fusion of two different gametes?
Answer:
Sexual reproduction.

Question 4.
Which gametogenesis goes on till life span in human beings after attaining puberty?
Answer:
Spermatogenesis.

Question 5.
The stoppage of menstrual cycle in a 50 yrs. old female is known as.
Answer:
Menopause.

Question 6.
What is pregnancy?
Answer: The time period between fertilization to the birth of child is called pregnancy.

Question 7.
Where is carpora cavernosa found?
Answer:
Carpora cavernosa is found in penis.

Question 8.
What is the gestation period in elephant, dog and cat?
Answer:
Elephant 641 days, dog 58 – 68 days, cat 63 days.

Question 9.
Name the hormone that relaxes pubic symphysis during parturition.
Answer:
Relaxin hormone.

Human Reproduction Short Answer Type Questions

Question 1.
Why testes are found outside the abdominal cavity in males?
Answer:
In male, one pair of testes are found in the scrotum or scrotal sac, which are situated outside the abdomen. Temperature of this scrotum is always 2°C less than the body temperature, which is suitable for formation and growth of sperm, otherwise spermatogenesis will not occur. Therefore, testes are situated outside the abdomen in man.

Question 2.
What will happen if leydig cells of testis in males are destroyed?
Answer:
The endocrine cells of the testis are the leydig cells, they are situated in between the seminiferous tubules. Leydig cells secrete the male sex hormones androgens. Testes secrete four types of androgens:

1. Testosterone
2. Androsterone
3. Epiandosterone and
4. Dihydroepiandrosterone.

Out of these male sex hormone is testosterone.

Functions of Testosterone:

1. Testosterone stimulates testes to descend into the scrotum in embryos.
2. It helps in the development of secondary sexual characters.
3. Stimulates spermatogenesis.

If leydig cells are removed from the body of males, then the above mentioned functions will stop.

Question 3.
Describe the structure of human egg.
Or
Draw neat well – labelled diagram of human ovum which is ready for fertilization.
Answer:
The egg of human being is rounded and non – motile. It lacks yolk and contains a large Cytoplasm Zona pellucida. amount of cytoplasm. A nucleus (haploid) is present in the centre of egg. Whole egg is covered by a translucent and non – cellular membrane known as zona pellucida. The zona pellucida is irregularly covered by follicle cells. This layer is called as corona radiata. The cells of corona radiata are disintegrated before fertilization.

Question 4.
What is menstrual cycle ? Which hormones regulate menstrual cycle?
Answer:
The reproductive cycle in the female primates is called menstrual cycle. The uterus linings becomes thick and spongy to receive fertilised egg. If the egg is not fertilised, this lining is not needed any longer so, it slowly breaks and comes out through vagina along with blood and mucus. This is called menstruation. It is repeated at an average interval of about 28/29 days.

Following hormones regulate this cycle:

1. Gonadotropin
2. Estrogen
3. Luteinizing hormone
4. Follicular stimulating hormone
5. Progesterone

Question 5.
What is parturition? Which hormones are involved in induction of parturition?
Answer:
The process of delivery of the foetus (child birth) at the end of the pregnancy is called parturition. The signals for parturition originate from the fully developed foetus and the placenta which trigger the release of oxytocin from the maternal pitutary. Oxytocin acts on the uterine muscles and induces stronger uterine contractions leading to expulsion of the baby. Relaxin hormone released by the ovary widens the vagina to facilitate birth.

Following hormones are involved in induction of parturition:

1. Cortisol
2. Estrogen
3. Oxytocin.

Question 6.
In our society the women are often blamed for giving birth to daughters. Can you explain why this is not correct?
Answer:
Women are blamed for giving birth to daughters. This is wrong because sex of the baby is determined by the sperm that can have either X or Y – chromosome. Women have only one type of chromosome (X) in all the ova.

1. If the sperm having X-chromosome fertillises the ovum (X), the resulting zygote (XX) will become a female.
2. If the sperm having Y-chromosome fertillises the ovum (X), the resulting zygote (XY) will become a male.

Question 7.
How many eggs are released by a human ovary in a month? How many eggs do you think would have been released if the mother gave birth to identical twins? Would your answer change if the twins born were fraternal?
Answer:
Only one egg is released by a human (female) ovary in a month. Only one egg is released if the mother gave birth to identical twins. Yes, two or more eggs are released in case fraternal twins are born.

Question 8.
Name the hormones involved in regulation of spermatogenesis.
Answer:
The hormones involved in regulation of spermatogenesis are:

1. Gonadotropin releasing hormone
2. Luteinizing hormone (LH)
3. Follicle stimulating hormone and
4. Testosterone.

Question 9.
Define spermiogenesis and spermiation.
Answer:
Spermiogenesis:
The process involving transformation of spermatid into spermatozoa is called spermiogenesis.

Spermiation:
After spermiogenesis, sperm heads became embedded in the sertoli cells and are finally released from the seminiferous tubules by the process called spermiation.

Question 10.
Give composition of seminal plasma.
Answer:
Composition of seminal plasma : Fructose, calcium ion, some enzymes prostaglandins.

Question 11.
Draw a labelled diagram of male reproductive system.
Answer:

Question 12.
Draw a labelled diagram of female reproductive system.
Answer:

Question 13.
Write two major functions each of testis and ovary.
Answer:
Functions of Testis:

1. Production of sperms by seminiferous tubules.
2. Production of male sex hormone, testosterone by leydig cells.

Functions of Ovary:

1. Production of ova (eggs).
2. Production of female sex hormones, estrogen and progesterone.

Question 14.
Explain menarchy or menopause.
Answer:
Menopause:
In every human female, puberty period starts from 12 – 13 yrs of age to 45 – 50 yrs of the age. During this period except pregnancy at every interval of a month during 26th day to 28th day. If pregnancy does not occur then the internal wall of the uterus secretes out mucilaginous liquid along with blood. Secretion continues for 3 – 4 days called menses. As it comes at definite period so, it is called menstruation cycle. At the age of 40 – 50 yrs. menses stop and females reach to a stage called menopause. Ability of pregnancy also stops after attaining menopause.

Question 15.
Draw a well labelled diagram of the T.S. of human testis.
Answer:

Question 16.
What is the position of fallopian tubule in female reproductive organs? What are their significance?
Answer:
Fallopian tubules are a pair of small muscular tubes, one each on either side of the uterus. These tubules extend from the vicinity of the ovary to the ovary. Each tubule is about 10 cm in length. The free end of each tube lies near the ovary of its side. This end is funnel shaped and fimbriated. It is called ostium and infundibulum. Infundibulum opens in the abdominal cavity by means of abdominal ostium. The fallopian tubule is kept in position by a mesentery which is attached to the uterus.

Significance or Functions of Fallopian Tubes:

1. By their lashing movement of the cilia present in the lining of infundibulum and nearby area help in pulling the released ovum into fallopian tube.
2. Passage of ovum into uterus is aided by muscular movement of fallopian tube as well as beating of cilia present in the lining layer of tube.
3. Fertilization of ovum mostly takes place in the ampulla part of fallopian tube.

Question 17.
Draw a labelled diagram of a section through ovary.
Answer:

Question 18.
Draw a labelled diagram of a graafian follicle.
Answer:

Question 19.
Write the functions of the following :

1. Corpus luteum
2. Endometrium
3. Acrosome
4. Sperm tail
5. Fimbriae

Answer:
The functions of the following:

1. Corpus luteum secretes large amount of progesterone which is essential for the maintenance of endometrium of the uterus.

2. Endometrium is necessary for the implantation of the fertillised ovum, for contributing towards making of placenta and other events of pregnancy.

3. Acrosome is filled with enzymes that help in dissolving the outer cover of the ovum and entry of sperm nucleus.

4. Sperm tail facilitates motility of the sperm essential for reaching the ovum to fertilise it.

5. Fimbriae are finger – like projections at the mouth of fallopian tubules that help in collection of the ovum after ovulation.

Human Reproduction Long Answer Type Question

Question 1.
Describe the structure of a seminiferous tubules.
Answer:
Seminiferous tubules are highly coiled tubes, which are lined on the inside by:
1. Male germ cells called spematogonia that undergo meiotic division to form sperm cells.

2. Sertoli cells provide nutrition and molecular signals to the germ cells.

Question 2.
What is spermatogenesis? Briefly describe the process of spermatogenesis.
Answer:
Spermatogenesis:
Formation of sperms in the testis is called as spermatogenesis. It involves in the following steps:

1. Multiplication phase:
In this phase, sperm cells are formed in testes. The inner layer of seminiferous tubules of testes is formed of germinal epithelium. Some of these cells called primary germ cells divide mitotically into spermatogonia which become separated in the germinal layer. Other cells of this layer serve as nutrition for the dividing cells.

2. Growth phase:
In this phase, spermatogonia starts growing, absorbing nutrient substances. These large cells are called primary spermatocytes.

3. Maturation phase:
It is a very important phase. Primary spermatocytes divide twice. The first division is meiotic due to which the number of chromosomes is reduced to half. In this process, primary spermatocyte divides into two halves which are known as secondary spermatocytes. The second division is mitotic and no change takes place in the number of chromosomes. Thus, from two secondary spermatocytes four spermatids are formed. In this manner from one primary spermatocyte four spermatids are formed. These spermatids change into sperm cells of spermatozoa by a process called metamorphosis.

Question 3.
Draw a labelled diagram of human sperm and explain its defferent parts.
Answer:
Structure of sperm:
A mature sperm is a delicate microscopic, motile structure. A typi¬cal mammalian sperm consists of the following three parts:

1. Head
2. Middle piece and
3. Tail.

1. Head:
Head is knob like terminal part of the sperm. It is composed of a large nucleus and an acrosome. At the time of entry of the sperm into egg acrosome secretes spermlysin which dissolve the egg membrane and thus facilitates entry of sperm into the egg or ovum.

2. Middle piece:
It is short and lies between head and tail. It contains two granules called the proximal and distal centrioles in front side and towards posterior side cylindrical middle part of sperm. It is considered as the power house of sperm as it contains compact mass of mitochondria, which provides energy for metabolism and movement of sperm.

3. Tail:
It is situated on posterior part of sperm. It moves with the help of axial filament. The posterior part of the tail is called as end piece and it is not covered by membrane.

Question 4.
What are the major functions of male accessory ducts and glands?
Answer:
The main functions of male accessory ducts and glands are as follows:

1. Rete testis : They transport sperms from seminiferous tubule to vas efferentia.
2. Vas efferentia : Transports sperms to epdidymis.

Question 5.
Describe oogenesis with suitable diagram.
Or
Explain the different phases of oogenesis with ray diagram.
Or
What is oogenesis? Describe its various phases.
Answer:
The process of formation of ova from oogonia in the ovaries is called oogenesis. It consists of three phases:

1. Multiplication phase
2. Growth phase and
3. Maturation phase.

1. Multiplication phase:
The primordial germ cells divide by mitosis to produce oogonia. These oogonia divide by repeated mitotic divisions forming clusters of oogonia called ovigerous cords. These lie close to germinal epithelium. When oogonia stop dividing they are called oocytes. In each cluster of oocytes only one enters to the growth phase and is known as primary oocyte, while the remaining oocytes form follicle cells and provide nourishment to the developing ovum, the primary oocyte.

2. Growth phase:
Growth phase of primary oocyte is very long. It varies from a few days to many years. It takes about 6 – 14 days in hen after ovulation, but three years in frog and in women all the oocytes are present at the time of birth but no one grows till the attainment of puberty, i.e., 12 – 14 years. However afterwards they grow one by one. During growth phase, following changes occur:

(i) Increase in size:
The primary oocyte increases many folds. For example, primary oocyte of the frog in the beginning has a diameter of about 50μ and on maturation it is about 1000μ to 2000μ. In man also on maturation oocyte increases in size about 7 times. The size increases due to the accumulation of reserve food like proteins and fats in the form of yolk. Due to heavy weight it is usually concentrated towards and lower portion of the egg forming vegetative pole. The portion of the cytoplasm with egg pronucleus remains often separated from the yolk and occurs towards the upper portion of the egg forming animal pole.

(ii) Number of mitochondria increases and in certain cases (birds, amphibia) they are concentrated in the same places to form mitochondrial clouds.

(iii) Increase the amount of ER and activity of golgi complex.

(iv) Synthesis of yolk or Vitellogenesis:
Chemically, yolk is a lipoprotein composed of protein, phospholipids and neutral fats along with little quantity of glycogen. The yolk is synthesized in the liver of female in soluble form and is transported through circulation to the follicle cells surrounding maturing ovum. From follicle cells it is absorbed by the ovum and is deposited in the form of yolk granules and platelets in the ooplasm. The mitochondria and golgi complex are said to be responsible for the conversion of soluble yolk into insoluble granules or platelets.

(v) Formation of thin vitelline membrane around the oocyte.

(vi) Increase the size of nucleus:
Due to the increase in the amount of DNA, nuclear sap and number of nucleoli, nucleus increases in size.

(vii) Gene amplification:
In growth phase the nucleolar genes which code for ribosomal RNA and are located in the nucleolar organizer region multiply to facilitate rapid synthesis of ribosomal RNA. This multiplication of genes without mitosis is known as gene amplification or redundancy.

3. Maturation phase:
In this phase, the nucleus of oocyte undergoes two maturation divisions. The first division is meiotic, as a result two haploid (n) cells are produced. In this division, cytokinesis is unequal, the large daughter cell with almost entire cytoplasm and yolk forms the secondary oocyte. While the smaller one with haploid nucleus (n) and almost without cytoplasm forms the first polar body which is given off from the surface of oocyte at the animal pole. The secondary oocyte with haploid number of chromosomes undergoes second maturation division or second meiotic division (it is meiotic division).

This division is also unequal the large one containing yolk is called ovum and small cell is the second polar body. The first polar body may also divide thus, producing total three bodies which degenerate soon. So, as a result of oogenesis only one functional ovum is formed from a primary oocyte. In most of the vertebrates, the first meiotic division occurs with the commencement of the growth phase, and second maturation division occurs when egg is activated by the entry of sperm.

Question 6.
Describe the structure of ovary.
Answer:
These are a pair of female gonads or primary sex organs lying one on each side of uterus. Ovary is attached to abdominal wall as well as utems by means of ligaments. It is surrounded by a fold of peritoneum named mesovarium. Ovary is internally differentiated into four parts : Germinal epithelium, tunica albuginea, cortex and medulla.

Germinal epithelium is the outermost layer of cuboidal to flattened cells. Germinal epithelium is followed by a sheath of condensed connective tissues which is termed as tunica albuginea. It is followed b.y cortex. The central part of ovary contains medulla. A large number of groups of specialized cells are present in the cortex which are termed as ovarian follicles. These follicles are found in four developmental stages.

1. Incipient follicle:
The central part of these follicles contains a large cell which is covered by many smaller cells.

2. Primary follicle:
These follicles are developed from incipient follicles.

3. Vascular follicle:
It is formed from primary follicles. The oocyte of these follicle is covered by a many layered thick wall.

4. Graafian follicle:
Mature ovarian follicle is termed as graafian follicle. It is covered by two sheaths derived from cortex. The follicle contains a single oocyte. A group of follicular cells surrounds the oocyte or ovum. It is called cumulus ovaricus. Another group produces membrane granulosa. Oocyte has two noncellular membranes, inner vitelline membrane and outer zona pellucida.
Note:

Question 7.
Describe the process of fertilization and give its significance.
Answer:
Fertilization:
Fertilization is the fusion of male and female gametes to produce a single diploid cell, called zygote. Fertilization in human female takes place in fallopian tube. In a sexual mating or coitus the male ejaculates semen into the vaginal passage of the female using the copulatory organ, the penis. In a single coitus as many as 200 million sperms are introduced into the female genital tract but out of this huge number of sperms only one is destined to fuse with the ovum, provided the fallopian tube lodges of fully developed secondary oocyte.

Sperms travel through the vaginal passage and enter the uterus through the cervix. They travel further through the uterus and finally enter the fallopian tube.The vaginal passage is highly acidic to prevent any bacterial infection but this acidic medium is not suitable for the survival of sperms. Many sperms die on the way. The liquid medium of the semen is alkaline which can neutralize the acidity of vagina to some extend and keep the sperms alive and active. The sperms move with the speed of 1-5 to 3 mm per minute.

The ovum gets surrounded by a large number of sperms but usually only one fuses with the ovum. The sperm penetrates the ovum using certain chemical substances of enzymatic nature.These chemicals are called spermlysins which are present in the acrosome. Certain receptors on the cell surface of the ovum enable the sperms to penetrate the wall of ovum. The ovum is surrounded by follicle cells.

These cells are joined together by a glue like substance known as mucopolysaccharide, an acid, called hyaluronic acid. The sperm produces spermlysin, known as hyaluronidase. The over all changes in a sperm before the fertilization is called capacitation. The hyaluronidase enzyme facilitates the sperm to pen-etrate through the corona radiata (follicle cells), zona pellucida and the plasma membrane of ovum. The nucleus and the cytoplasmic components get inside the ovum, leaving the tail outside. The entry of sperm stimulates the ovum and the signal is transmitted to the egg surface incapacitating all the other cells surrounding the ovum.

Nucleus of sperm move towards the nucleus of ovum and they fuses with each other to form zygote. It takes 2 – 2\(\frac { 1 }{ 2 }\) hours to complete fertilization process. Once the ovum has been fertilized a barrier forms around it that normally prevents other sperms from entering. Now fertilized egg reaches to the uterus and within seven days of fertilization it is transplanted to the wall of the uterus.

Significance of Fertilization:

1. Egg becomes active after entry of sperm and completes its second maturation division.
2. Formation of fertilization membrane prevent entry of other sperms in the ovum. In human this membrane is not formed.
3. It restores the diploid number (2n) of chromosomes in the zygote.
4. It combines characters of male and female resulting in the introduction of varia-tions. These variations make the offspring better equipped for struggle against environmental conditions to ensure the existence.
5. The ovum is stimulated to cleavage.
6. After fertilization ovum rotate inside the membrane.
7. Ovum do not contain centriole and obtain it from sperm during this process thus zygote continuously divides.
8. It is necessary for the egg to attain maturity.

Question 8.
Describe development of embryo up to the formation of three germ layer. Give the names of organs formed by three germ layer.
Or
Define cleavage. Describe the changes that occur in embryo till gastrulation.
Answer:
The term cleavage refers to a series of rapid mitotic divisions of the zygote following fertilization forming a many celled blastula. Following are the various steps of embryonic development in human up to the formation of three germ layer:

1. Formation of morula:
The fertilized zygote divides. It undergoes successive quick mitotic cell divisions called cleavage. First cleavage is holoblastic, unequal and meridional. It divides the oyum completely into two unequal blastomeres. The plane of cleavage passes
through animal vegetal axis, i.e., it is meridional. Large blastomere divides little earlier than the small one giving a transitional three cell stage.

As a result of further cleavages, a solid mass of mulberry shaped embryo is formed called morula. Morula is of the size of zygote but consists of 32 cells. These cells are of two types , The outer layer of smaller cells around, inner larger cells. Within 72 hours of fertilization, morula reaches the uterus.

2. Formation of blastula:
Transformation of morula into a blastula starts by the rearrangement of blastomeres. This leads to the formation of a central cavity inside the morula. The outer cells of morula absorb the nutritive fluid secreted by the uterine mu¬cous membrane and transform into trophoblast. The fluid absorbed by these cells collects in the central cavity called biastocoel. This cavity separates the trophoblast from the inner mass of larger cells except on one side and is termed blastocyst. The inner cell mass is pushed to one pole as a small knob. This knob gives rise to the embryo and is termed as embryonal knob.

3. Formation of gastrula:
In this embryonic stage development of three germ layer occurs. In this stage morphogenic movement of cells of embryo occurs, as a result of this three germ layers are formed. A cavity develops at the centre called as archenteron which opens outside through blastopore.

4. Formation of three germ layers:

Formation of endoderm:
The enlargement of blastodermic vesicle is followed by the separation of few cells from the inner cell mass. These cells push out from the blastocoel to become the initial cells of the innermost layer of gastrula, the pattern of a tube within a tube. The inner tube is called primitive gut. It is differentiated into gut tract which is within the body and a yolk sac that communicates with the gut of the embryo. The remaining cells of the inner cell mass are organized to form the embryonic disc.

Formation of mesoderm:
After the formation of endoderm an increased rate of cell proliferation takes place at the caudal end of the embryonic disc. This results in the localised increase in the thickness of the disc. These cells subsequently get detached from the embryonic disc and get organized to a well demarcated mesodermal layer.

Formation of ectoderm:
After the formation of endoderm and mesoderm, the remaining cells of the embryonic disc arrange themselves in a layer to form ectoderm.

Question 9.
Write differences between spermatogenesis and oogenesis.
Answer:
Differences between Spermatogenesis and Oogenesis:

Spermatogenesis:

• Sperms are produced by this process.
• In this process primary spermatocytes are formed by maturation of germinal epithelium cells.
• Primary spermatocyte divides to form four spermatids.
• There is equal division.
• Large number of sperms are formed by this process.

Oogenesis:

• Ovums are produced by this process.
• In this process primary oocytes are formed by maturation of germinal epithelium.
• Primary oocytes divides to form one ovum and three polar bodies.
• There is unequal division.
• Less number of ovums are formed by this process.

MP Board Class 12th Biology Important Questions

MP Board Class 12th Economics Important Questions Unit 1 Introduction

Micro Economics Introduction Important Questions

Micro Economics Introduction Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
Indian economy is:
(a) Centrally planned economy
(b) Market economy
(c) Mixed economy
(d) None of these.
Answer:
(c) Mixed economy

Question 2.
Who used the word ‘micro’ for the first time:
(a) Marshall
(b)Boulding
(c) Keynes
(d) Ragnar Frisch
Answer:
(d) Ragnar Frisch

Question 3.
Who said economics is the ‘Science of wealth:
(a) Prof. Robbins
(b) Prof. J.K. Mehta
(c) Prof. Marshall
(d) Prof. Adam Smith
Answer:
(d) Prof. Adam Smith

Question 4.
What is the shape of production possibility curve:
(a) Concave to the origin
(b) Concave
(c) Straight line
(d) None of the above.
Answer:
(a) Concave to the origin

Question 5.
The reason for downward shape of production possibility curve is:
(a) Increasing opportunity cost
(b) Decreasing opportunity cost
(c) Same opportunity cost
(d) Negative opportunity cost
Answer:
(b) Decreasing opportunity cost

Question 6.
The point of optimum utilization of resources lies on which side of PPC curve:
(a) Towards left
(b) Towards right
(c) Inside
(d) Upwards
Answer:
(d) Upwards

Question 2.
Fill in the blanks:

1. Every person has ………………… quantity of goods.
2. ……………………economics is the study of individual economic units.
3. Opportunity cost ………………….. in production list.
4. Micro and Macro-economics are ……………………… to each other.
5. Economic growth is related to ………………………… economics.
6. Economy is a group of ………………….. units.
7. Mixed economy is composed of ………………………. and …………………………
8. The goods and services which help in the production of other goods and services are ………………………. goods.

Answer:

1. Few
2. Micro-economics
3. Changes
4. Complement
5. Macro
6. Production
7. Socialism, Capitalism
8. Intermediate

Question 3
State true or false:

1. Production possibility curve is convex towards main point.
2. Central problem in the capitalist economy is solved by price mechanism.
3. An economy can be capitalist, socialist or opportunist.
4. Today all economics of the world are almost mixed economics.
5. Macro-economics is the study of the problems of unemployment, price inflation etc.
6. In socialism, the feeling of personal profit is prominent.

Answer:

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

Question 4.
Match the following:

Answer:

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

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

1. Which economy is adopted in India ?
2. What is the production possibility curve towards its origin ?
3. The governmentalization of exploitation is the fault of which economy ?
4. The struggle class is the specialty of which economy ?
5. Which economy has limited the scope of private sector ?
6. What is the heart of all the institutions of capitalism ?
7. What are central problems of an economy known as ?
8. Based on priorities, who determines the production area and quantity of production ?

Answer:

1. Mixed economy
2. Concave
3. Socialist
4. Capitalism
5. Socialism
6. Profit
7. Basic work
8. Central Planning Authority

Micro Economics Introduction Very Short Answer Type Questions

Question 1.
What do you mean by macro-economics ?
Answer:
Macro-economics aims at dealing with the aggregates and averages. It is not interested in the individual items but as total savings, total consumption, total employment, aggregate demand, etc.

Question 2.
What do you mean by micro-economics ?
Answer:
Micro-economics studies the economic actions of individuals i.e., particular firm, individual households, wages, interest, profit etc. In other words it is infact a microscopic study of the economy.

Question 3.
What is the central point of macro-economics ?
Answer:
The central point of marco-economics is the analysis of national income.

Question 4.
What do you mean by goods ?
Answer:
All physical, tangible objects which satisfy human wants and need i.e., objects which possess utility, are called goods.
For example : Tables, cars, etc.

Question 5.
What do you mean by economic activity ?
Answer:
Economic activities are those activities which increases the material, welfare of man and which are used for increasing wealth and welfare.

Question 6.
How are services ?
Answer:
Services are non – material, intangible goods which can not be seen, touched or stored and have power to satisfy human wants and needs. For example, services provided by doctor.

Question 7.
Write the meaning of ‘a person’.
Answer:
By person, we mean the decision taking units.

Question 8.
How many branches are there of Economics ?
Answer:
Economics has two branches:

1. Micro-economics
2. Macro-economics

Question 9.
What to you mean by resources ?
Answer:
Those goods and services which are used to produce other goods are known as resources. They are traditionally known as factors of production.

Question 10.
What do you mean by economy ?
Answer:
It refers to the sum total of economic activities in an area, which may be a village, a city, a district, or a country as a whole. They provide source of livelihood.

Micro Economics Introduction Short Answer Type Questions

Question 1.
What do you mean by macro-economics ? Write its two characteristics.
Answer:
Macro-economics:
Macroeconomics is the study of aggregate factors such as employment, inflation and gross domestic product and evaluating how they influence the economy as a whole.

The characteristics of macro-economics are as follows:
1. Broader perspective:
The concept of macro-economics is broader. In it small units are not given importance but with the help of it National and International economic problems.

2. Broad analysis:
In macro-economics broad analysis is given importance. For example, under the subject matter of macro-economics we study the monetary and fiscal policies of the government. It studies the general problems of national level like the effects on – monetary policy, fiscal policy, general price level, general employment etc. If the effect of public finance and public expenditure is good on society then we can conclude that the . effect of it is also good on each person of the society.

Question 2.
Explain the main types of Macro-economics.
Answer:
Following are the types of Macro-economics:

1. Macro static:
Macro static method explains the certain aggregative  relations in 1 stationary state. It does not reveal the process by which the national economy reaches the equilibrium. It deals with the final equilibrium of the economy at a particular point of time. It does not analyse the path by which the economy reaches equilibrium. It presents a “still” picture of the economy as a whole at a particular point of time. Pro. Keynes has explained by this equation:

Y = C +1.
Here, Y = Total income, C = Total consumption expenditure, I = Total investment expenditure.

2. Comparative macro statics:
The various macro variables in the economy are subject to charge with the passage of time. Total consumption, total investment and total income etc. go on changing and so the economy reaches different levels of equilibrium.

3. Macro dynamics:
This is a realistic and new method of economic analysis. Under this method, we study how the equilibrium in the economy is reached as a result of changes in the macro variables and aggregates. This method enables us to see the movie picture of the entire economy as progressive whole. This method is a complex method. It is recently developed by Frish, Robertson, Hicks, Tinburzon, Samulson etc.

Question 3.
What is economic problem ? Why do economic problem arises ?
Answer:
An economic problem is basically the problem of choice which arises because of scarcity of resources. Human wants are unlimited but means to satisfy them are limited. Therefore, all human wants cannot be satisfied with limited means.

An economic problem arises because of the following causes:
1. Human wants are unlimited :
With the satisfaction of one want, another want arises. These is a difference in the intensity of wants also. Thus, there is an unending circle of wants, when they arise, are satisfied and arise again.

2. Limited resources:
Means are limited for the satisfaction of wants. Scarcity of resources is a relative term, for satisfying a particular want, resources can be in abundance, but for the satisfaction of all the wants, resources are scarce. Thus, scarcity of resources gives rise to economic problems.

Question 4.
“Scarcity is the mother of all economic problems”. Explain.
Answer:
The statement is true, no matter, how well a particular economy is endowed with resource, these resources will be relatively scarce to fulfill its unlimited wants. Moreover, these scarce resources have alternative uses and can be allocated to the production of different goods and services. Thus, it is due to the scarce availability of resources to fulfill the different and competing unlimited wants that an economy faces the economic problem of choice. Thus, it is rightly said that Scarcity of resources is the mother of all economic problems.

Question 5.
What do you understand by positive economic analysis ?
Answer:
Positive economic analysis is confined to cause and effect relationship. In other words, it states “What is it relates to, what the facts are, were or will be about various economic phenomena in the economics, e.g., it deals with the analysis of questions like what are the causes of unemployment.

Question 6.
What do you understand by normative economic analysis ?
Answer:
Normative economic analysis is concerned with ‘What ought to be’. It examines the real economic events from moral and ethical angles and judge whether certain economic events are desirable or undesirable, e.g., it deals with the analysis of questions like what should be the prices of food grains, unemployment is better than poverty, rich persons should be faxed more.

Question 7.
Write main assumptions of production possibility curve.
Answer:
Following are the main assumptions of production possibility curve:

1.  Economy produces only two goods X and Y in different proportions.
2.  Amount of resources available in an economy are given and fixed.
3.  Resources are not specific i.e., they can be shifted from the production of one goods to the other goods.
4.  Resources are fully employed, i.e., there is no wastage of resources.
5.  State of technology in an economy is given and remains unchanged.
6.  Resources are efficiently employed.

Question 8.
What is production possibility curve ? Explain with example.
Answer:
Production possibility curve shows graphical presentation of various combination of two goods that can be produced with available technologies and given resources assuming that the resources are fully and efficiently employed. The production possibility curve is also known as transformation curve. PPC can be explained with the help of example and imaginary schedule.

Question 9.
What do you mean by opportunity cost ?
Answer:
The opportunity cost of a good is the value of the next best alternative good is forgone for it. In other words opportunity cost of any commodity is the amount of other good which has been given up in order to produce that commodity.

Question 10.
A school teacher takes two years of leave for study to get the degree of doctorate of philosophy from a university. His monthly income is Rs 35,200 and the fees of research degree is Rs 40,000. What will be his opportunity cost for doctorate degree ?
Solution:
Opportunity cost = (35,200 × 12 x 2) + 40,000
= (35,200 × 24) + 40,000
=  Rs 8,84,800.

Question 11.
Why is production possibility curve downward sloping ?
Answer:
Production possibility is a curve which shows various production possibilities with the help of given limited resources and technology. It is also known as production possibility frontier and transformation curve. It i&downward sloping from left to right because in a situation of fuller utilization of the given resources, production of both the goods cannot be increased together. More of goods X can be produced only with less of goods Y as resources are scarce. Because of this un use relationship between production of both the goods, PPC is downward sloping.

Question 12.
Why is production possibility curve concave to the origin ?
Answer:
Production possibility curve is concave to the origin because to produce each additional unit of goods X, more and more unit of goods Y is to be sacrificed. Opportunity cost of producing every additional unit of goods ‘A’ tends to increase in terms of the loss of production of goods Y. It is so because factors of production are not perfect substitute of each other. As we move down along the PPC, the opportunity cost increases. And this causes the concave share of PPC.

For example, if in any state, production of mango is more and it may not be same in other state, the other state may lead in the production of sugar cane. So, it is not Goods (A) necessary that a person who is efficient in the production of one goods will also lead in the production other good. This shows increase in marginal opportunity cost reason of marginal opportunity cost that PP curve is concave to the origin.

Question 13.
What is studied in Economics ?
Answer:
It is an important question that what should be studied under subject matter of economics. Wants are unlimited but resources are limited. It is decided in economics that row resources should be economically and more efficiently used. Study of subject-matter of economics includes the rational use of resources. The ultimate air of any economy is to have maximum economic welfare.

In any economy, what economic system we use is based on macro and micro-economics. In micro-economics, we study principle of consumers, price determination, producers behavior, monetary policy, inflation, Government budget, exchange rate etc. is studied.

Micro Economics Introduction Long Answer Type Questions

Question 1.
Distinguish between Micro-economics and Macro-economics.
Answer:
Differences between Micro-economics and Macro-economics;

Question 2.
Define micro-economics and explain its characteristics.
Answer:
The word ‘micro’ is originated from the Greek word micros; which means small. Micro-economics studies the economic actions of individuals. Under this branch the whole economy is divided into small individual parts i.e., a particular firm, individual household, wages, interest, profit etc. According to Chamberlain, “The micro model is built solely on the individual and deals with interpersonal relations only.”

Characteristics:
Followings are the characteristics of micro-economics:
1. Study of individual units :
The first characteristics of micro-economics is that it studies individual units. It helps to explain personal income (individual income), individual production, individual consumption etc. Micro-economics studies the individual problems and helps in analyzing the whole economic system.

2. Study of small variable:
Micro-economics gives importance to the study of small variable. These variables have such little influence that they do not affect the whole economy.
For e.g., a single consumer by his consumption or a single producer by his production cannot have influence over the demand and supply of whole economic system.

3. Determination of individual price :
Micro-economics is also called the price theory. It determines the individual price of different products by analyzing the demand and supply i. e., behavior of buyers and sellers.

4. Based on the concept of full-employment:
While studying micro-economics the concept of full employment is taken into consideration.

Question 3.
Write any five importance of Micro-economics.
Answer:
The importance of micro-economics can be studied under the following points:
1. Essential for the knowledge of whole economy:
The sum of individual demand, individual production etc., make the aggregated demand and combined supply. Hence, micro-economics analysis is essential for knowing the position of whole economy.

2. Helpful in solving economic problems :
The problems of pricing of product and pricing of factors of production are main economic problems. Each factor of production demands more remuneration for it, each seller wants to get maximum price for his product. What price should be paid, at what price the problems should be sold all these problems are studied in micro-economics,

3. Helpful in determining economic policies:
The economic policies of government are studied in micro-economics in order to know as to how they influence the functioning of individual units.

4. Investigation of condition of economic welfare:
The study of micro-economics also reveals the effects of public expenditure and public revenue along with the position of individual consumption individual living standard etc. The classical economists favored micro-economic analysis as a measuring rod of economic welfare.

5. Helpful in decision making for individual units:
Micro-economics analysis proves helpful in taking rational decision about the problems of individual units profit of individual firm, individual income etc. Each consumers wants to get maximum satisfaction from his limited means, each firms want to get maximum profit.

Question 4.
What are the limitations of macro-economics ?
Or
Write defects of macro-economics.
Answer:
The limitations of macro-economics are as follows :

1. Ignorance of individual units :
Macro-economics gives importance to aggregate rather than individual units. The sum of small individual economic units make the wall of whole economy. The whole economy depend on the economy of individual unit. Thus, the small individual units play the role of foundation which are ignored in the macro-economic analysis.

2. Conclusions are not practical :
The conclusions drawn from macro-economic analysis are after misleading. For example, if the general price index number is unchanged, it cannot be concluded that the price level is unchanged. The increase in prices of certain commodities and decrease in prices of other commodities may make the general price level in – charged but the fluctuations are found in the prices of individual commodities.

3. Measurement of aggregates is difficult:
The measurement of aggregates itself presents serious problems in certain cases. Despite several improvements in statistical techniques in recent years, it has not been possible to obtain reliable measures of aggregates.

4. Macro-economics does not depict correct picture of Individual units :
Macro-economics does not depict the true picture of individual units. For example, if the aggregate demand increases, the production will rise but there may be certain firms whose cost and output may increase or decrease.

Similarly if the level of income increases the consumption of some goods may increase and that of some may decrease also. The out of those goods will be reduced whose consumption tends to decrease and the output of those goods will be reduced whose consumption tends to decrease and the output of those goods will be in-creased whose consumption tends to increase.

5. It may not influence all the sectors of economy:
The principles or analysis of Macro-economics may not influence all the sectors of economy. For example, a general rise in prices may not affect all the sections of the community in a similar manner. Some sections may be affected more adversely than others. Some industries may get more benefit than others.

6. No consideration of composition of the aggregate:
Macro-economic analysis takes into consideration the size and types of the aggregate but does not take into consideration the composition of the aggregate. Unless and until the composition and all the components of the aggregate are not analysed, the forecasts of Macro-economic analysis are baseless the suggestions given on their basis will be of no use.

Question 5.
Explain any five points of importance of macro-economics.
Or
Write any five advantages of macro-economics.
Answer:
The importance of macro-economics is clear from the following facts:

1. Helpful in making and executing governmental economic policies:
The study of macro-economics is essential for formulation of the economic policies of the government. Government has to make policies of general level of production, general price level. Macro-economists help.in formulation of such policies.

2. Helpful for Micro-economics:
The study of macro-economics is helpful for studying micro-economics. No micro-economic law can be formulated without studying macro-economics.

3. Measurement of economic development:
Macro-economics deals with the aggregates (output, consumption, income, capital formation) which help in measuring the economic development of the country.

4. Study of inflation and deflation:
The study of aggregate demand and aggregate supply of currency enables us to analyse the rate of inflation and deflation in the country. By this we can get the idea of economic conditions and standard of living of people.

5. Helpful in the study of fluctuation in economy:
Macro-economics proves helpful in the study of fluctuations in the economy through the analysis of national aggregates like; income, output saving, investment etc.

Question 6.
Write any five limitations of Micro-economics.
Answer:
Following are the limitations of micro-economics:

1. Conclusions drawn are not accurate:
What is true in the case of individual units may not be true in the case of aggregates. For example, individual saving is good but if the entire community starts saving more, effective demand will be reduced.

2. Based on unrealistic assumptions:
Micro-economist assumes other things being equal, and is based on the assumption of full employment in society. This is unrealistic assumption.

3. Concentration on small parts:
Instead of studying the total economy, micro-economics studies only small parts of it. It fails to enlighten us the collective functioning of the national economy.

4. Unable to analyse certain problems:
There are certain economic problems which cannot be analysed with the aid of Micro-economics. For example, important problems relating to public finance, monetary and fiscal policy etc., are beyond purview of microeconomics.

5. Infeasible:
Micro-economics fails to provide us with a description of the real world as it is. It is not in a position to take into accountable the entire economic data of the real world.

Question 7.
What is opportunity cost ? Explain with suitable example.
Answer:
Opportunity cost is defined as the value of a factor in its next best alternative use or it is the cost of foregone alternatives, or it can be defined as the value of the benefit that is sacrificed by choosing an alternative. We can also say that opportunity cost of any commodity is the amount of other goods which has been given up in order to produce that commodity. It is also known as opportunity lost or transfer earning of a factor e.g., a person is working in college ‘A’ at the salary of ? 70,000/- per month, he has two more options to work:

1. To work in college “C” at Rs 65,000 per month.
2. To work in college “D” at Rs 62,000 per month.

In this case opportunity cost of working in college “A” is Rs 65,000 i.e., salary he would get in college “C” (cost of foregone alternative) because it is the value of next best alternative between college “C” and college “D”. Thus, opportunity cost is very important concept in economics. It is because our re-sources are limited, we are always making choices from the available alternatives. Thus, the opportunity cost of using a resource is defined as the value of the next best use to which that resource could be put.

Question 8.
What is production possibility curve ? Explain with example.
Answer:
Production possibility curve:
Production possibility curve shows graphical presentation of various combination of two goods that can be produced with available technologies and given resources assuming that the resources are fully and efficiently employed. The production possibility curve is also known as transformation curve. PPC can be explained with the help of example and imaginary schedule.
Example:

We can show the basic problem of choice or all forms of economic problems with the help of this production possibility curve. This is shown in the table and diagram. Here, for the sake of simplicity we have presumed that only two commodities i.e., wheat and machines are being produced in an economy with limited capital.

From the table, it is clear that when the production of machine is zero then production of rice is 500 tone. If, the production of machines increase from 1 to 2 then the production of rice will be decreased from 500 to 450 ton. If all resources are implied on production of machines then production of machines will become 4 and production of rice will be zero. So suitable combination is essential for production.

Question 9.
What do you mean by Marginal Opportunity Cost ? Explain with the help of an imaginary schedule.
Answer:
Marginal Opportunity Cost can be explained as if the resources are transferred from one use to the other, it is obvious that there would be loss in production of one goods in order to increase output of the other. This loss is marginal opportunity cost which is technically termed as marginal rate of transformation. It is also called as rate of sacrifice.

i.e., \(\frac { ΔY }{ ΔX }\)
Here,
ΔY = Increase in production of Goods.
ΔX = Increase in production in Goods of X.

From the above table it is clear that in order to produce one unit of commodity ‘A’ he has to sacrifice all the units of commodity ‘B’. After combination ‘E’ to ‘F’ marginal opportunity cost increases to 25.0. Thus, it is clear that production possibility curve is also known as transformation curve or rate of sacrifice.

Question 10.
“Micro-economics and Macro-economics are not competitive to each other but complementary to each other”. Explain.
Answer:
Interdependence of micro and macro can be studies as follows:

1. Macro – economics depends 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-economic theory of investment. Thus, we can say, that macro-economics depends on micro-economics.

2. Micro-economics depends on macro-economics:
Micro-economics 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 depends 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 microeconomics 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 11.
Search for new entrepreneurs so that expansion of industries can be done and more use of capital intensive technology can be done in the country.
Answer:
When the economy is below its potential due to unemployment, the economy operates inside the PPC. When the government starts employment generation scheme, it enables the economy to utilise its existing resources in the optimum manner. The resources which were sitting idle, now get

job and the economy functions at its maximum capacity and moves from inside the PPC to points on the PPC. Thus, economy moves from point ‘a’ below PPC, to any point on PPC as shown in the figure.

Question. 12.
Explain the subject matter of macro-economics under five headings.
Answer:
We can study the subject matter of economics under the following heads :

1. Income and level of employment:
Income and level of employment is the main subject matter of Macro-economics. Level of employment and income depends on effective demand. Effective demand is determined by total expenditure.

2. Price theory :
It includes the study of inflation and deflation. Macro-economics also studies the normal level of prices of goods. It also studies the causes of inflation.

3. Theory of economic growth:
Macro-economics studies the economic growth by economic planning we can solve the problems of economic growth.

4. Theory of distribution :
During distribution of shares of national income many problems arise. How much should be paid as wages, what should be rent, how much interest should be paid all are the main elements of the subject matter of macro economics.

5. Theory of public finance:
Public revenue, public expenditure, public debts, taxation, fiscal policies are the subject matter of macro-economics.

Question 13.
Explain the five factors determining demand.
Answer:
1. Price of commodity:
Price is a dominating factor. The demand for a commodity is increased when the price of it decreases and the demand for it decreases when the price increases. For example, if the price of a commodity is Rs 50 then its demand is 100 units. If the price increases to Rs 100, its demand will be 50 units. In other words, there is an inverse relation between price and demand.

2. Price of substitutes:
If the price of substitutes of a commodity rises, the price of the commodity will also rise. If the price of substitute of a commodity goes down, the price of the commodity will also go down. For example, tea and coffee are substitutes to each other. If the price of tea rises, the demand for coffee will increase. In other words, the increase or decrease in the price of the substitute of a commodity results in the increase or decrease in the price of the commodity.

3. Price of complementary goods:
If the price of complementary goods increases, the price of the commodity will decrease. For example, the increase in the price of petroleum results in the decrease of demand for motor-cars and scooters etc. If the price of petroleum decreases, the demand for motor-car and scooter etc. will increase.

4. Income of consumer :
There is a direct correlation between the income of consumer and demand. If the income of a consumer increases, the demand for commodities will also increase. If the income of a consumer decreases, the demand for commodities will also decrease. The main reason for this tendency is that the purchasing power of a consumer increases or decreases as a result of increase or decrease in income.

5. Tastes and preferences of consumers:
The consumers, often, consume those commodities which suit to their taste and preference. If a commodity does not suit to their taste and preference, there will no remarkable change its demand as a result of increase or decrease in its price. If the price of a commodity of consumer’s taste and preference goes down, the demand for it will certainly increase and vice-versa.

Question 14.
Distinguish between Market Economy and Centrally Planned Economy.
Answer:
Differences between Centrally planned economy and Market economy:

MP Board Class 12th Economics Important Questions

MP Board Class 12th Biology Important Questions Chapter 2 Sexual Reproduction in Flowering Plants

Sexual Reproduction in Flowering Plants Important Questions

Sexual Reproduction in Flowering Plants Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
Apomixis in plants means the development of a plant :
(a) Fusion of gametes
(b) Without fusion of gametes
(c) Stem cuttings
(d) Root cuttings.
Answer:
(b) Without fusion of gametes

Question 2.
Polygonum type of embryo sac is :
(a) 8 – nucleated
(b) 16 – nucleated
(c) 24 – nucleated
(d) 32 – nucleated
Answer:
(a) 8 – nucleated

Question 3.
In angiosperms, female gametophyte is represented by :
(a) Synergids
(b) Carpel
(c) Egg
(d) Pollen grain
Answer:
(c) Egg

Question 4.
The term ‘xenia’ denotes the effect of pollen on the :
(a) Endosperm
(b) Flower
(c) Somatic tissue
(d) Root.
Answer:
(a) Endosperm

Question 5.
The fusion of male gamete with the secondary nucleus of the embryo sac is a process of:
(a) Fertilization
(b) Double fertilization
(c) Parthenocarpy
(d) Parthenogenesis.
Answer:
(b) Double fertilization

Question 6.
Which of the following is formed as a result of double fertilization :
(a) Endosperm
(b) Megaspore
(c) Seed
(d) Fruit.
Answer:
(a) Endosperm

Question 7.
What is the fusion product of polar nucleus and male gamete :
(a) Secondary nucleus
(b) Triple fusion
(c) Primary endosperm nucleus
(d) Zygote.
Answer:
(c) Primary endosperm nucleus

Question 8.
In which of the following plants, water is not necessary for fertilization :
(a) Vallisneria
(b) Pisus sativum
(c) Funaria
(d) Fern.
Answer:
(b) Pisus sativum

Question 9.
Tepetum is a part of :
(a) Male gametophyte
(b) Female gametophyte
(c) Ovary wall
(d) Anther wall.
Answer:
(d) Anther wall.

Question 10.
The endosperm is generally :
(a) Haploid
(b) Diploid
(c) Triploid
(d) Tetraploid
Answer:
(c) Triploid

Question 11.
The exine of pollen grain is made up of:
(a) Cellulose
(b) Pectdcellulose
(c) Lignin
(d) Sporopollenin
Answer:
(d) Sporopollenin

Question 12.
After fertilization ovary develops in to :
(a) Embryo
(b) Fruit
(c) Endosperm
(d) Seed
Answer:
(b) Fruit

Question 13.
A typical embryo sac is eight nuleate and :
(a) Single celled
(b) Seven celled
(c) Eight celled
(d) Four celled
Answer:
(b) Seven celled

Question 14.
Germ pore is the place where exine is :
(a) Thick
(b) Uniform
(c) Thick and Uniform
(d) Absent.
Answer:
(d) Absent.

Question 2.
Fill in the blanks:

1. The main function of endosperm in embryo is ……………. storage.
2. Type of pollination which occurs by birds is called …………….
3. Apple is the example of ……………. fruit.
4. Ovules are situated on these tissue is called …………….
5. In sunflower ……………. types of anther is found.
6. In plants fruit is formed by …………….
7. Single cotyledon of maize is called …………….
8. Outer membrane of pollen grain is called …………….
9. Process of double fertilization is discoverd by …………….
10. The process of pollination of Vallisneria is occurs by …………….
11. The study of pollen grain is called …………….
12. Smell and nectar is the adaptation of ……………. pollinated flowers.
13. Pollination in cobra plant is occurs through the …………….
14. Tetradynamous stamen are found in …………….

Answer:

1. Food material
2. Omithophily
3. False fruit
4. Placenta
5. Syngenesious
6. Ovary
7. Scutellum
8. Exine
9. Nawaschin
10. Water
11. Palynology
12. Insect
13. Snail
14. Mustard.

Question 3.
Match the followings :
I.

Answer:

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

II.

Answer:

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

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

1. What is the ploidy of microspore tetrad?
2. Which component prepare intine of the pollen grain?
3. Name a scar on a seed marking the point of attachment of the ovule.
4. Name the type of pollination in which found in Salvia.
5. What is the ploidy of angiospermic endosperm.
6. Stigma, style and oVary is the part of.
7. Name the largest flower of the world.
8. Name the plant in which found in longest style and stigma.
9. Name the hormone which is induced the ovary in the form of fruit.
10. Name the layer of pollen grain which has binuleated cell.
11. Name the mass of cells which is produced in culture medium.

Answer:

1. Haploid
2. Cellulose and Pectin
3. Hilum
4. EntomophiIy
5. Triploid
6. Female gamete
7. Rafflesia
8. Maize
9. Auxin
10. Tapetum
11. Callus.

Sexual Reproduction in Flowering Plants Very Short Answer Type Questions

Question 1.
Development of female gametophyte occurs in which cell?
Answer:
By functional megaspore mother cell.

Question 2.
What is the other name of female gametophyte?
Answer:
Embryo sac.

Question 3.
Ovule derives nourishment from which part of the carpel?
Answer:
Ovule derives nourishment from placenta.

Question 4.
What are cleistogamous flowers? Give an example.
Answer:
The flowers which do not open are called cleistogamous flowers, e.g., Commelina.

Question 5.
What is the substance found on the exine of pollen grains?
Answer:
Sparopollenin.

Question 6.
Give the characters of wind pollinated flowers.
Answer:
White in colour, small in size and.pollen grains are formed in large number.

Question 7.
What is the ploidy of angiospermic endosperm?
Answer:
Triploid.

Question 8.
Give an example of a monocotyledonous endospermic seed.
Answer:
Ricinus.

Question 9.
Give example of two false fruit.
Answer:
Apple, Jackfruit.

Question 10.
What are monocious plants ?
Answer:
Plants which have both male and female flower.

Sexual Reproduction in Flowering Plants Short Answer Type Questions

Question 1.
Write three merits of sexual reproduction in plants.
Answer:

1. Due to sexual reproduction variations possibilities of evolution become more.
2. Seeds thus produced can be preserved for years.
3. It helps the plants to develop adaptations.

Question 2.
Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
Answer:
Development of male gametophyte takes place in anther and female gametophyte in ovary.

Question 3.
Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events ? Name the structure formed at the end of these two events.
Answer:
Differences between Microsporogenesis and Megasporogenesis:

Microsporogenesis:

• In this process haploid microspores are formed from diploid microspore mother cell.
• The four microspores formed from a single microspore mother cell are generally aranged in a tetrahedral structure.
• All the four microspores arranged in a tetrahedral tetrad are functional.

Megasporogenesis:

• In this process, haploid megaspores are formed from diploid megaspore mother cell.
• The four megaspores formed from a me – gaspore mother cell are arranged in the from of a linear tetrad.
• Only one megaspore remain functional while the other three degenerates.

Meiosis occurs during micro and megasporogenesis. Microspores (pollen grain) are formed at the end of microsporogenesis and female gametophyte (embryo sac) are formed at the end of megasporogenesis.

Question 4.
Arrange the following terms in the correct developmental sequence :
Pollen grain, sporogenous tissue, microspore tetrad, pollen mother cell, male gametes.
Answer:
Sporogenous tissue → Pollen mother cell → Microspore → Tetrad → Pollen grain → Male gametes.

Question 5.
With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.
Answer:
Structure of Ovule: Each ovule consists of the following parts as visible in a longitudinal section:

1. A small stalk or funicle by which the ovule remains attached with the placenta of the ovary.

2. Hilum is the point at which it is attached with the ovule. In inverted ovule the funicle fuses with the main body of the ovule and is called as raphe.

3. The ovule is surrounded on all sides by two integuments but not at the apex where an aperture called micropyle is present. This end of the ovule is called as micropylar, while the end of the ovule opposite to it is called as chalazal end.

4. Embryo sac is situated inside the nucellus.

5. Towards the micropyle end of embryo sac one egg or oospore and 2 synergids are found, and towards the chalaza end of embryo sac 3 antipodal cells are fpund. At the centre secondary nuclei is found.

Question 6.
Differentiate self – pollination and cross – pollination.
Answer:
Differences between Self and Cross – pollination:

Self – pollination:

• It is the process of transfer of pollen grains from one flower to the stigma of same flower or another flower of same plant.
• Medium is not required for pollination.
• Pollination is sure.
• Less number of pollen grains are produced.
• Plants do not show any special character.
• Pure breed can be obtained.

Cross – pollination:

• It is the process of transfer of pollen grains from one flower to the stigma of flower of another plant.
• Medium is required for pollination.
• Pollination depends on medium.
• More number of pollen grains are produced.
• Attractive, coloured, scent or honey bearing flowers are produced to attract insects.
• Hybrids are produced.

Question 7.
What is apomixis and what is its importance?
Answer:
Apomixis is the process of asexual production of seeds, without fertilisation. The plants that grow from these seeds are identical to the mother plant.
Uses:

1. It is a cost effective method for producing seeds.
2. It has great use for plant breeding when specific traits of a plant have to be preserved.

Question 8.
With a neat diagram explain the 7 – celIed, 8 – nucleate nature of the female gametophyte.
Answer:
Explanation:
Nucleus of the functional megaspore undergoes mitosis resulting in 2 – nuclei that move to two opposite poles forming 2 – nucleate embryo sac. Two more mitotic nuclear divisions result in 4 – nucleate and later 8 – nucleate stages of the embryo sac. so far no cytokinesis (cytoplasmic division) has taken place. Now cell walls start to build leading to the organisation of female gametophyte or embryo sac. Six of the 8 – nuclei are bound by cell wall and the ramaining 2 – celled polar nuclei lie below the egg apparatus in the large central cell.

Seven – celled stage:
Three cells are grouped together at the micropylar end and constitute the egg apparatus, which is constituted of two synergids and one egg cell. Three cells at the chalazal end are called antipodals. The large central cell has 2 – polar nuclei. Thus, a typical angiosperm embryo sac at maturity is 7 – celled but 8 – nucleated as the central cell has 2 – nuclei.

Question 9.
What are chasmogamous flowers? Can cross – pollination occur in cleistogamous flower? Give reason for your answer.
Answer:
Chasmogamous flowers are open flowers with exposed stamens and stigma which facilitate cross – pollination. No cross – pollination occurs in cleistogamous flowers. As these flowers are closed and never open and thus no transfer of pollen from outside to stigma of the flower is possible. So there is no cross – pollination.

Question 10.
What is polyembryony?
Answer:
Polyembryony:
When more than one embryo develops in one seed then this condition is called as polyembryony. It is generally found in citrus family. It is also found in nicotiana, conifers, rice, wheat. It occurs when fertilization occurs in all embryo sacs found in the ovule,

Question 11.
Mention two strategies evolved to prevent self – pollination in flowers.
Answer:
Two strategies evolved to prevent self – pollination are:

1. Pollen release and stigma receptivity is not synchronized.
2. Anthers and stigma are placed at such positions that pollen doesn’t reach stigma.

Question 12.
What is self – incompatibility? Why does self – pollination not lead to seed formation in self – incompatible species?
Answer:
Self – incompatibility is a genetic mechanism to prevent self – pollen from fertilizing the ovules by inhibiting pollen germination or pollen tube growth in the pistil, In these cases, self – pollination does not lead to seed formation because fertilization is inhibited.

Question 13.
What is bagging technique? How is it useful in a plant breeding programme?
Answer:
It is the covering of female plant with butter paper or polythene to avoid their contamination from foreign pollens during breeding programme.

Question 14.
What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.
Answer:
Triple fusion refers to the process of fusion of three haploid nuclei. It takes place , in the embryo sac. The 3 – nuclei that fuse together are, nucleus of the male gamete and 2 – polar nuclei of the central cell to produce a triploid primary endosperm nucleus,

Question 15.
Why do you think the zygote is dormant for sometime in a fertilized ovule?
Answer:
The zygote is dormant in fertilized ovule for sometime because at this time, endosperm needs to develop. As endosperm is the source of nutrition for the developing j embryo, the nature ensures the formation of enough endosperm tissue before starting the process of embryogenesis.

Question 16.
Differenciate between:
(a) Hypocotyl and Epicotyl
(b) Colcoptile and Coleorhiza,
(c) Integument and Testa
(d) Perisperm and Pericarp.
Answer:
(a) Differences between Hypocotyl and Epicotyl:

Hypocotyl:

• The region of the embryonal axis that lies between the radicle and the point of attachment of cotyledons is called hypocotyl.
• Hypocotyl pushes the seed above the soil in epigeal germination.
• It is an important component of embryonic root system.

Epicotyl:

• The region of the embryonal axis that lies between the plumule and cotyledons is called epicotyl.
• Epicotyl pushes the plumule above the soil in hypogeal germination.
• It is an important component of embryonic shoot system.

(b) Differences between Coleoptile and Coleorhiza:

Coleoptile:

• The shoot apex and few leaf primordia are enclosed in epicotyl region is called coleoptile.
• It comes out of the soil.

Coleorhiza

• The redicle and rootcap are situated at the lower end of embryonal axis are enclosed by protective sheath called coleorhiza.
• It remains inside the soil.

(c) Differences between Integement and Testa:

Integument:

• It is the protective covering of the ovule.
• It is a part of pre fertilisation.

Testa:

• It is the protective covermg of the seed.
• It is a part of post fertilisation.

(d) Differences between Perisperm and Pericarp:

Perisperm:

• It is the part of nucellus which remains in form of thin layer after seed germination.
• It is a part that belongs to seed.
• It is usually dry.

Pericarp:

• Ovary is convert into pericarp after fertilisation.
• It is a part that belongs to fruit.
• It can be dry and fleshy.

Question 17.
Why is apple called a false fruit? Which part of the flower forms the fruit?
Answer:
Apple is called a false fruit because it develops from the thalamus instead of ovary (thalamus is the enlarged structure at the the base of the flower).

Question 18.
What is meant by emasculation? When and why does a plant breeder employ this technique?
Answer:
Emasculation means removal of anthers, with a forceps, from the flower bud before dehiscence. Plant breeder employs this technique to prevent contamination of stigma with the undesired pollen. This is useful in artificial hybridisation, where desired pollen is required.

Question 19.
If one can induce parthenocarpy through the application of growth sub – stances, which fruits would you select to induce parthenocarpy and why?
Answer:
Orange, lemon, litchi could be potential fruits for inducing the parthenocarpy because seedless variety of these fruits would be much appreciated by the consumers.

Sexual Reproduction in Flowering Plants Long Answer Type Questions

Question 1.
Describe structure of ovule with labelled diagram.
Answer:
Structure of Ovule:
Each ovule consists of the following parts as visible in a longitudinal section:

1. A small stalk or funicle by which the ovule remains attached with the placenta of the ovary.

2. Hilum is the point at which it is attached with the ovule. In inverted ovule the funicle fuses with the main body of the ovule and is called as raphe.

3. The ovule is surrounded on all sides by two integuments but not at the apex where an aperture called micropyle is present. This end of the ovule is called as micropylar, while the end of the ovule opposite to it is called as chalazal end.

4. Embryo sac is situated inside the nucellus.

5. Towards the micropyle end of embryo sac one egg or oospore and 2 synergids are found, and towards the chalaza end of embryo sac 3 antipodal cells are found. At the centre secondary nuclei is found.

Question 2.
Describe structure of anther with labelled diagram.
Answer:
Structure of Anther:
Transverse section of anther shows that it consists of 2 lobes which are connected by connective. Each lobe contains two pollen sacs. Innermost layer of pollen sac is called as tapetum. Tapetum is a layer rich in nutritive contents which supplies food material for the developing pollen grains. At first many pollen mother cells are formed in them which divides meiotically to form haploid pollen grains.

Question 3.
Give four contrivances for self – pollination.
Answer:
Contrivances for self – pollination:
1. Bisexuality:
When male and female parts are found in same flower then possibility of self – pollination increases.

2. Cleistogamy:
In Commelina benghalensis both cleistogamous and chasmogamous flowers are produced. The former are the underground flowers and the latter are the aerial ones developed on branches. In the small, inconspicuous cleistogamous flowers the pollen are shed within the closed flowers so that self – pollination is a must. This is also observed in Impatiens, Oxalis, Viola, Portulaca etc.

3. Homogamy:
Here the stamens and carpels mature at the same time. So, there is a greater chance of self – pollination as compared to cross – pollination, example Mirabilis, Argemone etc.

4. Failure of cross – pollination:
In some flowers generally cross pollination occurs but if they fails to do cross-pollination then self pollination occurs.

Question 4.
What do you mean by micropropagation?
Answer:
Micropropagation:
It is a modem method of reproduction. By this process thousands of new plants can be obtained from few tissues of mother plant. This method is based on tissue and cell culture technique. In this process a small part of tissue is separated from the plant and then it is grown in nutrient medium in aseptic condition. The tissue develops to form a cluster of cells which is called as callus.

This callus can be preserved for long time for multiplication. A small part of the callus is transferred to nutrient medium, where it grows into a new plant. This plant is then transferred to the field. By this process Orchids, Carnations, Chrysanthemum plants can be grown successfully.

Question 5.
What is self – pollination? Give advantages and disadvantages of self – pollination.
Answer:
Self – pollination:
When the pollen grain of one flower are transferred to the stigma of the same flower then the process is called as self – pollination.

Advantages of self – pollination : These are the advantages of self – pollination:

1. Parental characters can be preserved indefinitely in several generations.
2. Self – pollination helps in maintaining pure lines for experimental hybridization.
3. It is most economical method of pollination. The plants do not consume their energies in the production of large number of pollen grains, nectar and coloured corolla.
4. It ensures seed production and flowers do not take chances of the failure of fertilization.

Disadvantages of self – pollination : These are the disadvantages of self – pollination:

1. The weaker characteristics or defects of the plant can never be eliminated from the race.
2. No useful characters can be introduced in the race.
3. The immunity of race towards diseases falls and ultimately it falls prey to many diseases.

Question 6.
Describe development of endosperm.
Answer:
Development of endosperm:
It develops from the triploid tissue of the fertilized embryo sac after the act of double fertilization. It is of the following three types:

1. Free nuclear endosperm.
2. Cellular type of endosperm.
3. Helobial type of endosperm.

The name refers to the type of nuclear divisions of the endosperm nucleus. If triploid nucleus divides by free nuclear division the endosperm produced contains many nuclei ly¬ing freely in it and hence it is termed as free nuclear endosperm. If the nuclear division is followed by wall formation it is called as cellular type. If endosperm is intermediate between the two types it is called as helobial type.

Question 7.
Differentiate between:

1. Embryo sac and Endosperm,
2. Seed and Ovule.

Answer:
1. Differences between Embryo sac and Endosperm:

Embryo sac:

• It is haploid structure.
• It is found in ovule.
• It is formed before fertilization.
• Nutritive materials are stored.
• It consists of antipodal cells, egg cell, synergid cells and two polar nuclei.

Endosperm:

• It is triploid structure.
• It is found in seed.
• It is formed after fertilization.
• Nutritive materials are not stored.
• Antipodal cells, egg cell, synergid cells are absent and all cells are similar

2. Differences between Seed and Ovule:

Seed:

• It is formed in the fruit seed is formed after fertilization of ovule.
• Seed is surrounded by integument. Outer covering is called outer integument and inner covering is called inner integument.
• Embryosac is absent in seed.
• Embryo is present in seed
• Endosperm may be found in seed
• Seed germinates to produce new paint.

Ovule:

• Before fertilization ovule is found into the ovary called mega sporangium.
• Nucellus is present below the ovule and is surrounded by inner and outer covering.
• Embryosac is present in ovule.
• Embryo is absent in ovule.
• Endosperm is not found in ovule.
• Ovule does not germinate.

Question 8.
Explain any five differences between pollination and fertilization.
Answer:
Differences between Pollination and Fertilization:

Pollination:

• In pollination, pollen grains are transferred from stamens to stigma of the flower.
• Two male gametes are formed in this process.
• Haploid cells participating in this process.
• A medium is required for this process.
• There is no morphological change after this process.

Fertilization:

• Fertilization is a process in whieh male and female gametes fused to form the zygote.
• Zygote is formed at the end of this process.
• Haploid cells fused to form a diploid cell.
• Medium is not required for this process.
• Flower is modified into fruit and seed after this process.

Question 9.
What do you understand by double fertilization? Write its importance.
Answer:
Double fertilization:
It is the process of fusion of one male gamete with the egg nucleus and other male gamete with the polar nuclei or secondary nucleus is called double fertilization. In all angiospermic plants there is double fertilization. This process was discovered by S. N. Navaschin (1898) and Grignard (1899) in Lilium and Fritillaria. In this process, pollen grains reach stigma and then germinate. A short pollen tube comes out through a germpore. The pollen grain nucleus divides mitotically into a tube nucleus and a generative nucleus. The generative nucleus again divides into two male nuclei.

The pollen tube may enter the ovule through micropyle or through integuments or through chalazal end. One of the two male nuclei fuses with the egg nucleus and forms a zygote and this process is called syngamy. The male nucleus fuses with the two polar nuclei or secondary nucleus (diploid) and gives rise to triploid primary endosperm nucleus. This process is called triple fusion and whole process is called double fertilization. This triploid nucleus forms endosperm of the seed.

Importance:
After double fertilization triploid nucleus (endosperm nucleus) developed to form an endosperm which provide nourishment to the developing embryo resulting in the formation of healthy seed and plant.

MP Board Class 12th Biology Important Questions

MP Board Class 12th Biology Important Questions Chapter 1 Reproduction in Organisms

Reproduction in Organisms Important Questions

Reproduction in Organisms Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
The endosperm in angiospermic plant is :
(a) Haploid
(b) Diploid
(c) Triploid
(d) Polyploid.
Answer:
(c) Triploid

Question 2.
The function of tapetum innermost layer of the anther is :
(a) Dehiscence
(b) Mechanical
(c) Protection
(d) Nutritional.
Answer:
(c) Protection

Question 3.
In angiosperms, female gametophyte is represented by :
(a) Synergids
(b) Carpel
(c) Egg
(d) Pollen grain
Answer:
(c) Egg

Question 4.
The endocarp of coconut is :
(a) Liquid
(b) Soft
(c) Fibrous
(d) Very hard and stony.
Answer:
(b) Soft

Question 5.
In Vallisneria, pollination takes place by :
(a) Water
(b) Insect
(c) Animal
(d) Air
Answer:
(d) Air

Question 6.
Movement of male gamete towards archegonium in prothallus of fern is :
(a) Thermotactic
(b) Chemotropic
(c) Chemotactic
(d) Hygroscopic movement.
Answer:
(d) Hygroscopic movement.

Question 7.
The process of double fertilization (triple fusion) was discovered by: (MP 2012)
(a) Navaschin
(b) Leeuwenhoek
(c) Strasburger
(d) Hofmeister.
Answer:
(a) Navaschin

Question 8.
Clonal cell line is obtained from :
(a) Tissue culture
(b) Tissue isolation
(c) Tissue mixture
(d) Tissue system.
Answer:
(a) Tissue culture

Question 9.
Plants simillar to their parents can be obtained by :
(a) Seeds
(b) Stem cutting
(c) Cutting
(d) Both (a) and (b).
Answer:
(d) Both (a) and (b).

Question 10.
A scion is grafted over stock. The quality of fruit depends on :
(a) Scion
(b) Stock
(c) Both (a) and (b)
(d) None of these.
Answer:
(a) Scion

Question 11.
The life span of a parrot is :
(a) One – two week
(b) 15 years
(c) 20 years
(d) 140 years.
Answer:
(d) 140 years.

Question 12.
Stem cutting are commonly used for the propagation of :
(a) Banana
(b) Rose
(c) Mango
(d) Cotton.
Answer:
(b) Rose

Question 13.
If the organism is forged from male gamete without fertilization :
(a) Parthenogenesis
(b) Parthenocarpy
(c) Apogamy
(d) Apospory.
Answer:
(a) Parthenogenesis

Question 2.
Fill in the blanks:

1. Coconut water is the example of ………………
2. ……………… is the fusion of male and female gamete.
3. After fertilization of ovule ……………… is formed.
4. ……………… is formed from ovary.
5. The endosperm of gymnosperms is ………………
6. The fusion of male and female gamete of the same flower of same plant is called ………………
7. ……………… is called the end of reproductive cycle.
8. The outer wall of pollen grain is called
9. In Oxalis vegetative propagation takes place by ………………
10. In Penicilliumasexual reproduction takes place by ………………

Answer:

1. Endosperm
2. Fertilization
3. Seed
4. Fruit
5. Haploid
6. Self polli – nation
7. Ageing
8. Exine
9. Bulbils
10. Conidia.

Question 3.
I.

Answer:

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

II.

Answer:

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

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

1. Name the process in which fruits are formed without fertilisation.
2. Name the mode of reproduction in which new plants are formed from vegetative parts of the plants.
3. Transfer of pollen grains from pollengrains to stigma of flower is called.
4. Name the outer covering of seed.
5. How many male gametes found in a pollen tube?
6. Who provide nutrition to developing embryo?
7. Write the name of an algae in which reproductive metshod occurs by zoospores.
8. Give an example of vegetative propagation which is occurs by leaf.
9. Name the animal which is reproduced by asexual reproduction.
10. Split part of the body which is reproduce and developed in new plant is called.
11. What we called the population of genetically similar organisms formed by asexual reproduction?
12. Name the animal in which reproduction occurs by transverse binary fission.

Answer:

1. Parthenogenesis
2. Vegetative propagation
3. Pollination
4. Seedcoat
5. Two
6. Endosperm
7. Chlamydomonas
8. Bryophyllum
9. Spongilla
10. Fragmentation
11. Clone
12. Paramoecium.

Reproduction in Organisms Very Short Answer Type Questions

Question 1.
What is meant by life span?
Answer:
The period from birth to the natural death of an organism is called life span.

Question 2.
Give definition of fertilization.
Answer:
Fertilization is a process in which male and female gametes fused to form the zygote.

Question 3.
What is clone?
Answer:
Morphologically and genetically similar individuals who are produced by single parent is called clone.

Question 4.
Give the name of an organism in which asexual reproduction occurs through conidia.
Answer:
Penicillium.

Question 5.
In which plant vegetative propagation occurs through rhizome?
Answer:
In Ginger and Turmeric.

Question 6.
Give the name of an organism in which transverse binary fission occurs.
Answer:
Paramoecium.

Question 7.
What is ageing?
Answer:
When humans are not capable for reproduction is known as ageing.

Question 8.
Give two examples of hermaphrodite plants.
Answer:
Cucurbita and Coconut are hermaphrodite plants.

Reproduction in Organisms  Short Answer Type Questions

Question 1.
Name the types of reproduction occur in the living organisms.
Answer:
Two types of reproduction occur in the living organisms:

1. Asexual reproduction
2. Sexual reproduction.

Question 2.
Which is a better mode of reproduction, sexual or asexual. Why?
Answer:
Sexual mode of reproduction is better because it is biparental reproduction and introduces variation among offsprings and their parants due to crossing over and recombination during gamete formation by meiosis.

Question 3.
Why is the offspring formed by asexual reproduction referred to as clone ?
Answer: In sexual reproduction, the offspring is morphologically and genetically identi-cal to the parent and to each other. Hence, it is called clone.

Question 4.
Write three advantages of asexual reproduction.
Answer:
Following are the three advantages of asexual reproduction:

1. Large number of offsprings can be produced by single parent.
2. Purity can be maintained.
3. It helps in dispersal to far off places.

Question 5.
Offsprings formed due to sexual reproduction have better chances of survival. Why? Is this statement always true?
Answer:
Offsprings formed due to sexual reproduction have better chance of survival because:

1. The offspring consists of hybrid characters which may adapt better with the different environment.
2. Genetic variations are introduced among the offsprings which increases the bio – logical tolerance.
3. Sexual reproduction occurs in adverse condition in lower plant kingdom, so sexual spores survive in adverse condition.

Sexual reproduction may not always show better chances of survival because the off – spring may be inferior to the parents.

Question 6.
How does the progeny formed from asexual reproduction differ from those formed by sexual reproduction?
Answer:
The progenies have similar genetic make up and are exact copies of their parents in asexual reproduction but the progenies have different genetic make up and different from each other and dissimilar to the parent in sexual reproduction.

Variation is absent in asexual reproduction but it is a common phenomenon of sexual reproduction. In asexual reproduction, variation may occur due to mutation whereas variation occurs due to mutation, crossing over and recombination in sexual reproduction.

Question 7.
Distinguish between asexual and sexual reproduction. Why is vegetative reproduction also considered as a type of asexual reproduction?
Answer:
Differences between Asexual and Sexual reproduction:

Asexual reproduction:

• In this type of reproduction only one parent is required.
• Whole body or a single cell acts as reproductive unit.
• Offsprings remain pure, i.e., alike their parents.
• It occurs by mitosis cell division.
• Variation does not occur.

Sexual reproduction:

• In this type of reproduction two parents of different sexes are required.
• Reproductive units are called as gametes which are produced by specific tissues.
• Offsprings differ from their parents.
• Gametes are formed by meiosis cell division and zygote develops by mitosis cell division.
• Variation occurs.

Vegetative reproduction is considered as a type of asexual reproduction because:

1. It is uniparental reproduction.
2. There is no involvement of gametes or sex cells.
3. Cell division and no reduetional division take place.
4. Vegetative propagules are somatic cells.

Question 8.
What is vegetative propagation? Give two suitable examples.
Answer:
In plants, the vegetative propagules (runner, rhizome, sucker, etc.) are capable, of producing new offsprings by the process called vegetative propagation. As the formation of these vegetative propagules does not involve both the parents, the process involved is asexual.
Examples:

1. Adventitious buds in the notches along the leaf margins of bryophyllum grow to form new plants.
2. Potato tuber having buds when grown, develops into a new plant.

Question 9.
Define:

1. Juvenile phase
2. Reproductive phase
3. Senescent phase.

Answer:
1. Juvenile phase:
It is the pre – reproductive in which all organisms require a certain growth and maturity in the life before reproducing sexually.

2. Reproductive phase:
Reproductive phase is the phase in the life cycle, where an organism possesses all the capacity and potential to reproduce sexually. It is the end of juvenile phase or vegetative phase.

3. Senescent phase:
It is the post reproductive phase in the life cycle where an organism slowly looses the rate of metabolism, reproductive potential and show deterioration of the physiological activity of the body.

Question 10.
Higher organisms have resorted to sexual reproduction inspite of its complexity.Why?
Answer:
Higher organisms have resorted to sexual reproduction to:

1. Get over the unfavourable conditions.
2. Restore high gene pool in a population.
3. Restore vigour and vitality of the race.
4. Get proper parental care.
5. Introduce variations to enable better adaptive capacity.

Question 11.
Explain, why meiosis and gametogenesis are always interlinked.
Answer:
Gametogenesis (formation of male and female gametes) is associated with reduction in chromosome number. Thus, the gamete formed contains half chromosome set of the parental cell. So, gametogenesis is interlinked with meiosis because in meiosis reduction of chromosome number from diploid set (2n) to haploid set (n) takes place.

Question 12.
Identify each part in a flowering plant and write whether it is haploid (n) or diploid (2n).
Answer:

Question 13.
Define external fertilization, mention its disadvantages.
Answer:
The fusion of compatible gametes (male and female) outside the body of an organism is called external fertilization, example in Frog.
Disadvantages of external fertilization:

1. It requires a medium for fusion of gametes.
2. The young ones are often exposed to the predators.
3. After fertilization, offsprings are produced large in number but no parental care is provided.

Question 14.
Differentiate between a zoospore and zygote.
Answer:
Differences between Zoospores and Zygote:

Zoospore:

• These are endogenously, asexually produced, unicellular, naked and motile spores having one or two flagella.
• It may be haploid or diploid.
• Zoospores takes part in dispersal.

Zygote:

• Zygote is a diploid cell formed by fusion of male and female gametes.
• It is always diploid.
• Zygote does not have significant role in dispersal.

Question 15.
Differentiate between gametogenesis and embryogenesis.
Answer:
Differences between Gametogenesis and Embryogenesis:

Gametogenesis:

• It is the formation of gametes from me – iocytes.
• This is a pre – fertilization event.
• It occurs inside reproductive organs.
• It produces haploid gamete.
• The cell division during gametogenesis is meiotic in diploid organisms.

Embryogenesis:

• It is the formation of embryo from zyg – ote cell.
• This is a post fertilization event.
• It occurs outside or inside the female body.
• It gives rise to diploid embryo.
• The cell division during embryogenesis is mitotic in diploid organisms.

Question 16.
What is gootee? How it is prepared?
Answer:
Gootee or Air layering:
It is a modified form of layering in which the cut or injured branch is not buried in the soil but is bound with mud and rags, etc. which is kept moist with the help of water kept in an earthen pot. The roots develop at this portion within a period of about a month or two. Now, the branch is cut and separated from the parent plant and planted in the soil. This method is applied for the vegetative, propagation of Lemon, Orange, Litchi, Guava, Lokat, etc.

Question 17.
What do you understand by grafting? Write down the method of grafting.
Answer:
Vegetative propagation:
Vegetative reproduction or vegetative propagation is the process of multiplication in which a portion or fragment of the plant body functions as propagate and develops into new individual. Grafting is a type of artificial vegetative propagation.

Importance of vegetative propagation:

1. Pure variety can be produced
2. It increases production.

Grafting:
This is a very significant method and is extensively used for growing Roses and Mangoes. Grafting is making a twig or bud of one plant grow on the trunk and root system of another. In this process a detached portion of one plant is inserted into the stem or root system of another plant. The former is called scion (short piece of detached shoot containing several dormant buds) and the latter stock (lower portion of the plant which is fixed to the soil by its root system).

Grafting is done in such a way that the cambium tissue of both scion and stock comes in contact and forms a cambium layer common to both. Consequently the scion and the stock grow together and the scion becomes part of the plant into which it is grafted.

MP Board Class 12th Biology Important Questions