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Students get through the MP Board Class 11th Biology Important Questions Chapter 6 Anatomy of Flowering Plants which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 6 Anatomy of Flowering Plants

Anatomy of Flowering Plants Class 11 Important Questions Very Short Answer Type

Question 1.
What is tissue?
Answer:
A group of cells which are similar in origin and performing a particular function is collectively called as tissue.

Question 2.
Write main elements present in phloem.
Answer:
The main elements present in phloem are :
Sieve tubes, companion cells, phloem fibres and phloem parenchyma.

Question 3.
What is meristematic tissue?
Answer:
It is the simple type of tissue, composed of similar and immature cells, which continuously divide and form new cells. This type of cells mostly present in the apical portion and help in the growth of plant body.

Question 4.
Vascular bundles are formed by which tissue?
Answer:
Vascular bundles are formed by xylem and phloem.

Question 5.
Differentiate exarch and endarch vascular bundles.
Or,
What do you mean by endarch and exarch vascular bundles?
Answer:

• Endarch V.B.: Vascular bundles, the protoxylem of which is arranged towards the periphery and metaxylem in the central region are called endarch V.B. e.g., V.B. of roots.
• Exarch V.B.: Vascular bundles, the protoxylem of which is aiTanged in the centre and metaxylem towards the peripheral region are called as exarch V.B. e.g., V.B. of stems.

Question 6.
Write the main functions of xylem.
Answer:
The main functions of xylem is to conduct the absorbed water and minerals by root from the soil and to provide mechanical support to the plant.

Question 7.
Where is xylem vessel found ? Write their functions.
Answer:
Xylem vessels are found in the xylem tissues of the vascular bundles. Xylem vessels are responsible for the conduction of absorbed substances.

Question 8.
Write the functions of pericycle.
Answer:

• It forms lateral roots.
• When composed of parenchymatous cells, it may act as storage region.
• In dicot roots, their cells become meristematic and forms part of the cambium.
• Thick walled pericycle gives rise to lateral and adventitious roots.

Question 9.
What is stomata?
Answer:
These are small openings on the surface of the leaf through which exchange of vapour and gases takes place. Stomata performs transpiration.

Question 10.
Which type of vascular bundles are found in the stem of sunflower plant?
Answer:
Conjoint, collateral, open type of vascular bundles are found in the stem of sunflower plant.

Question 11.
What is cambium? Give its function.
Answer:
Cambium is a meristematic tissue. During secondary growth, cells of cambium are divided to form secondary xylem towards inner side and secondary phloem towards outer side of it, thus plant part increases in thickness.

Question 12.
Where is cambium found?
Answer:
Cambium is found in the vascular bundle of dicot stem in between xylem and phloem as meristematic tissue.

Question 13.
Where guard cells are found? Give its function.
Answer:
Stomata (pores) found in the epidermis of leaves are surrounded by two kidney shaped guard cells. Guard cells regulate opening and closing of stomata.

Question 14.
What are Bast fibres?
Answer:
Sclerenchyma cells (fibres) found associated with phloem are called as Bast fibres or phloem fibres.

Question 15.
Write main elements present in xylem.
Answer:
The main elements present in xylem are :

• Xylem tracheids,
• Xylem tracheae (vessels),
• Xylem fibres (wood),
• Xylem parenchyma.

Question 16.
What is tissue system?
Answer:
In flowering plants group of tissues derived from meristematic tissue perform one or many functions together. This system of tissues is called as tissue system.

Question 17.
When transverse section of a part of a plant is observed under compound microscope following structures are observed :
(a) Conjoint vascular bundles, scattered and surrounded by sclerenchymatous sheath.
(b) Phloem parenchymatous.
Identify the plant part.
Answer:
This is transverse section of monocot stem.

Anatomy of Flowering Plants Class 11 Important Questions Short Answer Type

Question 1.
How is study of Anatomy useful to us?
Answer:
Study of external morphology helps us to find out similarity and differences between shape, structure and colour of the organism. Many organisms may look similar externally but may be different in structure internally.

Study of internal structure of plant or animal is called as Anatomy. It helps us to understand about different types of cells and tissues found in them and their arrangement in the plant part. It also helps us to understand about their functions. Such as epidermis helps for protection. Xylem and Phloem are located at the central part which help for conduction of water, minerals and food respectively.

Question 2.
How does structure and location of epidermal cells help the plants to per-form specific function?
Answer:
Epidermis is the outermost protective layer of plant organs. It is usually single layered. In stems and leaves this layer is protected by cuticle (made up of cutin a fatty substance).
Epidermal cells perform several functions, e.g. protection of stems and leaves, absorption (in roots), excretion, secretion, gaseous exchange and regulation of transpiration.
In some monocot leaves (such as grasses), epidermal cells become larger, thin walled and have vacuoles. Such cells are called as bulliform cells or motor cells. These cells brings about rolling of leaves during dry season and this reduces transpiration as in Ammophila, Zea mays etc.

Question 3.
What are the various types of meristems based on their locations? Give their functions.
Answer:
Following are the various types of meristems based on their location :
(i) Apical meristem :
It lies at the apex of the stem and the root of vascular plants, they may also be present at the apices of leaves. Due to its activity the organs increase in length. The growth begins by one or more cells found at the tip of the organ, these cells are called apical cells or apical initials, as they initiate the growth.

(ii) Intercalary meristem :
These are the portions of apical meristems that separate from the apex during development by layers of more mature or permanent tissues and left behind as the apical meristem moves on in growth. The intercalary meristems are intemodal in position. They are found lying in between masses of permanent tissues either at the leaf base or at the base of intemode. This type of meristem is found in stems of monocots. based on their position.

(iii) Lateral meristem :
It is composed of such initials which divide mainly in one plane (periclinal) and increase the diameter of an organ. They may add to the existing tissue or give rise to new tissues. The cambium and cork cambium are the examples of this type.

Question 4.
Write differences between following based on their anatomy :
(a) Dicot and monocot root
(b) Dicot and monocot stem.
Answer:
(a) Differences between Anatomy of Dicot and Monocot Roots

(b) Differences between Diocot and Monocot Stems

Question 5.
Give four characteristics of meristematic tissue.
Answer:
A group of cells which is capable of showing division and redivisions is called as meristematic tissue. Following are the characteristics of meristematic tissue :

1. Cells contain homogeneous thin wall.
2. They contain large nuclei associated with abundant cytoplasm.
3. Intercellular spaces are not present in between them.
4. Cells contain dense protoplasm and do not contain vacuoles. These cells are found in active metabolic state.

Question 6.
Write differences between Vascular Bundles of Root and Stem.
Or,
Write differences between Radial and Conjoint Vascular Bundles.
Answer:
Differences between Radial and Conjoint Vascular Bundles

Question 7.
What is Periderm? How is periderm formed in dicot stem?
Answer:
In many woody plants further increase in girth takes place by the formation of new tissues in extrastelar region (cortical region). These new tissues are called periderm or cork which were formed from some meristematic tissues called cork cambium or phellogen.

Periderm is made up of following three types of tissues :
1. Phellogen (cork cambium):
It is secondary lateral meristem arising from hypo- dermis or outer cortex. It consists of a single layer of narrow, thin walled rectangular mer¬istematic cells. The cork cambium cuts-off cells to its both the sides.

2. Phellem (cork):
The cells formed as a result of tangential and periclinal divisions of phellogen cells towards outer side, are called phellem or cork. The cork cells are
suberized and impervious to water and air. Cork cells also possess thermal insulating properties.

3. Phelloderm (secondary cortex):
The cells formed on inner side of the phellogen are called phelloderm or secondary cortex. It consists of parenchymatous cells which often contain chloroplast. Due to rapid growth of secondary cortex sometimes the general cortex is crushed.

Question 8.
Write short note on lenticel.
Answer:
Lenticels:
These are aerating pores formed in the bark, through which exchange of gases takes place. Externally they appear as scars on the surface of the stem. In the region of a lenticel, the cells cut off by the cork cambium towards the outside become rounded to form a loose mass with plenty of intercellular spaces. The tissue is known as complementary tissue. Through the lenticel, tissues inside the cork can communicate with the outside atmosphere.

Question 9.
Write difference between anatomy of Dicot and Monocot leaves.
Answer:
Differences between Anatomy of Dicot and Monocot leaves

Question 10.
Why Xylem and Phloem are called as complex tissues?
Answer:
Complex permanent tissues:
Vascular tissues of plant are complex tissue, which help for conduction of various substances from one part of the plant to other part. Therefore, these are also called as conductive tissues.
Complex permanent tissue is a group of many types of the tissues, which functions as a unit together. Xylem and phloem are main examples of complex tissues.
Tissues which help in the conduction of water and minerals against gravitational force towards upsides are called xylem or wood and tissues which helps to translocate prepared food to different parts of plant are called as phloem or bast. As these tissues consist of more than one type of tissues, therefore they are called as complex tissues.

Anatomy of Flowering Plants Class 11 Important Questions Long Answer Type

Question 1.
Describe anatomy of dicot leaf (Dorsiventral) with labelled diagram.
Answer:
Anatomy of dicot (Dorsiventral) leaf: This type of leaves are commonly horizontal in orientation which contain distinct upper and lower surface. The upper surface which faces the sun is darker than the lower surface. The different parts are :
1. Upper epidermis :
It is made up of tightly packed rectangular barrel shaped, transparent parenchymatous cells in which chloroplast is absent. In this layer stomata are generally absent.

2. Mesophyll :
It is the ground tissue which is situated between upper and lower epidermis. It can be differentiated into two distinct layers.
(i) Palisade parenchyma :
This portion lies just next to the upper epidermis and are roughly rectangular in shape. They are remarkably placed at right angles to the surface of the leaf in order to absorb maximum sunlight for the process of photosynthesis. They are arranged in many parallel rows like palisade anji therefore also called as palisade mesophyll. They contain abundant chloroplast and help in photosynthesis.

(ii) Spongy parenchyma :
The cells of this region are irregular in shape and are not very compact in arrangement. They enclose large air spaces between them which give them spongy characteristic. These cells are simple parenchyma and hence this tissue is known as spongy parenchyma. The intercellular spaces of this tissue communicate with the external atmosphere through the stomata. These cells may develop chloroplast also.

3. Vascular bundles:
They are meant for distributing water and minerals to the lamina of the leaf. These vascular bundles are conjoint, collateral and endarch. The phloem is situated towards the abaxial side and protoxylem points towards the adaxial side. Each vascular bundle has its own vascular sheath around it.

4. Lower epidermis :
This layer is made of a single layer of compactly arranged rectangular, transparent parenchymatous cells. Lower epidermis contains large number of pores called stomata.

Question 2.
What is stomatal system? Describe structure of stomata with labelled diagram.
Answer:
Stomata are minute pores found on the epidermal layer of leaves and other green aerial parts of the plant body. Each stoma or aperture is bounded by two kidney shaped cells, called Guard cells. Guard cells are living and contain chloroplast. The outer wall of guard

cell adjacent to epidermal cell wall is thin whereas the inner wall lying towards the stomata is thicker. In certain plants, some specialized epidermal cells are present. These cells are called Subsidiary or Accessory cells. Each stomata open below in a large cavity, called Sub-stomatal cavity.

In xerophytes, stomata are found sunken in grooves. This greatly reduces rate of transpiration. Function of stomata is exchange of gases and control of transpiration.
Stomatal pore, guard cells and subsidiary or accessory cells together form stomatal system.

Question 3.
Describe the process of secondary growth in the stem of woody angiosperms with labelled diagrams. Give its importance.
Answer:
Secondary growth :
Increase in thickness of the root and stem of dicot plants due to addition of secondary tissues by the activity of cambium and cork cambium is called as secondary growth.
Dicot plants convert into trees due to secondary growth and monocot plants cannot develop to form a tree due to absence of secondary growth. Except a few plants monocot do not shows secondary growth whereas dicot stem as well as root both shows secondary growth.

Secondary growth in dicot stem:
In a typical dicot stem secondary growth occurs in following ways:
1. Activity of cambium:
The vascular bundles in the dicot stem are open type, that is to say that bundles contain intrafascicular cambium in between xylem and phloem which is a primary meristem. The parenchymatous cells found in between the intrafascicular cambium of the adjacent bundles become meristematic to form strip of interfascicular cambium, which laterally join to the intrafascicular cambium to complete a circular ring of cambium. This is known as cambium ring.
Cambium ring cuts secondary phloem towards outside and secondary xylem towards inside.
Generally secondary xylem is produced in more quantity as compared to secondary phloem therefore cambium ring moves towards the periphery.

The primary phloem becomes crushed. Not only this, but there is a continuous collapsing and disintegration of the secondary phloem in its outer region and continuous addition in the inner region just outside the cambium ring. However, the amount of secondary xylem goes on increasing continuously.

2. Formation of annual rings :
In annual herbs, there is little secondary growth. However, in the perennial plants, especially the arborescent ones, secondary growth is more or less continuous process. The process usually starts in the spring, the amount of wood which is formed during the spring and summer is much more than that formed during the winter. Further, the xylem elements which are formed during the spring and subsequent summer are larger in diameter than those formed during the winter.

The spring (or summer) wood is, therefore, lighter in colour and lesser in density in comparison to the winter wood which is comparatively darker in colour and greater in density. The sequence of spring and winter wood on a cut log of a wood is seen in the form of dark and light coloured concentric rings. One light and a dark coloured zone represents one years growth and is known as a growth ring or annual ring.
Thus, by counting the number of growth rings, one can estimate the age of the wood with a fair degree of correctness.

3. Cork cambium or Phellogen and its activity :
With the progressive increase in diameter of the secondary wood, the primary tissues outside the secondary phloem, including the cortex and the epidermis becomes greatly stretched and may even radially crack open. However before this eventuality arises, another cambium arises, in the cortex. This is the
cork cambium.

The cork cambium is completely secondary in nature.
The cells of the cork cambium are brick-shaped and tangentially elongated.
Derivatives are cut off both towards the outside, as well as towards the inside. The outer derivatives become suberized and lead to form the cork or phellem. The inner derivatives may slightly round up but remain arranged in radial rows. They develop plenty of chloroplasts and constitute the secondary cortex or Phelloderm. The cells of the secondary cortex can be distinguished from those of primary cortex by their arrangement in radial rows and presence of chloroplasts.

With the formation of cork which is impervious, both to water and air, all primary tissues of the stem outside the cork cambium are cut off from water supply, dry up and are ultimately shed.
The cork, cork cambium and secondary cortex are collectively known as periderm. Phellem tissue is impervious to water and provides protection to the underlying secondary tissues. In this cork cells certain areas of the cork remain thin walled and loosely arranged. They help in gaseous exchange and are called as lenticels. They are generally produced at the site of the stomata which were present in the young stem.

Question 4.
Differentiate the following :
(a) Vessel and TVacheids,
(b) Parenchyma and Collenchyma,
(c) Heart wood and Sap wood,
(d) Open and Closed Vascular bundle.
Answer:
(a) Differences between Vessels and Tracheids

(b) Differences between Parenchyma and Collenchyma

(c) Differences between Heartwood and Sapwood

(d) Differences between Open and Closed Vascular Bundle

Question 5.
You observe transverse section of young stem of a plant under compound microscope. How will you identify that it is dicot stem or monocot stem? Give reason for it.
Answer:
Dicot stem and Monocot stem can be identified by following characteristics :
The T.S. of a dicot stem shows following structures :
(1) Epidermis :
It is single layered, which produces multicellular hairs and are covered by cuticle.

(2) Cortex:
It is below epidermis. The outer cortex is known as hypodermis and are generally made up of collenchyma. The inner cortex is made up of parenchymatous cells with intercellular space. Cortex is followed by single layered endodermis.

(3) Pericycle:
Below endodermis, parenchymatous pericycle is present.

(4) Vascular bundle:
Vascular bundles are made up of xylem, phloem and cambium arranged in the same radius. V.B. are conjoint, collateral, endarch and open. Xylem is made of xylem vessels, tracheids, wood fibres and xylem parenchyma. Phloem is made up of sieve tubes, companion cells and phloem paren¬chyma. A cambium ring is present between xylem and phloem.

(5) Pith :
It is very elaborated and occupies the major central portion of the stem and is composed of rounded or polygonal thin walled cells with intercellular spaces.
The anatomy or T.S. of monocot stem (maize stem) shows the following structures :
(i) Epidermis: It is an outermost layer of the stem which is single layered and without hairs. A layer of cuticle is present outside the epidermis.
(ii) Hypodermis : It is situated just below the epidermis and may be made up of 2 to 4 layers of sclerenchymatous cells.
(iii) Ground tissue: It is made up of parenchymatous cells with plenty of intercellular spaces. These cells are situated below the hypodermis and scattered up to the centre of stem.

(iv) Vascular bundle :
In monocot stem, the vascular bundles are found to be scattered in the ground tissues. They are conjoint, collateral and closed. The xylem is endarch and the vessels are arranged in the form of the letter ‘Y\ the phloem being situated in between the two limbs of the ‘Y’ and consists of sieve tubes and companion cells only. Lysigenous cavity is found below the protoxylem in each vascular bundle.
(v) Pith : Pith is absent.

Question 6.
Describe various types of vascular bundles.
Answer:
Types of vascular bundles: According to the arrangement of xylem and phloem, the vascular bundles are of the following types :
1. Radial vascular bundle :
When xylem and phloem form separate bundles and lie on different radii alternating with each other, is said to be radial vascular bundles as in roots.

2. Conjoint vascular bundle :
When xylem and phloem combine into one bundle. There are different types of conjoint bundles :
(i) Collateral: When xylem and phloem lie together on the same radius, xylem being internal and phloem external. When in a collateral bundle the cambium is present, as in dicotyledonous stems, the bundle is said to be open and when the cambium is absent it is said to be closed, as in monocotyledonous stems.

(ii) Bicollateral vascular bundle :
When in a collateral bundle both phloem and cambium occur twice, once on the outer side of xylem and then again on its inner side. The sequence is outer phloem, outer cambium, xylem, inner cambium and inner phloem. Bicollateral bundle is characteristic of the ground family. It is always open.

3. Concentric vascular bundles:
These are those vascular bundles where one type of the tissue encircles or envelops the other tissue. They are again of two types :

1. Amphivasal vascular bundles: When xylem surrounds the phloem as in Dracena and Yucca.
2. Amphicribral vascular bundles : When phloem encircles the xylem as in Ferns.

Anatomy of Flowering Plants Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Radial vascular bundles are found in :
(a) Dicot stem
(b) Monocot stem
(c) Dicot root
(d) Monocot root.
Answer:
(d) Monocot root.

Question 2.
Bicollateral vascular bundles are found in :
(a) Liliaceae
(b) Cucurbitaceae
(c) Compositae
(d) Malvaceae.
Answer:
(a) Liliaceae

Question 3.
In amphivasal vascular bundles :
(a) Phloem is covered by xylem
(b) Xylem is covered by phloem
(c) Both are radially arranged
(d) None of these.
Answer:
(d) None of these.

Question 4.
In dicot vascular bundles are :
(a) Open, collateral and endarch
(b) Closed, collateral and endarch
(c) Open, collateral and exarch
(d) Closed, collateral and exarch.
Answer:
(a) Open, collateral and endarch

Question 5.
The chief function of velamen tissue is :
(a) Absorption of water from host plant
(b) Absorption of water from atmosphere
(c) Absorption of mineral salts
(d) None of these.
Answer:
(c) Absorption of mineral salts

Question 6.
The lateral meristem is responsible for :
(a) Increasing height
(b) Increasing thickness
(c) Increasing permanent tissue
(d) None of these.
Answer:
(b) Increasing thickness

Question 7.
Companion cells are associated with :
(a) Sieve tubes
(b) Xylem
(c) Collenchyma
(d) Cambium.
Answer:
(a) Sieve tubes

Question 8.
Tissue responsible for secondary growth is :
(a) Cambium
(b) Cortex
(c) Pericycle
(d) Endodermis.
Answer:
(a) Cambium

Question 9.
Secondary growth is found in :
(a) Monocot plants
(b) Dicot plants
(c) Both (a) and (b)
(d) Bryophytes.
Answer:
(b) Dicot plants

Question 10.
Phellogen forms:
(a) Phloem
(b) Xylem
(c) Cork
(d) Cork and secondary cortex.
Answer:
(d) Cork and secondary cortex.

Question 11.
Lenticel found in bark is :
(a) Air pore
(b) Vessel
(c) Tissue
(d) Stele.
Answer:
(a) Air pore

Question 12.
Annual ring is made up of:
(a) Spring wood
(b) Autumn wood
(c) Both (a) and (b)
(d) None of these.
Answer:
(c) Both (a) and (b)

Question 13.
Brick-shaped suberized cells found outside the cork cambium is :
(a) Secondary cortex
(b) Phellem
(c) Epidermis
(d) Endodermis.
Answer:
(b) Phellem

Question 14.
Balloon shaped structures present inside the vessels are called :
(a) Histogen
(b) Tyloses
(c) Phellogen
(d) Tunica.
Answer:
(b) Tyloses

Question 15.
Periderm includes :
(a) Cork cambium (phellogen), cork (phellem) and secondary cortex (phelloderm)
(b) Cork cambium and cork
(c) Cork
(d) Cork and secondary phloem.
Answer:
(a) Cork cambium (phellogen), cork (phellem) and secondary cortex (phelloderm)

Question 16.
The best method to determine the age of tree is to :
(a) Measure its diameter
(b) Count the number of leaves
(c) Count the number of annual rings at the base of main stem
(d) Find out the number of branches.
Answer:
(c) Count the number of annual rings at the base of main stem

Question 17.
Wood is common name of:
(a) Cambium
(b) Vascular bundles
(c) Phloem
(d) Secondary xylem.
Answer:
(d) Secondary xylem.

Question 18.
Where do casparian strips occur :
(a) Epidermis
(b) Endodermis
(c) Pericycle
(d) Phloem.
Answer:
(b) Endodermis

Question 19.
Dendrochronology is the study of:
(a) Height of tree
(b) Diameter of a tree
(c) Age of the tree by counting the number of annual rings in the main stem
(d) None of these.
Answer:
(b) Diameter of a tree

Question 20.
In roots, lateral branches grow from :
(a) Epiblema
(b) Pericycle
(c) Cortex
(d) Endodermis.
Answer:
(b) Pericycle

Question 21.
Sunken stomata occur in :
(a) Mesophytes
(b) Xerophytes
(c) Hygrophytes
(d) Hydrophytes.
Answer:
(b) Xerophytes

Question 22.
Polyarch and exarch condition is found in:
(a) Monocot stem
(b) Monocot root
(c) Dicot stem
(d) Dicot root.
Answer:
(b) Monocot root

Question 23.
Meristem present in a vascular bundle is:
(a) Fascicular/intrafascicular cambium
(b) Interfascicular cambium
(c) Phellogen
(d) Procambium.
Answer:
(b) Interfascicular cambium

Question 24.
Cork cambium is also called :
(a) Phelloderm
(b) Phellem
(c) Periderm
(d) Phellogen.
Answer:
(d) Phellogen.

Question 25.
Periderm is produced by:
(a) Vascular cambium
(c) Phèllogen
(b) Fascicular cambium
(d) Intrafascicular cambium.
Answer:
(c) Phellogen

Question 26.
Endodermis of dicot stem is also called :
(a) Bundle sheath
(b) Starch sheath
(c) Mesophyll
(d) Water channel.
Answer:
(b) Starch sheath

Question 27.
Tyloses are thickenings seen in :
(a) Ray parenchyma
(b) Collenchyma
(c) Phloem cells
(d) Ray parenchyma and xylem cells.
Answer:
(d) Ray parenchyma and xylem cells.

Question 28.
Casparian strips contain :
(a) Cutin
(b) Pectin
(c) Suberin
(d) Wax.
Answer:
(c) Suberin

Question 29.
A component of xylem is:
(a) Seive tube
(b) Medullary ray
(c) Sclereid
(d) Tracheid.
Answer:
(d) Tracheid.

Question 30.
Vascular bundles occur in a ring in :
(a) Monocot stem
(b) leaf
(c) Root
(d) Dicot stem.
Answer:
(d) Dicot stem.

Question 31.
Secondary xyLem is:
(a) Bast
(b) Bark
(c) Cork
(d) Wood.
Answer:
(d) Wood.

Question 32.
Gymnosperm wood is soft as it:
(a) Lacks cambium
(b) Lacks vessels
(e) Does not yield timber
(d) None of the above.
Answer:
(b) Lacks vessels

Question 33.
Branch of Botany dealing with internal organization of plants is :
(a) Physiology
(b) Anatomy
(c) Ecology
(d) Cytology.
Answer:
(b) Anatomy

Question 34.
Phellogen is also knwon as :
(a) Vascular cambium
(b) Periderm
(c) Cork cambium
(d) Apical meristem.
Answer:
(c) Cork cambium

Question 35.
In an annual ring, the light coloured part in :
(a) Heartwood
(b) Sap wood
(c) Early wood
(d) Late wood.
Answer:
(b) Sap wood

Question 36.
Which is not a part of periderm :
(a) Phellogen
(b) Cork
(c) Secondary cortex
(d) Wood.
Answer:
(d) Wood.

Question 37.
Palisade parenchyma is absent in leaves of: (CBSE 2009)
(a) Gram
(b) Soyabean
(c) Sorghum
(d) Mustard.
Answer:
(c) Sorghum

2. Fill in the blanks:
(A)
1. Phellogen form the ………………….
Answer:
Cork and secondary cortex

2. Arenchyma is a kind of ………………….
Answer:
Parenchyma

3. Bicollateral vascular bundles are found in …………………..
Answer:
Liliaceae

4. Radial vascular bundles are found in …………………..
Answer:
Monocot root

5. Living member of the phloem tissue is ……………………
Answer:
Companion cells

(B) Fill in the blanks :
1. Dermatogen, Periblem and Plerome are found in …………………
Answer:
Root apex and stem apex

2. Bladder like ingrowths in the xylem vessels are called as ………………..
Answer:
Tyloses

3. Latex vessels are found in ………………….
Answer:
Cortex

4. Increase in ……………… of stem and root of dicot plants is called as secondary growth.
Answer:
Thickness

5. Secondary growth occurs due to activity of ………………..
Answer:
Cambium and cork cambium

6. Cortex consists of ………………. tissue.
Answer:
Parenchyma

7. Annual ring in plants is formed due to ………………. and ……………..
Answer:
Spring wood, autumn wood

8. ……………….. and …………… are vascular tissues.
Answer:
Xylem, phloem

9. Companion cells are found in …………………
Answer:
Phloem

10. Radial vascular bundles are found in ……………….
Answer:
Roots

3. Match the following:
(A)

Answer:
1. (d) Non-functional wood
2. (e) Phloem
3. (a) Phellogen
4. (b) Bark
5. (c) Functional wood

(B)

Answer:
1. (c) Conjoint, collateral, open vascular bundle
2. (d) Radial, less than 6 vascular bundles
3. (a) Conjoint, collateral, closed vascular bundle
4. (e) Radial, more than 6 vascular bundles.
5. (b) Bulliform cells

(C)

Answer:
1. (d) Conjoint, collateral, closed vascular bundle
2. (e) Ingrowth in the xylem.
3. (a) Dicot plant
4. (c) Narrow and small vessels
5. (b) Broad and large vessels

(D)

Answer:
1. (b) Secondary vascular bundle
2. (a) Periderm
3. (d) Tyloses.
4. (c) Companion cells

(E)

Answer:
1. (d) Root apex
2. (e) Internode.
3. (a) Cork cambium
4. (b) Sunflower stem
5. (c) Maize root

4. Write true or false:

1. Intercalary meristem occurs in Mint and Grasses.
Answer:
True

2. The xylem having protoxylem towards the centre is called exarch.
Answer:
False

3. Casparian strip is found in passage cells.
Answer:
True

4. The complex tissue includes scierenchyma.
Answer:
False

5. In dicot vascular bundles are open, collateral and endarch.
Answer:
True

6. Secondary growth is not found in monocot plants.
Answer:
True

7. Cork cambium is formed in vascular bundles.
Answer:
False

8. Cork cambium is also known as phellogen.
Answer:
True

9. Heartwood is commercially more important.
Answer:
True

10. Autumn ring is more prominent than spring ring.
Answer:
False

11. Radial vascular bundles are found in dicotyledonous stem.
Answer:
False

12. Lenticels are the pores on the surface of bark of stem.
Answer:
True

13. Isobilateral leaves are found in dicot plants.
Answer:
False

5. Answer in one word:

1. The cell wall of xylem is rich in …………………..
Answer:
Lignin

2. Tissue responsible for secondary growth is ………………..
Answer:
Cambium

3. Tyloses thickening are seen in …………………
Answer:
Ray Parenchyma and Xylem cells

4. Which tissues have only living cells?
Answer:
Parenchyma

5. Brick shaped suberized cells found outside the cork cambium is …………………
Answer:
Cork

6. Abnormal secondary growth is found in ………………..
Answer:
Dracena

7. The tissue responsible for translocation of food material is ……………….
Answer:
Sieve tubes

8. In trees, the growth rings represent………………..
Answer:
Age

9. Vascular cambium and cork cambium are…………………
Answer:
Meristemâtic tissues

10. Maximum activity of cambium is during………………….
Answer:
Summer

11. Write the name of vascular tissue of plants which is non-living.
Answer:
Xylem

Students get through the MP Board Class 11th Biology Important Questions Chapter 5 Morphology of Flowering Plants which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 5 Morphology of Flowering Plants

Morphology of Flowering Plants Class 11 Important Questions Very Short Answer Type

Question 1.
What are respiratory roots?
Answer:
There is lack of air in saline swampy areas. Roots of the plants grows in such areas grows vertically upward and comes out of the ground, which bears lenticels (some pores) called as pneumatophores through which gaseous exchange occurs during respiration e.g., Rhizophora.

Question 2.
From which part of seed, root develops?
Answer:
Root develops from radicle.

Question 3.
What is mycorrhizal root?
Answer:
These roots are commonly found in gymnosperms. In this root the portion of tap Toot and its branches becomes closely invested by the hyphae of a fungus. These fungal hyphae develop a close mat around the external surface of the root, and root hairs are absent e.g., Pinus.

Question 4.
What is taproot?
Answer:
The root which develops from the radicle and form main root. The lateral branches arising from the tap root or main root are termed as secondary roots. This root goes deep into the soil. It is characteristic of most of dicots, e.g., Mustard.

Question 5.
What is adventitious root?
Answer:
A root arising from any part of the plant other than radicle such as from stem or nodes is called as adventitious root. These roots are present just below the soil and they are present in group.

Question 6.
Write the name of two rootless plants.
Answer:
Wolffia and Utricularia are the two rootless plants.

Question 7.
Cuscuta plant do not bear leaves, how does they obtain their food?
Answer:
Cuscuta (Amarbel) is a parasitic plant. The stem and branches of this plant possessing specialized parasitic roots called as sucking or haustorial roots, through which they absorb food from host plant.

Question 8.
Write the two main characters of root.
Answer:

1. Roots are usually positively geotropic, hydrotropic and negatively phototropic.
2. The tip of a root usually covered by a small conical root cap, which protects root tip.

Question 9.
How do roots transfer water and minerals to various parts of the plant?
Answer:
Root hair zone of the root helps in transfer of water and minerals to various parts of the plant.

Question 10.
What is root cap? Write its importance.
Answer:
Root cap :
It is cap like parenchymatous multicellular structure which covers the root meristem. The cells of the root cap secrete mucilage. The latter lubricates the passage of root through the soil. Cells of root cap also possess starch grains. Meristematic tissue known as calyptrogen, help in the formation of root cap.

Question 11.
Write the name of root which helps in photosynthesis.
Answer:
Assimilatory root, e.g., Tenosporea, Trapa.

Question 12.
What are lateral roots?
Answer:
Lateral roots are endogenous in origin. Lateral roots arise from pericycle.

Question 13.
What are buttress roots?
Answer:
Buttress roots are the roots found around the base of stem and are formed by the branches of main root in which primary growth is unsymmetrical. These look like extra walls built to support any fort’s wall, e.g., Ficus.

Question 14.
Give examples of Napiform root and Conical root.
Answer:

• Napiform root: e.g., Turnip, beet root.
• Conical root: e.g., Carrot.

Question 15.
Stem develops from which part of the plant?
Answer:
Stem develops from plumule of seed of the plant.

Question 16.
Write the names of subaerial modification of stem.
Answer:

• Runner,
• Stolon,
• Offset,
• Sucker.

Question 17.
Distinguish between stolon and runner.
Answer:

• Stolon is a slender lateral branch that arises from the base of the main axis which afterwards grow above soil whereas runner is growing horizontally above ground.
• Stolon is relatively thick whereas runner is thin.

Question 18.
Write the difference between vascular bundle of root and stem.
Answer:
The vascular bundle of root is radial and exarch and in stem vascular bundles are conjoint, collateral and endarch.

Question 19.
What is cladode?
Answer:
These are green stems branches of limited growth which have taken over the function of photosynthesis from the leaves, e.g., Asparagus, Ruscus etc.

Question 20.
Bulb of Onion is stem. Why?
Answer:
Bulb of Onion is stem, because :

• They have nodes and reduced intemodes.
• Adventitious roots arise from its base.
• Scale leaves are present.

Question 21.
Write the edible part of Potato and Onion.
Answer:
The edible part of Potato is stem and that of Onion is fleshy scale leaves.

Question 22.
Write the names of aerial modification of stem.
Answer:

• Stem tendril,
• Stem thorn,
• Phylloclade,
• Cladode,
• Bulbils.

Question 23.
Write differences between Rhizome, Corm and Bulbs.
Answer:
Differences between Rhizome, Corm and Bulbs

Question 24.
Write the three main difference between root and stem.
Answer:

1. Nodes and intemodes are absent in root and nodes and intemodes are present in stem.
2. Roots contain root cap and root hairs but they are absent in stem.
3. Apical bud is present in stem but it is absent in root.

Question 25.
Write important functions of the stem.
Answer:
Functions of stem :

• Stem plays an important role in the transportation of water, mineral salts and food materials.
• It helps in photosynthesis in young stage.
• Stem forms aerial system of the plant body.
• Stem provides mechanical support to the plant.
• Some stems help in vegetative propagation.

Question 26.
Write differences between Runner, Sucker and Offset.
Answer:
Differences between Runner, Sucker and Offset

Question 27.
Write differences between Stolon and Runner.
Answer:
Differences between Stolon and Runner

Question 28.
What is pseudo stem?
Answer:
In some monocot stem leaf base becomes broad and flat and covers a part of the node of stem and sheathing of many leaves jointly make a stem like structure known as false stem or pseudo stem e.g., Banana.

Question 29.
Write name of two monocot plants whose leaves contain reticulate venation.
Answer:
Smilax and Dioscorea.

Question 30.
Write short note on phyllotaxy.
Answer:
Phyllotaxy is the arrangement of leaves on the stem and branches. The leaves of each plant are arranged in a definite pattern on the stem or branches. Main purpose of phyllotaxy is to provide sufficient light to the leaves. When a single leaf arises at each node and two leaves at adjacent nodes are held opposite to each other the leaves are called alter¬nate. The phyllotaxy is opposite when two leaves arise from each node in opposite directions but when more than two leaves arise from each node and form a whorl around it, they are called whorled.

Question 31.
What is Isobilateral leaf?
Answer:
In Isobilateral leaf both the surfaces are equally illuminate as both the surfaces can face the sun. So, the two surfaces can face the sun. e.g., wheat, rice.

Question 32.
Why insectivorous plants catches insect as a food?
Answer:
Insectivorous plants are present in swampy areas where deficiency of nitrogen occur. For fulfil this deficiency the plant catches insects.
e.g., Pitcher plant, Utricularia.

Question 33.
What are stipules?
Answer:
Leaves of some plants have lateral outgrowths on each side of leaf base, which are called to be as stipules. The leaves without stipules are known as exstipulate. Main function of stipules is to protect the leaf in the bud. When green, these synthesize food also.

Question 34.
What are dorsiventral leaves?
Answer:
A leaf is called as dorsiventral when it grows in such a way that the ventral surface gets more sunlight and is bright green in colour, whereas the dorsal surface gets less light and dull-green in colour.

Question 35.
Write differences between Parallel and Reticulate venation.
Answer:
Differences between Parallel and Reticulate Venation

Question 36.
What is a flower?
Answer:
Flower is a modified shoot, the leaves of which are modified into specialized structures called as floral leaves. A typical flower consists of two accessory whorls Calyx and Corolla and two essential whorls Androecium and Gynoecium.

Question 37.
Write floral formula of a flower, which is actinomorphic, hermaphrodite, hypogynous, 5 sepals, gamosepalous, 5 petals, polypetalous, 5 stamens, polyandrous, bicarpellary syncarpous with superior ovary.
Answer:
Floral formula:

Question 38.
What is floral diagram?
Answer:
The diagrammatic representation of no. of individual members of different floral whorls and their arrangement is called floral diagram.

Question 39.
Explain floral formula along with example.
Answer:
The symbolic representation of the number of individuals present in different floral whorls, their arrangement and general characteristics of the flower is called floral formula, e.g., The structure of the flowers of mustard plant can be expressed by the following floral formula:

Question 40.
Write the floral formula of Cruciferae family.
Answer:

Question 41.
What is androphore and gynophore?
Answer:
In flowers, in between corolla and androecium, structure is present called androphore and in between androecium and gynoecium a floral structure is called gynophore. Both are collectively called gynandrophore.

Question 42.
Write the floral formula of ray and disc florets present in sunflower.
Answer:
Ray florets :
Disc florets :

Question 43.
What do you mean by hypogynous flower?
Answer:
When the ovary occupies the highest position and the stamen, petals and sepals are developed below the ovary, the condition is known as hypogyny and the flowers are called hypogynous. In a hypogynous flower, therefore the ovary is superior, e.g., Mustard, Brinjal, China rose, etc.

Question 44.
Write floral formula of Chinarose flower.
Answer:

Question 45.
What is actinomorphic flower?
Answer:
The flower which can be divided into two equal half portions by any plane are called actinomorphic flower.

Question 46.
Write differences between Superior and Inferior ovary.
Answer:
Differences between Superior and Inferior Ovary

Morphology of Flowering Plants Class 11 Important Questions Short Answer Type

Question 1.
Give general characteristics of stem.
Answer:
General characteristics of stem :

• It is negatively geotropic and positively phototropic.
• It develops from the plumule portion of the embryo during seed germination.
• It is differentiated into nodes and intemodes. Leaves are borne on the nodes.
• Axillary buds are found at the axil of leaves.
• Apical bud is found at the terminal end of the stem, which helps to increase size of the stem.
• The branches of the stem are exogenous in origin.
• Multicellular stem hairs are found on the stem.

Question 2.
Write any four differences between Root and Underground stem.
Answer:
Differences between Root and Underground Stem

Question 3.
Give functions of the stem.
Answer:
Functions of the stem :

• The stem acts as the main support for the branches and leaves.
• It prepares food by photosynthesis process in young stage.
• It helps in conduction of water and minerals absorbed by the roots.
• It helps in translocation of food materials synthesized by the leaves to different parts of the plant.
• In desert plants, it helps to prepare and store food.
• In some plants, it helps for vegetative propagation. Example : Potato, Ginger.
• In some plants, stem is modified into thorn which is mainly defensive in function.

Question 4.
Give general functions of leaf.
Answer:
General functions of leaf:

• It manufactures food material by photosynthesis process.
• It helps for exchange of gases through stomata.
• It helps for transpiration through stomata.

Question 5.
Give special functions of leaf.
Answer:
Special functions of leaf:

• Some leaves store food materials in them.
• Some leaves are modified for defence, climbing, reproduction etc.
• Some leaves changes their colour and help for pollination by attracting insects and animals.
• Some leaves help for vegetative propagation.
• Some leaves are modified into roots and help for absorption of water and minerals.

Question 6.
Distinguish between Phylioclade and Phyllode.
Answer:
Differences between Phylioclade and Phyllode

Question 7.
Give functions of calyx.
Answer:
Functions of calyx :

• Protection of floral organs in bud condition.
• Provide support to the base of mature flower.
• Attraction of insects and help in pollination when they are coloured.
• Dispersal of fruits and seeds.
• Help in photosynthesis because they contain chlorophyll.

Question 8.
What do you mean by adhesion of stamens? Describe its various types.
Answer:
Adhesion : Fusion among members belonging to different whorls of flower is called as Adhesion.
Following are the different types of adhesion of stamen to other floral whorls :

1. Epipetalous : When the filaments are fused to the petals to a greater or lesser extent.
   Example: Datura.
2. Epiphyllous : When the filaments are fused to the petals of perianth.
   Example: Onion.
3. Gynandrous : When the stamens adhere to the gynoecium either loosely or very intimately.
   Example: Calotropis.
4. Gynostegium : A protective covering of gynoecium formed by the androecium and not involving any fusion between the androecium and the gynoecium.
   Example: Orchidaceae.

Question 9.
What do you mean by insertion of floral leaves?
Or,
What do you mean by hypogynous, perigynous and epigynous ovary?
Answer:
Insertion of floral leaves : Position of the gynoecium and other floral whorls like calyx, corolla and androecium on the thalamus is called as insertion of floral leaves. It is of following three types :
1. Hypogynous :
When thalamus swells to form a ball like structure then the ovary of the gynoecium occupies the highest position on the thalamus and the stamen petals and sepals develops below the ovary on the thalamus. This type of insertion is called as Hypogynous. The ovary in this case is superior, e.g., Mustard.

2. Perigynous :
In this type the periphery of the thalamus expand to varying degrees making the thalamus disc shaped, cup shaped or flask shaped. The apex of the thalamus lies at the centre to which ovary of the gynoecium is found attached. The remaining parts are borne on the periphery.
Example : Pisum sativum. The ovary in this case is half inferior.

3. Epigynous :
The thalamus is hollowed out in the form of a cup or flask but its internal walls are fused with the wall of the ovary. Only the style and stigma of the pistil are observable in this condition. The other parts of the floral leaves are borne at the top of the ovary.
The ovary is termed as inferior and the thalamus is called as Epigynous.

Question 10.
What do you understand by modification of roots ? Which type of modifications are found in following :
(a) Banyan,
(b) Turnip,
(c) Mangrove?
Answer:
Modification in roots:
Besides the common functions like absorption and fixation the roots are further modified to perform specialized functions such as storage of food, support, respiration etc. This is known as modification.
(a) Banyan :
In banyan trees adventitious roots arise from horizontal branches, grow vertically downwards and penetrate into the soil. These branches increase in thickness by secondary growth and give mechanical support to the horizontal branches. This type of modification of root in banyan tree is called as Prop root.

(b) Turnip :
In turnip tap root is swollen to form spherical shaped structure, which is tapering at the lower part due to storage of food. This type of modification of root in turnip is called as Napiform root.

(c) Mangrove :
Mangrove plants grow in saline swamps or marshy areas, which develop special kind of roots called as respiratory roots or pneumatophores. Roots of these plants do not have proper gaseous exchange due to saline and marshy areas, thus some roots (pneumatophores) grow vertically up and become negatively geotropic, which are provided with air pores called lenticels. Lenticels help for gaseous exchange during respiration.

Question 11.
On the basis of external features give reason for following statements :
(a) All underground parts of plants are not roots.
(b) Flower is a modified shoot.
Answer:
(a) All underground parts of plants are not roots :
It is true that root always
grows down into the earth but some stems are exceptions. Such as ginger, onion and potato. These are examples of underground modification of stems.
Tuber of potato is an underground modification of stem. When a tip of a positively geotropic lower branch of potato stem swells-up due to the accumulation of reserve foods then a potato tuber is formed.
We can differentiate tuber of potato from root by following points :

• Nodes and intemodes are found in it.
• Scale leaves are found in it.
• Buds are found in the form of eyes.
• It is a modified structure for storage of food.

(b) Flower is a modified shoot:
Following points prove that flower is a modified shoot:

• Thalamus of the flower looks like a stem in which nodes and intemodes are condensed.
• The phyllotaxy of floral leaves is similar to those of vegetative leaves. Actually they are modified leaves to perform special functions.
• Sepals of some plants look like leaves which proves that sepals are modified leaves, e.g., Water lily.
• In some plants thalamus elongates and exhibits clear nodes and intemodes. It con¬firms the view that thalamus is a modified branch.
• Like stems flower also develops from a bud.

Question 12.
How Pinnate compound leaf differs from Palmate compound leaf?
Answer:
There are two types of compound leaves :
1. Pinnate compound leaf and
2. Palmate compound leaf, which differs from each other in following ways :

1. Pinnate compound leaf:
The leaf blade is divisible into several leaflets, arranged laterally on the midrib portion. It is of four types :
(a) Unipinnate : When the rachis directly bears the leaflets. In this, rachis acts as midvein and the leaflets are found on its either side.
e.g., Rose, Cassia.
When, there are even numbers of leaflets on the midrib, it is known as paripinnate, e.g., tamarind, and when there are odd number of the leaflets on the midrib it is called as imparipinnate. e.g., Rose, Neem.
(b) Bipinnate : In this type rachis branches only once and bears the leaflets.
Example: Gulmohar.
(c) Tripinnate: When the secondary branches divides once again bearing the leaflets.
Example: Moringa.
(d) Decompound : When there are more than three incisions of the lamina.
Example: Coriander.

2. Palmate compound leaf:
In this type margin of leaf is incised to divide the base of the blade or the petiole in such a manner so that the leaf blade is divided into a number of segments or leaflets. The arrangement of the leaflets look like the fingers of human palm and hence this type of the compound leaf is known as Palmate compound leaf. Depending upon the number of leaflets they are divided into the following types :
(a) Unifoliate : A unifoliate compound leaf is the result of reduction of all leaflets of a multifoliate compound leaf, except the terminal leaflets as in Citrus sp.
(b) Bifoliate : When there are only two leaflets as in Hardwickia.
(c) Trifoliate : When there are three leaflets as in Aegel marmelos.
(d) Quadrifoliate : When there are four leaflets as in Oxalis and Marsileas.
(e) Multifoliate or Digitate: When more than four leaflets are present as in Salmalia sp.

Question 13.
Describe various kinds of phyllotaxy with example.
Answer:
Phyllotaxy is defined as the arrangement pattern of leaves on the stem and branches in order to provide sufficient light and air. It is interesting to note that leaves are never arranged haphazard but with mathematical precision at definite and regular intervals.

Type of phyllotaxy:
This is usually of three types:
1. Alternate : From each node, single leaf arises, two leaves arise from the adjacent nodes and are held opposite to each other, e.g., Sunflower, Mango. These may be of the following types:

• Distichous,
• Tristichous,
• Pentastichous.

2. Opposite :
Two leaves are present on a single node but are opposite to each other that is at 180° to each other. It may be of two types :

• Opposite superposed : When the successive pairs of leaves are placed one above another forming two vertical rows when seen from the top. e.g., Guava.
• Opposite decussate : When are pair of leaf is placed at right angle to the next e.g.
  Tulsi.

3. Whorled or Verticillate :
When there are more than two leaves at each node,arranged in a circle or whorled.

Morphology of Flowering Plants Class 11 Important Questions Long Answer 

Question 1.
Define following terms :
(a) Aestivation,
(b) Placentation,
(c) Actinomorphic,
(d) Zygomorphic,
(e) Superior,
(f) Perigynous,
(g) Epipetalous.
Answer:
(a) Aestivation : Aestivation is the arrangement of floral leaves (Calyx, corolla or perianth) in the bud condition. The various types of the aestivation are :

1. Valvate,
2. Twisted,
3. Imbricate,
4. Descending imbricate,
5. Quincuncial.

(b) Placentation :
The arrangement of the ovules on the placenta of ovary is called as Placentation. The various types of placentations are :

1. Marginal,
2. Parietal,
3. Basal,
4. Axile and
5. Free central type.

(c) Actinomorphic :
When the flower can be divided into two equal halves along more than one vertical plane passing through the middle of the flower then the flower is called as Actinomorphic. e.g., China rose.

(d) Zygomorphic:
When flower can be divided into two equal halves along only one plane then flower is called as Zygomorphic. e.g., Pea.

(e) Superior :
When thalamus of the flower is ball or conical shaped then position of ovary is superior to all other parts of the flower. Such ovary is called as Superior ovary. e.g., China rose, Mustard, Brinjal etc.

(f) Perigynous :
When thalamus of the flower is cup shaped and position of the ovary as compared to other floral parts is half inferior then the flower is called as Perigynous. e.g., Pea, rose, bean etc.

(g) Epipetalous :
When the filaments of stamens are fused to the petals to a greater or lesser extent then stamens are called as Epipetalous. e.g., Dhatura.

Question 2.
Write differences between following :
(a) Racemose and Cymose inflorescence
(b) Tap root and Adventitious root.
(c) Apocarpous and Syncarpous.
Answer:
(a) Differences between Racemose and Cymose Inflorescence

(b) Differences between Tap and Adventitious Root Systems

(c) Differences between Apocarpous and Syncarpous

Question 3.
What is flower? Describe various parts of a typical angiosperm flower.
Answer:
Flower is a modified shoot which performs the function of sexual reproduction and arises either at the tip of a branch or at the axil of a leaf. It leads to formation of fruits and seeds.

A typical flower has following four parts :

1. Calyx,
2. Corolla,
3. Androecium,
4. Gynoecium.

(A) Accessory parts of flower :
(1) Calyx :
Outermost whorl of the flower is called as Calyx. Unit structure of calyx is called as Sepal. It protects the flower in bud condition. Generally it is green in colour due to presence of chlorophyll, thus can prepare food by photosynthesis process.

(2) Corolla :
It is the second whorl of the flower, which consists of unit structures called as Petals. Generally it is large and colourful to attract insects for pollination.

(B) Essential parts of the flower :
(3) Androecium :
It is the male reproductive part of the flower which forms third whorl of the flower. Unit structure of androecium is called as Stamen. Each stamen consists of three parts :

1. Filament,
2. Anther and
3. Connective. Pollen grains are formed inside the anther. Male gametes are formed in the pollen grains.

(4) Gynoecium :
It is the innermost and fourth whorl of the flower. It is the female reproductive part of the flower. Unit structure of gynoecium is called as Carpel or Pistil. Each pistil consists of three parts:

1. Stigma,
2. Style and
3.  Ovary. Egg is formed in the ovules present in the ovary.

Question 4.
Describe various types of placentations found in flowering plants.
Answer:
Placentation : The arrangement of the ovules on the placenta of the ovary is called as placentation. It is of the following types :

(i) Marginal:
It is found in monocarpellary pistils which bears a longitudinal placenta on the ventral surface. The placenta bears one or two rows of ovules.
Example: Pea.

(ii) Parietal:
The parietal placenta shows two or more than two placentae attached to the wall of ovary. It is found in syncarpous pistils with unilocular ovary. The ovules are borne near the periphery of the ovary and the placenta are situated on the fused margins of the adjacent carpels.
Example: Poppy, Mustard.

(iii) Basal:
The pistil is usually polycarpellary and syncarpous. The ovary is unilocular and possesses one placenta which bears a single ovule towards the base of the ovary.
Example: Helianthus (Sunflower).

(iv) Superficial:
Here the ovules are not restricted to the margins of the carpels but are found on the whole inner surface of the ovary.
Example: Nymphaea.

(v) Axile :
It is found in polycarpellary syncarpous pistils. The ovary is partitioned into two or more chambers or loculi depending upon the number of the fusing carpels. The placentas are found in the centre of the ovary at the place of union of the septa so that a central or axile column is formed which bears the ovules.
Example: China rose.

(vi) Free central:
In this case the pistil is polycarpellary and syncarpous but ovary is unilocular. The ovules are found all around a central column which runs throughout the middle of the ovary.
Example: Dianthus.

Question 5.
How modifications of leaves are helpful to plants?
Answer:
Main function of leaves are photosynthesis and transpiration. In order to perform certain peculiar function the leaves change their shape accordingly. However the main types of modifications are as follows :

1. Leaf spines :
When leaf is modified into sharp pointed slender structures called as spines. They provide protection to the leaf and also checks excessive transpiration.
Example : Asparagus, Ulex etc.

2. Leaf tendrils :
Tendrils are slender wiry often closely coiled structures which helps in climbing of the plant on its support, Whenever they come in contact with a neighbouring living or non-living object they coil around it and help the plant to rise up. For this purpose either full leaf or some leaflets are changed into tendrils.
Example : Pisum sativum, Begonia etc.

3. Leaf hooks :
Here leaf is modified into thick sharp, stiff and curved structures called as hooks. These hooks cling to the bark of a tree and support the climbing plant.
Example: Begonia.

4. Scale leaves :
When leaf is reduced in the form of thin, dry membranous structure to protect the axillary buds in their axil. They are frequently observed in case of underground modification of stem.
Example : Potato, Ginger, Onion etc.

5. Storage leaves :
Leaves of some plants become fleshy due to storage of water and food material, such leaves are called as storage leaves.
Example : Agave, Aloe, Bryophyllum etc.

6. Leafy roots :
When the leaf modified into a root like structure.
Example: Salvinia.

7. Leaf pitcher:
When the entire or a part of the leaf is changed into a dilated pitcher like structure to catch insects to fulfil their nitrogen requirement.
Example : Nepenthes, Dischidia rafflesiana.

8. Leaf bladders:
When some leaves are modified into small oval or circular bladder into a trap-door entrance. This modification is most conspicuous in insectivorous but not in hydrophytic plant species like Utricularia.
Example: Utricularia.

Question 6.
Define inflorescence. Describe on the basis of types of inflorescence found in flowering plants.
Answer:
Inflorescence:
Arrangement of flowers on the floral axis of a plant is known as inflorescence. The central axis of an elongated inflorescence is called as Peduncle.
In some plants flowers arise singly at the apex and are called as Solitary terminal flowers as in Poppy. In some cases like Oxalis, guava etc., single flowers arise in the axil of the leaf and are called as Solitary axillary flowers. The inflorescence may be of following types:
(A) Simple inflorescence,
(B) Compound inflorescence,
(C) Special inflorescence and
(D) Mixed inflorescence.

(A) Simple inflorescence : When flowers are directly bom on the main axis. It is of two types :
(1) Racemose or indefinite : When the growth of the inflorescence continues indefinitely and produces flowers laterally in acropetal succession. It may be of following types :
(a) Typical raceme : e.g.,Mustard
(b) Spike : e.g., Amaranthus
(c) Spikelet: e.g., Wheat
(d) Spadix : e.g., Banana
(e) Catkin : e.g., Mulberry
(f) Umbel: e.g., Coriander
(g) Corymb : e.g.Jberis amara
(h) Capitulum or Head: e.g., Sunflower.

(2) Cymose or definite :
When the growth of the main axis is limited as the terminal bud is modified into a flower. The subsequent flowers are produced in basipetal succession. It may be of following types:
(a) Uniparous or Monochasial cyme : It is of two types :
(i) Helicoid cyme : e.g., Begonia
(ii) Scorpioid cyme : e.g., Heliotropium.

(b) Biparous or Dichashial cyme : e.g., Ixora
(c) Multiparous or Multichashial cyme : e.g., Calotropis.

(B) Compound inflorescence : When the main axis of the inflorescence is branched and the branches bear flowers of the inflorescence, it is called as compound inflorescence. It is of following types :
(a) Compound raceme : e.g.,Goldmohar,
(b) Compound spike : e.g., Spinach,
(c) Compound spadix : e.g., Coconut,
(d) Compound corymb : e.g., Cauliflower,
(e) Compound umbel: e.g., Coriander.

(C) Special inflorescence :
There are certain inflorescences which do not agree to the characteristics already described above. So these may be grouped under the special types and are of the following types :
(a) Cyathium : e.g., Euphorbia
(b) Verticillaster : e.g., Oscimum (Tulsi)
(c) Hypanthodium : e.g., Peepal.

(D) Mixed inflorescence: When the inflorescence is neither true racemose nor cymose but a mixture of two, it is said to be mixed inflorescence. It is of following types :
(a) Spadix of cyme : e.g., Musa sp.
(b) Cyme of umbels : e.g., Lantana
(c) Cyme of corymb : e.g., Oldenlandia, corymbosa.
(d) Cyme of capitula : e.g., Vernonia.

Question 7.
Give one-one example of Fabaceae and Solanaceae families and describe them in biotechnical language and draw their floral diagrams.
Answer:

(A) Family Fabaceae : Family Fabaceae was earlier called as Family Papilio- naceae. Pea plant represent Family Fabaceae or Papilionaceae.
Description of Pea flower (Pisum sativum):

1. Inflorescence: Generally racemose. In Crotolaria, it is terminal raceme, in Melilotus it is corymbose raceme whereas in Cicer arietinum it is solitary axillary.
2. Flowers : Pedicellate, bracteate, bisexual, zygomorphic, hypogynous or perigy- nous, complete and pentamerous.
3. Calyx : 5 sepals, gamosepalous, campanulate or tubular, imbricate aestivation.
4. Corolla: 5 petals, polypetalous, papilionaceous, posterior petal is largest and known as standard. Two lat¬eral petals are known as wings. Two anterior petals fuse to form boat shaped keel. The aestivation is vexillary.
5. Androecium: Generally, 10 stamens are present in two groups 9 + 1. It is known as diadelphous condition. The 9 stamens are fused through filament. In Crotolaria and Pongamia, it is monoadelphous. Anthers are dithecous, basifixed and introse.
6. Gynoecium : Monocarpellary, unilocular, su¬perior or half inferior. Marginal placentation. Style simple, stigma capitate.
7. Fruits : Legumes or Pods.
8. Seeds: Non-endospermic.
9. Floral formula:
   Pisum sativum : im

(B) Family Solanaceae :
Dhatura flower belongs to Family Solanaceae.
Description of Datura alba (Dhatura) flower :

1. Inflorescence : Inflorescence seen in the plants is of cymose type. Datura shows dichasial cyme, Solarium shows helicoid cyme, Atropa belladonna shows scorpioid cyme and Nicandra shows solitary axillary type of inflorescence.
2. Flower : Usually the flowers are pedicellate, bisexual, complete, pentamerous, actinomorphic, hypogynous and bracteate or ebracteate. Flower is zygomorphic in Hyosymus niger and Salpiglossis. The flowers of Salpiglossis are always cleistogamous.
3. Calyx : 5 sepals, gamosepalous, hairy, persistent with twisted aestivation.
4. Corolla : 5 petals, gam’opetalous, usually white in colour with valvate aestivation.
5. Androecium : 5 stamens, polyandrous, epipetalous, filament hairy with long anthers.
6. Gynoecium : Bicarpellary, syncarpous, bilocular, oblique ovary, superiorly placed. Placentation is axile with numerous swollen ovules found on the placenta. Style is simple and stigma is bilobed.
7. Fruits : Fruits are either of berry type e.g., Tomato, Brinjal etc. or capsule type e.g., Durantum.
8. Seeds : Seeds are endospermic.
9. Floral Formula :

Question 8.
Explain modification of adventitious roots for storage of food.
Answer:
Modification of adventitious roots for storage of food : Following modifications are found in adventitious roots for storage of food :
1. Fasciculated roots : These are like the tuberous roots but occur in a fascicle or cluster at the base of the stem.
Example : Dahlia, Asparagus etc.

2. Tuberous roots: The root is swollen and fleshy and may assume any shape, rounded, fusiform or any irregular shape, e.g. Sweet potato.
3. Nodulated roots : In this type, the fibrous adventitious roots abruptly become swollen at the tip.
Example : Curcuma amada (Haldi).
4. Moniliform roots : In this type, the root shows alternately swollen and thin portions.
Example: Pasella, Vitis.
5. Annulated roots : In this type, the root shows a series of ring like swellings separated by ring like grooves.
Example : Cephaelis, Ipecac uanha.

Question 9.
Explain modification of adventitious roots for providing mechanical support to the plant.
Answer:
Modification of adventitious roots for providing mechanical support: Following types of modifications are found in adventitious roots for providing mechanical strength:

1. Prop root:
These roots give support to the branches of a tree as the props in a tent. In the Banyan tree (Ficus benghalensis) the prop roots arise from the horizontally growing branches. The prop roots hang down vertically for quite a number of years and then enter the soil. The branches rest on them. The Great Indian Banyan Tree of the Indian Botanical Garden, Sibpur, Calcutta has produced more than 800 such prop roots. It is 200 years old and has occupied 300 sq.m. area.

2. Stilt root:
Stem of monocot plants are very weak and can not stand straight due to their weight. Some roots arise from the basal nodes of such stem and grow obliquely downward, ultimately strike the ground and thus support the plant. These roots are called as stilt root.

3. Buttress root:
The buttress roots are plate like structure formed by the bases of the main roots of tropical trees. It provides support to the plant.
Example : Prombab malabaricum.
Fig. Buttress root.

4. Climbing root:
These roots arise from the nodes of a climbing stem and cling very tenaciously to the substratum which may be a wall or the trunk of tree and thus help the plant in climbing.
Example : Money plant, Black pepper, Pan.

5. Clinging root:
These roots are found in epiphytes. These roots secrete a sticky substance which quickly dries up and aids in the sticking of the root to substratum.
Example: Vanda.

Question 10.
Write down the modification of tap root.
Or,
Explain modification of tap root for food storage with diagram.
Answer:
Modification of tap root:
(I) For food storage:
The tap root becomes swollen and fleshy with the stored food. The secondary roots remain thin. Hypocotyl (embryonic region between cotyledons and radicle) may also join the tap root in storing food. Stem is reduced and discoid in the beginning and bears radicular leaves. Depending upon the shape, the fleshy tap roots are of the following types:
1. Fusiform roots :
When the root is swollen in the middle and gradually tapering towards the apex and base it is called a fusiform root. It is more or less spindle shaped, e.g., Radish (Raphanus sativus).

2. Conical roots:
When the root is broad at the base and gradually tapers towards the apex like a cone, it is said to be conical root. It bears many secondary roots throughout the length, e.g., Carrot (Daucus carota).

3. Napiform roots :
When the root is considerably swollen at the upper part and becoming almost spherical and shaiply tapering at the lower part, it is said to be napiform. e.g., Turnip or Saljam (Brassica rapa), Beet root (Beta vulgaris). Base of root shows radicular leaves. In turnip most of the swollen part is formed hypocotyl. The lower narrow, pointed apical region bears threadlike secondary roots. In beet both the tap root and hypocotyl are swollen.

4. Tuberous roots :
These roots are thick and fleshy and do not maintain any definite shape, e.g.. Four o’clock (Mirabilis jalapa), Parwal (Trichosanthes), etc.

(II) For respiration (Pneumatophore or Respiratory roots):
Many plants growing in estuaries, saline swamps, marshes and salt lakes develop special kinds of roots called respiratory roots or pneumatophores. The plants which develop pneumatophores are called halophytes. These plants do not have proper gaseous exchange due to saline conditions, as a result their growth becomes hindered.

Pneumatophores are helpful in respiration. From the underground roots of the plant, pneumatophores grow vertically upwards and come out of the water in the form of conical spikes. They occur in large numbers around the tree trunks and are provided with air pores called lenticels. Air pores help in proper respiration. e.g., Rhizophora, Avicenna, Sonneratia, Heritiera (vem. Sundri), Kutch vegetation, Mangroves, etc.

Question 11.
Describe various underground modifications of the stem.
Answer:
Underground modifications of the stem : Such stems which grows under the ground are called as underground modifications of stems. It helps plants to survive in unfavourable condition. Stem become modified in various ways for certain special functions, i.e., storage of food material and vegetative propagation.
Following types of modifications are found in underground stem :
1. Rhizome,
2. Stem tuber,
3. Bulb,
4. Corm.

1. Rhizome:
It is a perennial underground stem which shows unlimited growth and develops in favourable condition to form upright shoot and leaves. It is a prostrate, thickened stem, creeping horizontally under the surface of the soil. It is provided with distinct nodes and long or short intemodes. It possesses a bud in the axil of scaly leaf and it ends in a terminal bud. From underside adventitious roots grows.
Example: Ginger, Fern.

2. Stem tuber:
The tubers are solid, thick¬ened stems or branches serving for storage of food and also vegetative propagation. When it develops from root it is called root tuber but when it develops from stem it is called as stem tuber. In Potato plant, tip of a positively geotropic, fleshy stem growing in a vertical direction swells due to the accumulation of reserve foods. These tubers bear temporary scale leaves with buds in their axils called ‘eyes’. Even a single detached bud may grow into a new plant. In this way it helps for vegetative propagation.
Example : Potato.

3. Bulb :
The bulb is a specialized underground reduced stem. In this the stem remains comparatively small and the food material is stored in the large, fleshy scales which invest and overlap the stem. However the stem is no more than a thick disc or very flat cone, but it has an apical bud on the upper side, and adventitious roots are formed in an annual plant from the marginal portion of the underside.

There are two types of bulbs:
(a) Tunicated bulb : In this type of bulb, one scale leaf totally overlap another. Towards the outside cover of dry scale leaves are found.
Example: Onion.

(b) Scaly bulb : In scaly bulb, the fleshy scale composing the main bulk overlap at their margin. No tunic is found to enclose the whole buds.
Example: Garlic.

4. Corm:
Corm is st, fleshy and thickened underground em growing in
vertical directions. There are many buds present in the axil of scale leaves which develop in daughter corms. At the bases or even from sides of stem the adventitious roots develop.Corms are also called condensed rhizomes, help in vegetative propagation and storage.
e.g., Arbi or Ghuiyan (Colocasia), Zimikand (Amorphophallus), Crocus.

Question 12.
Explain the aerial modifications of stem.
Answer:
Aerial Modifications or Metamorphosed Stems :
Sometimes vegetative and floral buds instead of growing into branches and flowers undergo modifications to form specialized structures like tendrils, thorns, phylloclades or bulbils to perform specific functions. These stems are called as metamorphosed stems.

1. Stem tendril:
It is a modification of stem in which axillary bud of leaves modifies, to form a filamentous structure called tendril. They help the plant to attach itself to the support and climb it. They are found in weak stemmed plants. The tendrils are leafless, coiled structures with sensitive tactile pits and adhesive glands to promote fixation of weak stem.
Stem tendrils are of four types :
(a) Axillary : e.g., Passiflora. »
(b) Extra axillary: e.g., Cucurbita, Lagenaria, Luffa.
(c) Leaf opposed : e.g., Grapevine.
(d) Floral bud or Inflorescence tendril: e.g., Antigonon,
Cardiospermum (Balloonvine).

2. Stem thorn :
In this modification, axillary bud is modified into thorn (Duranta) known as stem thorn. Leaves, branches and flowers are developed on thorns. It clarifies that thorn is a modified stem, e.g., Citrus, Bougainvillaea, Pome¬granate, Alhagi, etc.

3. Phylloclade:
It is a modified stem in which stem gets modified into leaflike structures and leaves get modified into spines. The phylloclade is green and flattened (e.g., Opuntia or Nagphani), cylindrical (e.g., Casuarina) or ribbon like (e.g., Zygocactus or Muhlenbeckia) and has distinct nodes and intemodes.

They are green in colour and capable for the synthesis of food by photosynthesis. Formation of phylloclade reduces loss of water through transpiration and therefore conserve water and food. In Opuntia, the phylloclades are fleshy and segmented. Phylloclade develops from branches of unlimited growth. Internally, phylloclades contain many mucilage glands to promote retention of water.

4. Cladode:
These are green stems branches of limited growth (usually one intemode long) which have taken over the function of photosynthesis from the leaves. The true leaves are reduced to scales or spines, e.g., Asparagus, Ruscus, etc. In Ruscus aculeatus, the cladodes are leaflike in appearance with spiny tip, ovate outline and roughly parallel veins. The cladodes are borne in the axils of scale leaves. The stem nature of the cladode of Ruscus is clear from :

• Origin in the axil of scale leaf,
• Bearing a scale leaf in the middle,
• Formation of a bud in the axil of the scale leaf bore in the middle,
• Development of flowers from the axillary bud produced in the middle of cladode.

5. Bulbils :
When axillary bud becomes fleshy and round due to storage of food (as
carbohydrate) then bulbils are formed. These fall down and form new plants, e.g., Aloe, Agave, Onion, Garlic.

Question 13.
What is Venation? Describe its various types.
Answer:
Venation:
Arrangement of veins and veinlets in the lamina (leaf blade) is known as venation. Veins are the conducting tissues consist of xylem and phloem and are found in continuation with the conducting tissue of petiole.
They are concerned with the conduction of water, mineral, salts and food and they form structural framework of the lamina. There are mainly two types of venations :
(A) Reticulate venation, (B) Parallel venation.

(A) Reticulate venation :
Venation in which veins are arranged in such way that they form a network of vein, is called reticulate venation. It is the characteristic feature of dicot leaves. It is of two types :
1. Unicostate: Venation in which leaflets contain a strong midrib or costa, from which lateral veins are arising and these veins form a network is called unicostate venation, e.g., Mango, Guava, Peepal.

2. Multicostate :
Venation in which many strong veins arising from terminal portion of the stalk and then form a network is called multicostate venation. It is also of two types :
(a) Divergent: Venation in which veins arise from the centre and runs towards margin apart from each other is called divergent venation, e.g., Castor, Cotton.
(b) Convergent: Venation in which many veins arising from the centre of stalk, moving towards the margin of the leaf and finally fused is called convergent venation, e.g., Zizyphus (Ber), Smilax.

(B) Parallel venation :
In this type of venation veins in lamina run almost parallel to one another, e.g., Maize, Grass, etc. It is of the following two types :
1. Unicostate : In this type only one midvein is found from which veinlets arise parallel to each other, e.g., Banana, Canna.
2. Multicostate : In this type more than one mid veins are present. It is of two types :

• Convergent: In this type, all midveins run parallel to each other from the base of lamina and unite at the apex, e.g., Grass, Rice, Bamboo, etc.
• Divergent : In this type, all the midveins, instead of going towards the apex, spread out towards the periphery away from each other, e.g., Borassus (Taad).

Question 14.
What do you mean by aestivation of flower? Describe various types of aestivations found in flower.
Answer:
Aestivation :
Aestivation is the arrangement of floral leaves (calyx, corolla or perianth) in the bud condition. The various types of the aestivations are:

• Valvate: Margins of the adjacent petals touch each other but without overlapping.
  Example: Datura.
• Twisted: In this type one margin of the petal overlaps regularly the margins of the adjacent petal, the other margin being overlapped by the margin of another adjacent petal.
  Example: China rose.
• Imbricate : In this type irregular overlapping of petals by one another. It has three subtypes beside the imbricate proper.
  Example: Gulmohar.
• Quincuncial: In this type two petals are external, two internal and one with one margin external while its other margin is internal.
  Example: Pumpkin.
• Descending imbricate or Vexillary: In this type the posterior vexillum or standard petal overlapping the two lateral wings or alae, the latter being external to the two anterior petals forming keel or carina.
  Example: Pea family.

Question 15.
Explain the types of germination.
Answer:
Types of Seed Germination : There are two types of seed germination takes place in higher plants :
1. Hypogeal germination :
At the time of seed germination when the epicotyl elongates and becomes curved, it brings the plumule above the soil. Cotyledons remain underground. Such types of seed germination is called as hypogeal.
Example: Gram, Pea, Maize, Mango, Jackffuit, Paddy, Wheat, Coconut, Date palm etc.

2. Epigeai germination :
In bean, hypocotyl grows actively and becomes curved. It brings the seed above the soil. After coming above the surface of the soil the hypocotyl straightens. The loosened seed coats fall down and cotyledons turn green. Such a type of seed germination is called epigeai. Now epicotyl grows and the plumule gives rise to green leaves. The cotyledons fall down ultimately.

Question 16.
Describe structure of gram seed with labelled diagram.
Answer:
Structure of gram seed :
It is dicotyledonous and non-endospermic seed and is formed in green pod or legume fruit produced on the plant.

External structure :
It is light or dark brown coloured seed. The seed is broad at one end and pointed at the other end. A furrow is found on one side of the seed. A narrow ridge called raphe runs in the furrow. At the middle of raphe an oval shaped chalaza is found. A small oval shaped scar lies on the same side called as hilum. It is the part of the seed by which it was attached to the funicle. In between the hilum and pointed end of seed a small pore is found called as micropyle.

Internal structure :
The gram seed is covered over on all sides by two seed coats. The outer seed coat is brown and hard structure and is called as testa while the inner seed coat is in the form of a white membranous structure called as tegmen. The seed coat encloses embryo containing a short embryo axis. Embryo consists of following parts :
(i) Cotyledons :
Two large and broad structure attached to the embryo axis are called as cotyledons. Food materials are stored in the cotyledons.

(ii) Embryo axis :
The tip of embryo axis towards the micropyle end is called radicle(the future root). The outer end of the embryo axis found deeper in between the cotyledons is the plumule (the future shoot). The part of the embryo axis between the point of attach¬ment of the cotyledons and the plumule is known as epicotyl and that between the point of attachment of cotyledons and radicle as hypocotyl.

Question 17.
Draw labelled diagram of Longitudinal section (L.S.) of following :
(i) Gram seed,
(ii) Maize seed.
Answer:
(i) Gram seed :

(ii) Maize seed:

Morphology of Flowering Plants Class 11 Important Questions Objective Type

1. Choose the correct answers:

(A)
Question 1.
Respiratory roots are found in :
(a) Betel
(b) Chestnut
(c) Jussiaea
(d) Maize.
Answer:
(c) Jussiaea

Question 2.
Roots that absorb oxygen from environment are called :
(a) Hygroscopic
(b) Suckers
(c) Digestive roots
(d) Pneumatophores.
Answer:
(d) Pneumatophores.

Question 3.
Velamen cells are found in :
(a) Respiratory roots
(b) Stilt roots
(c) Fleshy roots
(d) Aerial roots of Orchids
Answer:
(d) Aerial roots of Orchids

Question 4.
Which one of the following is not a Rhizome :
(a) Ginger
(b) Colocasia
(c) Lotus
(d) Turmeric.
Answer:
(c) Lotus

Question 5.
Pneumatophores are found in:
(a) Xerophytes
(b) Epiphytes
(c) Mangrove plants
(d) Hydrophytes.
Answer:
(c) Mangrove plants

Question 6.
Respiratory roots help in:
(a) Transpiration
(b) Carbohydrate metabolism
(e) Protein synthesis
(d) Respiration.
Answer:
(d) Respiration.

Question 7.
Which of the following is partial root parasite :
(a) Cuscuta
(b) Orobanche and Balanophora
(c) Striga and Santalum
(d) Loranthus.
Answer:
(c) Striga and Santalum

Question 8.
Sweet potato is a modification of:
(a) Leaf
(b) Adventitious root
(c) Tap root
(d) Stem.
Answer:
(b) Adventitious root

Question 9.
Type of roots observed in Pandanus is :
(a) Prop roots
(b) Stilt roots
(c) Tuberous roots
(d) Climbing roots.
Answer:
(b) Stilt roots

Question 10.
Adventitious roots:
(a) Develop from radicle
(b) Develop from any part of plant body except the radicle
(c) Develop from flowers
(d) Develop from embryo.
Answer:
(b) Develop from any part of plant body except the radicle

Question 11.
The thick roots that hang down from the Banyan tree are called :
(a) Buttress roots
(b) Pneumatophores
(c) Prop roots
(d) Stilt roots.
Answer:
(c) Prop roots

(B)

Question 1.
Largest (tallest) plants of the world are associated with :
(a) Dicots
(b) Monocots
(c) Angiosperms
(d) Pteridophytes.
Answer:
(c) Angiosperms

Question 2.
Coms in:
(a) A horizontal underground stem
(b) An underground erect stem
(c) An underground root
(d) An underground stem.
Answer:
(b) An underground erect stem

Question 3.
The main function of the stem is:
(a) Storage
(b) To produce branches and leaves
(c) Conduction
(d) All of these.
Answer:
(d) All of these.

Question 4.
Tuber of potato is a modified:
(a) Root
(b) Stem
(c) Creeper
(d) Bulb.
Answer:
(b) Stem

Question 5.
The underground swollen edible part of onion is:
(a) Root
(b) Bulb
(c) Underground stem
(d) Corm.
Answer:
(b) Bulb

Question 6.
In aerial stems food is stored in :
(a) Large roots
(b) Inflorescence
(c) Swollen stems
(d) Swollen leaf bases.
Answer:
(c) Swollen stems

Question 7.
Stem is enlarged in :
(a) Stem tuber
(b) Corm
(c) Bulbs
(d) Rhizome.
Answer:
(b) Corm

Question 8.
The leafy stem of onion which is growing to bear flower is called:
(a) Peduncle
(b) Rachis
(c) Scape
(d) Floral axis.
Answer:
(b) Rachis

Question 9.
The leaves of Bryophyllum produce small plantlets on its margin. After
separation these plantlets can grow into a new plant. It is a form of:
(a) Sexuaireproduction
(b) Fission
(c) Vegetative propagation
(d) Bisexuality.
Answer:
(c) Vegetative propagation

Question 10.
Adnate stipules are found in:
(a) China rose
(b) Cotton
(c) Rose
(d) Polygonum.
Answer:
(c) Rose

Question 11.
Tendrillar stipules are found in:
(a) Smilax
(b) Bean
(c) Acacia
(d) Magnolia.
Answer:
(a) Smilax

Question 12.
When petiole is modified into a leafy structure, ¡t is caLled: (CPMT 1987)
(a) Phylloclade
(b) Leafy petiole
(c) Cladode
(d) True leaf.
Answer:
(b) Leafy petiole

Question 13.
Accessory buds are developed on:
(a) Apex of branch
(b) Stem apex
(c) The margins of axillary buds
(d) The axis of leaves.
Answer:
(c) The margins of axillary buds

Question 14.
Leaves are modified into hooks in:
(a) Bignonia
(b) Duranta
(c) Antigonon
(d) Ruscus.
Answer:
(a) Bignonia

Question 15.
Leaf without petiole is called:
(a) Petiolate
(b) Sessile
(c) Pedicellate
(d) Asparagus.
Answer:
(c) Pedicellate

Question 16.
Stipules get modified into tendrils in:
(a) Smilax
(b) Ascodilus
(c) Gloriosa
(d) Asparagus.
Answer:
(a) Smilax

Question 17.
Phyllode represents:
(a) Green stem
(b) Leaf base
(c) Green root
(d) Petiole.
Answer:
(d) Petiole.

Question 18.
Leaflet tendrils are found in :
(a) Clematis
(b) Pea
(c) Gloriosa
(d) Smilax.
Answer:
(b) Pea

Question 19.
Leaf bladders are found in :
(a) Nepenthes
(b) Utricularia
(c) Drosera
(d) Casuarina.
Answer:
(b) Utricularia

Question 20.
Parallel venation is found in the leaves of:
(a) Castor
(b) Grasses
(c) Moss
(d) Ferns.
Answer:
(b) Grasses

Question 21.
Leaf apex is modified in tendril in :
(a) Pisum
(b) Smilax
(c) Bryophyllum
(d) Rose
Answer:
(d) Rose

Question 22.
The pinnate leaf of Tamarind is :
(a) Tripinnate
(b) Bipinnate
(c) Imparipinnate
(d) Paripinnate.
Answer:
(d) Paripinnate.

Question 23.
In Utricularia, leaf segments are modified into :
(a) Spines
(b) Tendrils
(c) Thorns
(d) bladders.
Answer:
(d) bladders.

Question 24.
Petioles are modified into tendrils in :
(a) Antigonon
(b) Passiflora
(c) Gloriosa
(d) Clematis.
Answer:
(d) Clematis.

Question 25.
A leaf is modified into phyllode in :
(a) Potato
(b) Australian acacia
(c) Citrus
(d) Dalbergia.
Answer:
(b) Australian acacia

(C)

Question 1.
Tissue which connects ovules with ovary is called :
(a) Placenta
(b) Chalaza
(c) Funicle
(c) Hilum.
Answer:
(a) Placenta

Question 2.
Inflorescence which bears sessile and unisexual flower is called :
(a) Spadix
(b) Catkin
(c) Achene
(d) Panicle.
Answer:
(b) Catkin

Question 3.
Inflorescence of Onion is :
(a) Corymb
(b) Cymose umbel
(c) Racemose umbel
(d) Catkin.
Answer:
(b) Cymose umbel

Question 4.
The function of tapetum, innermost layer of the anther is :
(a) Dehiscence
(b) Mechanical
(c) Protection
(d) Nutritional.
Answer:
(c) Protection

Question 5.
Epicalyx is :
(a) Bract whorl
(b) An additional cycle of corolla
(c) A whorl of bracteoles
(d) A whorl of bracts.
Answer:
(c) A whorl of bracteoles

Question 6.
Tetradynamous stamens having :
(a) 6 stamens-2 short and 4 long
(b) 6 stamens-2 small stamens on outer whorl and 4 larger stamens on inner whorl
(c) 6 stamens-2 long and 4 short
(d) 4 stamens-2 long and 2 short.
Answer:
(b) 6 stamens-2 small stamens on outer whorl and 4 larger stamens on inner whorl

Question 7.
Unilocular ovary, in which placenta develops directly on thalamus and bears
a single ovule at the base of ovary is called:
(a) Marginal
(b) Free central
(c) Basal
(d) Parietal.
Answer:
(c) Basal

Question 8.
Tissue which connects ovules with ovary is called:
(a) Placenta
(b) Chalaza
(e) Funicle
(d) Hilum.
Answer:
(a) Placenta

Question 9.
Ovule is jointed with placenta by means of:
(a) Hilum
(b) Funiculus
(c) Petiole
(d) Pedreel
Answer:
(b) Funiculus

Question 10.
In angiosperms an ovule shows:
(a) Megasporophyll
(b) Megasporangium
(c) Megaspore
(d) Megaspore mother cell.
Answer:
(b) Megasporangium

Question 11.
In Monoadeiphous stamen:
(a) Anther and filament are fused
(b) Anthers are fused and filaments are free
(c) Filaments of all stamens are fused and anthers are free
(d) None of these.
(c) Filaments of all stamens are fused and anthers are free

Question 12.
A floral formula will show:
(a) The functions of flower
(b) Symmetry of flower
(c) Graphical representation of the characteristics of flowers
(d) Position of flower.
Answer:
(c) Graphical representation of the characteristics of flowers

Question 13.
Largest flower of the world is:
(a) Cuscuta
(b) Rafflesia
(c) Lora nihus
(d) Drosera.
Answer:
(b) Rafflesia

Question 14.
The national flower of India is:
(a)Rafflesia
(b) Lotus
(c) Rose
(d) Wolfia.
Answer:
(b) Lotus

Question 15.
Presence of unilocutar, monocarpellary, syncarpous ovary having marginal
placentation is the characteristic feature of:
(a) Solanaceae
(b) Cruciferae
(c) Leguminosae
(d) Compositae.
Answer:
(c) Leguminosae

Question 16.
Morphologically the edible part of the apple is :
(a) Cotyledon
(b) Thalamus
(c) Endocarp
(d) Mesocarp.
Answer:
(b) Thalamus

Question 17.
Pollen receiving part of the gynoecium is :
(a) Style
(b) Stigma
(c) Ovule
(d) Ovary.
Answer:
(b) Stigma

Question 18.
The aestivation of corolla of pea is called :
(a) Contorted
(b) Valvate
(c) Vexillary
(d) imbricate.
Answer:
(c) Vexillary

Question 19.
Basal placentation is present in :
(a) Compositae
(b) Solanaceae
(c) Malvaceae
(d) Mimosidae.
Answer:
(a) Compositae

Question 20.
The edible part of cauliflower is :
(a) Fruit
(b) Bud
(c) Inflorescence
(d) Flower
Answer:
(c) Inflorescence

Question 21.
The condition in which stamens are attached with corolla is called :
(a) Episepalous
(b) Gynandrous
(c) Epipetalous
(d) All of these.
Answer:
(c) Epipetalous

Question 22.
Tetradynamous condition is associated with :
(a) Androecium
(b) Gynoecium
(c) Inflorescence
(d) Epicalyx.
Answer:
(a) Androecium

Question 23.
Flower is a shoot with :
(a) Elongated nodes
(b) Condensed shoot
(c) Elongated intemodes
(d) Condensed intemodes.
Answer:
(d) Condensed intemodes.

Question 24.
Smallest flower is found in :
(a) Colocasia antiquorum
(b) Wolffia microscopia
(c) Rosa indica
(d) Ranunculus scleratus.
Answer:
(b) Wolffia microscopia

(D)

Question 1.

is the floral formula of:
(a) Brassica sp.
(b) Pisum sativum
(c) Candytuft
(d) Datura alba.
Answer:
(a) Brassica sp.

Question 2.
In Cruciferae family, inflorescence is generally of the following type :
(a) Solitary axillary
(b) Dichasial cyme
(c) Spike of spikelet
(d) Racemose.
Answer:
(d) Racemose.

Question 3.
Ray florets and disc florets are parts of this type of inflorescence :
(a) Spike of spikelet
(b) Capitulum inflorescence
(c) Corymb inflorescence
(d) Dichasial cyme.
Answer:
(b) Capitulum inflorescence

Question 4.
Oblique ovary is found in this family :
(a) Graminae
(b) Solanaceae
(c) Cruciferae
(d) Liliaceae.
Answer:
(b) Solanaceae

Question 5.
Type of fruits usually found in Cruciferae family :
(a) Siliqua and siliqula
(b) Legume or pod
(c) Caryopsis
(d) Achenal or cypsela.
Answer:
(a) Siliqua and siliqula

2. Fill in the blanks:
(I) Root, Stem And Leaves

1. The type of roots normally found in monocotyledonous plants are ………………….
Answer:
Fibrous

2. The roots in Banyan tree are named ………………..
Answer:
Prop roots

3. Tuber is a modified …………………. and the example is ………………
Answer:
Stem, Potato

4. ………………… in the arrangement of leaves on the nodes of a stem and its branches.
Answer:
Phyllotaxy

5. The plant is which haustoria are found is ………………..
Answer:
Cuscuta

6. The plants which complete their life cycle in many seasons are called ……………………
Answer:
Perennials

7. …………………… are the leafy outgrowths on either side of the leaf base.
Answer:
Stipules

8. The structure that develops from radicle of germinating seed is ……………….
Answer:
Root

9. ……………….. are small pore present in the bark of stem, where exchange of air and water takes place.
Answer:
Lenticel

10. The tip of root usually remains covered by a small conical cap like structure, called ………………..
Answer:
Root cap

(II) FLOWER

1. If a bisexual flower does not open in its life cycle is called ………………………..
Answer:
Cleistogamous

2. Tissue which connects ovules with ovary is ………………..
Answer:
Placenta

3. Ovule is jointed with placenta by means of …………………
Answer:
Funiculus

4. Catkin or verticillaster is a type of …………………….
Answer:
Racemose

5. The inflorescence of Onion is ………………….
Answer:
Cymose umbel

6. Cyathium inflorence is found in ……………………..
Answer:
Euphorbia

7. Embryo is developed from …………………
Answer:
Ovule

8. The central stalk present in each spikelet is called ………………..
Answer:
Rachis

9. Tetradynamous condition is associated with ………………….
Answer:
Androecium

10. The placentation of Cruciferae is ……………………
Answer:
Parietal

11. ………………… pollination occurs in Pinus.
Answer:
Anemophilous type.

(III) PLANT FAMILIES

1. In Solanaceae family, ovary is …………………
Answer:
Oblique

2. Example of Cruciferae family is ………………….
Answer:
Mustard

3. Rice, Wheat, Maize etc. belong to family …………………
Answer:
Poaceae

4. Ray florets and disc florets are parts of ……………….. type of inflorescence.
Answer:
Capitulum

5. Androecium are of ………………… type in family Compositae.
Answer:
Syngenesious

3. Match the following:
(I) Root, Stem And Leaves

(A)

Answer:
1. (d) Rhizome
2. (e) Opuntia.
3. (a) Phloem
4. (b) Root
5. (c) Conical

(B)

Answer:
1. (c) Guttation
2. (d) Sucker
3. (e) Fasiculated
4. (a) Lenticel
5. (b) Stilt root

(II) FLOWER
(A)

Answer:
1. (d) Swollen placenta
2. (e) Inflorescence.
3. (a) Oily endosperm
4. (b) Cymose umbel
5. (c) Mesocarp
(B)

Answer:
1. (d) Lodicules
2. (e) Capitulum.
3. (a) Thalamus
4. (b) Superior
5. (c) Cruciform

(III) PLANT FAMILIES

Answer:
1. (d) Onion
2. (e) Mustard
3. (a) Datura
4. (b) Pea
5. (c) Composite

4. Write true or false:
(I) Root, Stem And Leaves

1. Radish is an example of phylloclade.
Answer:
False

2. Nepenthes (Pitcher plant) is an example of carnivorous plant.
Answer:
True

3. Casparian strips are found in epidermis.
Answer:
False

4. Secondary growth results in the growth of the girth of the plant and not in the length only.
Answer:
True

5. Scleroids and fibres are the components ofXylem tissue.
Answer:
False

(II) FLOWER

1. An inflorescence which contains gall flower is hypanthodium.
Answer:
True.

2. Water is not necessary for fertilization in Vallisnaria plant.
Answer:
False

3. The protein storing layer of endosperm is called aril.
Answer:
True.

4. The inflorescence of compositae is spike.
Answer:
False

5. Caryopsis fruits are found in family Graminae.
Answer:
True.

(III) PLANT FAMILIES

1. Perianth means calyx and corolla are present.
Answer:
False

2. Botanical name of Cabbage is Brassica rapa.
Answer:
False

3. Replum is characteristic feature of family Cruciferae.
Answer:
True

4. Family Graminae and Cruciferae belong to monocotyledons.
Answer:
False

5. Caryopsis fruits are found in family Cruciferae.
Answer:
False

5. Answer in one word:
(I) Root, Stem And Leaves

1. Tuber of potato is modified.
Answer:
Stem

2. Stem which is green and leaf like is called.
Answer:
Phylloclade

3. In Opuntia, spines are modified.
Answer:
Leaves

4. The function of prop roots of Banyan is.
Answer:
To provide support

5. In aerial stems food is stored in.
Answer:
Swollen roots

6. Name one negatively phototropic organ of the plant.
Answer:
Root

7. The structure that develops from plumule of the germinating seed.
Answer:
Stem

8. Phylloclade of single intemode is.
Answer:
Cladode

9. Name of one nitrogen fixing bacteria.
Answer:
Rhizobium

10. Give the example of assimilatory root.
Answer:
Trapa

11. Write the example of respiratory root.
Answer:
Jussiaea

12. Which plants have reticulate venation ?
Answer:
Dicot leaves.

(II) FLOWER

1. Largest flower of the world is.
Answer:
Rafflesia

2. Spadix inflorescence is found in.
Answer:
Banana

3. The endosperm in angiospermic plant is.
Answer:
Triploid

4. Monosporic and nucleate embryo sac is referred as.
Answer:
Polygonum type

5. The edible part of cauliflower is.
Answer:
Inflorescence

6. Which type of inflorescence found in Tulsi?
Answer:
Verticillaster inflorescence

7. Which type of corolla is found in Mustard?
Answer:
Crossed or Cruciform

(III) PLANT FAMILIES

1. Corolla arranged in the form of a cross in family.
Answer:
Cruciferae

2. Rice, Wheat, Maize etc. belong to family.
Answer:
Poaceae

3. Oblique ovary is found in family.
Answer:
Solanaceae

4. Spike of spikelet type of inflorescence is found in family.
Answer:
Poaceae

5. Type of fruits usually found in Cruciferae family.
Answer:
Siliqua

6. Write the botanical name of Tomato.
Answer:
Lycopersicum esculentum

Students get through the MP Board Class 11th Biology Important Questions Chapter 18 Body Fluids and Circulation which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 18 Body Fluids and Circulation

Body Fluids and Circulation Class 11 Important Questions Very Short Answer Type

Question 1.
Which type of circulation is found in unicellular organisms?
Answer:
Unicellular organisms shows intracellular circulation. Cytoplasm of cell of the unicellular organism shows streaming movement called cyclosis. It helps in the circulation and distribution of materials in the cells e.g. Amoeba, Paramoecium etc.

Question 2.
What is known as heart block?
Answer:
Heart block : It is a condition in which bundle of His’ does not function properly then heartbeating impulse of atrial node does not reach ventricles, thus ventricle cannot exhibit their movement and thus circulation of blood is inhibited. This condition is called as heart block.

Question 3.
Where does the ‘Lubb’ and ‘Dup’ sounds are produced in Cardiac cycle?
Answer:
Lubb: ‘Lubb’ sound is produced during closure of atrioventricular valve (Bicuspid and Tricuspid valves). It is the first heart sound, which is low pitched but are of longer duration.
Dup : It is produced during closure of semilunar valves present at the base of arterial trunks. It is the second heart sound which is high pitched but of shorter duration.

Question 4.
Give reason that arteries are thick walled than that of veins.
Answer:
Arteries are thick walled than that of veins: When heart contracts blood enters into the arteries with great pressure as heart is responsible for supply of blood to each part of the body. To exert this pressure arteries are thick walled, whereas veins carry blood from different parts of the body to the heart without any pressure thus they are thin walled.

Question 5.
Write two functions of pericardial fluid.
Answer:
Two main functions of pericardial fluid are :
(i) It protects the heart from outer injuries,
(ii) It protects the heart from dryness.

Question 6.
Human heart is called myogenic. Why? (NCERT)
Answer:
Myogenic hearts are those where waves of contraction originate in special muscle fibres of heart.

Question 7.
What do you understand by double circulatory system? What is its significance? (NCERT)
Answer:
Double circulatory system: The circulatory system in which blood passes twice through heart for completing one cycle is called double circulatory system. In this type of circulatory system, oxygenated and deoxygenated blood flow remain separate. This type of circulation is found in all mammalian animals. In this system, first the deoxygenated blood is collected by veins into the heart and then it goes to the lungs for oxygenation. It returns to the left part of the heart and then to the body organs through arteries. Thus, the blood has to travel twice in the heart before it circulates in the body.

Question 8.
What is carboxyhaemoglobin?
Answer:
P-wave It is complex formed by the combination of haemoglobin with the CO₂. It provides blue colour to the blood in the vein.
Hb + CO₂ → Hbc

Question 9.
What are thrombocytes ? Where do they occur?
Answer:
In human blood, some irregular shaped cells are present which help in clotting of blood are called thrombocytes. They are formed in bone marrow.

Question 10.
In blood vessels, the flowing blood do not clot, why?
Answer:
In blood vessels, the flowing blood do not clot because in blood plasma, antiprothromb in, heparin named carbohydrate is present which takes the active thrombin to passive prothrombin direction due to which vessels do not clot.

Question 11.
What is pulse? What is the pulse rate of human beings?
Answer:
Beating of the heart is also felt in the surface arteries as regular jerk called as pulse. Each ventricular systole starts a new pulse, which proceeds as a wave of expansion through arteries, which is repeated after every 08 seconds.
It can be felt at the radial artery of wrist, temporal artery in front of the ear and carotid artery of the neck etc. Pulse rate of normal adult is 72 times per minute. In children, it is 120 times per minute and in old persons it is 60 times per minute.

Question 12.
How does partial pressure of respiratory gases control diffusion of oxygen from blood capillaries to the tissue?
Answer:
In the body tissue, P02 is very low that is about 40mm Hg, hence oxygen from arterial blood where P02 is about 95mm Hg. Thus oxygen separates from haemoglobin and diffuses into the tissues until the P02 goes down to 40mm Hg.

Question 13.
How does regulation of heartbeat occurs?
Answer:
The normal rate of heart beat is regulated by the following three ways :

1. Nervous control: Cardiac centre lies in the medulla of brain regulate heartbeat.
2. Hormonal control: Adrenalin and Noradrenalin hormone increases and decreases heart activity respectively.
3. Chemical control: Vagus nerve on stimulation secretes acetyl-choline which slows down the heartbeat while tip end of sympathetic nerve fibre secretes adrenalin, which accelerates heartbeat.

Question 14.
What is Heart sound?
Answer:
Various valves present at the inlet and outlet of ventricles regulate the flow of blood in the heart. Action of these valves, while closing the apertures, create the heart sound. Each heartbeat is accompanied by two heart sound ‘Lubb’ and ‘Dup’. It can be heard using a device called as stethoscope.

Question 15.
What is haemocoel?
Answer:
In higher invertebrates like arthropods and molluscs, open circulatory system is found. Blood vessels of them*are not divided into capillaries and open into write spaces called as sinuses in the body cavity, the blood fills in the body cavity and baths the organs. The body cavity filled with blood is called as haemocoel and the blood which is colourless called as haemolymph.

Body Fluids and Circulation Class 11 Important Questions Short Answer Type

Question 1.
Explain heart sound. (NCERT)
Answer:
Refer Q. No. 3 and 14 of Very Short Answer Type Questions.

Question 2.
Define Cardiac cycle and Cardiac output. (NCERT)
Answer:
Cardiac cycle: Contraction of the heart is called as Systole and relaxation of heart is called as Diastole. The sequence of one systole followed by one diastole is known as Cardiac cycle. It takes 0-8sec time to complete one cardiac cycle.
Cardiac output: At each heartbeat ventricle pump about 70ml blood. This volume is called as stroke volume. The heart beats 72 times per minute, which is known as heart rate. Quantity of blood pumped by the heart in one minute is called as cardiac output, i. e. 72 x 70ml = 5040ml blood per minute.

Question 3.
Where bicuspid, tricuspid and semilunar valves are present in human heart ? Write its functions.
Answer:
1. Bicuspid valve: The atrioventricular opening between left auricle and left ventricle is guarded by two flaps known as Bicuspid valve. It prevents backflow of blood.

2. Tricuspid valve: The right atrioventricular opening is guarded by three flaps known as tricuspid valve.

3. Semilunar valve: These are half-moon shaped flaps arising from the base of the pulmonary artery and aorta. A set of three semilunar valves guard the opening of right ventricle into pulmonary artery and another set is present where aorta arises from the left ventricle. All these valves present backflow of blood into ventricles.

Question 4.
Why blood is transported from auricles to ventricles during the relaxation of ventricles or ventricular diastole ?
Answer:
The volume of the ventricles is increased during the relaxation of ventricles and the inside pressure of it is low in comparison to the pressure of arteries. This will cause the closure of semilunar valves. Ventricles are remain in the position of relaxation even after closing of these semilunar valves.

Thus, lower pressure of their wall is maintained as it is. To balance this pressure aurio-ventricular valves are opened and blood flows from auricles to ventricles and fill up their cavity. After then ventricles contracts and thus the blood of its cavity is transported into arteries. Both of these processes (contraction and relaxation) occur alternatively.

Question 5.
What do you understand by blood pressure? Explain systolic and diastolic blood pressure.
Answer:
The pressure exerted on blood capillaries by pumping action of heart or by circulating blood of the body is called blood pressure.
Or
The force or pressure which the blood exerts on the walls of the artery in which it is contained is known as blood pressure.
Systolic pressure: Due to contraction of heart, blood is thrown out from the heart into artery which causes maximum blood pressure. This maximum pressure of blood in the blood capillary is called systolic blood pressure. The systolic pressure of a person is 120 mm Hg.

Diastolic pressure: The blood pressure of biood capillaries is minimum during the relaxation of ventricles. The minimum blood pressure of blood capillaries is called diastolic pressure. The diastolic blood pressure of an adult person is 80 mm Hg.

Question 6.
Where is sinoauricular node (SAN) situated? Why is SA node called pacemaker (speed motivator) of heart? (NCERT)
Answer:
Sinoauricular node (SA node) is situated in the upper part of right auricle of the heart. It is the site where heartbeat originates. It is also called as pacemaker or pacesetter. It is called pacemaker of the heart because cardiac rhythms commence here. When SA node does not function accurately the rate of heart beating will be irregular, slow or it stops. In this condition heart can not pump the blood according to requirement. In this condition artificial cardiac pacemaker is the substitute for a natural defective pacemaker which controls the beating of heart. Thus, SA node determines the rate of heartbeat and initiates it and so it is called as pacemaker of the heart.

Question 7.
Describe any four differences between sinoauricular and auriculo-ven- tricular node.
Answer:
Differences between S.A. Node and A.V. Node

Question 8.
Write differences between the following : (NCERT)
(a) Closed and Open Circulatory system
(b) Mitral value and Semilunar value.
Answer:
(a) Differences between Closed and Open circulatory system

(b) Differences between Mitral value and Semilunar value

Question 9.
Write any four differences between an Artery and a Vein.
Answer:
Differences between an Artery and a Vein

Question 10.
What are open and closed vascular system? Give two significance of closed vascular system.
Or,
What is closed vascular system?
Answer:
Open vascular system: The circulatory system in which blood flows indepen-dently in the coelomic cavity is called as open circulatory system.
Example: Cockroach.
Closed vascular system: The circulatory system in which blood flows through closed vessels.
Example: Earthworm, human.
Significance of closed vascular system :

1. Blood contains haemoglobin which helps to carry oxygen during respiration.
2. It helps in fast removal of excretory substance from the body.
3. Valves present in its blood vessels, prevents backward flow of blood.

Question 11.
Write differences between Blood and Lymph.
Answer:
Differences between Blood and Lymph

Question 12.
Give importance of Plasma protein. (NCERT)
Answer:
There are three plasma proteins :

1. Serum globulin,
2. Serum albumin,
3. Fibrinogen.

Functions or Importance of Plasma protein :
1. Immunity of the body: Globulin protein acts as antibody thus provide immunity to disease.
2. Prevent loss of blood by blood clotting: Fibrinogen and prothrombin are essential for clotting of blood.
3. Maintain fluidity of blood: Albumin and globulin possesses the ability to retain water in the blood plasma by their osmotic effects.
4. It helps for transport of protein and other substances.
5. It helps to maintain the pH of the blood.
6. It helps to maintain constant temperature of the body.
7. It helps to conduct heat.

Question 13.
Describe various components of blood and give one function of each component. (NCERT)
Answer:
Various component of blood and their functions :
Blood: Blood is a liquid connective tissue. Its matrix is liquid called as plasma. 90% of plasma is water in which various inorganic and organic substances are found in dissolved form. Three types of cells are found embedded in plasma called as corpuscles :
1. Erythrocytes or Red Blood Corpuscles (R.B.Cs.): These are biconvex, disc shaped, anucleated cells which contains a pigment haemoglobin. It helps to carry O₂ and CO₂ during respiration.

2. Leucocytes or White Blood Corpuscles (W.B.Cs.): These are nucleated, colourless, amoeboid cells. They are found in less number. They are of two types: It prevents the body from diseases by digesting and killing pathogenic germs.

3. Blood platelets: These are small, colourless, flat, granular, non-nucleated corpuscles, which helps for clotting of blood at injured part of the body.

Question 14.
Why blood is considered as connective tissue?
Answer:
Group of cells which are similar in their structure, function and origin are called as tissue.
Structurally blood is similar to connective tissue as it has a liquid matrix called as plasma in which various types of blood cells, RBCs, WBCs and Blood platelets are found in scattered form. It is also functionally similar to connective tissue as it connects all parts of the body by transporting materials. Thus blood is called as liquid connective tissue.

Body Fluids and Circulation Class 11 Important Questions Long Answer Type

Question 1.
Write differences : (NCERT)
(a) Blood and Lymph
(b) Open and Closed Circulatory System
(c) Systole and Diastole
(d) P-wave and T-wave.
Answer:
(a) Differences between Blood and Lymph

(b)
(a) Differences between Closed and Open circulatory system

(b) Differences between Mitral value and Semilunar value

(c) Differences between Systole and Diastole

(d) Differences between P-wave and W-wave

Question 2.
Draw a Unit of ECG and explain its various segments. (NCERT)
Answer:
Electrocardiogram (ECG): A graphic record of the electrical variations produced by the beating of the heart is called electrocardiograph. These variations are due to the development of electrical negativity of excited muscles as compared with unexcited tissues. An instrument used to observe the working of the heart is called electro-cardiogram. It was discovered by Einthoven (1906).

ECG is formed by a series of ridges and furrows. Normal pattern of ECG for a healthy person is given below.
In this, ‘P’ wave indicates the impulse of contraction generated by S.A. node. ‘QRS’ wave indicates the spread of impulse of contraction from A. V. node to the wall of ventricles, whereas the ‘T’ wave represents the relaxation of ventricles.
Any abnormality in the working of the heart changes the wave pattern of ECG and can be interpreted by a trained physician to diagnose a particular disorder. The technique to detect the abnormalities of the heart with the help of ECG is called electrocardiography.

Question 3.
Give reasons of following :
(a) Arteries are thick walled than that of veins.
(b) Doctors give injection in the veins.
(c) Veins are provided with valves but not arteries.
(d) Veins are blue coloured whereas arteries are red in colour.
Answer:
(a) Arteries are thick walled than that of veins: When heart contracts blood enters into the arteries with great pressure as heart is responsible for supply of blood to each part of the body. To exert this pressure arteries are thick walled, whereas veins carry blood from different parts of the body to the heart without any pressure thus they are thin walled.

(b) Doctors give injection in the veins: Doctors give injection in the veins because they are found in the surface of the body and carries blood to the heart, from where medicine can be distributed to all parts of the body through arteries.
But if doctors will give injection to the arteries then medicine will reach to particular part only.

(c) Veins are provided with valves but not arteries: Veins carries blood from dif-ferent part of the body to the heart without any pressure thus in order to prevent backward flow of blood and to direct the blood towards the heart, veins are provided with valves. Whereas arteries carry blood from heart to different parts of the body with pressure thus blood can easily reach to all parts of the body. Therefore arteries are not provided with valves.

(d) Veins are blue coloured whereas arteries are red in colour: Outer wall of the vein consists of tunica externa. Cells of this layer contain a pigment substance which reflect blue light thus veins appears blue whereas such pigments are not found in the wall of the arteries. Thus, arteries appears red coloured due to presence of blood in it, which reflect red light.

Question 4.
Give reasons of following statements :
(a) Wall of the left ventricle is more thick as compared to the wall of the right ventricle.
(b) Wall of the left ventricle is thick as compared to the auricles.
(c) Lymph contains less protein as compared to the plasma.
(d) Closed circulatory system is better as compared to the open circulatory system.
(e) During systole ventricles of the heart becomes a closed chamber.
Answer:
(a) Wall of the left ventricle is more thick as compared to the wall of the right ventricle : Right ventricles contains impure blood. To pass blood to the pulmonary artery less pressure is required by the right ventricle whereas to send blood to cortico sys-temic aorta more pressure is required by the left ventricle thus wall of the left ventricle is thicker than that of right ventricle.

(b) Wall of the left ventricle is thick as compared to the auricles : Left ventricle is responsible for the supply of blood to all parts of the body through cortico systemic aorta thus more pressure is required by it where as auricle receives blood without any pressure. Therefore left ventricle is thick walled as compared to the auricles.

(c) Lymph contains less protein as compared to the plasma : Capillaries found in the lymph are impermeable thus plasma protein quantity of lymph is less as compared to the blood.

(d) Closed circulatory system is better as compared to the open circulatory system:
In open circulatory system blood do not flow through closed vessels. Blood is found in the haemocoel cavity and is direct in contact of the organs. Blood pressure in this system is very less, e.g. Cockroach. In closed circulatory system blood is enclosed by heart, arteries and veins. Blood flows fast through these vessels and come back to the heart.

In this way exchange of substances between blood and tissue occurs fast. Whereas in open circulatory system this type of regulation is not found, thus closed circulatory system is considered as best as compared to the open circulatory system.

(e) During systole ventricles of the heart becomes a closed chamber : During ventricular systole pressure of the ventricle is more than that of auricles. Thus when blood reaches to the ventricle from auricles auriculoventricular valves closes the auriculo-ven- triculi aperture and prevents backward flow of blood. As ventricular pressure is less than the pressure of pulmonary artery thus semilunar valves remain closed, thus ventricle con-tracts as a closed chamber.

Question 5.
Who can donate blood to whom, also write the precautions of blood donation?
Answer:
Blood transfusion depends mainly on blood group. Therefore :
1. A blood group can be donated to person with blood group type A and AB.
2. Person with blood group B can donate blood to person with blood group type B or AB.
3. Person with AB group can donate blood only to person with AB blood group.
4. Blood group O is called universal donor but he can receive blood of only group O type.
Similarly the persons with blood group AB are called universal recipient as they can receive blood from persons with any blood group type.

Precautions of blood donation :
1. The first and the foremost precaution for donation of blood is testing the blood groups of both the donor and the recipient so that the problem of agglutination can be avoided.

2. Many fatal diseases get transmitted through blood. Thus, the donor’s blood should be tested for the presence of HIV and Hepatitis virus and getting negative result should be confirmed before transfusion.

3. Only upto 500 ml of blood should be donated by a man at one time.
4. Blood should not be donated more than twice in one year.
5. Donor should be completely healthy.
6. Equipments used in the process of transfusion should be thoroughly sterilized before use.

Question 6.
What is Hepatic portal system?
Answer:
Generally after collecting deoxygenated blood veins pour the blood into heart. But some veins pour blood into some other organs before reaching to heart for its purification. There veins are called as portal veins, and the system formed by these veins is called as portal system.

Hepatic portal system of man : When portal veins carry blood to the liver instead of heart and then through some other veins from liver to heart, it is called as Hepatic portal system.
Hepatic portal veins of human collect blood from different parts of the alimentary canal and carry it to liver. From liver through hepatic vein blood reaches to post caval.
Hepatic portal system consists of following veins :

1. Lineogastric vein: It collects blood from all wall of the stomach and spleen.
2. Duodenal veins: It collects blood from duodenum.
3. Anterior mesenteric vein: It collects blood from small intestine, caecum and colon.
4. Posterior mesenteric vein: It collects blood from rectum and anus.

Question 7.
Describe the structure of mammalian heart.
Or,
Describe structure and mechanism of working of mammalia heart.
Or,
Draw a well labelled diagram of L.S. of heart.
Answer:
Structure of Human Heart:
Position and external structure of human heart: The mammalian heart including man is a hollow, cone-shaped, muscular structure that lies in the thoracic cavity above the diaphragm and in between the two lungs. It is about the size of a fist measuring about 12 cm in length and 9 cm in breadth. It’s weight is about 300 grams. It is four-chambered organ, having two auricles and two ventricles.

Heart lies in cavity called as Pericardium cavity. Pericardium cavity is surrounded by double membrane and is filled with pericardial fluid, which prevent the heart from external jerk, friction and keeps the heart moist.

Internal structure of human heart: The auricles are thin walled, sac like structures. The right and left auricles are separated from each other by a longitudinal muscular partition, called interauricular septum. The anterior and posterior vena cava open by separate apertures in the right auricles. The pulmonary veins open into left auricle by single common opening. The cavity of the ventricle is also divided into two by a thick and muscular interventricular septum. The wall of the left ventricle is much thicker than that of the right. The cavity of the left ventricle is circular while that of right is crescentic in outline in transverse sections. The right auricle opens into the right ventricle by a wide aperture called right auriculoventricular aperture. Similarly, the left auricle opens into the left ventricle by means of a large opening known as left auriculoventricular aperture.

The right auriculoventricular aperture is guarded by a valve which is formed of three flaps or cusps. This valve is called right auriculoventricular valve or tricuspid valve. The left auriculoventricular aperture is provided with a valve which has two cusps. It is known as left auriculoventricular valve or bicuspid valve or mitral valve. When the ventricles contract, both these valves close so that the blood is prevented from going back into the auricles from the ventricles. These valves are attached to columnae carnae or papillary muscles on the inner wall of the ventricles by means of thin threadlike structures called choradae tendinae.

The walls of the ventricles are much thicker than those of the auricles and are highly muscular. A special type of muscles are grouped together on the top of the interventricular septum to form a structure called Bundle of His or atrioventricular bundle. From the left anterior part of right ventricles arises the pulmonary arch which curves towards the left side of the heart passing below the carotid-systemic arch and goes to the lungs from the dorsal side of the heart.

Three semilunar valves are present at the origin of the pulmonary arch. These valves do not allow the blood to go back into the right ventricles. The aorta or carotid-systemic arch arises from the right anterior part of the left ventricle. This arch passes over the pulmonary arch to come over the dorsal side of the heart where it forms the dorsal aorta below the vertebral column. These semilunar valves are also present at the origin of this arch to check the backflow of the blood into the left ventricle.
Mechanism of working of Human heart:

Mechanism of human heart: The rhythmic contraction and relaxation of the auricles and ventricles of heart in a specific sequence is called heart beat. The contraction phase is called as systole and the relaxation phase is called diastole.
The systole and the diastole together constitute a heart beat. The movement of the auricles and the ventricles are repeated in a cyclic manner during each heart beat. The amount of blood ejected by each ventricle per stroke at rest is about 70-90 ml. The volume of blood is termed as the stroke volume. This leaves about 50 ml of blood in each ventricle at the end of a systole and is known as end-systolic ventricular blood volume.

The human heart beats about 72 times a minute and this is termed as heart rate. The stroke volume when multiplied by the heart rate gives the volume of blood pumped out by each ventricle per minute. This volume is referred to as cardiac output.

Cardiac cycle: The atrial and ventricular systole and diastole which occur during each complete heart beat is called a cardiac cycle. This happens for a specific duration and the blood flows through the heart in a specific direction. The duration of each cardiac cycle at a heart rate of 75 per minute is 0-80 seconds in which the duration of systole is 0-27 seconds and that of diastole is 053 seconds.

Late diastole: In the late diastole the bicuspid and the tricuspid valves between the auricles and ventricles are opened and the semilunar valves at the entrance of aorta and pulmonary artery are closed. Blood flows into the heart throughout diastole, filling the auricles and ventricles. The rate of filling declines as the ventricles become distended and the cusps of the A.V. valves drift toward the closed position.

Atrial systole: Over two-thirds of the ventricular filling occurs passively during dias-tole. Contraction of the auricles propels some additional blood into the ventricles. The con-traction of the atria is called atrial systole. Contraction of the atrial muscles that surrounds the orifices of the vena cava and pulmonary veins blocks their opening and so the atrial blood cannot pass back from the atria into these vessels, but there is some regurgitation of blood into the veins during atrial systole.

Ventricular systole : The simultaneous contraction of both the ventricles is called ventricular systole. The initial portion of ventricular systole is called isometric or isovolumetric ventricular contraction which lasts until the aortic and pulmonary valves open. The A.V. valves close at the start of isometric contractions. Intraventricular pressure rises rapidly and the ventricular ejection begins. Ejection is rapid at first, slowing down as the systole progresses.

Diastole: The relaxation of the heart chambers after the systole is called diastole. When the ventricles start contracting, the atria start the atrial diastole. During the atrial diastole the blood through the veins flows into the atria. At the end of ventricular systole, the ventricles start the ventricular diastole. Towards the end of a joint diastole a new cardiac cycle begins with the atrial systole.

Question 8.
Describe mechanism of human heart.
Answer:
Mechanism of human heart: The rhythmic contraction and relaxation of the auricles and ventricles of heart in a specific sequence is called heart beat. The contraction phase is called as systole and the relaxation phase is called diastole.
The systole and the diastole together constitute a heart beat. The movement of the auricles and the ventricles are repeated in a cyclic manner during each heart beat. The amount of blood ejected by each ventricle per stroke at rest is about 70-90 ml. The volume of blood is termed as the stroke volume. This leaves about 50 ml of blood in each ventricle at the end of a systole and is known as end-systolic ventricular blood volume.

The human heart beats about 72 times a minute and this is termed as heart rate. The stroke volume when multiplied by the heart rate gives the volume of blood pumped out by each ventricle per minute. This volume is referred to as cardiac output.

Cardiac cycle: The atrial and ventricular systole and diastole which occur during each complete heart beat is called a cardiac cycle. This happens for a specific duration and the blood flows through the heart in a specific direction. The duration of each cardiac cycle at a heart rate of 75 per minute is 0-80 seconds in which the duration of systole is 0-27 seconds and that of diastole is 053 seconds.

Late diastole: In the late diastole the bicuspid and the tricuspid valves between the auricles and ventricles are opened and the semilunar valves at the entrance of aorta and pulmonary artery are closed. Blood flows into the heart throughout diastole, filling the auricles and ventricles. The rate of filling declines as the ventricles become distended and the cusps of the A.V. valves drift toward the closed position.

Atrial systole: Over two-thirds of the ventricular filling occurs passively during dias-tole. Contraction of the auricles propels some additional blood into the ventricles. The con-traction of the atria is called atrial systole. Contraction of the atrial muscles that surrounds the orifices of the vena cava and pulmonary veins blocks their opening and so the atrial blood cannot pass back from the atria into these vessels, but there is some regurgitation of blood into the veins during atrial systole.

Ventricular systole: The simultaneous contraction of both the ventricles is called ventricular systole. The initial portion of ventricular systole is called isometric or isovolumetric ventricular contraction which lasts until the aortic and pulmonary valves open. The A.V. valves close at the start of isometric contractions. Intraventricular pressure rises rapidly and the ventricular ejection begins. Ejection is rapid at first, slowing down as the systole progresses.

Diastole: The relaxation of the heart chambers after the systole is called diastole. When the ventricles start contracting, the atria start the atrial diastole. During the atrial diastole the blood through the veins flows into the atria. At the end of ventricular systole, the ventricles start the ventricular diastole. Towards the end of a joint diastole a new cardiac cycle begins with the atrial systole.

Question 9.
How does normal heart beating is regulated?
Or,
What do you mean by S.A. node and A.V. node? Explain their functions.
Answer:
S.A. node and A.V. node : The normal rate of heart beating is regulated by a group of tissues situated on the upper part of the right atrium, these groups of tissues are called as the sinoauricular node (S.A. node). S.A. nodes are also called as the controller of heart beating. A similar node called as auriculo-ventricular node (A.V. node) is also found on the septum of atrium and ventricle. Both of these nodes are made up of muscles, nerve fibres and nerve cells. Two branches arising from A.V. node and enter the ventricles. These branches are called as bundle of His or Purkinje fibres.

Function of S.A. node and A.V. node or regulation of normal heart beating: The impulse to contract originates from S.A. node. Thus this area is called as pacesetter of the heart. The impulse from the S.A. node then passes in a wave like manner over the atria and it is collected at another area called A.V. node. Thus the impulses travels up to the ventricles. Blood from the various part of the body enters the right atrium and from lungs to the left atrium. Which then contracts sending the blood to the respective ventricles. Now the right ventricle contract with the result A. V. aperture is closed by three valves and the blood passes into the pulmonary artery and cortico-systemic aorta.

The action of S.A. node is controlled by a controlling centre known as cardiac centre. There are two parts in cardiac centre. First part is known as cardioinhibitor, send their impulse to the S.A. node whereas second part send their impulse into S.A. node through sympathetic nerves. First part decreasing the rate of heart beat whereas second part increasing it. Some hormones and chemicals like thyroxin, adrenalin and acetyl choline are also affecting the rate of heart beating.

Question 10.
What do you mean by double circulation ? Explain.
Or,
Explain mechanism of double circulation.
Answer:
Double circulation: Circulation in which blood flows twice through the heart is called as double circulation. At first heart receives deoxygenated blood from vena cava then send the blood to the lungs for purification through pulmonary arteries. After purification blood is received by heart again through pulmonary vein and then through aorta oxy-genated blood is distributed to whole parts of the body. In double circulation two circulations are found :

1. Systemic circulation,
2. Pulmonary circulation.

1.Systemic circulation: Vertebrates have a closed blood vascular system. The continuous flow of blood within the system is maintained by the regular rhythmic pumping action of heart. The left ventricle ejects blood into the aorta. Aorta through its branches supply blood to various organs of the body. After the exchange of gases the deoxygenated blood returns to the heart through a large number venules, veins and ultimately to the superior and inferior vena cava. This circulation is known as systemic circulation.

2. Pulmonary circulation: The right ventricle on contraction pumps blood into the pulmonary artery which carries the deoxygenated blood to the lungs. After the oxygenation process blood returns to the left atrium through two pairs of pulmonary veins. This circulation is known as pulmonary circulation.

Question 11.
Describe various heart diseases of man in brief.
Answer:
Heart diseases in man: General symptoms of heart diseases include breathlessness, ankle swelling, liver congestion, dry cough, fatigue and difficulty in lying down. The diseases are described below :

1. Arteriosclerosis: In this disease arteries and arterioles lose their elasticity. This loss of elasticity is due to deposition of cholesterol or calcium and thickening of the fibrous tissue in the inner lining of blood vessels. As a result the lumen of the arteries becomes narrow. High blood pressure and cerebral haemorrhage are the common disease symptoms.
2. Coronary heart diseases : A set of coronary arteries supply blood to the heart muscle. When they become hard and narrow, blood supply to heart is reduced. The affected person feels severe pain in the chest along the arms. Sometimes a clot may develop and stop the blood supply to the heart. This is called coronary thrombosis. Nitroglycerine tablets relax the arteries and thus reduce the pain. Heparin and dicumarol prevent blood clotting and promote its smooth flow.

3. Rheumatic heart: The disease is caused by the inflammation of the heart. It may affect:

• Inner lining of the heart including valves: It is called endocarditis.
• Outer covering of the heart: It is called pericarditis.
• Heart muscles: It is called myocarditis.

Inflammation may cause permanent damage to heart. Usually, it is followed by the’ infection of streptococci bacteria. The bacteria release the toxin which travels to the joints to cause rheumatic fever, i.e. swelling and pain in legs and fever.
Rheumatism causes permanent damage to heart in two ways :

1. Opening of the valves is narrowed and
2. Valves do not close properly. Both of these defects hinder the free flow of blood in the required direction.
3. Low blood pressure, joints swelling and pain in legs and fever are the typical symptoms. Bed rest is advised.

4. Hypertension: When a person suffers from nervous tension or emotional stress such as fear, worries, anxieties etc. they show high blood pressure because the walls of their arteries get contracted. This is hypertension. If such a stress is frequently found then it results in a persistent high blood pressure.

During this phase heart has to work harder to pump blood to different parts of the body. This may sometimes lead to destruction of the arteries of kidney causing chronic nephritis. Headache, dizziness, fatigue, restlessness are the typical symptoms of hypertension. Chlorothiazides are given as medicines. Bed rest, exercise and avoidance of alcoholism and smoking are advised.

5. Ventricular fibrillation: In this disease each part of ventricles contracts at different time.
6. Angioma: Due to formation of blood clot in the coronary artery, heart wall do not get sufficient supply of blood and causes severe chest pain.

7. Myocardial infraction or Heart attack: Due to obstruction in the coronary artery heart muscle do not get sufficient blood due to which the cells damage and fails to function properly. This condition is called as myocardial infarction or heart attack.

Body Fluids and Circulation Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
S. A. node is found in :
(a) Alimentary canal
(b) Aorta
(c) Liver
(d) Heart.
Answer:
(d) Heart.

Question 2.
Sphygmomanometer is used for the measurement of:
(a) Blood pressure
(b) Rate of heartbeat
(c) Rate of blood flow
(d) Temperature.
Answer:
(a) Blood pressure

Question 3.
Blood platelets are concerned with :
(a) Transport of CO₂
(b) Release of antitoxins
(c) Production of antibodies
(d) Release of thromboplastin.
Answer:
(d) Release of thromboplastin.

Question 4.
In which form the CO₂ is carried out by the blood :
(a) Sodium carbonate
(b) Sodium bicarbonate
(c) Potassium carbonate
(d) Magnesium bicarbonate.
Answer:
(b) Sodium bicarbonate

Question 5.
An antibody is :
(a) A molecule that specifically inactivates an antigen
(b) W.B.Cs. which invade bacteria
(c) Secretion of mammalian R.B.Cs.
(d) Component of blood.
Answer:
(a) A molecule that specifically inactivates an antigen

Question 6.
Carotid artery carries :
(a) Impure blood from brain
(b) Oxygenated blood to anterior region of body or to brain
(c) Impure blood to kidney
(d) Oxygenated blood to heart.
Answer:
(b) Oxygenated blood to anterior region of body or to brain

Question 7.
During diastole :
(a) Blood enters lungs
(b) Blood leaves the ventricle
(c) Blood leaves the heart
(d) Blood enters the heart.
Answer:
(d) Blood enters the heart.

Question 8.
Heart beat is regulated by the cranial nerve :
(a) Xth
(b) IXth
(c) find
(d) Vth.
Answer:

Question 9.
What is blood bank in human body :
(a) Spleen
(b) Lungs
(c) Heart
(d) Liver.
Answer:
(a) Spleen

Question 10.
Average cardiac output is :
(a) 4 litre per minute
(b) 63 litre per minute
(c) 5-3 litre per minute
(d) 73 litre per minute.
Answer:
(c) 5-3 litre per minute

Question 11.
Rh factor is a protein present:
(a) On R.B.Cs.
(b) In plasma
(c) On W.B.Cs.
(d) In serum.
Answer:
(a) On R.B.Cs.

Question 12.
During systole of ventricle:
(a) Blood enters the heart
(b) Blood leaves the heart
(c) Blood leaves the ventricle
(d) Blood enters lungs.
Answer:
(c) Blood leaves the ventricle

Question 13.
Pure blood (Oxygenated) is formed in:
(a) Pulmonary vein
(b) Renal vein
(c) Hepatic portal vein
(d) Pulmonary artery.
Answer:
(a) Pulmonary vein

Question 14.
The life of R.B.Cs. is:
(a) About 120 days
(b) 90 days
(c) 30 days
(d) 10 years.
Answer:
(a) About 120 days

Question 15.
Where is chordae tendineare found in the heart:
(a) Ventricle
(b) Left Ventricle
(c) Right Auricle
(d) None.
Answer:
(a) Ventricle

Question 16.
William Harvey is famous for the discovery of :
(a) Respiration
(b) Blood contraction
(c) Blood circulation
(d) digestion.
Answer:
(c) Blood circulation

Question 17.
Which part of vertebrate is responsible for pure blood:
(a) Gill
(b) Lungs
(c) Spleen
(d) Liver.
Answer:
(c) Spleen

Question 18.
Spleen is:
(a) Haemopoitic
(b) Lymphide
(c) Reproductive
(d) None.
Answer:
(b) Lymphide

Question 19.
Which structure of human when not working properly is replaced by pacemaker:
(a) S. A. node
(b) A.V. node
(c) Both (a) and (b)
(d) None.
Answer:
(a) S. A. node

Question 20.
Which instrument is used for measuring blood pressure :
(a) Stethoscope
(b) Electrocardiograph
(c) Sphygmomanometer
(d) None.
Answer:
(c) Sphygmomanometer

Question 21.
Which vitamin help for clotting of blood :
(a) Vitamin-E
(b) Vitamin-K
(c) Vitamin-C
(d) Vitamin-D.
Answer:
(a) Vitamin-E

Question 22.
Which blood cells kills pathogenic germs in the blood :
(a) Platelets
(b) Red blood corpuscles
(c) White blood corpuscles
(d) Skin cells.
Answer:
(c) White blood corpuscles

Question 23.
Hormone which regulate heartbeat and blood pressure :
(a) Thyroxin
(b) Adrenalin
(c) Gastrin
(d) Secretin.
Answer:
(b) Adrenalin

Question 24.
Where sinu-auricular node is located :
(a) In the Brain
(b) In the Liver
(c) In the Spleen
(d) In the Heart.
Answer:
(d) In the Heart.

2. Fill in the blanks:

1. The number of chambers in the heart of amphibian is ……………………………………. whereas number of chambers in human heart is ……………………………………. .
Answer:
Three, four,

2. ……………………………………. vascular system is found in sponges.
Answer:
Water,

3. Neurogenic heart is found in ……………………………………. .
Answer:
Invertebrates,

4. The oxygenated blood from lungs reaches left atrium of heart through ……………………………………. .
Answer:
Pulmonary artery,

5. Formation of blood is called ……………………………………. .
Answer:
Haemopoisis,

6. Pericardium is ……………………………………. layered.
Answer:
Two,

7. ……………………………………. is a lymphatic organ.
Answer:
7. Spleen,

8. ……………………………………. heart is found in mammals.
Answer:
8. Myogenic,

9. Blood cells are produced in the ……………………………………. .
Answer:
Bone marrow,

10. ……………………………………. is not found in human RBCs.
Answer:
Nucleus.

3. Match the following:

(A)

Answer:
1.  (c) A.V. Bundle,
2. (d) Pacemaker
3. (b) Systematic circulation
4. (e) Semiluner valve.
5. (a) AV. node.

(B)

Answer:
1.  (e) Four chambered.
2. (d) Three chambered
3. (a) Nerve fibre
4. (b) Spleen
5. (c) Left atrium and left ventrium.

(C)

Answer:
1.  (c) Prevent infection,
2.  (e) Transport of respiratory gas.
3. (b) Universal recipient
4.  (a) Blood clotting
5. (d) Contraction of heart.

4. Answer in one word:

1. Where does dub and lub sounds are produced in cardiac cycle.
Answer:
When auricle contracts, ventricle relax

2. Name the sounds produced due to following actions:
(a) Closing of atrio ventricular valve and initiation of ventricular contraction.
(b) Closing of semilunar valves and initiation of contraction of ventricle.
Answer:
Lub, dub,

3. What is carbaminohaemoglobin?
Answer:
Haemoglobin + CO₂,

4. Write the pulse rate of human.
Answer:
72 times per minute,

5. How many types of circulatory systems are found in animals?
Answer:
Two, Open and closed circulatory system,

6. Name the instrument meant for recording heartbeat?
Answer:
Electrocardiogram (ECG),

7. Where are Purkinje fibres situated?
Answer:
Auricular ventricular node (A.V.Node),

8. What is the blood pressure of a normal adult human being?
Answer:
120/80 mm Hg.,

9. Thrombocytes are present in which part of human body?
Answer:
Blood platelets,

10. Why blood is red in colour?
Answer:
Due to Haemoglobin

11. What is blood pressure of a normal man?
Answer:
120/180.

Students get through the MP Board Class 11th Biology Important Questions Chapter 19 Excretory Products and their Elimination which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 19 Excretory Products and their Elimination

Excretory Products and their Elimination Class 11 Important Questions Very Short Answer Type

Question 1.
Define Glomerular filtrate rate (GFR). (NCERT)
Answer:
Quantity of glomerular filtrate or Nephric filtrate filtered per minute by the kidney of human is called as Glomerular filtrate rate (GFR).
Rate of filtration in a normal adult person is about 125ml per minute.
[Average volume of GF per day by the kidney is 190 litres.]

Question 2.
Write the name of excretory organs of following phylum animals :
(a) Protozoa,
(b) Coelenterates,
(c) Molluscs,
(d) Arthropods
(e) Annelida.
Answer:
(a) Protozoans : Plasma membrane, contractile vacuoles.
(b) Coelenterates: Diffusion by plasma membrane.
(c) Molluscs: Renal organs or kidney.
(d) Arthropodes : Malphighian tubules.
(e) Annelida : Nephridia for excretion.

Question 3.
Write the name of hormone which causes Addison’s disease.
Answer:
Mineralocorticosteriod hormone is responsible to increase the amount of water and sodium in urine. This disease is called Addison’s disease.

Question 4.
How does human skin and lungs function as an excretory organ?
Answer:
Human skin possesses sebaceous glands and sweat glands. These glands excrete some excretory substances with their secretion like sebum and sweat. Hence, skin is also called as excretory organ.
Lungs help for excretion by exhalation of CO₂ from the body.

Question 5.
Why the excretion of uric acid in place of urea is more advantageous for birds and reptiles?
Answer:
Uric acid and their salts are relatively less harmful and water-insoluble, hence they are excreted in the form of solids and thus, water is not lost whereas, water is also lost in the excretion of urea. Thus, the excretion of uric acid in birds and reptiles is a mode of adaptation to prevent water loss.

Question 6.
In which part of body ammonia is converted into urea?
Answer:
Liver.

Question 7.
Explain the significance of ureotelism in ureotelic animals.
Or,
What is ureotelism? How it is advantageous over other excretions?
Answer:
Ureotelism is the urinary elimination of nitrogenous waste products mainly in the form of urea. Urea is relatively less harmful waste product in the nature. However urea is very soluble in water. Therefore, the ureotelic animals must be able to afford sufficient amount of water for excretion (in aquatic animals) concentrate urine (in Kangaroo and Rat) or retain considerable amount of urea in body fluids and blood (in Shark). Thus, this phenomenon is a type of adaptation in these animals.

Question 8.
What will be the ‘affect, if deamination process in the liver of human is stopped?
Answer:
If deamination process in the liver is stopped then conversion of ammonia into urea for its removal will stop. Excess amino acid reaches to the liver will fail to convert into carbohydrates by removal of amino group, as a result of which formation of pyruvic acid and ammonia will stop. Due to collection of toxic substances, other life activities will be affected.

Question 9.
Write the name of: (NCERT)
(a) One vertebrate in which excretion occurs through flame cells.
(b) Part of the kidney which lies embedded in between renal pyramids of medulla.
(c) Network of capillaries found surrounding Henle’s loop.
Answer:
(a) Planaria,
(b) Renal column of Bertini,
(c) Vasa recta.

Question 10.
What is Osmoregulation? (NCERT)
Answer:
The process by which osmotic pressure of the body fluids are maintained by addition or elimination of various substance like water, salt etc. is called as Osmoregulation.

Excretory Products and their Elimination Class 11 Important Questions Short Answer Type

Question 1.
Explain self regulation mechanism of Glomerular filtrate rate (GFR). (NCERT)
Answer:
Regulation of Glomerular filtrate rate (GFR) is done by ultrafiltration through glomerular capillaries, which is located at the joining of the afferent and efferent arterioles. Fall in glomerular filtrate rate induce glomerular capillaries to secrete renin, which activate renal blood circulation, thus again glomerular filtrate rate (GFR) become normal.

Question 2.
Describe Countercurrent mechanism in brief.
Answer:
Mammal excretes hypertonic urine. Henle’s loop and Vasa recta plays an important role, for this Vasa recta are in the form of loops, surrounding Henle’s loop, hence blood flows in opposite direction in the two limbs of each Vasa recta, the blood flowing in the descending limb comes closer to the outgoing blood in the ascending limb, this is called Counter current system.

Na⁺ and Cl^– are reabsorbed from the filtrate in ascending limb and subsequently released into the surrounding medullary tissue and retained by the vasa recta. This limb is impermeable to water. Thus, urine become progressively more hypotonic but the descending loop of Henle wall is permeable to water thus more water is reabsorbed by its wall and urine become hypertonic.

Question 3.
Generally terrestrial organisms excrete urea or uric acid not ammonia. Why? (NCERT)
Answer:
Sufficient water is not available for terrestrial animals for speedy elimination of ammonia. So, it is converted into urea in the liver or into uric acid.
Urea is less toxic than ammonia and requires less water for elimination from the body. Urea is excreted as urine, e.g., mammals, amphibians like frog, toad etc.

whereas in reptiles and birds ammonia is converted into uric acid, which is least toxic nitrogenous waste product and requires very little amount of water for elimination. In the cloaca of reptiles and birds, uric acid accumulates and further concentrated there and passes out the body as whitish semisolid crystal form. Actually, this is adaptation in terrestrial organisms due to their dry habitat.

Question 4.
Explain urination. (NCERT)
Answer:
Urination or Micturition: The process of excretion of urine out of the body from the urinary bladder when it gets filled is called as urination or micturition. A normal healthy man excrete 1 to 1 -5 litres of urine per day.
It is controlled by the nervous mechanism. When sufficient pressure is built up in the bladder, a spontaneous nervous activity is generated due to which smooth muscles of the bladder wall contract and the urethral sphincter are relaxed. As a result, urine comes out from the bladder through urethra.

Note: In adults, the sphincter opens only when it is convenient to urinate otherwise it remains closed even when the pressure inside the bladder is high. The act of urination may be both voluntary and involuntary, but voluntary control develops late.

Question 5.
Give importance of Liver, Lungs and Skin in excretion. (NCERT)
Answer:
1. Liver: Liver plays chief role in excretion. It converts the excessive amount of amino acids present in blood into ammonia and pyruvic acid in their oxidative deamination.
Pyruvic acid oxidizes to release energy while amino acids are converted into less harmful substance, the urea which is filtered from the blood by kidney. This urea is then released with urine.

Urea
Liver also separates dead R.B.Cs. from the circulatory system and also converts its haemoglobin into useful bile salts.
Liver also converts the cholesterol, skatol and indole into less harmful substances and then mixes them in circulatory system. Kidney filters these substances from the blood.

2. Skin or integument: In aquatic animals where excretory organs are not developed, excretion takes place through general body surface (integument) by the process of diffusion. Mainly ammonia is excreted out into the surrounding water by this process. Higher animals like mammals including man possess two types of glands in their skin, sebaceous glands and sweat glands.

3. Lungs: Lungs help to eliminate the excretory waste products like carbon dioxide and some water in the form of vapour.

Question 6.
Give importance of Juxtra medullary tubules in function of kidney. (NCERT)
Answer:
30% Nephrons of the kidney has longer size of Henle’s loop. These nephrons are called as Juxtra medullary tubule. These tubules plays an important role in concentration mechanism of urine. When there is deficiency of water in the body vasopressin hormone is secreted, which induces reabsorption of water by the wall of the descending loop of Henle of extramedullary tubule. As a result of which more and more water is reabsorbed and hypertonic urine is produced. This mechanism of concentration of urine is called as counter current mechanism.

Question 7.
How the permeability of distal convoluted tubule and collecting tubule is controlled due to which the amount of water in the body is maintained?
Answer:
When the amount of water in our body is increased then nephrons absorb it from blood and dilute it. But when the amount of water in our body is decreased then nephrons or renal tubules absorb least amount of water and thus, the amount of urine is also decreased and urine becomes concentrated. Changes in the nature of urine resulting due to changes in the permeability of distal convoluted tubules and collecting tubules and their permeability is controlled by hormones.

The first hormone is aldosterone, that increases the process of reabsorption of Na⁺ from the filtrate of renal tubules and thus the amount of Na⁺ is also maintained. Second hormone is vasopressin which controls the dilution and concentration of urine. Hormone aldosterone is formed from the cortex of adrenal gland and the vasopressin hormone is secreted by posterior lobe of pituitary gland.

Question 8.
Draw a well labelled diagram of nephron of human.
Answer:

Question 9.
Describe any four functions of kidney.
Answer:
The chief function of kidney is to excrete the nitrogenous excretory substances out of the body. In addition to excretion kidney performs the following functions :

1. Water balance: Kidneys play an important part in maintaining the concentration and osmotic pressure of blood by balancing the amount of water in the body. They remove excess amount of water out of the body.
2. Salt balance: They also maintain the concentration of salts in blood.
3. Acid-base balance: They maintain acid-base balance i.e., pH of the body fluid.
4. Elimination of harmful substances: Kidneys eliminate harmful substances and extra water-soluble vitamins, extra drugs, toxic chemicals and pigments out of the body. They are excreted through urine.

Question 10.
Explain function of aldosterone.
Answer:
Aldosterone hormone is secreted by the adrenal gland. It regulates quantity of Na⁺ in the body. Reabsorption is regulated by a substance renin secreted by the kidney, which converts angiotensin benzene into angiotensin. Angiotensin induces adrenal cortex to secrete aldosterone.

Question 11.
What are nephrostomes? Explain its mechanism of working.
Answer:
These are funnel shaped structures. At the broad part hairs are found. Broader part open into coelome and narrow part open into renal vein. By the movement of hairs coelomic fluid enters into the renal vein. Nephrostome is found in the embryonic stage of frog, after this stage it degenerates.

Question 12.
What do you mean by Homeostasis and Diuresis?
Answer:
Homeostasis: Keeping environment of the body permanent and regulated is called as Homeostasis. Nephrons and kidney tubules help for permanent regulation. They reabsorbs water, minerals and other nutritive substances whereas removes out excretory substances.

Diuresis: Increase in quantity of secretion of urine is called as diuresis. The substance which increases quantity of urine are called as diuretic substances. Urea is a diuretic substance which increases quantity of urine. Glucose, coffee, tea etc. are also examples of diuretic substances.

Excretory Products and their Elimination Class 11 Important Questions Long Answer Type

Question 1.
Explain the structure of kidney in brief.
Or,
Describe the structure of human kidney.
Answer:
External structure of kidney : Kidneys are bean shaped structure which lie behind the peritoneum in the lumber region, one on either side of vertebral column. It has a length of about 10 cm breadth at about 5 cm and a thickness of about 4 cm. A kidney is concave-convex in outline. The concavity lies on the inner-medium side. It possesses a longitudinal opening known as hilum.

Internal structure: L.S. of kidney showing two parts : Outer cortex and Inner medulla. The cortex is dark red while the medulla is pale in colour. Renal medulla possesses 8-18 striated conical masses called medullary pyramids. The bases of the pyramids are towards the outer side while the apices end in papillae 1-3 such papillae enter a minor calyx. The minor calyx open into major calyx which in turn produce the renal pelvis.

Urine is produced by minute thread like tubular structures named nephrons or uriniferous tubules. They constitute the structural and functional units of the kidneys. The urine formed by the nephron is poured into collecting ducts. The collecting ducts open into larger ducts of bellini. The later open at the apices or papillae of medullary pyramids.

Question 2.
Explain the structure of nephron with suitable diagrams.
Or,
Describe the structure of nephron of human with diagramshort ?
Or,
Draw well labelled diagram of human nephron.
Answer:
Nephron or renal tubules are the chief functional units of the kidney, which are made up of following two parts :
1. Bowman’s capsule: The initial part of each tubule is formed of glomerulus and a two walled cup shaped structure called Bowman’s capsule. It possesses a globular tufts of capillaries called glomerulus. Glomerulus is formed by an afferent and an efferent arteriole. Glomerulus is situated in cortex of the kidneys.

2. Secretory part: The backward portion of Bowman’s capsule is called secretory portion. It is made up of following three parts :

1. The coiled structure associated with Bowman’s capsule is called proximal convoluted tubule,
2. The mid ‘U’ shaped portion of nephron is called Henle’s loop. It is found in renal medulla,
3. The ascending limb of Henle’s loop passes into distal convoluted tubule. These tubules opens into larger ducts called collecting tubule or ducts.

For diagram:

Question 3.
What do you understand by Ammonotelism, Ureotelism and Uricotelism? Give example of each.
Answer:
Ammonotelic animals: Ammonotelic animals excreting the nitrogenous waste substances in the form of ammonia and the process of excretion is called Ammonotelism. For example Protozoans (e.g., Amoeba, Paramoecium), Sponges (Sycon), Coelenterates (e.g. Hydra), Annelids (e.g., Earthworm), Arthropods (e.g., Prawn), Molluscs (e.g., Sepia,Octopus) etc.

Ureotelic animals: Ureotelic animals excreting the nitrogenous waste products mainly in the form of urea. This process of excreting is called Ureotelism. For example Ascaris, Earthworm, Cartilagenous Fishes (Sharks), Amphibians (Frog, Toad), Aquatic reptiles (Turtles, Alligators.)

Uricotelic animals: Uricotelic animals are those which excrete thin nitrogenous waste product mainly as Uric acid. This process of excreting is called Uricotelism.
For example: Insects (Cockroach), Snake, Lizard, and birds etc.

Question 4.
Describe the process of urine formation.
Answer:
Urine is formed within kidney. Urine formation takes place in the following three stages:

1. Ultrafiltration,
2. Selective reabsorption,
3. Secretion.

Ultrafiltration: In each glomerulus, the nitrogenous excretory products such as urea etc. come with the blood through afferent arteriole and pass out through the glomerulus to efferent arteriole. The diameter of afferent arterioles is larger than that of the efferent arterioles. Because of it some amount of blood is retained in the glomerulus, therefore, some blood collects into glomerulus as a result of which a pressure is created, called as glomerular filtration pressure (GFP). It is about +75 mm Hg. The osmotic pressure of plasma protein of part of plasma is filtered out.

It is known as glomerular filtrate. It is isotonic with blood. It has most of the water, urea, amino acids, glucose, vitamin C, proteins having molecular weight less than 70,000, inorganic ions and salts etc. R.B.C. W.B.C., high molecular weight compounds and some water which is retained by the osmotic pressure of plasma proteins do not filter out.

2. Selective reabsorption: In man nearly 170 litres of glomerular filtrate is filtered out but only 1 -5 litres of urine is formed in 24 hours. The filtrate is isotonic whereas urine is hypertonic, the filtrate is slightly alkaline and the urine is acidic. It shows that some substances are reabsorbed by the renal tubules from the glomerular filtrate. This is called as selective reabsorption.

The second step in the urine formation is the selective reabsorption in which major portion of water and some physiologically important solutes like glucose, amino acids and inorganic salts like sodium chloride and sodium bicarbonates are reabsorbed back into the blood in the peritubular capillaries and vasa rectae. This reabsorption process takes place in the proximal convoluted tubule.

The tubular reabsorption may be of active reabsorption or of passive reabsorption. Glucose and amino acids which are of considerable importance to the body are actively reabsorbed. The active absorption is very rapid and continues even when the concentrations of these substances fall much below that in the blood. Rest of the useful substances like sodium, potassium, phosphates, bicarbonates etc. are passively reabsorbed by the physical process of diffusion. Water is reabsorbed by osmosis. Sodium ions are reabsorbed both by the active and the passive transport mechanism.
Vasa recta maintain a higher osmotic pressure of the extracellular fluid. In the descending limb of the loop of Henle about 5% of the glomerular filtrate is reabsorbed.

Almost the total amount of glucose, most of the amino acids, about 70 percent of potassium ions and a large amount of calcium ions are reabsorbed actively in the proximal convoluted tubule. 25 percent of potassium ions and some amounts of chloride ions and some sodium ions are reabsorbed actively by the ascending limb of the loop of Henle. The ascending limb is impermeable to water hence no water is reabsorbed into the ascending limb. This makes the filtrate dilute than plasma.

The distal convoluted tubules actively reabsorbs sodium ions and in exchange excretes some potassium ions. Some chloride ions are also reabsorbed by the DCT.

3. Secretion: The kidney tubules also excrete additional waste materials from the blood stream and put them into the filtrate. These excretory substances of blood are absorbed by the capillaries present in the wall of nephron. These absorbed excretory substances like urea, uric acid and ammonia etc. are diffused out from the capillaries of nephron and mixed with urine in nephron. This process of Bowman’s capsule is called as secretion.

Question 5.
Write short note on following :
(i) Green gland,
(ii) Nephridium.
Answer:
(i) Green glands: These are the principal excretory organs of Prawn. They are located in the second antennae. Each green gland consists of an end sac, a labyrinth and a bladder. Urine is first formed in the sac and passes through the fine tubules of labyrinth to the large sac-like bladder. A duct called ureter leads from the bladder to the base of antennae where it opens to the exterior. The end sac and the labyrinth probably excrete ammonia and uric acid respectively. The bladder also opens into thin-walled renal sac by a duct.

(ii) Nephridium: Annelids in general possess a excretory system consisting of long or short specialised tubules which are used for excretion and are called nephridia. Each nephridium consists of a ciliated funnel called nephrostome which opens into the body cavity or coelom. Nephrostome leads into a highly coiled tubule which finally opens outside the body through pores called nephridiopores present in the body wall. The nitrogenous wastes formed in the nephridia is propelled by ciliary movements and either thrown directly outside or into the alimentary canal.

Excretory Products and their Elimination Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
The process of filtration takes place in :
(a) Renal capsules
(b) Henle’s loop
(c) Neck
(d) Papilla.
Answer:
(a) Renal capsules

Question 2.
The excretory organ of crustaceans is :
(a) Uriniferous tubules
(b) Green glands
(c) Cloacal glands
(d) Malpighian tubules.
Answer:
(b) Green glands

Question 3.
Contractile vacuole is responsible for :
(a) Osmoregulation and excretion
(b) Respiration
(c) Osmoregulation
(d) Excretion of excretory substances.
Answer:
(a) Osmoregulation and excretion

Question 4.
Vasopressin is associated with :
(a) Urine concentration
(b) Dilution of urine
(c) Digestion
(d) Heart beating.
Answer:
(a) Urine concentration

Question 5.
The excretory substance of human beings is :
(a) Amino acid
(b) Ammonia
(c) Urea
(d) Uric acid.
Answer:
(c) Urea

Question 6.
Concentration of urea is minimum in :
(a) Pulmonary vein
(b) Hepatic artery
(c) Portal vein
(d) Renal vein.
Answer:
(d) Renal vein.

Question 7.
Excretory products of human urine formed by protein metabolism are:
(a) Uracil, ammonia, urea
(b) Urea, uric acid, NaCl
(c) Urea, melanin, guanine
(d) Urea, uric acid, creatinine.
Answer:
(d) Urea, uric acid, creatinine.

Question 8.
Ammonia is converted into urea in :
(a) Kidneys
(b) Liver
(c) Intestine
(d) Spleen.
Answer:
(b) Liver

Question 9.
Proteolytic enzyme secreted by kidney is :
(a) Rennin
(b) Trypsin
(c) Erepsin
(d) None of these.
Answer:
(a) Rennin

Question 10.
The stage of urine formation in which blood is also excreted with urine is called:
(a) Creatinine
(b) Haematuria
(c) Anuria
(d) Ketonuria.
Answer:
(b) Haematuria

Question 11.
Aquatic snakes are generally :
(a) Aminotelic
(b) Aminophilic
(c) Ureotelic
(d) Uricotelic.
Answer:
(c) Ureotelic

Question 12.
The function of green gland is excretion. It is found in :
(a) Spider
(b) Insects
(c) Scorpion
(d) Crayfish.
Answer:
(d) Crayfish.

Question 13.
Ureotelism is found in :
(a) Mammals
(b) Aquatic insects
(c) Tadpole
(d) Birds.
Answer:
(a) Mammals

Question 14.
Excess urine formation and its removal is called :
(a) Serosis
(b) Diuresis
(c) Sclerosis
(d) Osteoporosis.
Answer:
(b) Diuresis

Question 15.
Fluid in Bowman’s, capsule is called :
(a) Water
(b) Urine
(c) Blood cells with Blood
(d) Blood plasma without Blood corpuscles.
Answer:
(d) Blood plasma without Blood corpuscles.

Question 16.
The structural and functional unit of kidney is :
(a) Neuron
(b) Nephron
(c) Respiratory cell
(d) Malpighian tubule.
Answer:
(b) Nephron

Question 17.
It is called the graveyard of R.B.Cs.:
(a) Kidney
(b) Gall bladder
(c) Spleen
(d) Liver.
Answer:
(c) Spleen

Question 18.
Haemodialysis is helpful for which diseased patient:
(a) Uremia
(b) Anaemia
(c) Diabetes
(d) Goitre.
Answer:
(a) Uremia

Question 19.
In the kidney of mammals Henle’s loop lies at the :
(a) Medulla
(b) Cortex
(c) Pelvis
(d) Ureter.
Answer:
(a) Medulla

Question 20.
Human kidney is :
(a) Pronephron
(b) Mesonephron
(c) Metanephron
(d) Opisthonephron.
Answer:
(c) Metanephron

2. Fill in the blanks:

(A)
1. The excretory orgen of prawn is …………………….. .
Answer:
Green glands,

2. Aquatic animals excrete nitrogenous excretory substances as …………………….. .
Answer:
Ammonia,

3. The substances that increases urine formation are called …………………….. .
Answer:
Diuretics,

4. The artificial removal of excretory substances from the body is called …………………….. .
Answer:
Haemodialysis,

5. …………………….. is responsible for the concentration of urea.
Answer:
Henle’s loop,

6. The yellow colour of the urine is due to the presence of …………………….. .
Answer:
Bilirubin,

7. The formation of the urea takes place in …………………….. .
Answer:
Liver,

8. The functional unit of kidneys are …………………….. .
Answer:
Nephron.

(B)
1. Ascending loop of Henle is …………………….. to water, whereas descending loop of Henle is …………………….. to it.
Answer:
Impermeable, permeable,

2. In the distal convoluated tubule of nephron of the kidney reabsorption of water occurs due to …………………….. hormone.
Answer:
Anti diuretic hormone (ADH),

3. In the glomerular filtrate in addition to …………………….. all other substances of blood plasma are found.
Answer:
Nitrogenous wastes,

4. A normal healthy adult human excrete …………………….. urea per day.
Answer:
25-30gm.

3. Match the following:

(A)

Answer:
1. (d) Cockroach
2. (e) Earthworm.
3. (a) Vasopressin
4. (c) Glomerulus
5. (b) Bird.

(B)

Answer:
1. (d) Bile juice
2.  (a) Urecotelic
3. (e) Urea.
4. (b) Green gland
5. (c) Kidney.

(C)

Answer:
1. (c) Bony fishes
2. (e) Nephron.
3. (d) Urinary bladder
4, (a) Bird,
5. (b) Reabsorption of water.

4. Answer in one word :

1. Name the pigment found in urine.
Answer:
Urochrome,

2. Name the substance which regulates the excretion of sodium and potassium in urine and place where it is formed.
Answer:
Aldosterone, Adrenal cortex,

3. Name the factor which regulates the volume of urine.
Answer:
Vasopressin hormone,

4. Name the excretory organ of Hydra.
Answer:
Plasma membrane,

5. Name the hormone which regulates the secretion of urine in nephron.
Answer:
Vasopressin,

6. Name the excretory substance of Man.
Answer:
Urea, CO₂,

7. What is loop of Henle?
Answer:
U shape tube of nephron,

8. Name the artery which carries blood towards the kidney.
Answer:
Renal artery,

9. Where is urea formed?
Answer:
Liver.

5. Write true or false:

1. Micturition occurs by reflex action.
Answer:
True,

2. ADH helps for excretion of urine by making it hypotonic.
Answer:
False,

3. Henle’s loop plays important role in making urine concentrated.
Answer:
True,

4. In the Bowman’s capsule protein less liquid is filtered out from the blood plasma.
Answer:
False,

5. In the proximal convoluted tubule (PCT) active reabsorption of glucose occurs.
Answer:
True.

Students get through the MP Board Class 11th Biology Important Questions Chapter 4 Animal Kingdom which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 4 Animal Kingdom

Animal Kingdom Class 11 Important Questions Very Short Answer Type

Question 1.
Write down three main characters due to which birds are able to fly.
Answer:
Three main characters due to which birds can fly are :

1. Body is streamlined and is covered with feathers.
2. Forelimbs are modified as wings for flying.
3. Bones are pneumatic (Porous), this reduces the weight of the body.

Question 2.
Differentiate radial and bilateral symmetry. (Any two)
Answer:
Differences between Radial and Bilateral Symmetry

Question 3.
Write three characteristics of protochordata.
Answer:

1. They possesses notochord either throughout the whole life or in some phase of life.
2. Vertebral column does not develop.
3. They do not have a cranium and the jaws.

Question 4.
Give examples of three stationary organisms.
Answer:

1. Leucosolenia,
2. Sycon,
3. Grantia.
   All these organisms belong to phylum Porifera and are found attached to the stone or substratum.

Question 5.
Write two characters of sub-phylum :
(a) Urochordata,
(b) Cephalochordata,
(c) Hemichordata.
Answer:
(a) Urochordata :

• They are marine.
• They are sessile forms and possess the notochord in the tail region in the larval stage which is degenerated completely in the adult stage.
• Adults are always enclosed in a tunic composed of animal cellulose, e.g., Herdmania known as sea squirt, etc.

(b) Cephalochordata :

• Animals of this sub-phylum are exclusively marine and solitary animal.
• They are small, fishlike animals.
• Notochord is present from head to tail.
• Many gonads are present, e.g., Amphioxsus, Asymmetron, etc.

(c) Hemichordata :

• Its body is divided into Probosis, Colar and Neck.
• In Probosis, notochord like structure is formed.
• They are marine animals, e.g., Balanoglossus.

Question 6.
What are glass sponges?
Answer:
Skeleton of some sponges are transparent and their spicules or spines are silicious thus they are called as glass sponges.

Animal Kingdom Class 11 Important Questions Short Answer Type

Question 1.
Differentiate between Intracellular digestion and Extracellular digestion. (NCERT)
Answer:
Intracellular digestion :
The process of digestion which occurs inside the cell is called as intracellular digestion. Unicellular organisms like Amoeba, Paramoecium engulf food by endocytosis process then hydrolytic enzymes present in the lysosomes help for digestion. After absorption of digested food, undigested food is released out of the body by exocytosis process. Whereas Extracellular digestion is the process of digestion which occurs outside the cell. In multicellular organisms extracellular digestion occurs in the digestive system.

Question 2.
Write differences between Direct and Indirect development.
Answer:

• Direct development: In this type of development larva stage is not found. Zygote directly develops to form individual, e.g., Human, Rat, Elephant, Monkey etc.
• Indirect development: In this type of development zygote first develops into larva, then larva develops to form young individual, e.g., Cockroach, frog etc.

Question 3.
What is the importance of presence of air bladder in fishes?
Answer:
Air bladder present in the fishes help for buoyancy, due to which they may swim easily, even if it reaches to the bottom it can come up easily, e.g., Exocoetus, Rohu fishes.

Question 4.
Write differences between Chordates and Non-chordates.
Answer:
Differences between Chordates and Non-chordates

Question 5.
Explain adaptations in birds for aerial habitat.
Answer:
Basic features of birds with reference to habitat:
Birds are terrestrial organ-isms which can fly in the air. Following adaptations are found in them for aerial habitat:

• Body is covered with feathers which hold air and decreases body weight.
• Forelimbs are modified into wings.
• Digits of hind limbs are adapted for sitting on the branches of the tree.
• Bones are hollow and aerated thus decreases body weight for flying.
• Urinary bladder is not found and they do not store waste product in the body (As it is produced is released out from the body).
• Foot webs are found in aquatic birds for swimming.
• Air sacs are found on the lungs.
• Beak is adapted according to its food habit. It is toothless.

Question 6.
Write down the name of the animals which are related with the given organs :
1. Compound eye,
2. Carapace,
3. Medusa,
4. Flame cells,
5. Placoid scales,
6. Blabber,
7. Parapodia.
Answer:
Organs – Animals related to it

1. Compound eye – Periplanata
2. Carapace – Crab
3. Medusa – Aurelia
4. Flame cells – Plan aria
5. Placoid cells – Scoliodon
6. Blabber – Whale fish
7. Parapodia – Nereis
8. Tube feet – Starfish

Question 7.
Write down the difference between :
1. Coelomate and Pseudocoelomate,
2. Urochordata and Cephalochordata,
3. Flat worm and Round worm,
4. Bony fishes and Cartilage fishes, 5. Oviparous and Viviparous, 6. Diploblastic and Triploblastic.
Answer:
1. Coelomate and Pseudocoelomate:
Presence of true coelom with mesoderm surrounding the body cavity entirely is called Coelomate, whereas Pseudocoelomate are partially open fluid filled body cavity which develops in the blastocoel, so mesoderm does not entirely surround the body cavity.

2. Urochordata and Cephalochordata :
Urochordata are marine sessile animals possessing notochord in tail region in larval stage and degenerates in adult stage whereas Cephalochordata are marine and solitary animal possessing notochord from head to tail.

3. Flat Worm and Round Worm:
The animal body of Platyhelminthes are flat and tapering only at the anterior end are called Flat worm. Whereas the animal body of Nemathelminthes are round in shape, tapering at both ends.

4. Bony fishes and Cartilage fishes :
Fishes having bones are called Bony fishes and they are fresh water as well as marine whereas Cartilaginous fishes are having cartilage they are all marine.

5. Oviparous and Viviparous :
Oviparous animals lay eggs outside the body and fertilization may be internal or external, whereas Viviparous animals hatch eggs within the female body and fertilization is internal.

6. Diploblastic and Triploblastic :
Diploblastic animals are those where their embryo are made up of two germ layers : Ectoderm and endoderm, whereas Triploblastic animals are those where their embryo are made up of three germ layers : Ectoderm, meso-derm and endoderm.

Question 8.
What is False fish? Explain it with examples.
Answer:
Those animals which live in water and have the capacity to swim in water like fishes. But they do not come under class Pisces. So they are called false fish.
Example :

• Jelly fish : It is Aurelia genus and is in phylum Coelenterats.
• Silverfish : It is in phylum Arthropoda and is genus of Lepisma.
• Devilfish : It is in phylum Mollusca of genus Octopus.
• Starfish : It is in phylum Echinodermata of genus Asterias.

Question 9.
Describe the characteristic features of the class mammalia.
Or
In which class of Animalia human is included and why? Explain with five features of this class.
Answer:
Characteristics of class mammalia : It is the highly developed group of king-dom animalia.
Human is placed under the class mammalia, because of the following reason :

• They are isothermal. Body is covered by hairs. Skin contains sweat and oil glands.
• Females possess mammary glands, which secrete milk after the birth of young ones and thus, infant is given nutrition in the initial stage of growth.
• The heart is four chambered with two auricles and two ventricles. Only the left aortic arch is present.
• Ear with fleshy external ear or pinna.
• A muscular diaphragm is present, which separates the thoracic cavity from the abdominal cavity.
• They have well developed brain, this enables them to learn.
• Number of neck vertebrae is always seven.
• They are warm blooded animals.

Question 10.
What do you mean by Amphibian? Give eight characteristics of class Amphibia.
Answer:
Those animals of phylum Chordata which live both on land and in water are called Amphibian animals e.g., Frog (Rana tigrind), Bufo etc.
Characteristics of class Amphibia :

• Their body is fit for survival in water and on land.
• They are cold blooded animals.
• Their skin is moist, slippery and glandular, due to which they can respire both on land and in water.
• They possess ears which consists of tympanum.
• R.B.Cs. are nucleated.
• Heart is three chambered.
• Webs are present between the digits of hind limb.
• External fertilization occurs in water.

Question 11.
What do you understand by symmetry of animals? How many kinds of symmetry is found in animals ? Write at least any one character and give one example from each type of symmetry.
Answer:
Symmetry :
The arrangement of various parts of the body of organisms is called as symmetry .There are three types of symmetry found in animals :

1. Asymmetry :
   In asymmetrical arrangement body of animals cannot be divided into two equal parts in any plane, e.g., Gastropods, Sponges.
2. Radial symmetry :
   In this type, body of animals can be divided into two equal halves by cutting in any of the radial planes, e.g., Hydra and Starfish.
3. Bilateral symmetry :
   In this type, body of animals can be divided into two equal halves through only one plane i.e., main axis of the body passing through the center, e.g., All vertebrate animals.

Question 12.
Write the characters of the phylum Annelida.
Answer:
Characteristic features of the phylum Annelida :

• They are mostly aquatic, marine or fresh water, burrowing or living in tubes.
• The body is thin, elongated, cylindrical and is metamerically segmented, externally by transverse groove and internally by septa into a number of divisions, each division is called segment or metamere.
• Body is bilaterally symmetrical, triploblastic and coelomatic, which is covered by a contractile and muscular body wall. Epidermis is cuticulized.
• A straight, tube like alimentary canal is found in the center of body cavity which is extending from mouth to anus.
• Locomotion takes place by setae or chaetae.
• Blood vascular system is closed type. Blood is red due to presence of haemoglobin. R.B.Cs. are not found in the blood.

Question 13.
Describe the characteristic features of the kingdom Animalia.
Answer:
Characteristic features of the kingdom Animalia :

• The organisms of this kingdom are eukaryotic, multicellular, heterotrophic and holozoic in nutrition.
• Cell wall and plastids are absent.
• Locomotion and movement occur.
• All of them are consumers.
• They reproduce sexually, except some lower animals.
• They possess muscles, which possess the capacity of expansion and contraction.
• Body is triploblastic, bilaterally symmetrical and possesses the capacity of sensation.
• They possess nervous and hormonal systems for coordination.

Question 14.
Describe the important adaptations of the Arthropods.
Answer:
Phylum Arthropoda is the largest phylum of the animal kingdom. The following adaptive characters are found in the arthropods :

• Body is covered with a chitinous cuticle forming exoskeleton.
• The salts of CaC03 and calcium phosphates are also present in the exoskeleton, which increase the hardness of the body.
• Respiration through general body surface by gills in aquatic forms, trachea or booklungs in terrestrial forms.
• Moulting is present in the exoskeleton.
• The body is bilaterally symmetrical and metamerically segmented.
• Exoskeleton is solid, hence it provides the space for joining the muscles.
• The animals are suited for aquatic as well as terrestrial environment.
  Ex. Butterfly, Scorpion, Cockroach, Housefly, Mosquito.

Question 15.
Describe the characteristic features of the phylum Chordata.
Or
(A) Write three important characters of phylum Chordata.
(B) Write the name of phylum of the following animal:
(i) Star fish,
(ii) Jelly fish,
(iii) Octopus,
(iv) Earthworm,
(v) Tape worm,
(vi) Paiaemon.
Answer:
Characteristic features of the phylum Chordata :

• Notochord is present in any stage of life.
• Nervechord is present.
• Gills are present in any stage of life.
• A heart made up of muscles is present.
• Presence of closed circulatory system and blood cells contain R.B.Cs.
• Endoskeleton is present, which is made up of bones and cartilages.
• Presence of two pairs of appendages and well developed system. e.g., Man, Frog, Lizards, etc.

(B)
Name of related animal and their phylum :
Animal – Phylum

• Starfish- Echinodermata
• Jellyfish – Coelenterata
• Octopus – Mollusca
• Earthworm – Annelida
• Tapeworm – Platyhelminthes
• Paiaemon – Arthropoda.

Question 16.
Give characteristic features of phylum Moliusca.
Answer:
Characteristic features of Moliusca :

• They are essentially aquatic, mostly marine, few fresh water and some terrestrial forms.
• The body is soft, bilaterally symmetrical and consists of head, foot, circular mantle and visceral mass.
• Body is protected by an exoskeletal of calcareous shell, secreted by mantle.
• They possess a mantle cavity between body wall and mantle, in which digestive system, reproductive system and kidneys are opened.
• Head is distinct, bearing the mouth and provided with eyes, tentacles and other sense o-gans.
• Ventral body is modified into muscular flat or foot, which is variously modified for creeping, burrowing and swimming.
• Pharynx contains a rasping organ the radula except in bivalvia (pelecypoda).

Question 17.
Name the class which is represented by bats. Give three reasons.
Answer:
Bats are placed under the class Mammalia due to the following features :

• It has mammary glands with teats,
• Body is covered by hairs and skin possessing sweat and oil glands,
• Females give birth to young ones,
• It has four chambered heart.

Question 18.
Why whale fish is placed under the class mammalia? Give four reasons.
Or
Why is whale included in Mammalia? Explain with five reasons.
Answer:
Whale is placed under the class Mammalia, because of the following reasons :

• Females give birth to young ones.
• It contains mammary glands with teats.
• Their heart is four chambered.
• Fertilization is internal.
• Young ones develop within uterus.

Question 19.
Why frogs are placed under the class Amphibia? Give four reasons.
Answer:
Frogs are placed under the class Amphibia, because of the following reasons :

• Their body is fit for survival in water and on land,
• They are cold blooded animals,
• Their skin is moist, slippery and glandular, due to which they can respire both on land and in water,
• They possess ears.

Question 20.
Give at least one example of the following animals :
1. Egg laying mammal,
2. Flying mammal,
3. Flying reptile,
4. Flying fish.
Answer:
Animal – Example

1. Egg laying mammal – Echidna
2. Flying mammal – Bat
3. Flying reptile – Draco
4. Flyingfish – Exocetus.

Question 21.
What do you understand by Bilateral Symmetry? Explain it with example.
Answer:
Bilateral symmetry : If the body can be divided into two equal halves by one plane only it is called bilateral symmetry. Here the body organs are paired and occur on the two sides of a central axis, e.g., all vertebrates like fishes, human beings, birds, etc.

Such animals possess a front or anterior end and a rear or posterior end. They also possess an upper back or dorsal side and a lower belly or ventral side. On the basis of dorsal and ventral sides the right and left side® ‘if the body are called lateral sides. Man, Snake, Earthworm are the examples of Bilateral symmetry.

Question 22.
Differentiate between Starfish and Flyingfish on the basis of their body
symmetry and exoskeleton.
Answer:
Differences between Starfish and Flyingfish

Question 23.
Write down the name of phylum and class of the following animals :
1. Roundworm,
2. Leech,
3. Scorpion,
4. Bat.
Answer:

1. Roundworm:Phylum – Aschelminthes
   Class – Nematoda
2. Leech :Phylum – Annelida
   Class – Hirudinia
3. Scorpion:Phylum – Arthropoda
   Class – Arachnida
4. Bat:Phylum – Chordata
   Class – Mammalia.

Question 24.
Write down the name of phylum and class of the following animals :
1. Tapeworm,
2. Nereis,
3. Cockroach,
4. Starfish.
Answer:

1. Tapeworm:Phylum – Platyhelminthes
   Class – Cestoda
2. Nereis:Phylum – Annelida
   Class – Polychaeta
3. Cockroach :Phylum – Arthropoda
   Class – Insecta
4. Starfish: Phylum – Echinodermata
   Class – Asteroidia.

Question 25.
Write down the name of phylum and class of the following animals :
1. Hydra,
2. Earthworm,
3. Unio,
4. Horsefish,
5. Turtle.
Answer:

1. Hydra :Phylum – Coelenterata
   Class – Hydrozoa
2. Earthworm:Phylum – Annelida
   Class – Oligochaeta
3. Unio: Phylum – Mollusca
   Class – Gastropoda
4. Horse fish :Phylum – Chordata
   Class – Osteichthyes
5. Turtle:Phylum – Chordata
   Class – Amphibia.

Question 26.
Draw a well labelled diagram of Earthworm.
Answer:

Fig. Earthworm (Pheretima) : (A) Ventral view; (B) Segment 1, 2 and 3; (C) Reproductive organs

Question 27.
Write down the zoological name of the following animals :
1. Housefly,
2. Elephant,
3. Ostrich,
4. Roundworm,
5. Kangaroo.
Answer:
Common Name – Zoological Name

1. Housefly – Musca domestica
2. Elephant – Elephas maximus
3. Ostrich – Struthio
4. Roundworm – Ascaris lumbricoidis
5. Kangaroo – Macropus.

Question 28.
Pila and Octopus are kept in same phylum why?
Answer:
Pila and Octopus are kept in same phylum because :

• Their body is soft covered by shell.
• Body consists of head, visceral mass and foot.
• Whole body is covered by muscular mantle.

Question 29.
Write the name of locomotory organs of the following animals :
1. Amoeba,
2. Earthworm,
3. Paramoecium,
4. Snake,
5. Starfish,
6. Hydra,
7. Euglena.
Answer:
Animal – Name of the locomotory organs

1. Amoeba – Pseudopodia.
2. Earthworm – Setae.
3. Paramoecium – Cilia.
4. Snake – Ribs and scales.
5. Starfish – Arms.
6. Hydra – Tentacles.
7. Eugiena – Flagella.

Question 30.
Write the phylum of following animals :
1. Starfish,
2. Jellyfish,
3. Dogfish,
4. Horsefish,
5. Devilfish,
6. Whalefish,
7. Silverfish.
Answer:
Animal – Phylum

1. Starfish – Echinodermata
2. Jellyfish – Coelenterata
3. Dogfish – Chordata
4. Horsefish – Chordata
5. Devilfish – Mollusca
6. Whalefish – Chordata –
7. Silverfish – Arthropoda.

Question 31.
Give one example of each of the following :
1. Animal with largest life span,
2. Largest lizard,
3. Largest snake,
4. Largest animal of the world.
Answer:
Animal – Examples

1. Animal with largest life span – Turtles
2. Largest lizard – Kamado dragon
3. Largest snake – Python
4. Largest animal of the world – Blue whale.

Question 32.
All vertebrates are chordates, but all chordates are not vertebrates. Explain.
Answer:
All vertebrates have three important characteristics :

• Presence of Notochord,
• Presence of nerve chord and
• Presence of gill slits.

All vertebrates are bilaterally symmetrical, Notochord is replaced by vertebral column, Heart is ventrally situated, Level of organisation is observed, closed circulatory system is found in them, tail is found in them. On the basis of all above characteristics it is clear that all vertebrates are chordates, whereas all chordates are not vertebrates because in vertebrates notochord is found in embryonic stage whereas in adult stage it is replaced by vertebral column and chordate may or may not has cranium jaws, vertebral column and brain.

Thus, it is clear that all vertebrates are chordates but all chordates are not vertebrates.

Question 33.
Write the scientific name of the following animal:
1. Frog,
2. Man,
3. Cat,
4. Ox.
Answer:
Common Name – Zoological name

1. Frog – Ran a tigrina
2. Man – Homo sapiens
3. Cat – Felis domestica
4. Ox – Bos indicus.

Question 34.
Classify the classes of Phylum chordata.
Answer:
Phylum chordata is classified into seven classes :
Class – Example

1. Cyclostomata – Petromycin
2. Chondricthyes – Scoliodon
3. Osteichthyes – Labeo
4. Amphibia – Rana
5. Reptilia – Snakes
6. Aves – Columbia
7. Mammals – Macropus (Kangaroo)

Question 35.
Write five phylum giving examples.
Answer:
Five Phylum are :
Phylum – Example

1. Porifera – Sycon
2. Coelenterata – Hydra
3. Platyhelminthes – Planaria
4. Nemathelminthes – Ascaris
5. Annelida – Pheritima.

Question 36.
Write short notes on :
1. Haemocoel,
2. Porifera,
3. Insecta,
4. Cyclostomata,
5. Protochordata,
6. Nematoda,
7. Metamerism.
Answer:
1. Haemocoel: Coelom is a cavity which lies between body wall and digestive tract. It is filled with a fluid called coelomic fluid, but in phylum Arthropoda, in place of coelomic fluid, blood is filled, therefore it is called Haemocoel. It works as transporter.

2. Porifera :
General characteristics of phylum Porifera :

• They are radially symmetrical, multicellular and diploblastic animals.
• They are mainly marine except few sedentary and colonial or solitary.
• The skeleton is formed of calcareous or siliceous spicules present in between gelatinous substance.
• Body is perforated by numerous pores called Ostia.
• Nervous system is absent. Digestion is intracellular. No respiratory and excretory organs are present, e.g., Sycon, Spongilla.

3. Insecta :
It is the class of Phylum Arthropoda, which has following points :

• Body is divisible into head, thorax and abdomen.
• Thorax is three segmented and carries three pairs of legs and two pairs of wings.
• Mostly terrestrial but some are aquatic.

4. Cyclostomata :
It is a part of Phylum chordata, which have following characters :

• It consists of Cranium box, Jaws are absent, but mouth is suctorial.
• Body is long, narrow, cylindrical with laterally compressed tail. ‘
• It appears like fish, but skin is naked glandular.
• Single nostril is found on the dorsal surface of the head, e.g., Petromyzon.

5. Protochordata :
It is a part of chordata, having following characters :

• Notochord is not properly developed.
• Cranium and Jaws are absent.
• Body is laterally compressed and leaf like.

6. Nematoda:

• Nematodes have tube within a tube body plan with mouth, pharynx, intestine and anus. Body is covered with thick cuticle.
• They have unsegmented triploblastic and bilaterally symmetrical cylindrical body.
• Posterior end of body is frequently curved in males while pointed in females. Males are always smaller than females.
• Body is not distinguished into different regions. Head is not distinct.
• They are pseudocoelomic.

7. Metamerism :
The body of many animals is formed of numerous segments which show serial repetition of parts. This kind of segmentation is called metameric segmentation and the phenomenon is known as metamerism.

Question 37.
Give eight characteristics of super class Pisces.
Answer:
Characteristics of super class Pisces :

1. They are aquatic vertebrates,
2. Body is covered by scales,
3. They are cold-blooded organisms (Poikilothermal),
4. Heart is two chambered,
5. Respiration by gills,
6. Tympanic membrane absent,
7. Lateral line is found on the body,
8. Fins present for swimming.

Question 38.
Compare the oviparous, viviparous and ovo-viviparous among animals.
Answer:
Comparison of Oviparous, Viviparous and Ovo-viviparous Animals

Question 39.
“Number of offsprings produced by oviparous and viviparous organisms is equal”. Yes or No? Give reason.(NCERT)
Answer:
Oviparous organisms lay eggs whereas Viviparous organisms gives birth to young one.
Number of offsprings produced by them are not equal because in oviparous organisms internal or external fertilization occurs. They lays large number of eggs which undergoes various stages of development. During this long period of development some eggs get spoiled and remaining hatches to produce offsprings, whereas viviparous organisms give birth to young individual which are very less in number. Development of embryo occurs directly in the uterus of mother and no larva stage appears.

Question 40.
If a specimen is provided to you, what step will you take to classify the organisms? (NCERT)
Answer:
Inspite of different external features and shapes, some basic similarities are found in cellular organization, body symmetry, type of coelome, digestive system, circulatory system and reproductive system of the organisms.
To classify, all these features can be considered.

Question 41.
How structure of coelome and coelomate is helpful in the classification of living organisms? (NCERT)
Answer:
Coelome is defined as a cavity lined by mesoderm, it lies between the body wall and the digestive tract in which various internal organs are found suspended. Presence or absence and nature of coelome is the main basis of classification. Organism with coelome is called as Coelomate. e.g., Annelids, Echinodermates and Chordates etc.

The animals without coelome are called as Acoelomate. eg., Sponges, coelentrates and flatworms. In some other organisms mesoderm is found in the form of small packs scattered in between outer ectoderm and inner endoderm. Such organisms are called are Pseudocoelomate. eg., Roundworms such as Ascaris.

Animal Kingdom Class 11 Important Questions Long Answer Type

Question 1.
Give the general characteristic of phylum Porifera.
Answer:
General characteristics of phylum Porifera :

• They are radially symmetrical, multicellular and diploblastic animals.
• They are mainly marine except few sedentary and colonial or solitary.
• The skeleton is formed of calcareous or siliceous spicules present in between gelatinous substance.
• Body is perforated by numerous pores called Ostia.
• Nervous system is absent. Digestion is intracellular. No respiratory and excretory organs are present, e.g., Sycon, Spongilla.

Question 2.
Give eight characteristics of phylum Coelenterata.
Answer:
Characteristics of phylum Coelenterata :

• They are multicellular animals showing cell-tissue level of body organisation with most of the cells specialised for different functions and some forming a tissue. They exhibit physiological division of labour.
• Cnidarians are diploblastic metazoans, the body wall is made up of two layers the outer ectoderm and inner endoderm (gastroderm) with middle non-living gelatinous layer mesoglea.
• Coelenterates exhibit a blind sac plan and are radially symmetrical.
• Cnidarians are acoelomate.
• Head and segmentation absent.
• These are short or slender, extensile projections called tentacles, encircle the mouth in one or more whorls and are used for food-capture, intake and defence.
• Coelome is not found in them. Only one cavity found in the body called coelenteron, which is enclosed by endoderm. e.g., Hydra, Aurelia.

Question 3.
“Arthropoda is regarded as largest group of animals.” Give reason.
Answer:
Arthropoda is regarded as a most successful and largest group of animals. It has about 9,00,000 species out of which 7,50,000 species are the members of class Insecta. Due to following adaptations they forms approximately two third (2/3) part of the total number of animals present in the world :

1. Legs are divided into small segments.
2. They are found in different habitats likes air, water, soil as parasites etc.
3. Body is triploblastic, bilaterally symmetrical.
4. The true coelome is greatly reduced.
5. Open circulatory system is found in them.
6. Excretory organs are malpighian tubules.
7. Compound eyes are found in them.
8. Respiration occurs through tracheal system.
9. The segments of the body bears paired, jointed and lateral appendages which are modified as jaws, gills and legs.
10. Body is covered by thick exoskeleton containing Chitin. e.g., Palaemon, cockroach, Julus, Crab etc.

Question 4.
Write down the characteristics of phylum Platyhelminthes.
Answer:
General characters of Platyhelminthes :

• Flatworms are triploblastic (i.e., consists of three germinal layers ectoderm, mesoderm and endoderm). Acoelomate, bilaterally symmetrical, dorsoventrally flattened organisms with anteriorly differentiated into a definite head.
• They have flattened body because of their primitive system of circulation and excretion. Each cell of the body must be near to the body surface to get nutrients and oxygen and for the removal of waste products and carbon dioxide.
• Platyhelminthes have unsegmented body except in tapeworms (Class-Cestoda). In Cestodes body is strobilated, i.e., it consists of large number of proglottids.
• Flatworms are with blind sac body plan.
• The alimentary canal is either absent or highly branched and only mouth is present and anus is absent.
• They do not have any body cavity or coelom, various organs are embedded in a sort of solid packing tissue known as mesenchyme or parenchyma.

Question 5.
Explain modern classification of Animal Kingdom giving two-two examples.
Answer:
Modem classification of Animal Kingdom, showing important phylum is as follows, Animal Kingdom is divided into three branches. They are :
(A) Mesozoa Branch :
They are tissueless group of cells. It consists of only one
phylum.
1. Phylum Mesozoa :

• Body is made up of group of cells.
• Found in water, e.g., Diacima.

(B) Parazoa Branch :
It has cellular organization, clear mouth, anus absent. It has only one phylum.
2. Phylum Parazoa :

• Body consists of numerous pores.
• It is found in stagnant and flowing water, e.g., Sycon, Euspongia.

(C) Eumetazoa Branch :
It consists of tissue, organ, mouth alimentary canal. It consists of following
phylum :
3. Phylum Coelenterata:

• Coelenteron present, radial symmetry and tissue present,
• It is a multicellular organism, e.g., Hydra, Aurelia.

4. Phylum Platyhelminthes :

• Body ribbon shaped,
• Body cavity absent, e.g., Taenia solium, Planaria.

5. Phylum Nematoda :

• Body is long and round,
• Female is longer than male. e.g., Ascaris.

6. Phylum Annelida :

• Body is segmented,
• Locomotion by setae. e.g., Leech, Earthworm.

7. Phylum Mollusca :

• Body is soft,
• Shell is present all round the body, e.g., Unio, Pila.

8. Phylum Arthropoda :

• Jointed legs,
• Exoskeleton made of Chitin,
• Eyes simple or compound, e.g., Cockroach, Scorpion.

9. Phylum Echinodermata :

• Body radially symmetrical,
• Skin covered with spines, e.g., Starfish.

10. Phylum Chordata:

• Animal having notochord, nervecord and gills are present.
• All organs are well developed, e.g., Frog, Man, Fish.

Question 6.
Write down the characteristics of Chordata; classify it giving two-two characters with examples.
Answer:
Characteristics of Chordata :
Characteristic features of the phylum Chordata :

• Notochord is present in any stage of life.
• Nervechord is present.
• Gills are present in any stage of life.
• A heart made up of muscles is present.
• Presence of closed circulatory system and blood cells contain R.B.Cs.
• Endoskeleton is present, which is made up of bones and cartilages.
• Presence of two pairs of appendages and well developed system. e.g., Man, Frog, Lizards, etc.

Phylum Chordata is further classified into 7 classes; they are :
1. Class Cyclostomata :

• Cranium box is present,
• Lower jaw absent,
• Suctorial mouth, e.g., Petromyzon, Myxine.

2. Class Chondrichthyes :

• Endoskeleton is cartilagenous,
• Operculum and air bladder are absent, e.g., Scoliodon, Torpedo.

3. Class Osteichthyes :

• Endoskeleton formed of bones,
• Gills are covered by operculum, e.g., Labeo, Hippocampus.

4. Class Amphibia :

• They are amphibian animals, living both on land and in water but its larva grows in water only,
• It consists of four limbs, e.g., Rana tigrina, Bufo.

5. Class Reptiles :

• They creep on land,
• Skin is dry. e.g., Calotis, Naja.

6. Class Aves :

• Forelimbs modified into wings, and whole body is covered by feathers,
• Air is filled in bones, e.g., Columba, Passer.

7. Class Mammals :

• Presence of hair on the body,
• Mammary glands with teats, e g., Macropus, Homo sapiens.

Question 7.
If there is lack of knowledge of basic features then will you face problem to classify animals? (NCERT)
Answer:
Following problems may be faced while classifying the animals :

• Different levels of organisations are found in different organisms, such as cellular level, tissue level, organ level etc.
• Some animals are radially symmetrical and some are bilaterally symmetrical.
• Some animals has closed circulatory system and some has open circulatory system.
• Some shows extracellular and some shows intracellular digestion.
• Some are acoelomate, some are coelomate and some are pseudocoelomate.
  Thus, lack of all above basic knowledge causes problems to classify animals.

Question 8.
Classify Mammalia into subclasses with characters and examples.
Answer:
There are three subclasses : Prototheria, Metatheria and Eutheria.
(A) Prototheria :

• Nippleless mammary glands.
• External ear absent.
• Egg laying mammals.
  Examples : Platypus, Ornithorincus.

(B) Metatheria :

• Mammary glands with nipples.
• External ear present.
  Examples: Kangaroo.

(C) Eutheria :

• These are true mammals with allantoic placenta.
• They give birth to fully developed young ones.
• Mammary glands and their teats are well-developed.
• Embryo develops inside the uterus and is nourished by a true allantoic placenta.
  Examples: Talpa, monkey, man, whale, dog, goat, rat, bat, elephant (Elephas), tigers, cows, horse, squirrel, etc.

Question 9.
Write short note on following :
(1) Class-Aves,
(2) Class-Reptilia,
(3) Class-Pisces.
Answer:
(1) Class-Aves:
It is an important class of phylum-Chordata. It includes organisms which can fly and has notochord, nerve cord and gill slits in some stages of its life cycle.
Characteristic features :

• They are warm blooded organisms,
• Body is covered with feathers,
• Body is divided into head, neck, trunk and tail,
• Air sacs are found on the lungs,
• Bones are hollow,
• Heart is four chambered,
• Forelimbs are modified into wings.
  Examples : Columba, Peacock, Ostrich etc.

(2) Class-Reptilia :
Class-Reptilia belongs to phylum-Chordata.
Characteristic features :

• They are cold blooded animals,
• Skin is dry and consists of scales,
• RBCs are nucleated,
• Mostly terrestrial but some are aquatic,
• Heart consists of three chambers,
• They show internal fertilization,
• Body is divided into head, trunk and tail,
• They are oviparous, a few snakes are viviparous.
  Examples : Lizard, Snake, Crocodile etc.

(3) Class-Pisces :
Class-Pisces is an important class of phylum-Chordata. It includes aquatic organisms.
Characteristic features :

• Body is streamlined,
• Body is covered by scales,
• They are cold blooded organisms,
• Heart is two chambered,
• Respiration by gills,
• Lateral line is found on the body,
• Fins help in swimming,
• Tympanic membrane is absent.
  Example : Scoliodon, Rohu fish, Torpedo etc.

Animal Kingdom Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Water vascular system is the characteristics feature of:
(a) Porifera
(b) Cnideria
(c) Echinodermata
(d) Chordata.
Answer:
(c) Echinodermata

Question 2.
All members of ………………. are marine :
(a) Porifera
(b) Coelenterata
(c) Echinodermata
(d) Anthozoa.
Answer:
(c) Echinodermata

Question 3.
Following is the important feature of arthropoda :
(a) Jointed legs
(b) Three pairs of legs
(c) Sheath on body
(d) Two pairs of wings.
Answer:
(a) Jointed legs

Question 4.
Which of the following is a true fish :
(a) Cuttlefish
(b) Silverfish
(c) Whale
(d) Flyingfish.
Answer:
(d) Flyingfish.

Question 5.
Amnion is found in the embryo of:
(a) Cockroach
(b) Tadpole
(c) Fish
(d) Lizard.
Answer:
(d) Lizard.

Question 6.
Animals found in the bottom of sea are called as :
(a) Lentic
(b) Lotic
(c) Benthic
(d) Pelagic.
Answer:
(c) Benthic

Question 7.
Pearl formed from Pearl oyster is :
(a) First drop of rain
(b) Drop of dew
(c) Egg which cannot come outside the body
(d) A round external cup buried in the skin.
Answer:
(d) A round external cup buried in the skin.

Question 8.
Phylum which contains largest number of species :
(a) Chordata
(b) Arthropoda
(c) Insecta
(d) Mollusca.
Answer:
(b) Arthropoda

Question 9.
Which of the following animal possessing exo and endoskeleton :
(a) Frog
(b) Earthworm
(c) Snake
(d) Leech.
Answer:
(c) Snake

Question 10.
Which of the following is not a fish :
(a) Liingfish
(b) Dogfish
(c) Catfish
(d) Silverfish.
Answer:
(d) Silverfish.

Question 11.
Locomotory organ of Amoeba is:
(a) Tentacle
(b) Pseudopodia
(c) Flagella
(d) Cilia.
Answer:
(b) Pseudopodia

Question 12.
Kangaroo is :
(a) Prototheria
(b) Metatheria
(c) Eutheria
(d) Reptiles.
Answer:
(b) Metatheria

Question 13.
Animals of …………… class has three pairs of legs :
(a) Arthropoda
(b) Gastropoda
(c) Insecta
(d) Crustacea.
Answer:
(c) Insecta

Question 14.
Mesoglea is the characteristic feature of the phylum :
(a) Porifera
(b) Coelenterata
(c) Annelida
(d) Hydrozoa.
Answer:
(b) Coelenterata

Question 15.
Leech is:
(a) Parasitic
(b) Autotrophic
(c) Roundworm
(d) Flatworm.
Answer:
(a) Parasitic

Question 16.
Which of the following is an oviparous mammal:
(a) Whale
(b) Platypus
(e) Rabbit
(d) Snake.
Answer:
(b) Platypus

Question 17.
Best definition of birds:
(a) They are flying
(b) Isothermic
(e) Winged bipedal
(d) Above tetrapod.
Answer:
(d) Above tetrapod.

Question 18.
Which of the following is a flying fox:
(a) Fox
(b) Bat
(e) Reptile
(d) Mollusca.
Answer:
(b) Bat

Question 19.
Causal organism of filaria disease is:
(a) Fasciola
(b) Taenia
(c) Wuchereria
(d) Mosquìto.
Answer:
(c) Wuchereria

Question 20.
Light blue colour of the blood of arthropods is due to:
(a) Haemoglobin
(b) Haemocyanin
(c) Hirudin
(d) None of these.
Answer:
(b) Haemocyanin

Question 21.
Blind chamber body arrangement is found in:
(a) Sponges
(b) Annelids
(c) Coelenterates
(d) Mammals.
Answer:
(c) Coelenterates

Question 22.
Cephalopoda is a class of animals having:
(a) Notochord is elongated up to head
(b) Feet are found on the head
(c) Head is found on legs
(d) Head is jointed with cephalothorax.
Answer:
(c) Head is found on legs

Question 23.
Pearl oyster is associated with the class:
(a) Gastropoda
(b) Pelecypoda
(e) Schiphozoa
(d) Amphineura.
Answer:
(b) Pelecypoda

Question 24.
Eutherian mammals are:
(a) Oviparous
(b) Viviparous
(c) Ovi-viviparous
(d) Both (a) and (c).
Answer:
(b) Viviparous

Question 25.
Mesoglea is made up of:
(a) Amoeboid cell
(b) Nerve cell
(e) Nematocyst
(d) A cellular jelly
Answer:
(d) A cellular jelly

2. Fill in the blanks:

(A)
1. The skeleton of Porifera is chiefly formed of ………………
Answer:
Spicules

2. Shell of Mollusca is secreted by …………………
Answer:
Mantle

3. Physalia is popularly known as ………………….
Answer:
Portuguese man of war

4. ………………… fishes are exclusively marine.
Answer:
Cartilaginous

5. Pneumatic bones are found in …………………..
Answer:
Birds

6. Jointed appendages is the important characteristic of ……………… phylum.
Answer:
Arthropoda

(B)
1. Arthropoda is classified on the basis of wings and ………………..
Answer:
Appendages

2. Silverfish belongs to …………………
Answer:
Arthropoda

3. Heart of amphibians consists of …………………. chambers.
Answer:
Three

4. Bones of birds are …………………..
Answer:
Hollow

5. Most of the flat worms are anaerobes, this is ………………… adaptation.
Answer:
Parasitic

6. Starfish is ………………… symmetrical.
Answer:
Radially

7. Jointed legs are found in …………………… phylum
Answer:
Arthropoda

8. Excretory organs of earthworm are …………….
Answer:
Nephridia

9. Malpighian tubules are the ……………….. organs of insect.
Answer:
Excretory

10. Presence of hairs on the body surface is the characteristic features of class …………………..
Answer:
Mammalia

3. Match the following:

(A)

Answer:
1. (d) Tetrapoda.
2. (a) Echinodermata
3. (b) Mollusca
4. (c) Pisces

(B)

Answer:
1. (b) Aves
2. (c) Mammalia
3. (d) Nematoda
4. (a) Platyhelminthes

(C)

Answer:
1. (d) Hydra
2. (c) Starfish
3. (a) Aurelia
4. (e) Nereis
5. (b) Planaria

(D)

Answer:
1. (h) Osteichthyes.
2. (e) Annelida
3. (d) Reptilia
4. (a) Ctinophora
5. (b) Mollusca
6. (g) Mammalia
7. (c) Porifera
8. (f) Cyclostomata or Chonichthyes

4. Write true or false:

1. All major groups of animals have evolved in the sea.
Answer:
True

2. Exoskeleton is absent in Vertebrates.
Answer:
False

3. Snakes and Lizards shed their scales as skin cast.
Answer:
True

4. Toad skin is dry and warty and cannot absorb water.
Answer:
False

5. Flatworms are acoelomate organisms.
Answer:
True

5. Answer in one word:

1. The excretory organs in earthworm are.
Answer:
Nephridia

2. The process of transformation of a larva into an adult is called.
Answer:
Metamorphosis

3. The body fat of whale is called.
Answer:
Blubber

4. Malpighian tubules are the organs in insects.
Answer:
Excretory

5. The largest class of molluscs are.
Answer:
Gastropods

6. Write name of one bisexual animal of the phylum annelida.
Answer:
Hirudinaria (the cattle Leech)

Students get through the MP Board Class 11th Biology Important Questions Chapter 20 Locomotion and Movement which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 20 Locomotion and Movement

Locomotion and Movement Class 11 Important Questions Very Short Answer Type

Question 1.
What is arthritis?
Answer:
Arthritis is a disease characterized by the inflammation of the joints. In this disease, the synovial membrane secretes extra fluid which causes swelling and pain in the joints. A hard tissue deposits over the articular cartilages. As a result the joints become stiff.

Question 2.
What is muscle twitch?
Answer:
When a muscle fibre receives only one stimulus, then it contracts only one time. This one time contraction of muscle fibre is called as muscle twitch.

Question 3.
How many vertebrates and ribs are found in human?
Answer:
In human 26 vertebrates, and 12 pairs of ribs are found.

Question 4.
Name the longest bone of human body.
Answer:
Longest bone of human body is femur.

Question 5.
Write name of the locomotory organs of the following organisms :
(i) Paramoecium,
(ii) Hydra,
(iii) Earthworm,
(iv) Octopus,
(v) Starfish.
Answer:
(i) Cilia,
(ii) Tentacle,
(iii) Setae,
(iv) Muscular arm,
(v) Tube feet.

Question 6.
What is Sliding filament theory? (NCERT)
Answer:
Sliding filament theory was proposed by Lein. Muscle fibres contract and relax on being excited by the nerve fibres. According to this theory, during the contraction of muscle, actin filaments slide over the myosin filaments.

Locomotion and Movement Class 11 Important Questions Short Answer Type

Question 1.
What is joint? Name the joints related to the following organs :
(i) Joint of knee,
(ii) Joint between glenoid cavity of pectoral girdle and acetabulum cavity of pelvic girdle with the humerus and femur,
(iii) Elbow joint,
(iv) Joint between skull bones,
(v) Joint between carpals and metacarpals of thumb,
(vi) Ankle joint.
Answer:
Joint: The region at which two or more bones of skeleton come in contact and move freely is called as Joint.
(i) Hinge joint,
(ii) Ball and Socket joint,
(iii) Hinge joint,
(iv) Immovable joint,
(v) Saddle joint,
(vi) Hinge joint.

Question 2.
How movement takes place in skeleton by muscles?
Answer:
The skeleton of our body is connected with each other by voluntary muscles. The fibres that connect the bones with any muscle are known as tendon, whereas the fibres that connect bones to bones are known as ligaments. Muscle cells are made up of muscle fibres having the property of contraction and expansion hence muscle cells also possessing these characteristics. The contraction and expansion of these muscles resulting in the movement of skeleton.

Question 3.
Describe any four functions of the skeletal system.
Answer:
The skeletal system of vertebrates performing the following functions:

1. It protects the heart, brain and other soft organs.
2. It provides base to the body and gives a definite shape to it.
3. Skeletal system functioning like a pendulum and thus performing the process of movement and locomotion.
4. The thick bones of skeleton system synthesise R.B.Cs. and W.B.Cs. within their bone marrow.

Question 4.
From where energy is obtained for contraction of muscles?
Answer:
The energy for the contraction of muscle fibres is obtained from a chemical substance known as adenosine triphosphate (ATP) which is found in mitochondria. This sub¬stance is the source of energy required for the metabolic activities of cells. The energy obtained by the oxidation of glucose which is stored in ATP. Little glucose is present in muscle fibres but myosin is rich in ATP. When the muscle is excited, ATP itself changes into adenosine diphosphate (ADP), thereby releasing energy.
ATP → ADP + P04 + Energy
ADP is again converted into ATP by the energy obtained from the creatine phosphate. CP + ADP → ATP + C. Creatine is resynthesized into creatine phosphate by the energy ob¬tained from glucose of muscle glycogen.

Question 5.
Name various parts of human skeletal system and write number of bones found in them.
Answer:

Question 6.
Red muscle fibres functioning up to a longer period of time than white muscle fibres, why?
Answer:
Red muscle fibres contain a large amount of myoglobin and mitochondria. Myo¬globin combine with oxygen to form oxymyoglobin. For muscular contraction oxygen is derived from oxymyoglobin. These muscles do not respire anaerobically due to presence of oxygen and thus lactic acid is not formed. Thus, red muscle fibres functioning up to a longer period of time without fatigue. White muscle fibres do not contain myoglobin.

The number of mitochondria is also few. Hence oxygen supply becomes irregular and lactic acid is formed in these muscle fibres due to anaerobic respiration. Thus, these muscles become fatigue and they do not functioning up to a longer period of time.

Question 7.
What is meant by twitch muscle and tetanus?
Answer:
Twitch muscle: When a muscle receive only one stimulus then it contracts only one time. This one time contraction of muscle fibre is called as muscle twitch.
Tetanus : It is the permanent contraction condition of the muscle which occurs due to continuous conduction of impulse. This may lead to death of the person.

Question 8.
What is oxygen debt?
Answer:
Oxygen debt: After heavy work or exercise muscle do not get oxygen to fulfil their energy requirement. Thus, they produces ATP by anaerobic process, and lactic acid is formed. In this stage more oxygen is required than normal stage. This requirement of extra quantity of oxygen is called as oxygen debt.

This extra oxygen is used up by the lactic acid for its aerobic oxidation. By this process creatine phosphate is produced. Some quantity of required oxygen is supplied by myoglobin which has capacity to store oxygen for future. During training of athletes rate of oxy- contraction of muscle is increased. Thus, athletes required less oxygen debt.

Question 9.
Write differences between Fixed joint and Synovial joint.
Answer:
Differences between Fixed joint and Synovial joint

Question 10.
Draw diagram showing one sarcomere of the striped muscle and label its various parts. (NCERT)
Answer:

Question 11.
How will you differentiate skeletal muscle and Cardiac muscle? (NCERT)
Or,
Write differences between Striped, Unstriped and Cardiac muscles.
Answer:
Differences between Striped, Unstriped and Cardiac muscles

Question 12.
Draw a labelled diagram of pelvic girdle of human.
Answer:

Question 13.
Name the type of joints found in the following : (NCERT)
(a) Atlas and axis,
(b) Carpal and metacarpal of thumb,
(c) Between phalanges,
(d) Femur and acetabulum,
(e) Between bones of skull,
(f) Between pubic bones of pelvic girdle.
Answer:
(a) Pivot joint,
(b) Saddle joint,
(c) Hinge joint,
(d) Ball and socket joint,
(e) Fibrous joint (sutures),
(f) Cartilaginous joint.

Locomotion and Movement Class 11 Important Questions Long Answer Type

Question 1.
Write the differences between following : (NCERT)
(a) Actin and Myosin
(b) Red muscle fibre and White muscle fibre
(c) Pectoral and Pelvic girdle.
Answer:
(a) Differences between Actin and Myosin filament

(b) Difference between Red and White muscle fibres

(c) Differences between Pectoral and Pelvic girdle

Question 2.
Describe main steps of muscular contraction. (NCERT)
Or,
Draw a labelled diagram of striped muscle and describe mechanism of muscular contraction in brief.
Answer:
Structure of striped or voluntary muscles: Since their movement is always at the will of the animal possessing them, they are known as voluntary muscles. They are always attached with the skeleton, hence called as skeletal muscles. Their cells are long and tubular and each is surrounded by thin membrane called sarcolemma. Many nuclei are found in the sarcoplasm surrounded by sarcolemma; therefore, muscular tissue is multinucleated or syncytial. A large number of parallel myofibrils are present in the sarcoplasm.
Transverse bands of light and dark shade are found in each muscle fibres. Dark bands are known as ‘A’ discs or Dobie’s dots while light bands are called ‘I’ discs. Each ‘I’ disc is divided into two another band known as ‘Z’ disc or Krause’s membrane. Similarly ‘A’ disc is also divided into two parts by Hensen’s disc or ‘H’ zone. The part between two ‘Z’ discs is known as sarcomere.

Electron microscopic studies have shown that these bands are formed of protein. ‘A’ bands are formed of parallel bars of a protein called myosin. ‘I’ bands are made up of similar bars of a protein known as actin. The muscles lengthen and shorten due to the contraction and expansion of these bars. These muscles take main part in the movement of organs as limbs, neck, eye etc.

Working of striped muscle fibre: The muscle fibres contract and relax on being excited by the nerve fibres. H.E. Huxley and A.F. Huxley explained the working of muscle fibres with the help of electron microscopic studies. The theory proposed by Lein is known as sliding filament theory. It says that during contraction the actin filaments slide over the myosin filaments. There is no change in the length of ‘A’ bands at the time of contraction.

The actin bars of T bands slide on the myosin bars of ‘A’ bands and come so close that they overlap each other in the region of Hensen’s discs. Thus the muscle fibres contract due to the shortening of sarcomeres. The muscle fibres remain in their normal state when the effect of excitation is over, i.e. actin and myosin bars come back in their normal position. The sarcomeres are the functional units of striped muscle fibres.

Question 3.
What are joints? Describe the various types of joints found in human beings Or, What is joint ? Describe perfect joint and explain any three types of it.
Answer:
Joints: The region at which two or more bones of skeleton come in contact and move freely is called as joint.
Basically three types of joints are found in the body or vertebrates :

1. Perfect joints,
2. Imperfect joints,
3. Immovable joints.

1.Perfect joints: These joints have synovial cavity which allow movement in more than one plane. The perfect joints may be of following types :

(a) Bail and Socket joint: Arthritis is a disease characterized by the inflammation of the joints. In this disease, the synovial membrane secretes extra fluid which causes swelling and pain in the joints. A hard tissue deposits over the articular cartilages. As a result the joints become stiff.

(b) Pivot joint: In this joint the articulating face of one bone is stationary like a pivot while the articulating face of the other can rotate over it. e.g. Joint between carotae and vertebral column.

(c) Hinge joint: It is just like a hinge of a door, allowing movement in one plane, e.g. Elbow joint, knee joint, ankle joint.
(d) Gliding joint : In such joint the articulating surface of the bone can glide one above the other, e.g. Joint between radio ulna and carpal.

(e) Saddle joint: It resembles the ball and socket joint except that in this case neither the ball nor the socket is fully developed, e.g. Metacarpal of the thumb joining the wrist bone in man.

2. Imperfect joint: These joints which do not possess synovial cavity or connecting ligaments are called imperfect joints, e.g. Joints between ileum of pelvic girdle and transverse process of sacral vertebrae.

3. Immovable joint: These joints which are permanently fixed and cannot perform any movement are termed as immovable joints, e.g. Bones of skull. These joints are called sutures. These joints lack synovial capsule.

Question 4.
What is Axial Skeleton? Describe various bones of Axial skeleton of human.
Answer:
Axial Skeleton: Skeleton which forms axis of the body is called as Axial skeleton. It consists of skull, Hyoid, vertebral column and ribs.
1. Skull: It is formed of 28 bones and is skeleton of the head region. Skull can be further divided into following regions :
(i) Cranium or brain box: It encloses the brain and is formed of eight bones namely frontal, parietal (two), temporal (two), occipital, sphenoid and ethmoid.

(ii) Facial bones : These form facial part of the skull and are fourteen in number. These include nasal 2, maxillary 2, squamosal 2, mandible 1, lachrymal 2, palatine 2, turbinals 2 and vomer 1.

(iii) Ear bones: These are three pairs of ear ossicles : malleus 2, incus 2 and stapes 2.
2. Hyoid: It supports tongue.
3. Vertebral column: It forms axis of the body and also known as backbone. Vertebral column supports the body like a beam. It is slightly curved vertical rod in the mid dorsal line of the body extended from the atlas vertebra to the caudal vertebra. Vertebral column protects the general viscera and houses the spinal cord also.
Vertebral column develops from the notochord part of the embryo. Total number of vertebrae in the vertebral column of human being is 26, however in primitive stage it is 33 in number. Vertebral column is differentiated into five regions, which are :

• Cervical vertebrae,
• Thoracic vertebrae,
• Lumbar vertebrae,
• Sacral vertebrae,
• Caudal vertebrae.

4. Sternum and ribs: It forms the floor of thoracic basket and supports anterior part of chest. Sternum has three parts manubrium, body and xiphoid process. 12 pairs of ribs are associated with the sternum.
Functions :
(i) Ribs form thoracic cavity along with sternum and vertebral column.
(ii) It protects lungs and heart.
(iii) These help in breathing.

Question 5.
What are Appendicular skeleton? Explain the bones of appendicular skeleton in man.
Answer:
Appendicular Skeleton: It is formed of bones appended to axial skeleton i.e., pectoral girdle, pelvic girdle and associated limbs.
Girdles: It consists of two types :
1. Pectoral girdle : It is found in the shoulder region where forelimbs join with it at the glenoid cavity. It is generally a duplex structure and functions as an intermediary structure through which the weight of the body is transferred to the forelimbs. Pectoral girdle is formed of two bones, scapula (2) and clavicle (2).

2. Pelvic girdle: It provides articulation with bones of hind limbs at acetabulum cavity. It has two halves, each half has three main bones ilium dorsal in position, ischium and pubis ventral in position. Each half of the girdle forms innominate bones or osinnominatum.

3. Limbs: These are meant for locomotion in tetrapod vertebrates. Limbs are differentiated into:
(i) A pair of forelimbs,
(ii) A pair of hind limbs.
(i) Forelimb : Forelimbs are attached to the pectoral girdle. Each forelimb has upper arm, forearm and hand. There are 30 bones in each forelimb namely, humerus in the upper arm, radius and ulna in forearm, eight carpals in the wrist, five metacarpals in the palm and 14 phalanges in the fingers of the hand.

(ii) Hind limbs : Hind limbs are attached to the pelvic girdle. Each hind limb has thigh, shank and foot. There are thirty bones in each hind limb namely, femur in the thigh, patella in the knee, tibia and fibula in the shank, 7 tarsals in the ankle, 5 metatarsals insole and 14 phalanges in the toes of the foot.

Locomotion and Movement Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Synovial joints are found between :
(a) Two vertebrae
(b) Two skull bones
(c) Humerus and ulna
(d) Caudal vertebrae.
Answer:
(c) Humerus and ulna

Question 2.
The fluid present in ball and socket joints and which reduces the friction is:
(a) Pericardial fluid
(b) Mucin
(c) Synovial fluid
(d) Coelomic fluid.
Answer:
(c) Synovial fluid

Question 3.
The number of vertebrae in human is :
(a) 30
(b) 31
(c) 32
(d) 33.
Answer:
(d) 33.

Question 4.
Hinge joint is found between :
(a) Radius ulna and humerus
(b) Femur and acetabulum
(c) Humerus and acetabulum
(d) None of these.
Answer:
(a) Radius ulna and humerus

Question 5.
The muscle fatigue is due to accumulation of:
(a) Lactic acid
(b) CO₂
(c) Acetic acid
(d) Sulphuric acid.
Answer:
(b) CO₂

Question 6.
The articulation of femur and pelvic girdle is an example of:
(a) Ball and socket joint
(b) Pivot joint
(c) Hinge joint
(d) None of these.
Answer:
(a) Ball and socket joint

Question 7.
Which one is the contractile protein of a muscle :
(a) Actin
(b) Myosin
(c) Tropomyosin
(d) Globulin.
Answer:
(a) Actin

Question 8.
Our wrist joint is a :
(a) Sliding
(b) Hinge joint
(c) Pivot
(d) Fixed joint.
Answer:
(a) Sliding

Question 9.
The joint between the lower jaw and skull is :
(a) Perfect joint
(b) Hinge joint
(c) Gomphoses
(d) Gliding joint.
Answer:
(c) Gomphoses

Question 10.
Ends of long bones are covered with.
(a) Cartilage
(b) Muscles
(c) Ligaments
(d) Blood cells.
Answer:
(a) Cartilage

2. Fill in the blanks:

(A)
1. ……………… joint is found in the bones of skull.
Answer:
Immovable joint,

2. Skeletal movement takes place due to ……………… muscles.
Answer:
voluntary muscles,

3. ……………… is the smallest bone of the human body.
Answer:
Stapes,

4. Myoglobin stores ……………… .
Answer:
Oxygen,

5. Haversian system is found in ……………… .
Answer:
Bones,

6. Bone is made of ……………… protein and cartilage is made up of ……………… protein.
Answer:
Ossein, Chondrin,

7. ……………………… element is essential for the constriction of muscles.
Answer:
Ca⁺⁺

8. Total ………………………  bones are found in the body of an adult human being.
Answer:
206.

(B)
1. In all vertebrates except few ……………… cervical vertebrates are found.
Answer:
7

2. In the fine fibre of myofibril 2 ‘F’ actin and two other proteins ……………… and ……………… are found.
Answer:
Tropomyosin, Troponin

3. In each human limb number of phalanges is ……………… .
Answer:
14,

4. In muscle fibre calcium is stored in the ……………… .
Answer:
Sarcoplasmic reticulum,

5. Cranium of human consists of ……………… bones.
Answer:
8.
3. Match the following:

(A)

Answer:
1.  (c) Tentacles,
2. (d) Tube feet
3. (e) Pseudopodia.,
4. (a) Cilia
5. (b) Setae

(B)

Answer:
1.  (b) Ball and Socket joint
2.  (c) Hinge joint
3. (d) Bone-bone
4. (e) Bone-muscle.
5. (a) Ear

(C)

Answer:
1. (d) Involuntary.,
2. (b) Fine fibre
3. Myoglobin
4. (a) Myoglobin.

4. Write true or false:

1. Actin is located in the fine fibre.
Answer:
True,

2. H-zone of striped muscle represents both thin and thick fibre.
Answer:
True,

3. Human skeleton consists of 206 bones.
Answer:
True,

4. Inhuman 11 pairs of ribs are found.
Answer:
False,

5. Sternum lies in the ventral surface of the body.
Answer:
True.

5. Answer in one word :

1. Name the joint found between humerus and radius ulna.
Answer:
Hinge joint,

2. What is the number of vertebrae and ribs in human being?
Answer:
33, 24,

3. Where is glenoid cavity found?
Answer:
In shoulder region,

4. Where is acetabulum found?
Answer:
In articulation of hind limbs,

5. Give one-one example of the following :
(a) Ball and socket joint,
(b) Immovable joint.
Answer:
(a) shoulder and hip joint
(b) Bones of the skull.

6. How many bones are there in human body?
Answer:
206

7. Name the smallest bone in human body. ‘
Answer:
Stapes

8. Name the longest bone in human body.
Answer:
Femur

9. Name the locomotory organ of Amoeba & starfish.
Answer:
Pseudopodia, Tube fee

Students get through the MP Board Class 11th Biology Important Questions Chapter 3 Plant Kingdom which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 3 Plant Kingdom

Plant Kingdom Class 11 Important Questions Very Short Answer Type

Question 1.
Draw a well labelled diagram of the Archegonia of Moss plant.
Answer:
Archegonia of Moss : (Female reproductive organ)

Question 2.
What do you understand by protonema?
Answer:
Juvenile forms (Protonema) :
It is a green branched filamentous structure. From green aerial filaments produced some branches which grows below substratum and are without chloroplasts are known as rhizoidal branches. They penetrate the soil and help in absorption of water and minerals. Several buds develops on protonema and each bud develops into leafy gametophore.

Question 3.
What do you understand by Mycorrhiza?
Answer:
It is a type of symbiotic association which is found in Pinus plant in between roots and fungi in which on outer side of root safety shell is present. Fungus absorbs water, mineral and protein for plants and in return from plants, it gets nutrition.

Question 4.
What do you understand by Apospory?
Answer:
Sometime the cells of sparophytes get separated from mother plant and fall on soil, where they germinate and form protonema. Sometime on top of protonema a leafy gametophore is formed from which a new plant is formed in which all the cells have double characters. Thus the protonema formed from the cell of sporophyte without division gametophyte develops. This is known as Apospory.

Question 5.
What do you understand by sulphur shower?
Answer:
At maturity, the microsporophylls separate and spread apart. The sporangia dehisce by longitudinal slit and shed large quantities of pollen grains. Since pollen grains flow in colour and are discharged in such a large number that their shedding is referred to as sulphur shower.

Question 6.
Give economic importance of Brown algae.
Answer:

• It is food for Japanese.
• More than 30% of dry weight of brown algae is KCl (Potassium chloride).
• Vitamin B, acetic acid and iodine are obtained from brown algae.
• Alginic acid obtained from sea kelps are used as thickeners in making ice-cream, cosmetics and in textile industries.

Question 7.
Name the algae from which agar-agar is obtained.
Answer:
Agar-agar is obtained from Grasillaria and Galidum.

Question 8.
Why Spirogyra is called as Pond silk?
Answer:
Pectin layer present outer to the cellulose cell wall of Spirogyra dissolves in water to form a mucilaginous sheath. Thus Spirogyra became slippery, after drying looks like a silk thread, that is why it is called as pond silk.

Question 9.
Name two algae used as food.
Answer:

1. Laminaria,
2. Porphyra.

Question 10.
Name the algae which causes rust of tea disease.
Answer:
Cephalurous algae.

Question 11.
Who is regarded as ‘Father of Indian Phycology’ in India?
Answer:
Indian scientist M.O.P. Iyengar is regarded as Father of Indian Phycology.

Question 12.
What is thallus?
Answer:
Plant which cannot be differentiated into root, stem and leaves are called as thallus.

Question 13.
Which terrestrial plants are primitive?
Answer:
Terrestrial plants of pteridophyta are primitive.

Question 14.
In which part of the fern plant sporangium is found ?
Answer:
In the sporophyll part of the leaves of fem plant sporangiums are found.

Question 15.
Give two fern like characteristics of Cycas plant of gymnosperm.
Answer:

1. Both are vascular plants,
2. Main plant is sporophytic.

Question 16.
Name the plant which produces largest flower.
Answer:
Rafflesia plant produces largest flower.

Question 17.
Give three examples of gymnosperms found in India.
Answer:

1. Pinus,
2. Cycas,
3. Cedrus deodara.

Question 18.
Give two important features of Angiosperms.
Answer:

1. They are flowering plants,
2. Seeds are formed within the fruit.

Question 19.
Give two medicinal importance of algae.
Answer:

• Vitamin B is obtained from Laminaria,
• Iodine is obtained from Kelps.

Plant Kingdom Class 11 Important Questions Short Answer Type

Question 1.
Where and when reduction division occurs in liverwort, moss, fern, gymnosperms and angiosperms? (NCERT)
Answer:
In liverwort, moss, fem and gymnosperms reduction division occurs in the spore mother cell to produce haploid spores.
In Angiosperms reduction division occurs during formation of pollen grains in the pollen sac of the stamen and during formation of embryo sac in the ovule of carpel.

Question 2.
Give ploidy of following :

1. Protonemal cell of Moss,
2. Nucleus of primary endosperm of Moss,
3. cells of leaves of Moss,
4. cells of Fern prothallus,
5. Gemma cells of Marchantia,
6. Meriste- matic cell of monocot plant,
7. Ovum of Liverwort,
8. Zygote of Fern. (NCERT)

Answer:

1. Protonemal cell of Moss – Haploid
2. Nucleus of primary endosperm of Moss – Triploid
3. Cells of leaves of Moss – Diploid
4. Cells of Fem prothallus – Haploid
5. Gemma cells of Marchantia – Haploid
6. Meristematic cell of monocot plant – Diploid
7. Ovum of Liverwort – Haploid
8. Zygote of Fem – Diploid.

Question 3.
Both Gymnosperms and Angiosperms produce seeds, inspite of that they are classified into different groups, why? (NCERT)
Answer:
Both Gymnosperms and Angiosperms produces seeds, inspite of that they are classified into different groups because seeds of gymnosperm are naked whereas seeds of angiosperms are formed within the fruit.

Question 4.
Draw a well-labelled diagram of moss capsule showing internal structure.
Answer:

Question 5.
What is Heterospory? Write a note on it and give two examples.
Answer:
Heterospory : Formation of two different types of spores, such as small microspores and large megaspores is called as Heterospory.
First of all heterospory was observed in Selaginella. It is also observed in Salvinia.
Megaspore (female) and microspore (male) develop to produce female and male gametophytes respectively.
Female gametophyte remains attached to sporophytic plant to fulfil its requirement.

Question 6.
Write economic importance of algae and gymnosperms.
Answer:
Economic importance of algae :
(A) Economic importance of Red algae :

• Agar : Agar is obtained from Gelidium and Gracilaria, which is mainly used in production of medium for culturing bacteria.
• Agar is used as laxative factor to prepare medicine.
• Some species of red algae are used in preparation of pudding, ice-cream, cheese, salad decoration etc.
• Irish agar obtained from Chondrus crispes, is used in preparation of chocolate.

(B) Economic importance of Brown algae :

• It is food for Japanese.
• More than 30% of dry weight of brown algae is KCl (Potassium chloride).
• Vitamin B, acetic acid and iodine are obtained from brown algae.
• Alginic acid obtained from sea kelps are used as thickeners in making ice-cream, cosmetics and in textile industries.

(C) Economic importance of Gymnosperms :

• It provides timber wood and firewood.
• Some plants are used as ornamental plants, such as Cycas, Pinus etc.
• Sago is obtained from Cycas.
• Many medicines are obtained from different species of gymnosperms, such as ephedrine medicine is obtained from Ephedra species.
• From some species of gymnosperms edible oil is obtained.
• Leaves of Cycas are used in making broom and rope.
• Some conifers are used in making paper.

Question 7.
Write four characteristics of Chlorophyta.
Answer:
Characteristics of Chlorophyta :

1. Photosynthetic pigment in green algae are chlorophyll-a, chlorophyll-b, β -carotene and Xanthophyll.
2. Cell wall is made up of cellulose.
3. Ciliated Zoospores are formed which are motile.
4. Stored food is starch.
5. Sexual reproduction ranges from isogamy to oogamy. e.g., Spirogyra, Ulothrix, Sargassum etc.

Question 8.
Give important characteristics of Angiosperms.
Answer:
Characteristics of Angiosperms :

• Plant body is differentiated into root, stem and leaves.
• Reproductive organs are flower having four whorls : Calyx, corolla, androecium and gynoecium.
• Ovules are covered within ovary.
• The ovary ripe into fruit which contains seeds.
• Vascular bundles are well developed.
• Double fertilization occurs in them.
• They may be parasitic (e.g., Cuscuta), Saprophytic (e.g., Orobanche), epiphytic (e.g., Orchid), insectivorous (e.g., Nepenthes) and antotrophic.
• They are well adapted for their environment. e.g., Mango, rose, wheat, rice etc.

Question 9.
Give important characteristics of Bryophyta.
Answer:
Characteristics of Bryophyta :

• Main plant is gametophytic.
• There is complete absence of true root, stem and leaves.
• Plant body is bilaterally symmetrical, branched and leaf like which bears Rhizoids on the ventral surface. They contain chlorophyll.
• They are non-vascular amphibian plants.
• Sporophyte partly depends on gametophyte.
• Reproductive organs are multicellular and found surrounded by jacket layer. Water is required for fertilization.
• They shows alternation of generation. e.g., Funaria, Riccia, Marchantia etc.

Question 10.
Write similarities between Gymnosperms and Angiosperms.
Answer:
Similarities between Gymnosperms and Angiosperms :

• Both are perennial plants.
• Both produces special reproductive organs.
• In both, main plant is sporophytic.
• In both, gametophyte depend on sporophyte.
• Both produces seeds.
• In both, ovules develop to form seeds.
• Both shows alternation of generation.

Plant Kingdom Class 11 Important Questions Long Answer Type

Question 1.
Name three groups of plants in which Archegonium is found. Describe Life cycle of any one of them. (NCERT)
Answer:
In following three groups of plants Archegonium is found :

1. Bryophyta,
2. Pterydophyta,
3. Gymnosperms.

Life Cycle of Bryophyta (Funaria):
In the life history of mosses two generations viz, gametophyte and sporophyte are found which regularly alternate with each other. The dominant phase is represented by the gametophyte which is haploid (n) and it reproduces sexually by the fusion of gametes (antherozoids and ovum) give rise to the sporophyte which is diploid structure (2n). Meiotic division takes place in the capsule of sporophyte during sporogenesis to form spores. These spores germinate to producer new gametophyte.

Question 2.
Write differences between Gymnosperms and Angiosperms.
Answer:
Differences between Gymnosperms and Angiosperms

Question 3.
Write differences between Pteridophytes and Bryophytes.
Answer:
Differences between Pteridophytes and Bryophytes

Question 4.
Explain following terms with example:
(i) Protonema,
(ii) Antheridium,
(iii) Archegonium,
(iv) Dipiontic,
(v) Sporophyll,
(vi) Isogamy. (NCERT)
Answer:
(i) Protonema :
It is the first stage of life cycle of Moss (Funaria). It is formed by germination of haploid spore. Protonema is multicellular, branched structure which contain chlorophyll, thus are autotrophs.

(ii) Antheridium:
Male reproductive organ of Bryophyta and Pterydophyta are called as Antheridium. It produces biflagellate spermatozoids or antherozoids.

(iii) Archegonium :
Female reproductive organ of Bryophyta and Pterydophyta are called as Archegonium. It is multicellular flask shaped structured, which produces haploid
egg.

(iv) Dipiontic :
In this mode of reproduction and life cycle, adults have diploid set (2x) of chromosome. During sexual reproduction (2x) individuals produces haploid (x) gametes by meiosis cell division which fuses to form diploid zygote (2x). This diploid zygote grows to form adult.
e.g., Life cycle of Saccharomycod.es ludurigii.

(v) Sporophyll:
In Pterydophytes leaves on which sporangium are formed called as Sporophyll. e.g., Fern.

(vi) Isogamy :
Similar gametes which fuses together to form zygote are called as Isogamy. e.g., Chlamydomonas.

Question 5.
Write differences between Monocot and Dicot plant.
Answer:
Differences between Monocot and Dicot Plant

Question 6.
Differentiate following :
(i) Red algae and Brown algae,
(ii) Liverwort and Moss,
(iii) Heterosporous and Homosporous pteridophytes,
(iv) Syngamy and Triple fusion, stem and leaves.

(i) Red algae and Brown algae :
Red alage:

• They are red in colour due to presence of pigments called phycobillins mainly phycocyanin and phycoerythrin.
• There is complete absence of motile stages in life.
• Stored food is floridian starch.
• Cell wall consists of cellulose pectic compounds and mucopolysaccharides.
• Sexual reproduction is Oogamous type.
  e.g., Porphyra, chordrus.

Brown algae :

• They are brown coloured due to presence of xanthophyll, fucoxanthin. In addition to this accessory pigments are chl-a, chl-c, β and C carotene are also found.
• Flagellate Zoospores are formed during reproduction which are motile.
• Stored food is manitol, laminarin and lipid.
• Cell wall is double layered. Inner layer consists of cellulose and outer layer is a gelatenous substance known as phycocolloids, alginic acid.
• Sexual reproduction varies from isogamy, anisogamy to oogamy.
  e.g., Laminaria, Macrocystis, Sargassum.

(ii) Liverwort and Moss :

• Rhizoid of liverwort is non-septate whereas Rhizoids of moss is septate.
• Gametophyte of liverwort is thallus flat leaf like whereas moss gametophyte is differentiated into rhizoid, stem and leaf like structure.
• Leaves of liverwort are not arranged in spiral way whereas leaves of moss are spirally arranged.
• lators are found in liverwort for dispersal of spores whereas elators are not found in moss.
• Liverwort belongs to group Hepaticeae whereas moss belongs to group Musci.

(iii) Heterosporous and Homosporous pteridophytes:
Heterosporous pteridophytes produces two types of spores Megaspores and microspores such as Selaginella, whereas Homosporous pteridophytes produces all similar sized spores such as Lycopodium.

(iv) Syngamy and Triple fusion :
In Angiosperms, process of fusion of first male gamete with haploid egg to produce a diploid zygote is called as Syngamy. Zygote develops to form embryo, whereas fusion of secondary nuclei and second male gamete to produce a triploid body is called as Triple fusion. Triploid body develops to produce endosperm.

Question 7.
Write important characteristics of gymnosperms.
Answer:
Characteristic features of Gymnosperms:

• Plants are perennial, woody trees or shrubs and xerophytic in nature.
• This subdivision includes vascular, naked seed plants.
• Plants are sporophytic which are differentiated into root, stem and leaves.
• Vascular bundle consists of xylem and phloem but the xylem is devoid of vessels and phloem that of companion cells.
• Reproductive parts borne in the form of cones or strobilus.
• Male cone contains several microsporophylls with microsporangia on their undersurface. Female cone contains many megasporophylls with one to several naked ovules.
• Inside the microsporangia microspores or pollen grains are formed by meiosis division of special cells, which germinate to produce male gametes.
• Female gametophyte develops inside the ovule and contains two or more arche-gonia at the anterior end.
• Pollination is anemophilous (wind pollinated).
• Pollen grain germinates to form pollen tube on female cone after pollination and produces male gametes which fuses with female gamete to form zygote. Embryo develops from zygote and ovule along with embryo forms seed, which germinate to form new plant.
• Secondary growth is present.
• Usually polyembryony is found in seed.
• Archegonia lack neck canal cells.
• Embryo bears two or more cotyledons.

Plant Kingdom Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Dominant stage of bryophytes is :
(a) Haploid
(b) Diploid
(c) Both are similar
(d) None of these.
Answer:
(a) Haploid

Question 2.
Zoospores are formed from :
(a) Asexual reproduction
(b) Sexual reproduction
(c) Amitotic division
(d) Mitosis.
Answer:
(a) Asexual reproduction

Question 3.
In the life history of Spirogyra, meiosis takes place during :
(a) The formation of gametes
(b) The formation of zoospores
(c) The germination of zygote
(d) The formation of zygote.
Answer:
(c) The germination of zygote

Question 4.
Habitat of mosses is :
(a) Dry place
(b) Fresh water
(c) Non-salty water
(d) Moist and shadow places.
Answer:
(d) Moist and shadow places.

Question 5.
Sperms of moss is:
(a) Uniflagellate
(b) Biflagellate
(c) Multiflagellate
(d) Non-motile.
Answer:
(b) Biflagellate

Question 6.
Mosses are found in moist and shadowy places because of the :
(a) Absence of vascular tissue
(b) Requirement of water for fertilization
(c) Absorption of water through general body surface
(d) All of these.
Answer:
(c) Absorption of water through general body surface

Question 7.
Female reproductive organ of Funaria is known as :
(a) Sporangium
(b) Spermatium
(c) Archegonia
(d) Sporophyll.
Answer:
(c) Archegonia

Question 8.
Sperms reach archegonia through :
(a) Air
(b) Water
(c) Animals
(d) Insects.
Answer:
(b) Water

Question 9.
Mosses will not be larger because of the :
(a) Absence of vascular tissue
(b) Presence of vascular tissue
(c) Absence of flower
(d) Absence of seeds.
Answer:
(a) Absence of vascular tissue

Question 10.
Fern prothallus is :
(a) Haploid
(b) Diploid
(c) Triploid
(d) Sporophyte.
Answer:
(a) Haploid

Question 11.
Shape of the prothallus is :
(a) Rounded
(b) Elongated
(c) Heart like
(d) Polygonal.
Answer:
(c) Heart like

Question 12.
Ferns are highly developed than mosses because of the :
(a) Presence of vascular tissue
(b) Dominance of sporophyte
(c) Root, stem and leaves are well developed
(d) All of these.
Answer:
(d) All of these.

Question 13.
Prothallus is:
(a) An independent structure
(b) A dependent structure
(c) Depend on gametophyte
(d) Depend on sporophyte.
Answer:
(a) An independent structure

Question 14.
In Spirogyra :
(a) Sexual reproduction between two adjacent cells
(b) Variable biflagellate antheridium and oogonium
(c) Sexual reproduction between various substances of a cell.
(d) Only sexual reproduction.
Answer:
(a) Sexual reproduction between two adjacent cells

Question 15.
Funaria possessing :
(a) Unicellular simple rhizoids
(b) Tuberculated rhizoids
(c) Differentially branched rhizoids
(d) Multicellular oblique rhizoids.
Answer:
(a) Unicellular simple rhizoids

Question 16.
Number of peristome teeth in the capsule of Funaria is :
(a) 4 in one ring
(b) 32 in two rings
(c) 16 in one ring
(d) 16 in two rings.
Answer:
(b) 32 in two rings

Question 17.
Type of gametes fused during sexual reproduction in Spirogyra is :
(a) Two identical motile gametes
(b) Two identical non-motile gametes
(c) One motile and one non-motilé gametes
(d) Two different non-motile gametes.
Answer:
(d) Two different non-motile gametes.

Question 18.
Cell of Funaria in which reduction division occur, is:
(a) Antheridial cell
(b) Archegonial cell
(c) Gametic cell
(d) Spore mother cell.
Answer:
(d) Spore mother cell.

Question 19.
Algae producing agar-agar is:
(a) Spirogyra and Nostoc
(b) Gracilaria and Gelidium
(d) Rivularia and Ulothrix.
(c) Volvox and Vaucheria
Answer:
(b) Gracilaria and Gelidium

Question 20.
Ulothrix is found in :
(a) Floating freshwater
(b) Floating marine water
(d)Pure marine water.
(c) Pure freshwater
Answer:
(a) Floating freshwater

Question 21.
In Funaria, stomata are found in
(a) Leaves
(b) Stem
(c) Theca
(d) Apophysis.
Answer:
(d) Apophysis.

Question 22.
Gametophyte of Funaria is :
(a) Monoecious
(b) Dioecious
(c) Both (a) and (b)
(d) Heterothallic.
Answer:
(a) Monoecious

Question 23.
In Pteridophytes, meiosis takes place :
(a) Sporogenesis
(b) Gametogenesis
(c) Prothallus formation
(d) Sex organ formation.
Answer:
(a) Sporogenesis

Question 24.
Cell wall of Spirogyra is made up of:
(a) Cellulose
(b) Pectin
(c) Lignin
(d) Chitin.
Answer:
(a) Cellulose

Question 25.
Ribbon like chloroplast is found in :
(a) Ulothrix
(b) Spirogyra
(c) Oedogonium
(d) Marc hantia.
Answer:
(a) Ulothrix

Question 26.
Main stage or dominant stage of bryophyta is :
(a) Gametophyte
(b) Cone Pinus
(c) Spore
(d) Hormogonium.
Answer:
(a) Gametophyte

Question 27.
Pinus species is :
(a) Monoecious
(b) Dioecious
(a) Chlorophyll-a
(c) Chlorophyll-c
Answer:
(b) Dioecious

Question 28.
Pigment found in green plant is:
(a) Chlorophyll-a
(b) Chlorophyll-b
(c) Chlorophyll-c
(d) Chlorophyll-m.
Answer:
(a) Chlorophyll-a

Question 29.
Life cycle of spirogyra is :
(a) Haploid
(b) Diploid
(c) Haplontic
(d) Diplontic.
Answer:
(c) Haplontic

Question 30.
Pinus is:
(a) Deciduous
(b) Dioecious
(c) Monoecious
(d) None of these.
Answer:
(c) Monoecious

Question 31.
In Funaria spore produces :
(a) Primary protonema
(b) Prothallus
(c) Proembryo
(d) Embryo.
Answer:
(a) Primary protonema

Question 32.
Meiotic division takes place in the zygote of :
(a) Selaginella
(b) Spirogyra
(c) Pinus
(d) Equisetum.
Answer:
(b) Spirogyra

Question 33.
In which meiosis does not occur :
(a) Green algae
(b) Fungi
(c) Bacteria
(d) Higher plants.
Answer:
(c) Bacteria

Question 34.
Non-motile gametes are found in:
(a) Spirogyra
(b) Ulothrix
(c) Funaria
(d) None of these.
Answer:
(a) Spirogyra

Question 35.
In Funaria plant stomata are present in :
(a) Foot
(b) Seta
(c) Capsule
(d) Leaf.
Answer:
(c) Capsule

2. Fill in the blanks:

1. The red colour of red algae is due to ………………..
Answer:
Phycoerythrin

2. The ………………… act as soil binders and prevent soil erosion.
Answer:
Mosses

3. The ……………… shoot of Pinus has limited growth.
Answer:
Dwarf

4. Phycology is known as the study of ………………..
Answer:
Algae

5. ………………… is given a nick name of pond scum.
Answer:
Spimgyra

6. Effective independent sporophytes are found in ……………….. group of plants.
Answer:
Tracheophyta

7. ……………….. are called as naked seed plants.
Answer:
Gymnosperms

8. Reproductive organs of ………………… are multicellular.
Answer:
Embryophyta

9. In …………………. polyembryony is found.
Answer:
Cycas

10. Life cycle of Funaria begins from ………………
Answer:
Haploid spore

11. In ………………… vascular tissues are not found.
Answer:
Bryophyta

12. …………………. are called as sea weeds.
Answer:
Brown algae

13. Heart shaped haploid independent structure of pterydophyta is called as …………………..
Answer:
Prothallus

14. In ………………… plants seed develops within the fruit.
Answer:
Angiosperms

15. In two kingdom classification algae and fungi are kept in …………….. group.
Answer:
Thallophyta

16. Algae found in the form of colony of cells is called as ………………….
Answer:
Volvox

17. Spimgyra belongs to class ………………..
Answer:
Chlorophyceae

18. ………………… are amphibian plants.
Answer:
Bryophytes

19.In angiosperms ……………… fertilization occurs.
Answer:
Double

20. Main plant of pterydophyta is ………………………
Answer:
Sporophytic

3. Match the following:

(A)

Answer:
1. (c) First terrestrial plant
2. (d) Pinus.
3. (a) Amphibian plants
4. (b) Not differentiated into root, leaf etc.

(B)

Answer:
1. (c) Marine algae
2. (d) Algae.
3. (b) Funaria
4. (a) Starch

(C)

Answer:
1. (d) Thallophyta.
2. (c) Non-flowering plants
3. (b) Bryophytes
4. (a) Flowering plants

(D)

Answer:
1. (c) Red algae
2. (e) Fungi.
3. (b) Alternation of generation
4. (a) Mycelium
5. (d) Bryophyta

(E)

Answer:
1. (c) Algae
2. (d) Gymnosperms.
3. (b) Pterydophyta
4. (a) Musci

4. Write true or false:

1. Bryophytes are found in marshy place not in water.
Answer:
False

2. Selaginella is a heterosporous pteridophyte.
Answer:
True

3. Mucor is a saprophytic fungi commonly known as bread mould.
Answer:
True

4. Spirogyra is marine algae also known as marine silk.
Answer:
False

5. Inside the seed of Pinus gerardiana, almond is present.
Answer:
False

5. Answer in one word:

1. The antherozoids of Selaginella are?
Answer:
Biflagellate

2. Ligule is present in the leaves of?
Answer:
Selaginella

3. Peristome is found in the capsule of?
Answer:
Pellia

4. The main plant body of Funaria is?
Answer:
Carposporophytic

5. The development of seed habit is started with?
Answer:
Heterospory

Students get through the MP Board Class 11th Biology Important Questions Chapter 21 Neural Control and Coordination which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 21 Neural Control and Coordination

Neural Control and Coordination Class 11 Important Questions Very Short Answer Type

Question 1.
Write the name, nature, origin and distribution area of that nerve which rotates tongue.
Answer:
Hypoglossal nerve rotates the tongue. It is stimulative in nature and originates from the medulla of brain and goes up to the muscles of tongue.

Question 2.
What would be happened in the absence of acetylcholine from synapse?
Answer:
In synapse, acetylcholine transmits the nerve impulse from the axon of one nerve cell to the dendrite of the other nerve cell. Thus in the absence of acetylcholine from synapse nerve impulses do not pass from one nerve cell to other and thus transmission of nerve impulses is inhibited.

Question 3.
Give one example of reflex action.
Answer:
Withdrawal of hand when it is pricked with a needle.

Question 4.
What are axons?
Answer:
The largest branch (dendrite) of nerve cells is known as axon. It plays an important role in the conduction of informations.

Question 5.
Name the humours found in the eyes and describe their functions?
Answer:
Eye has two types of humours :

1.  Aqueous humour: It is a fluid which is filled in aqueous chamber present between the cornea and lens. It
   protects the lens, iris and conjunctiva from direct light and outer forces.
2. Vitreous humour: It is jelly like liquid which is filled in vitreous chamber present between lens and retina. It provides an specific shape to eye ball and also protects it from adherence.

Question 6.
Describe the functions of the following :
(i) Cerebellum,
(ii) Iris,
(iii) Eustachian tube.
Answer:
(i) Cerebellum: The part of the brain which lies behind and below the cerebrum.
(a) Maintenance of posture and equilbrium of the body.
(b) Maintenance of muscle tone.
(c) It modulates and moderates voluntary movements initiated by cerebellum.
(a) It is the site of pain, touch and temperature.

• It controls voluntary movement of muscles, visual and audio sensation.
• Iris: It controls the amount of light that enters the eyes.
• Eustachian tube: It controls the pressure applied on tympanum (membrane between external and middle ears).

Question 7.
What is synapse?
Answer:
Nerve ending of axon of one neuron are connected with the dendrites of next neuron by specific joint is called as Synapse.

Question 8.
Name five sense organs and give their functions.
Answer:

Question 9.
Give nature of following nerves :
(a) Olfactory,
(b) Vagus,
(c) Auditory,
(d) Mandibular.
Answer:

Question 10.
Why owl cannot see during day time but it can see during night ?
Answer:
Owl cannot see during day time as cones are absent in their retina. But it can be able to see during night because their retina possessing a large number of rods.

Question 11.
(a) Which part of the ear determine pitch of the sound ?
(b) Which is the most developed part of the human brain ?
(c) Which part of the central nervous system functions as master clock ?
Answer:
(a) Internal ear,
(b) Cerebrum,
(c) Brain.

Neural Control and Coordination Class 11 Important Questions Short Answer Type

Question 1.
Give functions of cerebrum of man.
Answer:
Functions of cerebrum :

• Its parietal lobe is the centre of pain, touch and stimuli of temperature.
• Its motor area of frontal lobe regulates movement of voluntary muscles.
• Its premotor area of frontal lobe regulates all the functions regulated by autonomous nervous system.
• Its temporal lobe feels taste and smell.
• Visual area of occipital lobe is responsible for the knowledge of light and dark.
• Hypothalamus regulates hunger, thurst and quantity of urine. It also regulates secretion of anterior lobe of pituitary gland.

Question 2.
Write the names of brain ductules of human beings.
Answer:
Human brain consists of a hollow cavity from which the cavity of forebrain is called as lateral cavity. It represents first and second cavity. The cavity of diencephalon is called as third or tertiary cavity. The cavity of mid-brain is called as oieter whereas the cavity of hind-brain is known to be as fourth cavity.

Question 3.
Name the smallest bone of human ear. What happen if this bone is removed ?
Answer:
The smallest bone of human ear is stapes. This bone transmits sound vibration from the tympanic membrane to the membrane of the oval window. This bone increases the force of vibration thus acting like lever, when stapes is removed from ear the waves of sound do not enter the inner ear because stapes which is associated with fenestra ovalis, transmits the vibration of sound into perilymph of vestibular cavity.

Question 4.
What are adrenalin and acetylcholine? Give their functions.
Answer:
Adrenalin and acetylcholine are chemical substances secreted by sympathetic and parasympathetic nerve fibre. Both the chemicals function in opposite way. Adrenalin induces various activities and acetylcholine inhibits them.

Question 5.
What is mosaic vision?
Answer:
This type of vision is found in cockroach because they have compound eyes. Many small images are formed by them. Complete vision is compound form of these many small images and is called as mosaic vision.

Question 6.
Draw a well labelled diagram of longitudinal section of human eye.
Answer:

Question 7.
What is hypermetropia and myopia? (M.P. 1995 Set II)
Answer:
Hypermetropia (Far or Long-sightedness): It is a disease of eyes in which light rays strike the retina before being converged to form image i. e. image is formed beyond the retina. This happens because of (i) abnormally small eye ball, (ii) flattening or abnormally low convexity of the lens. Hypermetropia is corrected by using spectacles with suitable biconvex or convergent lenses.

Myopia (Short sightedness) : This defect results from abnormally long eye ball or abnormally high convexity of lens. The eyes are able to observe nearby objects clearly. However distant objects like writing on the black board or a bird sitting on a tree are not visible properly. It is because of the light rays from distant objects do not form the images on the retina but in front of it in the vitreous humour. The defect is corrected by using spectacles having suitable concave or divergent lens.

Question 8.
What do you understand by nervous system? Nervous system is divided into how many parts?
Answer:
The system which recieves the stimulus, transmits it to the other part of the body and the corresponding effects are shown is known as nervous system.
Nervous system consist of the following three parts :

1. Central nervous system : Comprising of brain and spinal cord.
2. Peripheral nervous system : Includes the nerves which arise from CNS.
3. Autoinomic nervous system : Has connections with central nervous system, but works somewhat independly to regulate the involuntary activites of the body e.g. Heart beat, peristalsis etc.

Question 9.
Explain the role of rods, cones and yellow spot in human eye. (MP 2000, 02, 06 Set C,)
Answer:
1. Rods : Rods are dark light receptors containing rhodopsin synthesized from vitamin A.
Rods are responsible for photopic vision and function best at night and dim light.

2. Cones: Cones are colour receptors containing iodopsin. They function in strong light and responsible for scotopic vision (colour vision).

3.Yellow spot: Posterior part of retina contains only cones and rods are absent and contains yellow pigment called yellow spot. It helps in the formation of clear picture of object.

Question 10.
How many types of nerves are there on the basis of their functions?
Answer:
According to the functions neurons are divided into three parts :

1. Sensory Nerves: These nerve fibers conduct impulses from receptor organ (such as nervous) towards the central nervous system.
2. Motor nerves : These nerve fibres carry the impulses from CNS to effector organs.
3. Mixed nerves: These nerves contain both sensory and motor nerve fibres, hence they do both the functions.

Question 11.
Differentiate the following : (NCERT)
(a) Central Nervous system and peripheral Nervous system.
(b) Resting Potential and Active potential.
(c) Choroid and Retina.
Answer:
(a) Central Nervous System (CNS): Originates from ectoderm part of the embryo. It consists of Brain and spinal cord. Neural tube part of the embryo develops to form this system. This part is responsible for processing of information, where as Peripheral Nervous system (PNS) includes the nerves which arise from the central nervous system.

Nerves arises from brain are called as Cranial nerves and nerves arises from spinal cord are called as spinal nerves. It fonns a communicating system by connecting central nervous system with sensory organs (receptors) through sensory nerves and effector organs through motor nerves.

(b) Resting Potential and Action Potential: At resting stage difference between electric potential of plasma membrane is called as Resting potential. Its value is -70mv, whereas whenever any part of the axon is stimulated depolarisation of Axolemma occurs, thus potential difference decreases up to 30 mV. This is called as Action potential.

(c) Choroid and Retina : Choroid is the middle or second coat of the wall of the eye made up of connective tissue, which is highly vascularised and pigmented. In the front side it fonns iris which has a hole in the centre called as pupil, where as Retina is the innennost layer of the eye wall, which consists of light sensitive cells called as rods (which perceives light) and cones (which distinguish colours).

Question 12.
Explain the structure and functions of spinal cord with diagram.
Or,
Draw a well labelled diagram of T. S. of spinal cord.
Answer:

Structure of spinal cord: The spinal cord consists of central canal surrounded by a central core of grey matter, which is surrounded by white matter. In transverse section, grey matter shows a butterfly shape, i. e., it is produced into two dorsal horns and two ventral horns. A central canal is present in the centre of the grey matter. The spinal cord serves as a centre for spinal reflexes and as pathways to and’from the brain.

The grey matter contains the bodies of neurons with tree-like branching of their dendrons and neurological cells. The white matter is composed of obliquely running medullated nerve fibers supported by pro¬longations of the neuroglia. The bands of fibers which extend transversely, one dorsal and other ventral, to the central canal are known as dorsal and ventral commissures, respectively, Thirty one pairs of spinal nerves arise from the spinal cord. Each nerve is attached to the spinal cord by dorsal and ventral root.

The sensory nerve fibres enter the spinal cord by way of dorsal root while the motor fibres emerge from the spinal cord by way of the ventral root to conduct motor impulses through spinal nerves to effector organs (gland and muscles).
Functions of spinal cord :
(i) Spinal cord controls and coordinates the reflex actions.
(ii) It acts as link between spinal nerves and brain and conducts the impulses of brain.

Question 13.
Write differences between :
(a) Yellow spot and Blindspot.
(b) Short sight and Long sight.
(c) Endolymph and Perilymph.
Answer:
(a) Differences between Yellow spot and Blind spot

(b) Differences between Short sight and Long sight

(c) Differences between Endolymph and Perilymph

Neural Control and Coordination Class 11 Important Questions Long Answer Type

Question 1.
Describe following processes : (NCERT)
(a) Polarisation of membrane of nerve fibre.
(b) Depolarisation of membrane of nerve fibre.
(c) Conduction of impulse through nerve fibre.
(d) Transmission of impulse across synapse (chemically).
Or,
What is nerve impulse? How is it conducted?
Answer:
Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.

Propagation of Nerve impulse :

1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

Question 2.
Give three-three functions of sympathetic and parasympathetic nervous system.
Answer:
Functions of Sympathetic Nervous System :

1. Sympathetic nervous system maintains the physical balance during distress conditions.
2. It stimulates the adrenal glands to secrete adrenalin. Thus, sympathetic nerves function with the adrenal glands as a well-integrated sympathetic-adrenal system having widespread effects.
3. This system is responsible for the increase in the rate of heartbeat and blood pressure.
4. It reduces the peristaltic movement of alimentary canal.
5. It brings about the extension of pupil.
6. It contracts the sphincter muscles of urinary bladder.
7. It increases the sugar level in blood.
8. It increases the number of RBCs in blood.

Functions of Parasympathetic Nervous System :

• Parasympathetic nervous system opposes the effects of the sympathetic autonomic system.
• It decreases rate of heartbeat.
• It decreases blood pressure.
• The nerve ending of this system secrete acetylcholine.
• It constricts pupil of the eyes.
• It relaxes the muscles of root hairs.
• It contracts the muscles of ureter.
• It increases the secretion of saliva and digestive juices.

Question 3.
Name the regulating centre of following in brain :
(a) Temperature,
(b) Hunger,
(c) Respiration,
(d) Water balance,
(e) Vision,
(f) Hearing,
(g) Menstrual cycle,
(h) Learning, (i) Pituitary gland,
(j) Coordination and equilibrium,
(k) Transport,
(l) Sleep,
(m) Heartbeat.
Answer:
(a) Temperature – Thalamus
(b) Hunger – Hypothalamus
(c) Respiration – Medulla oblongata
(d) Water balance – Hypothalamus
(e) Vision – Cerebral cortex
(f) Hearing – Cerebral cortex
(g) Menstrual cycle – Hypothalamus
(h) Learning – Cerebral cortex
(i) Pituitary gland – Hypothalamus
(j) Equilibrium and Coordination – Cerebellum
(k) Transport – Medulla oblongata
(l) Sleep – Cerebral cortex
(m) Heartbeat – Medulla oblongata.

Question 4.
Describe following structures in breif. (NCERT)
(A) Brain,
(B) Eye,
(C) Ear.
Answer:
(A) Brain: Mammalian brain is divisible into three parts :
1. Fore-brain or prosencephalon consists of cerebrum (telencephalon), olfactory lobes (rhinencephalon) and diencephalon (thalamencephalon).
2. Mid-brain or mesencephalon consists of optic lobes (corpora quadrigemina) and cerebral peduncle.
3. Hind-brain or rhombencephalon formed of cerebellum (metencephalon), medulla oblongata (myelencephalon) and pons varoli.

(1) Forebrain :

(i) Olfactory lobe : In mammals the olfactory lobes are located at the anterior end of brain, ventral in position. They are reduced and covered by cerebral hemisphere. Each lobe is further differentiated into olfactory bulb and olfactory tract. The olfactory tract ends in a rounded elevation, the tuberculum olfactory. But in human brain due to the over-development of cerebrum the olfactory lobes get incorporated with the cerebrum and are visible only in the ventral view. Olfactory lobes are concerned with the sense of smell. The nature of the nerve arising from the olfactory lobes are purely sensory.

(ii) Cerebrum: Cerebrum is the largest part of the brain. It is made up of two halves, the right and the left cerebral hemispheres. A deep median longitudinal groove is the demarkation between two halves. The two halves are connected by means of a broad transverse band of white matter called corpus callosum or cerebri.

Deep furrows divide each cerebral hemisphere into frontal lobe, temporal lobe, occipital lobe and a small lobe called insula. Insula is a triangular eminence lying deeply in lateral fissure of temporal lobe. The other lobes are named according to the position they occupy. The surface of cerebrum is folded, having elevation and depressions called sulci and gyri that increases surface area.

(iii) Diencephalon: It is a small area, it remains covered with cerebrum. It consists of following:
(a) Epithalamus: It forms the roof of diencephalon having anterior choroid plexus concerned with supply of nutrition of brain and vestigial pineal body.

(b) Optic thalami: These forms lateral walls of diencephalon and contain optic fibres which go towards cerebrum.
(iv) Hypothalamus : The base of the brain constitutes the hypothalamus. It forms the floor of diencephalon. It has a hypophysis or master gland or pituitary gland, which is an endocrine gland. Anterior to it is a geniculate body which relay optic impulses to cerebrum. An optic chiasma is formed by the crossing of optic fibres. The hypothalamus, consists of large amount of grey matter present within the white matter. It contains the nerve centres for control of temperature, hunger, thirst and emotions, sleep and sexual activities. It also produces various neurohormones that control the secretion of anterior pituitary. Hormones of posterior pituitary are produced in hypothalamus which reach the pituitary by hypophyseal portal vessels.

2. Mid-brain: The mid-brain or mesencephalon joins the cerebrum with the cerebellum. It consists of four lobes called quadrigemina. Anterior pair of lobes is concerned with vision and posterior ones with hearing. It has large number of nerve cells scattered within the white matter. These nerve cells are involved in controlling the voluntary muscle activities and also act as centres for auditory and visual reflexes. It can modify some motor activities initiated by cortex.

3. Hind-brain: The hind brain or rhombencephalon consists of cerebellum, pons and medulla and many visceral functions forms its major part and is a large reflex centre for the co-ordination of activities of voluntary muscles.
The brain-stem consists of pons varoli in front of cerebellum and behind it medulla oblongata is present. Pons varoli runs transversely and carries impulses from one portion of cerebellum to another. The medulla oblongata lies in between the pons varoli and spinal cord and controls various reflexes like breathing, swallowing, salivation, chewing, coughing, sneezing etc.

(B) Human Eye: L.S. of human eye : Human eye is a spherical ball like structure filled with a vitreous liquid. It is covered by upper and lower eyelids. The eyeball of human beings is made up of from the following three layers :

1. Sclerotic layer: It is the outermost layer of eye. Their 1/3 transparent part is called as cornea. Covering of cornea is a thin transparent membrane called conjunctiva. Cornea permits light to enter the eye.

2. Choroid layer: It is an extensive plexus of small blood vessels embedded in loose connective tissue. At the anterior margin of the choroid a greatly thickened structure projects immediately into the eyeball towards the margin of the lens.

This portion of the choroid is called as ciliary body. Anterior to the ciliary body the vascular tunic is thin and constitute the iris of the eye; in the middle of the iris is a round opening called the pupil. A lens (biconcave) is present below the iris which is encased in a strong fibrous lens capsule and containing a high concentration of protein.

3. Retina: It is the innermost part of the eye which lines the inside surface of the posterior two third of the eyeball and lies on the inner surface of the choroid. The retina containing light sensitive cells called rods and cones that detect light and colour and then send appropriate signals to the brain to cause vision.
Two functions of rods and cones are :

1. The photoreceptor, rod cells of retina contain rhodopsin. They function in dim light and enable us to see in darkness at night.
2. The photoreceptor, cone cells of retina contain iodopsin. They function in day light and artificial bright light. They are associated with perception of colours

Note: For

(C) Ear: Human ear is highly developed. It can be divided into three parts :

1. External ear: It consists of flap like structure called pinna which collects sound and pass it to the auditory canal, at the end of which tympanic membrane is found.

2. Middle ear: It consists of tympanic cavity which is present between the tympanic membrane and the internal ear. Three small bones called ear ossicles are found in the middle ear. The first bone, which is club-shaped and is attached at one end to the tympanic membrane is called malleus.
Its other end is attached to an anvil-shaped bone called incus. The narrow end of incus is attached to the bone called stapes which is stirrup-shaped and has an aperture in it.

The other end of stapes is fixed to the membrane on the fenestra ovalis. In mammals, all these three bones originate from the bones of the jaws, malleus from articular, incus from quadrate and stapes from hyomandibular. The tympanic cavity is connected with the pharynx by means of eustachian tube.

3. Internal ear: The membranou s labyrinth of internal ear consists of two chambers : utriculus and sacculus. These chambers are connected with each other by a narrow canal called saccularicular canal. Three semicircular canals arise from the utriculus. According to their position, they are known as anterior, posterior and external or horizontal semicircular canals. The anterior and posterior semicircular canals arise together and run for a short distance and then separate. After taking a curved course, their other ends again open into the utriculus where each of them enlarges to form an ampulla. Each ampulla contains a sensory crista which is formed of ciliated and supporting cells.

Two such cristae maculae are present in sacculus and one in the utriculus. The hind part of sacculus is coiled like a spring and is known as cochlear duct. Utriculus, ampullae, semicircular canals, sacculus and cochlear duct are all filled with a thick fluid called endolymph which contains minute particles of calcium carbonate known
as otoliths.

The internal ear is situated in the temporal region of the skull within the periotic bones which take the shape of the internal ear. Thus the whole internal ear, i.e., membranous labyrinth is enclosed in a bony labyrinth.
The space between these two is filled with a fluid called perilymph. The cochlea is associated with hearing. It is a bony tube coiled like a conch shell. It is wound around a bony cone of bone, known as central pillar or modiolus. The cochlear nerve passes through the modiolus. The scala media remains separated from the vestibular canal of the bony labyrinth by a vestibular membrane or resisters membrane. It is also separated from the underlying tympanic canal by a basilar membrane.

The basilar membrane possesses several rows of hair cells serving as auditory receptors all along its coiled course. This structure is known as Organ of Corti which is the organ of hearing. It is composed of several specialized cells. Corti’s rods are double row of arching rods based on basilar membrane and ‘forming the spiral tunnel of Corti. Hair cells are the sensory organ of Corti’s organ. Dieters cells are the supporting cells between rows of outer hair cells in organ of Corti. A tectorial membrane lies in contact with the hair cells.

Question 5.
Draw labelled diagrams of following :
(a) Neuron,
(b) Brain,
(c) Eye,
(d) Ear. (NCERT)
Answer:
(a) Neuron :

(b) Brain:

(A) Brain: Mammalian brain is divisible into three parts :
1. Fore-brain or prosencephalon consists of cerebrum (telencephalon), olfactory lobes (rhinencephalon) and diencephalon (thalamencephalon).
2. Mid-brain or mesencephalon consists of optic lobes (corpora quadrigemina) and cerebral peduncle.
3. Hind-brain or rhombencephalon formed of cerebellum (metencephalon), medulla oblongata (myelencephalon) and pons varoli.

(1) Forebrain :

(i) Olfactory lobe : In mammals the olfactory lobes are located at the anterior end of brain, ventral in position. They are reduced and covered by cerebral hemisphere. Each lobe is further differentiated into olfactory bulb and olfactory tract. The olfactory tract ends in a rounded elevation, the tuberculum olfactorium. But in human brain due to the over development of cerebrum the olfactory lobes get incorporated with the cerebrum and are visible only in the ventral view. Olfactory lobes are concerned with the sense of smell. The nature of the nerve arising from the olfactory lobes are purely sensory.

(ii) Cerebrum: Cerebrum is the largest part of the brain. It is made up of two halves, the right and the left cerebral hemispheres. A deep median longitudinal groove is the demarkation between two halves. The two halves are connected by means of a broad transverse band of white matter called corpus callosum or cerebri.

Deep furrows divide each cerebral hemisphere into frontal lobe, temporal lobe, occipital lobe and a small lobe called insula. Insula is a triangular eminence lying deeply in lateral fissure of temporal lobe. The other lobes are named according to the position they occupy. The surface of cerebrum is folded, having elevation and depressions called sulci and gyri that increases surface area.

(iii) Diencephalon: It is a small area, it remains covered with cerebrum. It consists of following:
(a) Epithalamus: It forms the roof of diencephalon having anterior choroid plexus concerned with supply of nutrition of brain and vestigial pineal body.

(b) Optic thalami: These forms lateral walls of diencephalon and contain optic fibres which go towards cerebrum.
(iv) Hypothalamus : The base of the brain constitutes the hypothalamus. It forms the floor of diencephalon. It has a hypophysis or master gland or pituitary gland, which is an endocrine gland. Anterior to it is a geniculate body which relay optic impulses to cerebrum.

An optic chiasma is formed by the crossing of optic fibres. The hypothalamus, consists of large amount of grey matter present within the white matter. It contains the nerve centres for control of temperature, hunger, thirst and emotions, sleep and sexual activities. It also produces various neurohormones that control the secretion of anterior pituitary. Hormones of posterior pituitary are produced in hypothalamus which reach the pituitary by hypophyseal portal vessels.

2. Mid-brain: The mid-brain or mesencephalon joins the cerebrum with the cerebellum. It consists of four lobes called quadrigeminal. Anterior pair of lobes is concerned with vision and posterior ones with hearing. It has large number of nerve cells scattered within the white matter. These nerve cells are involved in controlling the voluntary muscle activities and also act as centres for auditory and visual reflexes. It can modify some motor activities initiated by cortex.

3. Hind-brain: The hind brain or rhombencephalon consists of cerebellum, pons and medulla and many visceral functions forms its major part and is a large reflex centre for the co-ordination of activities of voluntary muscles.

The brain-stem consists of pons varoli in front of cerebellum and behind it medulla oblongata is present. Pons varoli runs transversely and carries impulses from one portion of cerebellum to another. The medulla oblongata lies in between the pons varoli and spinal cord and controls various reflexes like breathing, swallowing, salivation, chewing, coughing, sneezing etc.

(C) Ear:

Human ear is highly developed. It can be divided into three parts :

1. External ear: It consists of flap like structure called pinna which collects sound and pass it to the auditory canal, at the end of which tympanic membrane is found.

2. Middle ear: It consists of tympanic cavity which is present between the tympanic membrane and the internal ear. Three small bones called ear ossicles are found in the middle ear. The first bone, which is club-shaped and is attached at one end to the tympanic membrane is called malleus.
Its other end is attached to an anvil-shaped bone called incus. The narrow end of incus is attached to the bone called stapes which is stirrup-shaped and has an aperture in it.

The other end of stapes is fixed to the membrane on the fenestra ovalis. In mammals, all these three bones originate from the bones of the jaws, malleus from articular, incus from quadrate and stapes from hyomandibular. The tympanic cavity is connected with the pharynx by means of eustachian tube.

3. Internal ear: The membranou s labyrinth of internal ear consists of two chambers : utriculus and sacculus. These chambers are connected with each other by a narrow canal called saccularicular canal. Three semicircular canals arise from the utriculus. According to their position, they are known as anterior, posterior and external or horizontal semicircular canals. The anterior and posterior semicircular canals arise together and run for a short distance and then separate. After taking a curved course, their other ends again open into the utriculus where each of them enlarges to form an ampulla. Each ampulla contains a sensory crista which is formed of ciliated and supporting cells.

Two such cristae maculae are present in sacculus and one in the utriculus. The hind part of sacculus is coiled like a spring and is known as cochlear duct. Utriculus, ampullae, semicircular canals, sacculus and cochlear duct are all filled with a thick fluid called endolymph which contains minute particles of calcium carbonate known
as otoliths.

The internal ear is situated in the temporal region of the skull within the periotic bones which take the shape of the internal ear. Thus the whole internal ear, i.e., membranous labyrinth is enclosed in a bony labyrinth.
The space between these two is filled with a fluid called perilymph. The cochlea is associated with hearing. It is a bony tube coiled like a conch shell. It is wound around a bony cone of bone, known as central pillar or modiolus. The cochlear nerve passes through the modiolus. The scala media remains separated from the vestibular canal of the bony labyrinth by a vestibular membrane or reissners membrane. It is also separated from the underlying tympanic canal by a basilar membrane.

The basilar membrane possesses several rows of hair cells serving as auditory receptors all along its coiled course. This structure is known as Organ of Corti which is the organ of hearing. It is composed of several specialized cells. Corti’s rods are double row of arching rods based on basilar membrane and ‘forming the spiral tunnel of Corti. Hair cells are the sensory organ of Corti’s organ. Dieters cells are the supporting cells between rows of outer hair cells in organ of Corti. A tectorial membrane lies in contact with the hair cells.

(c) Eye :

Note: For

(d) Ear :

Human ear is highly developed. It can be divided into three parts :

1. External ear: It consists of flap like structure called pinna which collects sound and pass it to the auditory canal, at the end of which tympanic membrane is found.

2. Middle ear: It consists of tympanic cavity which is present between the tympanic membrane and the internal ear. Three small bones called ear ossicles are found in the middle ear. The first bone, which is club-shaped and is attached at one end to the tympanic membrane is called malleus.
Its other end is attached to an anvil-shaped bone called incus. The narrow end of incus is attached to the bone called stapes which is stirrup-shaped and has an aperture in it.

The other end of stapes is fixed to the membrane on the fenestra ovalis. In mammals, all these three bones originate from the bones of the jaws, malleus from articular, incus from quadrate and stapes from hyomandibular. The tympanic cavity is connected with the pharynx by means of eustachian tube.

3. Internal ear: The membranou s labyrinth of internal ear consists of two chambers : utriculus and sacculus. These chambers are connected with each other by a narrow canal called saccularicular canal. Three semicircular canals arise from the utriculus. According to their position, they are known as anterior, posterior and external or horizontal semicircular canals. The anterior and posterior semicircular canals arise together and run for a short distance and then separate. After taking a curved course, their other ends again open into the utriculus where each of them enlarges to form an ampulla. Each ampulla contains a sensory crista which is formed of ciliated and supporting cells.

Two such cristae maculae are present in sacculus and one in the utriculus. The hind part of sacculus is coiled like a spring and is known as cochlear duct. Utriculus, ampullae, semicircular canals, sacculus and cochlear duct are all filled with a thick fluid called endolymph which contains minute particles of calcium carbonate known
as otoliths.

The internal ear is situated in the temporal region of the skull within the periotic bones which take the shape of the internal ear. Thus the whole internal ear, i.e., membranous labyrinth is enclosed in a bony labyrinth.
The space between these two is filled with a fluid called perilymph. The cochlea is associated with hearing. It is a bony tube coiled like a conch shell. It is wound around a bony cone of bone, known as central pillar or modiolus. The cochlear nerve passes through the modiolus. The scala media remains separated from the vestibular canal of the bony labyrinth by a vestibular membrane or reissners membrane. It is also separated from the underlying tympanic canal by a basilar membrane.

The basilar membrane possesses several rows of hair cells serving as auditory receptors all along its coiled course. This structure is known as Organ of Corti which is the organ of hearing. It is composed of several specialized cells. Corti’s rods are double row of arching rods based on basilar membrane and ‘forming the spiral tunnel of Corti. Hair cells are the sensory organ of Corti’s organ. Dieters cells are the supporting cells between rows of outer hair cells in organ of Corti. A tectorial membrane lies in contact with the hair cells.

Question 6.
Write short notes on following : (NCERT)
(a) Mechanism of synaptic conduction.
(b) Mechanism of vision.
(c) Mechanism of hearing.
Answer:
(a) Mechanism of synaptic conduction:
Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.

Propagation of Nerve impulse :

1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(b) Mechanism of vision: For seeing clear distant object it is essential that image must be focussed on the retina so that photoreceptor rods and cones are stimulated. Rays of light from the object fall on the biconvex lens after passing through the conjunctiva, cornea and pupil. The size of the pupil regulates the amount of light entering the eyeball. Thus, an inverted image of the object is formed on the retina which is conveyed to the brain by the optic nerve. The image is then reinverted by the brain.

The eyes have got the property to form image of both far and near objects on retina by changing the convexity of the lens. This is called power of accommodation.

(c) Mechanism of hearing: The sound waves first strike the pinna which keeps on moving to direct the sound waves into tympanic cavity. These waves then strike the tympanic membrane which starts vibrating due to which the ear ossicles are vibrated.

Thus it is transmitted the membrane over the fenestra ovalis into scala vestibule of the cochlea. In this way, the perilymph filled in it also gets vibrated due to which Reissner’s and basilar membranes start vibrating. By the vibration of these membranes, the endolymph of scala media also vibrates as well as the tectorial membrane.

Because of the vibration of endolymph of scala media, the sensory hairs of the receptor cells of the organ of Corti are stretched and bent due to which the receptor cells gets stimulated and send the impulses to the brain through cochlear nerve. In the manner the sound is heard.

Question 7.
(a) Decribe role of Na⁺ in production of action potential.
(b) Describe role of Ca⁺⁺ in discharge of neurotransmitter at svnapse.
(c) Explain mechanism of production of impulse on the retina by light.
(d) Explain mechanism of production of nerve impulse by sound in the internal ear.
Answer:
(a)

Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.
Propagation of Nerve impulse :
1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(b)

(a)

Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.
Propagation of Nerve impulse :
1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(c)

(a) Mechanism of synaptic conduction:
Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.

Propagation of Nerve impulse :

1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(b) Mechanism of vision: For seeing clear distant object it is essential that image must be focussed on the retina so that photoreceptor rods and cones are stimulated. Rays of light from the object fall on the biconvex lens after passing through the conjunctiva, cornea and pupil. The size of the pupil regulates the amount of light entering the eyeball. Thus, an inverted image of the object is formed on the retina which is conveyed to the brain by the optic nerve. The image is then reinverted by the brain.

The eyes have got the property to form image of both far and near objects on retina by changing the convexity of the lens. This is called power of accommodation.

(c) Mechanism of hearing: The sound waves first strike the pinna which keeps on moving to direct the sound waves into tympanic cavity. These waves then strike the tympanic membrane which starts vibrating due to which the ear ossicles are vibrated.

Thus it is transmitted the membrane over the fenestra ovalis into scala vestibule of the cochlea. In this way, the perilymph filled in it also gets vibrated due to which Reissner’s and basilar membranes start vibrating. By the vibration of these membranes, the endolymph of scala media also vibrates as well as the tectorial membrane.

Because of the vibration of endolymph of scala media, the sensory hairs of the receptor cells of the organ of Corti are stretched and bent due to which the receptor cells gets stimulated and send the impulses to the brain through cochlear nerve. In the manner the sound is heard.

(d)

(a) Mechanism of synaptic conduction:
Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.

Propagation of Nerve impulse :

1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(b) Mechanism of vision: For seeing clear distant object it is essential that image must be focussed on the retina so that photoreceptor rods and cones are stimulated. Rays of light from the object fall on the biconvex lens after passing through the conjunctiva, cornea and pupil. The size of the pupil regulates the amount of light entering the eyeball. Thus, an inverted image of the object is formed on the retina which is conveyed to the brain by the optic nerve. The image is then reinverted by the brain.

The eyes have got the property to form image of both far and near objects on retina by changing the convexity of the lens. This is called power of accommodation.

(c) Mechanism of hearing: The sound waves first strike the pinna which keeps on moving to direct the sound waves into tympanic cavity. These waves then strike the tympanic membrane which starts vibrating due to which the ear ossicles are vibrated.

Thus it is transmitted the membrane over the fenestra ovalis into scala vestibule of the cochlea. In this way, the perilymph filled in it also gets vibrated due to which Reissner’s and basilar membranes start vibrating. By the vibration of these membranes, the endolymph of scala media also vibrates as well as the tectorial membrane.

Because of the vibration of endolymph of scala media, the sensory hairs of the receptor cells of the organ of Corti are stretched and bent due to which the receptor cells gets stimulated and send the impulses to the brain through cochlear nerve. In the manner the sound is heard.

Question 8.
(a) How do you see colour of any object?
(b) Which part of our body helps to maintain equilibrium (balance) of the body?
(c) How does eyes regulate light which falls into the retina.
Answer:
(a) Retina contain two types of light receptor cells: Rods and cones. In the presence of light rods perceive light, whereas the cones are colour receptors, containing adoption or visual violet. They function in strong light and are meant for scotopic vision (colour vision), that is why we can not see colour in dim light or dark.

On the basis of pigments there are three types of cones :

1. Cones respond to red light due to presence of erythroblast pigment.
2. Cones respond to green light due to presence of chlorolabe pigment.
3. Cones respond to blue light due to presence of cyanolabe pigment.
   The colour that we see results from a mixture of impulses of the above types of cone
   types.

(b) Ears play an important role in hearing and the maintenance of equilibrium and orientation of body, hence are called as balancing organ. Sensory cells are present in the ampullae of the semilunar canals and utriculus. Several particles of calcium carbonate or otoliths are scattered around the cilia of these cells. When the equilibrium of the body disturbed, the otoliths move and press upon the cilia or sensory cells which get stimulated and send the impulse to the brain. Thus brain receives the information and sends instructions to different organs to set right the equilibrium of body.