Important Questions from Anatomy of Flowering Plants | Class 11 Biology | NEET 2023

Study of internal structures of plants is called anatomy. Here is a collection of all important questions regarding the structural organisation and internal structure of higher plants that is crucial for NEET 2023.

    1. Match the following columns.
Column I Column II
A. Cuticle 1. Guard cells
B. Bulliform cells 2. Single layer
C. Stomata 3. Waxy layer
D. Epidermis 4. Empty colourless cell

(a) A-3, B-4, C-1, D-2

(b) A-1, B-2, C-3, D-4

(c) A-3, B-2, C-4, D-1

(d) A-3, B-2, C-1, D-4

Answer: (a)

Explanation: Cuticle is a waxy layer present just outside the epidermis that prevents excess evaporation of water from the plant. Bulliform cells, found in monocots such as grasses are modified epidermal cells that become enlarged, empty, colourless and with a vacuole that help in preventing loss of water from the plant. Stomata are pores found on the epidermis of leaves that control the rate of gas exchange. Epidermis is the single outermost protective layer present on plants.

    1. Interfascicular cambium and cork cambium are formed due to

(a) Cell division

(b) Cell differentiation

(c) Cell dedifferentiation

(d) Redifferentiation

Answer: (c)

Explanation: Interfascicular cambium are the ones found in between two vascular bundles. When medullary rays participate in secondary growth, they undergo differentiation to form interfascicular cambium. Because these cambium are formed by medullary rays which are differentiated cells, the phenomenon is known as cell dedifferentiation. Here, the medullary rays regain their capacity to differentiate and form the cambium.

    1. Cells of meristems are characterised by

(a) Continuous division

(b) Large vacuoles

(c) Chloroplasts

(d) All of the above

Answer: (a)

Explanation: Meristematic cells are characterised by thin cells, continuous division, large nucleus, no intercellular space and a dense cytoplasm.

    1. Identify the odd one out of the following.

(a) Intercalary meristem

(b) Promeristem

(c) Primary meristem

(d) Secondary meristem

Answer: (a)

Explanation: The cells that are continuously dividing are known as meristematic cells. Based on growth they are of two types – primary and secondary meristems. Based on location, they are of three types – apical, lateral and intercalary.

The promeristems grow into primary meristems after embryonic growth. The primary meristems differentiate to form primary permanent tissues. The primary permanent tissues differentiate to form secondary meristems which undergo secondary growth to form secondary tissues.

    1. Buoyancy in hydrophytes is due to the presence of

(a) Spongy parenchyma

(b) Chlorenchyma

(c) Aerenchyma

(d) Collenchyma

Answer: (c)

Explanation: Buoyancy in hydrophytes is due to the presence of aerenchyma that has large intercellular spaces present between them.

    1. A permanent tissue is different from a meristematic tissue in that

(a) It is found in the root and shoot apices

(b) It gives rise to more tissues

(c) It helps in elongation of the stem

(d) It has lost the ability to divide

Answer: (d)

Explanation: When a meristematic tissue differentiates to form specialised cells that perform specific functions, they are known as permanent tissue. Permanent tissues are different from meristematic tissue because permanent tissues lose their ability to divide while meristematic cells are continuously dividing cells.

    1. Read the following statements.

I. Collenchyma contains lignin in its wall thickenings.

II. Collenchyma is found only in aerial primary parts and is absent from the roots.

III. Chlorenchyma is parenchyma with chloroplasts in them.

IV. Collenchyma does not have intercellular spaces.

Which of the following combinations are correct?

(a) I, II and III

(b) II, III and IV only

(c) III and IV only

(d) I, II, III and IV

Answer: (b)

Explanation: Collenchyma is a simple living mechanical tissue. Its cell wall is made up of cellulose, hemicellulose and pectin. It does not have any free intercellular spaces. Pectin is deposited between cells to make the structure compact. It is found in aerial primary parts such as leaf margins and young stems of dicot plants. It is absent in the roots except in aerial roots of some plants. When parenchyma cells contain chloroplasts, they are known as chlorenchyma that are found in the mesophyll of leaves.

    1. Two cross-sections of root and stem appear simple when viewed by naked eye. But under microscope, they can be differentiated by

(a) Exarch condition of root and stem

(b) Endarch condition of stem and root

(c) Endarch condition of root and exarch condition of the stem

(d) Endarch condition of the stem and exarch condition of the root

Answer: (d)

Explanation: Endarch and exarch conditions are formed on the basis of positions of metaxylem and protoxylem. Protoxylem are the first formed primary xylem elements while metaxylem are the later formed primary xylem elements. When the metaxylem is present in the centre and protoxylem towards the periphery, it is considered as an exarch condition that is found in roots. When the protoxylem is present in the centre and metaxylem towards the periphery, it is considered an endarch condition, found in shoots.

    1. Conjoint and closed vascular bundles with no phloem parenchyma are observed in:

(a) Monocot stem

(b) Dicot stem

(c) Monocot root

(d) Dicot root

Answer: (a)

Explanation: When vascular bundles are present at different radius from the centre, it is known as radial vascular bundle. It is commonly found in roots. When xylem and phloem are present in the same radius, they are called conjoint vascular bundles, commonly found in shoots. When cambium strip is present in between xylem and phloem in conjoint conditions, it is referred to as open type, and when cambium is absent, it is referred to as closed type. Cambium helps in secondary growth which is seen only in dicot shoots. Therefore conjoint and closed vascular bundles are found in monocot stems only.

    1. Choose the correct statement with reference to the internal structure of leaves.

(a) All dicot leaves have an equal number of stomata on both surfaces of their leaves.

(b) Conjoint vascular bundles are found in leaves.

(c) Upper epidermis is called the abaxial epidermis and the lower epidermis is called adaxial epidermis.

(d) Leaves have cambium.

Answer: (b)

Explanation: In leaves, the upper epidermis is called adaxial epidermis, while the lower epidermis is called abaxial epidermis. The mesophyll of the leaf is differentiated into spongy mesophyll and palisade mesophyll. Conjoint vascular bundles are found in leaves. They (dicot leaves) don’t have an equal number of stomata on both the surfaces. Leaves do not have cambium because they do not show secondary growth.

    1. The mesophyll tissue is part of

(a) Epidermal tissue system

(b) Ground tissue system

(c) Vascular tissue system

(d) Conducting tissue system

Answer: (b)

Explanation: There are three types of tissue systems found in plants – ground, vascular and epidermal. All the plant tissues except epidermis and vascular bundles constitute the ground tissue system.

The mesophyll tissue present between the upper and lower epidermis is part of the ground tissue system. The mesophyll tissue consists of chloroplasts (chlorenchyma) and helps in photosynthesis.

Leaf anatomy

    1. Some vascular bundles are described as open because they

(a) Possess conjunctive tissue between xylem and phloem

(b) Are not surrounded by bundle sheath

(c) Do not have cambium in between xylem and phloem

(d) Have cambium in between xylem and phloem

Answer: (d)

Explanation: The vascular bundles that have joint xylem and phloem are referred to as conjoint vascular bundles. When they have a strip of cambium present in between the xylem and phloem, they are referred to as open conjoint, whereas when cambium is not present, it is referred to as closed conjoint vascular bundles.

    1. Ground tissue system is constituted by

(a) All tissues except epidermis and vascular bundles

(b) Cortex and epidermis

(c) All tissue internal to endodermis

(d) All tissue external to endodermis

Answer: (a)

Explanation: All tissues in the plant body except the epidermis and vascular tissue constitute the ground tissue system. It consists of hypodermis, coretx, endodermis, pericycle, medullary rays and pith.

    1. Age of a tree can be estimated by

(a) Its height and girth

(b) The number of annual rings

(c) Its biomass

(d) The diameter of the heartwood

Answer: (b)

Explanation: The scientific method of finding out the formation of the exact year of growth rings or annual rings in a tree is known as dendrochronology, also called tree-ring dating.

    1. Heartwood differs from sapwood in

(a) Being susceptible to pests and pathogens

(b) Presence of rays and fibres

(c) Absence of vessels and parenchyma

(d) Having dead and non-conducting elements

Answer: (d)

Explanation: Heartwood is a dark brown conducting xylem that has depositions of tannins, resins, oils, gums, essential oils and aromatic compounds. They are dead tissue that have highly lignified walls and do not conduct any water. They do not have ray cells and fibres. It is hard and durable and provides mechanical support. They are also resistant to microorganisms and insects.

Sapwood is a light brown secondary xylem that arises from cambium. It is a living tissue that conducts water and minerals. It has ray cells and fibres. In young trees, all of the wood is sapwood.

    1. The periderm includes

(a) Bark and cork

(b) Cork and cork cambium

(c) Secondary cortex

(d) Both (b) and (c)

Answer: (d)

Explanation: The periderm is a collective term used for cork, cork cambium and secondary cortex.

    1. Lenticels help in

(a) Protection of the plant

(b) Checking the evaporation of water

(c) Facilitating gaseous exchange

(d) Secondary growth of the plant

Answer: (c)

Explanation: Lenticels are pores with large intercellular spaces found on the periderm that facilitate gaseous exchange between the internal tissues of the plant and the atmosphere.

    1. Choose the correct statement with respect to medullary rays.

(a) Medullary rays can be parenchymatous or collenchymatous in nature.

(b) Primary medullary rays are present inside primary vascular bundles.

(c) Secondary medullary rays are formed by the cork cambium.

(d) They help in radial conduction of food and water.

Answer: (d)

Explanation: Medullary rays are parenchymatous cells arranged radially between adjacent vascular bundles. Secondary medullary are formed by the vascular cambium. Both primary and secondary medullary rays help in radial conduction of food, water and minerals.

    1. Choose the elements in column I with their corresponding features in column II.
Column I Column II
A. Sieve tubes I. Absent mostly in monocots.
B. Companion cells II. Sclerenchymatous cells
C. Phloem parenchyma III. Nucleus controlling sieve tubes
D. Bast fibres. IV. Conducting element

(a) A-I, B-II, C-III, D-IV

(b) A-I, B-II, C-IV, D-III

(c) A-III, B-IV, C-II, D-I

(d) A-IV, B-III, C-I, D-II

Answer: (d)

Explanation: Phloem is composed of sieve tube elements, companion cells, phloem parenchyma and phloem fibres. The sieve tube elements are the main conducting elements of the phloem. The nucleus of the companion cells controls the activity of the sieve tube element as sieve tube elements lack nucleus. The phloem parenchyma have a dense cytoplasm and nucleus and are absent in most monocots. The phloem fibres or bast fibres are made up of sclerenchymatous cells and are found in secondary phloem.

Refer: Difference Between Xylem And Phloem

    1. Which one among the following is correct?

(a) Tracheids are unicellular with a wide lumen

(b) Vessels are multicellular with a wide lumen

(c) Tracheids are multicellular with narrow lumen

(d) Vessels are unicellular with narrow lumen

Answer: (b)

Explanation: Xylem is composed of tracheids, vessels, xylem parenchyma and xylem fibres. Tracheids are unicellular with a narrow lumen and highly thickened walls. They are present in all vascular plants and do not have endplates. Vessels are multicellular with a wide lumen and walls less thickened than tracheids. They are found only in angiosperms and have perforated endplates.

Stay tuned to BYJU’S for more updates related to NEET. Refer to Important Notes of Biology for NEET: Anatomy of Flowering Plants for detailed information.

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