Biology · Science General

Botany and Plant Science

5,038 Questions

Botany and plant science delve into the biological study of plant life, covering structural anatomy, physiological processes, and reproductive mechanisms. Key topics include inflorescence patterns, root modifications, and seed development, which are vital for biology sections in medical entrance exams. This collection of practice questions helps solidify understanding of complex plant functions.

Plant ReproductionPlant AnatomyRoot ModificationsInflorescence PatternsPlant Morphology

Botany and Plant Science Questions

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

The air spaces in the leaf is created by 

  1. Chlorenchyma

  2. Aerenchyma

  3. Palisade parenchyma

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The spongy tissue that forms air spaces between the cells of leaves, stems and roots of some plants are called aerenchyma cells. It helps in the gaseous exchange between the shoot and the root and also provides buoyancy to the aquatic plants. So, the correct option is 'Aerenchyma'.
Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Which of the following cells helps in the rolling of leaves in dry weather?

  1. Bulliform cells

  2. Guard cell

  3. Parenchyma cell

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bulliform cells are found in the axial or upper surface of the epidermis of monocots. These are large, colourless, bubble-shaped (empty) cells found in clusters near the mid vein. In the presence of insufficient water, these cells loose water and become flaccid. In response to this condition, the leaf rolls inward (to expose the minimum part of the leaf) to minimise the water loss. So, the correct 'Bulliform cells'.

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

A modification of petiole is

  1. Phyllode

  2. Phylloclade

  3. Cladode

  4. Corm
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Phyllode is a green, expanded structure formed by the modification of petiole or rachis of the leaf. In most of the xerophytes, leaves are reduced to prevent water loss in such plants phyllodes develop to carry out photosynthesis.

An example is Acacia.
So the correct option is 'Phyllode'

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Swollen lower end of leaf stalk is

  1. Petiole

  2. Pulvinus

  3. Thalamus

  4. Disc
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A swelling at the base of a petiole is known as pulvinus. It is a joint-like thickening at the base of a plant leaf or leaflet that facilitates growth-independent movement. For example, mango, pea and gram.
Therefore, the correct answer is option B.

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Leaves develop from

  1. Nodes

  2. Internodes

  3. Epidermis

  4. Endodermis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Leaves develop from nodes. Apart from leaves, branches and aerial roots also develop from nodes from the stem. It also holds buds. Adventitious roots may also develop from it. Internodes are the intervals between the nodes. 

Thus, the correct answer is 'Nodes.'

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Sometimes a few epidermal cells in the vicinity of guard cells become specialized in their shape and size are known as 

  1. Stomatal aperture

  2. Trichomal cell

  3. Subsidiary cells

  4. Stomata
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The few epidermal cells surrounding the guard cells are modified to act as subsidiary cells. They lack chloroplasts and help in functioning of the guard cells by maintaining the water and solute balance with the guard cells.

A. Stomatal aperture is the opening of the stomata. It is also called stomatal pore.
B. Trichome cells give rise to the hair-like outgrowth called the trichomes.
C. Subsidiary cells are the modified epidermal cells near the guard cells.
D. Stomata are surrounded by the guard cells.
Hence, the correct answer is 'Subsidiary cells'

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

A distinct endodermis is a constant feature of

  1. Dicot leaves

  2. Monocot stems

  3. Monocot leaves

  4. Dicot stema
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The cells of the endodermis typically have their primary cell walls thickened on four sides radial and transverse with suberin, a water-impermeable waxy substance which in young endodermal cells is deposited in distinctive bands called Casparian strips.
So the correct option is 'Dicot leaves'.
Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Midrib is observed in which part of leaf?

  1. Leaf base

  2. Lamina

  3. Petiole

  4. Stipule
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The leaf consists of the following parts-
1) Leaf blade (lamina) is the broad and flat part of the leaf where photosynthesis occurs is also known as epipodium.
  • The midrib is the central prominent vein on the lamina which helps to transport water, minerals to different cells of the leaf.
2) Leaf base is the lowermost part of the leaf and is also known as hypopodium
3) The petiole is the stalk-like part of the leaf which connects the leaf blade to the stem.
  • Stipule is a small flap-like structure which grows at the base of the petioles and protects the growing petioles or falls off.
  • So, the correct answer is 'Lamina'.
Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Broad part of a leaf is

  1. Leaf base

  2. Petiole

  3. Lamina

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Broad part of leaf is lamina. The lamina is the expanded portion of a leaf and it is specialized for photosynthesis. For this purpose, a leaf is typically flat and thin, to expose the chlorenchyma to light over a broad area and to allow light to penetrate fully into the tissues. 
Thus, the correct answer is option C.

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

A leaf is

  1. Differentiated into nodes and internodes

  2. A lateral outgrowth of stem

  3. Endogenus in origin

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Exogenous, flattened, green, lateral appendages arising from nodes of the stem or branches in acropetal succession are called as leaves. Leaves arise from shoot apical meristem and bear buds in their axils and help in assimilation of food, exchange of gases and transpiration. So, leaf is a lateral outgrowth of stem.  

Thus, the correct answer is option B.

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

The leaf arises at the __________ on the stem.

  1. Internode

  2. Axil

  3. Node

  4. Petiole
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • Node: The leaves arise in the regions of the plant known as the plant nodes and are therefore the point of attachment of the leaves. 
  • The region of the plant between two nodes is known as the internode.
  •  The angle between the upper surface of the leaf and the stem from which it arises is known as the axil. 
  • The petiole is the stalk which attaches the leaf to the stem. 
So, the correct option is 'Node'.

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

In monocot leaf 

  1. Bulliform cells are absent from the epidermis

  2. Veins form a network

  3. Mesophyll is well differentiated into these parts

  4. Mesophyll is not differentiated into palisade and spongy parenchyma
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

leaf is a green outgrowth of a stem. It performs photosynthesis and provides food to the rest of the plant body. There are different types of leaves found due to climate, water availability, etc. A leaf consists of lamina and petiole, leaves can be monocot or dicot. It contains stomate which helps in gaseous exchange.


(D) Mesophyll is not differentiated into palisade and spongy parenchyma where as it is present in dicot leaves.

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Meristem present at Lamina margin is

  1. Apical meristem

  2. Intercalary meristem

  3. Both of (A) and (B)

  4. Marginal meristem
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Marginal meristem is the meristem located along the margin of a leaf primordium and forming the leaf blade. The apical meristem or growing tip, is a completely undifferentiated meristematic tissue found in the buds and growing tips of roots in plants.
Intercalary meristems are capable of cell division, and they allow for rapid growth and regrowth of many monocots. Intercalary meristems at the nodes of bamboo allow for rapid stem elongation, while those at the base of most grass leaf blades allow damaged leaves to rapidly regrow.
In mass meristem the cells divide in all planes to form bulk of tissue. this type of meristem takes part in the formation of cortex, pith, endosperm and sporangia.
Therefore, the correct answer is option D.

Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Hydathodes occur on

  1. Stem

  2. Leaf

  3. Root

  4. Fruit
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A hydathode is a type of secretory tissue in leaves, usually found in angiosperms, that secretes water through pores in the epidermis or margin of leaves, typically at the tip of a marginal tooth or serration. 

Hydathodes are mainly found in aquatic plants and in some herbaceous plants growing in moist places. They probably evolved from modified stomata and are connected to the plant vascular system by a vascular bundle. Hydathodes are commonly seen in water lettuce, water hyacinth, rose, balsam etc.