Tag: morphology of leaf

Questions Related to morphology of leaf

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

The cuticle present above the epidermis is helpful in reducing 

  1. Transpiration

  2. Respiration

  3. Photosynthesis

  4. None of the above

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cuticle is comprised of polymers of wax. This layer is present on the surface of the epidermis of leaf and stem. This is the waxy and waterproof layer. This layer prevents the loss of water from the leaves and stem. This protective layer allows the retention of the water. This helps to reduce the loss of water in the form of water vapour by transpiration. 

Thus, the correct answer is option A. 

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

A Leaf of $20 \,cm^2$ grows $5 \,cm^2$ per hour and $B$ Leaf of $25 \,cm^2$ grows $5 \,cm^2$ per hour
The relative growth rate of leaf $A$ and $B$ respectively is

  1. $25\%$ and $20\%$

  2. $20\%$ and $25\%$

  3. $50\%$ and $100\%$

  4. $25\%$ and $50\%$

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Relative growth is the increase in size relative to the size of the plant leaf present at the start of a given time interval. It can be also expressed as percentage increase.

Hence, for leaf A, relative growth = 5/20 × 100 = 25
For leaf B, relative growth = 5/25 × 100 = 20.
So, the correct option is '25 and 20'.

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

Go through the following matches.

(i) China rose Twisted aestivation
(ii) Calotropis Valvate aestivation
(iii) Gulmohur Ascending imbricate aestivation
(iv) Pea Descending imbricate aestivation

Which of these are correct?

  1. (i), (ii) and (iii)

  2. (ii), (iii) and (iv)

  3. ii), (iii), (iv)

  4. All are correct

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
i) China rose - One margin of the appendage overlaps that of the next one (Twisted aestivation).
ii)Twisted aestivation -  The sepals or petals in whorl just touch one another at the margin (Valvate aestivation).
iii) Gulmohar botanical name is Delonix - Ascending imbricate aestivation.
iv) Tephrosia is a genus of flowering plants in the pea family - Descending imbricate aestivation.
So, the correct option is 'All are correct'. 
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

Guard cells are kidney shaped in 

  1. Rice

  2. Beans

  3. Grasses

  4. Maize

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Guard cells are specialized epidermal cells present on the surface of leaves and stems of plants that control the gaseous exchange in plants.
  • The guard cells form stomatal pores through which gaseous exchange and transpiration take place.
  • In monocots, the guard cells are dumbbell shape.
  • In dicots, they are kidney or bean shaped.
  • So, the correct answer is 'Beans'.