Question

Choose the correct statements out of the following.

• A. There is unequal transpiration from the two surfaces of a dorsiventral leaf.
• B. There is equal transpiration from the two surfaces of a dorsiventral leaf.
• C. Desert plants have thicker cuticles to cut down photosynthesis.
• D. Desert plants have thicker cuticles to cut down transpiration.

Answer 1

Answer: (A), (D)

The correct options are
A There is unequal transpiration from the two surfaces of a dorsiventral leaf.
D Desert plants have thicker cuticles to cut down transpiration.

$\bullet$ The number of stomata is more on the lower surface of a dorsiventral leaf, so more transpiration occurs from the lower (dorsal) surface of the leaf than the upper (ventral) surface. And hence there is unequal transpiration occuring from the two sides of the leaves.
$\bullet$ Cuticle is the waxy layer secreted by the epidermis on the two surfaces of the leaf. The thickness of the cuticle varies from plant to plant. The thicker the cuticle, the more the resistance to evaporation of water, and the lesser the water loss.