Question

Give scientific reasons for the following statement.

The leaves of certain plants roll up on a bright sunny day.

Answer 1

Transpiration

1. Transpiration is the loss of water through the stomata, lenticels, or cuticles of a plant.
2. It produces a cooling effect on the plant.
3. However, as the rate of transpiration increases on a bright sunny day, the leaves of plants roll up to prevent excess water loss through transpiration.
4. It is one of the methods to reduce transpiration and prevent wilting of the plant.

Hence, the leaves of certain plants roll up on a bright sunny day because it helps to reduce transpiration and prevent excess loss of water by the plants.