Question

Water vapor comes out from the plant leaf through the stomatal opening. Through the same stomatal opening, carbon dioxide diffuses into the plant during photosynthesis. Reason out the above statements using one of following options :

• A. Both processes cannot happen simultaneously
• B. Both processes can happen together because the diffusion coefficient of water and $C{O}_2$ are different.
• C. The above processes happen only during night time.
• D. One process occurs during day time and the other at night

Answer 1

The correct option is B Both processes can happen together because the diffusion coefficient of water and $C{O}_2$ are different.

Diffusion of water vapour and carbon dioxide are independent processes. Their diffusion depends on the difference in their partial pressures in the atmosphere as well as inside the leaves.So both processes can happen simultaneouly. Both gases can diffuse through the stomata both during the day and the night, if and whenever the stomata are open.