Question

Water vapour 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 the following options.

• A. Both processes can happen together because the diffusion coefficient of water and $CO _{2}$ is different
• B. The above processes happen only during night time
• C. One process occurs during daytime and the other at night
• D. Both processes cannot happen simultaneously

Answer 1

Answer: (A)

The reason given in option (a) is correct.
During photosynthesis, water vapour comes out through a stomatal opening of the leaf of a plant. And through the same opening $CO _{2}$ diffuses into the leaf. This simultaneous entry and exit of $CO _{2}$ and water vapour, respectively, occurs due to a difference in the diffusion coefficient of $CO _{2}$ and water vapour.