Question

Water vapour comes out from the planet 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 option : -

• A. Both processes cannot happen simultaneously.
• B. Both processes can happen together because the diffusion coefficient of water and ${CO}_2$ is 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 A Both processes cannot happen simultaneously.

There are two processes involved :

1. Photosynthesis - it is the process of diffusion of gases i.e., the exchange of gases through the stomatal opening and formation of glucose molecules as food. It occurs mostly during the day but in some plants, it may occur at night.
2. Transpiration - It is the process of diffusion of a water droplet through the stomatal opening. It is simply the loss of water through leaflets. It occurs mostly at night or early morning.

Both processes occur at different timings of the day.

So, the correct option is 'Both processes cannot happen simultaneously'.