Question

Explain how the direction of exchange of gases in plants changes during a day.

Answer 1

Change in the direction of gaseous exchange in plants throughout the day:

1. During the daytime, in the presence of sunlight, plants prepare their food by the process of photosynthesis.
2. The raw materials for the process of photosynthesis are carbon dioxide and water.
3. Respiration is the process by which plants break down complex materials for the release of energy.
4. The process of respiration occurs throughout the day and carbon dioxide and water are released as the by-product of the reaction.
5. Since, respiration occurs all the time in the plants while photosynthesis takes place only during a certain amount of time during the day, the direction of gaseous exchanges changes depending upon the time of the day.
6. During the daytime, the carbon dioxide from respiration is used by the plants for the process of photosynthesis and is not released into the environment.
7. In the nighttime, since photosynthesis stops, the carbon dioxide from respiration is released into the air.