Question

State the utility of oxygen for respiration in plants

Answer 1

Respiration in plants:

1. Plants respire during the day and night.
2. Plants respire through tiny pores on the surface of the leaves called ‘stomata’.
3. The stomata help in taking in the oxygen of the air and giving out carbon dioxide. Thus, they function as respiratory organs.
4. Plants do not perform bodily activities and hence need less energy than animals. The rate of respiration in plants is thereby slower than in animals.

Photosynthesis in plants:

Photosynthesis is a process by which green plants prepare their own food in the presence of sunlight and chlorophyll.

1. In the leaf of a green plant are present leaf cells which contain chloroplasts in which is present a green pigment called chlorophyll.
2. During photosynthesis which occurs during daytime, carbon dioxide and water in the presence of sunlight and chlorophyll is changed into glucose, and oxygen is released out.
   \[\ce{Carbon dioxide + Water ->[Sunlight][Chlorophy II]Glucose + Oxygen + Water}\]
3. Hence oxygen in the air is renewed by photosynthesis and therefore the amount of oxygen in the air does not get depleted or removed from the air.