Photosynthesis

Q.

Oxygen is returned to the atmosphere mainly by ______.

1. photosynthesis

2. burning of fossil fuel

3. decomposition

4. respiration

Q.

The process in which plant use CO2 present in the air is called transpiration.

1. True

2. False

Q.

Question 24
Oxygen is returned to the atmosphere mainly by:

(a) burning of fossil fuel
(b) respiration
(c) photosynthesis
(d) fungi

Q.

Name the plant organ which is responsible for:
(a) making of food.
(b) absorption of water and minerals.

Q.

Name the two important biological processes in which air is essential.

Q.

What is function of stomata ?

Q. Which gas is produced by the plants during the process of photosynthesis?

1. Nitrogen
2. Carbon dioxide
3. Carbon monoxide
4. Oxygen

Q. The component of air used by green plants to make their food is:

1. Sulphur dioxide
2. Nitrogen
3. Oxygen
4. Carbon dioxide

Q. Which of the following process releases oxygen into the air?

1. Transpiration
2. Respiration
3. Photosynthesis
4. Digestion

Q. The proportion of oxygen and carbon dioxide in the atmosphere is maintained by ___ .

1. machines
2. both plants and animals.
3. plants
4. animals