Describe the exchange of gases which takes place in the leaves of a plant:
(a) During daytime, and
(b) At night
(a) During daytime, and
(b) At night
Exchange of gases in the leaves of a plant during daytime:
∙ Both photosynthesis and respiration occur during the day. But, the rate of photosynthesis is more than the rate of respiration. So, the plants release oxygen during daytime.
∙ Leaves use some of the oxygen, produced from photosynthesis for respiration, and the rest of the oxygen diffuses out into the air.
∙ Again, during the daytime, carbon dioxide produced by respiration is used up in photosynthesis by leaves. Even more carbon dioxide is taken in from the air.
Exchange of gases in the leaves of a plant at night:
∙ At night, no photosynthesis occurs. So, no oxygen is produced. The oxygen from the air diffuses into the leaves to carry out respiration.
∙ Carbon dioxide produced by respiration diffuses out into the air.
∙ So, the net gas exchange in leaves at night is: Oxygen diffuses in; carbon dioxide diffuses out.
Exchange of gases in the leaves of a plant during daytime:
∙ Both photosynthesis and respiration occur during the day. But, the rate of photosynthesis is more than the rate of respiration. So, the plants release oxygen during daytime.
∙ Leaves use some of the oxygen, produced from photosynthesis for respiration, and the rest of the oxygen diffuses out into the air.
∙ Again, during the daytime, carbon dioxide produced by respiration is used up in photosynthesis by leaves. Even more carbon dioxide is taken in from the air.
Exchange of gases in the leaves of a plant at night:
∙ At night, no photosynthesis occurs. So, no oxygen is produced. The oxygen from the air diffuses into the leaves to carry out respiration.
∙ Carbon dioxide produced by respiration diffuses out into the air.
∙ So, the net gas exchange in leaves at night is: Oxygen diffuses in; carbon dioxide diffuses out.
