Describe the process of respiration in the following parts of a plant:
(a) The respiration in roots takes place by the diffusion of respiratory gases through the root hair. The root hair take the oxygen required for respiration from the air present in-between the soil particles, by the process of diffusion. The oxygen reaches all the other cells of the root for respiration. During respiration, the carbon dioxide gas produced in the cells of the root moves out through the same root hair by the process of diffusion.
(b) The stems of herbaceous plants have stomata. The oxygen from air diffuses into the stem of a herbaceous plant through stomata and reaches all the cells, for respiration. The carbon dioxide gas produced during respiration diffuses out into the air, through the same stomata. In woody stems, the bark has lenticels for gaseous exchange.
(c) The leaves of a plant have tiny pores called stomata. The oxygen from air diffuses into a leaf through stomata and reaches all the cells, where it is used in respiration. The carbon dioxide gas that is produced during respiration, diffuses out from the leaf into the air through the same stomata.
Lakhmir Biology 2013