Plants have no special organs for exchange of gases. In plants gaseous exchange
occurs in each part. The different methods are as under: -
Through Stomata: -
Gaseous exchange takes place through stomata present on the lower side of the leaf.
Land plants get their oxygen from air directly through stomata.
Through Lenticels: -
In woody stems and roots there are dead cells under the epidermis which form cork
tissues. These tissues have pores called lenticels. These lenticels are also involved in
gaseous exchange.
Through Diffusion: -
The aquatic plants obtain oxygen by diffusion from water.