How does the leaves of a plant carry out respiration?

Leaves and young green stems have pores on them. These pores are called stomata. The exchange of gases takes place through these stomata. There are more stomata on the lower surface of leaves. Oxygen and water vapour leave the plant through the stomata while carbon dioxide enters through them. Each stoma has two bean-shaped cells called guard cells. The inner walls of the guard cells are thicker than the outer walls. When the guard cells are full of water, they swell and bulge outwards, opening the stomata. When the guard cells lose water, they lose their turgidity closing the stomata. When the stomata open, the exchange of gases takes place by the process of diffusion.