Write a brief note on respiration in plants.
1) In most plants exchange of gases takes place through stomata.
2) There are other areas on the plant body as well, through which gaseous exchange takes place like surface of roots, lenticels on stem, etc.
3) Some plants have specialized structures like, breathing roots of mangrove plants as well as the tissue in orchids.
4) Breathing roots and tissue in orchids help plants to take oxygen to produce energy and carbon dioxide is released.
5) Inside the plants stomatal openings lead to a series of spaces between the cells which form a continuous network all over the plant.
6) The whole system works by diffusion.
7) As the oxygen is used up by the cells a gradient develops between the cells and the air in the spaces and similarly between the air spaces and the air outside stomata and lenticels, so oxygen passes in:
8) In the same way, as more carbon dioxide is given out by the cells, a gradient occurs in the reverse direction and it passes out.