Question

How does the stomata control transpiration in plants?

Answer 1

Transpiration is the process of water movement through a plant by the help of evaporation from aerial parts, such as leaves, stems and flowers.

Plants regulate the rate of transpiration by controlling the size of the stomatal apertures. The stomata are pores in the leaf and the primary control mechanisms, which reduce the loss of water. They are able to do this very quickly. Stomata are sensitive to the environmental indicator, which trigger the stomata to open or close. They allow gas exchange where water vapor departs the plant and carbon dioxide enters. Special cells known as guard cells, which control opening or closing of pores. When stomata are open, rates of transpiration increase and when they are closed, rates of transpiration decrease.

The major role of stomata is to allow carbon dioxide entry to drive the process of photosynthesis and at the same time allow the exit of water as it evaporates, cooling the leaf.