Structure of Stomata

Stomata are composed of two specialized cells called guard cells, which surround a pore. The guard cells are responsible for regulating the opening and closing of the stomatal pore.

Function of Stomata

1. Gas Exchange: Stomata allow for the exchange of gases, such as carbon dioxide and oxygen, between the plant and the surrounding atmosphere. 2. Transpiration: The opening and closing of stomata control the rate of transpiration, which is the process of water evaporation from the plant's surface.

Regulation of Stomatal Opening

The opening and closing of stomata are regulated by various factors, including light, humidity, and the plant's internal water status. Light triggers the uptake of potassium ions by the guard cells, leading to their swelling and the opening of the stomatal pore. Conversely, a decrease in light levels or high humidity causes the loss of potassium ions, leading to the shrinking of the guard cells and the closure of the stomatal pore.