What are stomata? Give the structure and function of stomata.

The word ‘Stomata’ is taken from the Greek word which means ‘Mouth’.

It is a pore, found in the epidermis of leaves, stems, and other organs, that facilitates the exchange of gases such as oxygen, carbon dioxide, and water vapour to diffuse between the interior and outer surface of the plant tissues.

Structure:

The stomatal pore is guarded by two kidney bean-shaped cells known as guard cells. It helps in the closing and opening of the stomatal pore.

The structure of stomata is like tiny mouths which open and close as they assist in transpiration.

Functions:

1. Stomata allow the exchange of gases. Commonly carbon dioxide is consumed and oxygen is released through stomata during photosynthesis, while oxygen is consumed and carbon dioxide is released through stomata during respiration.

2. Through stomatal pore, the excess amount of water is released from aerial parts of the plant in the form of water vapour through transpiration.

3. It also maintains the moisture balance according to weather by opening and closing.