MP Board · Class 9 · Science · TissuesWhat are stomata? Describe their structural features and state two essential functions performed by them in plants.

Stomata are tiny microscopic pores present mainly on the epidermal layer of leaves and young stems of plants.

Structural Features:

• Each stomatal pore is enclosed and guarded by two kidney-shaped specialized epidermal cells known as guard cells.
• Guard cells control the opening and closing of stomata by swelling when water flows into them and shrinking when water exits.

Two Essential Functions:

1. Transpiration: Facilitates the loss of excess water from plant aerial parts in the form of water vapor, generating a suction pull that transports water and minerals while cooling the plant body.
2. Gaseous Exchange: Allows exchange of essential gases like carbon dioxide ($CO_2$) and oxygen ($O_2$) during photosynthesis and respiration.