Question

How do the guard cells regulate the opening and closing of stomatal pores?

Answer 1

Guard cells:

1. Guard cells are specialized cells present inside the epidermis of leaves.
2. They assist in the exchange of gases.
3. They surround a pore known as a stomatal aperture through which the exchange of gases occurs.
4. Upon the incoming of water inside the guard cells, they swell up to become like a curved banana surface, due to which the stomatal pore opens up.
5. When the guard cells lose water, they become flaccid and straight and thus, close the stomatal aperture.
6. Guard cells and stomata regulates the respiration process in plants.

Functions of stomata:

1. The exchange of Co₂ and O₂ occurs via the stomatal aperture.
2. It regulates the control of water loss via the transpiration pull.
3. The opening and closing of the stomatal aperture depend upon moisture availability in the atmosphere.
4. During photosynthesis it allows the movement of Co₂ and releases O₂ in the atmosphere.
5. The closure of stomata during the night prevents water loss through pores.