Question

The guard cells become turgid at the time of opening of stomata due to?

Answer 1

Guard cells:

1. Guard cells are two kidney-shaped epidermal cells present around the pore known as the stoma.
2. The cell walls of guard cells are unevenly thickened, the outer wall is thin and the inner wall is thick.
3. Due to this differential, they attain a turgid state and open the stomatal pores (stoma) because of the turgor pressure that expands the cells.
4. When the turgor pressure is zero, these cells become flaccid and the stomatal pore will be closed.

Opening and closing of stomata:

1. The opening and closing of stomata are due to the change in turgor pressure of the guard cell.
2. During the daytime, the roots absorb more water due to greater transpiration pull and it is transported to different parts of the plant through the xylem.
3. The guard cell, on receiving this water, swells and attains a turgid state.
4. As a result of this, the stomatal pore is open.
5. At night, the roots absorb less water, thus the guard cell becomes flaccid and shrinks.
6. As a result, stomatal pores close.