Question

Opening and closing of stomata is due to

(a) Hormonal change in guard cells

(b) Change in turgor pressure of guard cells

(c) Gaseous exchange

(d) Respiration

Answer 1

Correct option  (b) Change in turgor pressure of guard cells

Explanation :

When the guard cells become rurgid, the stomata open. On the other hand, if the guard cells loose water, these become flaccid, the inner wails sag and the pore closes. 

Thus, stomatal movement occurs due to changes in turgor pressure of guard cells.