Question

The opening and closing of the stomatal pore depends upon

(a) Oxygen
(b) Temperature
(c) Water in the guard cells

Answer 1

(c) Water in the guard cells

Guard cells are specialised cells present in the epidermis of leaves, stems and other organs that are used to control gas exchange. Guard cells regulate the opening and closing of stomata for the exchange of gases. Guard cells when swollen in the presence of water makes the stomata open and in the absence of water they shrink, and it leads to closing of stomata.