NEET BIOLOGY

Detailed explanation-1: -The opening and closing of stomatal pores is regulated by guard cells by increasing or decreasing the amount of water in them. When water enters the guard cells, they become turgid. This results in opening of stomata) pore. When water exits from the guard cells, they become flaccid.

Detailed explanation-2: -Most plants regulate the size of stomata with guard cells. Each stoma is surrounded by a pair of sausage-shaped guard cells. In bright light the guard cells take in water by osmosis and become plump and turgid . In low light the guard cells lose water and become flaccid, causing the stomata to close.

Detailed explanation-3: -When there is no light, the sugar in guard cells turns to starch. The starch is insoluble, so the guard cells have a lower concentration than the neighboring cells, and the neighboring cells osmotically remove the water from the guard cells, rendering them flaccid and the stomata close.