LIFE SCIENCE

Detailed explanation-1: -Guard cells are cells surrounding the stomatal pores. Stomata regulate the process of transpiration and gaseous exchange. Guard cells regulate the opening and closing of stomata. The outer walls of guard cells are thin and their inner walls are thickened.

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: -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. When the guard cells lose water, they become flaccid and straight and thus, close the stomatal aperture. Guard cells and stomata regulates the respiration process in plants.