Question

How do guard cells regulate opening and closing of stomatal pores​

Answer 1

The opening and closing of stomata are controlled by the guard cells. When water flows into the guard cells, they swell up and the curved surface causes the stomata to open. When the guard cells lose water, they shrink and become flaccid and straight thus closing the stomata.

Answer 2

Answer:

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.