How do the guard cells regulate opening and closing of stomatal pores?

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

Answer:

The swelling of guard cells due to absorption of water causes opening of stomatal pores while shrinking of guard cells closes the pores. Opening and closing of stomata occurs due to turgor changes in guard cells. When guard cells are turgid, stomatal pore is open while in flaccid conditions, the stomatal aperture closes.