Question

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

Answer 1

the opening and closing of the stomata is controlled by the gured cell

Answer 2

Guard cells shrink during the dry season to stop the evaporation of water from leaves but during favourable climate when plant get sufficient water then guard cells open for evaporation of excess water which is absorb by them.The evaporation of water from leaves through stomata called transpiration