What causes the opening and closing of guard cells of stomata during transpiration?
Explanation Opening and closing of pores called stomata occurs due to changes in turgor in guard cells. Due to endosmosis an increase in turgor of guard cells takes place which finally results in stretching and bulging out of their outer thin walls. This results in the pulling apart of the opposed inner thicker walls creating an opening or pore in guard cells of stomata. When the turgor pressure of guard cells decreases, inner walls sag, leading to closure of space between them. This is due to the loss of water from guard cells, resulting in thicker walls to move closer and finally shut the opening. Final Answer You all have seen the surface of a green leave, there are several pores that can be seen on the surface, these pores are known as stomata. The function of stomata includes exchange of gases. The stomata also contain dumbbell shaped cells called guard cells. The opening and closing of the guard cells are been controlled by the arrangement of micro fibrils. When the turgor pressure is high, the micro fibrils are radial arranged, which leads to the opening of guard cells. When the turgor pressure is low, the micro fibrils are arranged longitudinally, which leads to the closure of guard cells.
