Opening and closing of stomata is due to the:

Step-by-step solution

The guard cells are filled with chloroplasts. The guard cells are rapidly influenced by changes in the turgor pressure that regulate the opening and closing of the stomata. In the case of dicot plants, the wall of the guard cells near the pore is thick and inelastic, whereas, the outer wall is thin, elastic and semi-permeable. When the turgor develops in the guard cells, the outer thin walls expand towards the outer side. This draws the thick inner walls slightly apart and creates a pore between the two guard cells