Question

How do guard cells regulate the closing of stomatal pores?

Answer 1

Guard cells regulate the closing of the stomatal pores by losing their internal water pressure.

• When water flows out of the guard cells, the turgor pressure drops, causing the cells to shrink and become flaccid.
• Without the internal water pressure stretching the cells outward, the tension on the cell walls is completely released.
• The thick inner walls relax and collapse back into their original, resting position, coming together to completely close the stomatal pore and prevent further water loss.