The opening and closing of guard cells is most directly determined by uptake and release of

Question

Quizplus · Accepted Answer

The opening and closing of guard cells are most directly determined by the uptake and release of potassium ions (K+). When potassium ions are taken up by the guard cells, water follows osmotically, causing the cells to swell and the stomatal pore to open. Conversely, when potassium ions are released, water exits the cells, leading to their shrinkage and the closing of the stomatal pore.

The Opening and Closing of Guard Cells Is Most Directly