Question

Which essential element plays an important role in the opening and closing of stomata?

• A. Phosphorus
• B. Potassium
• C. Sodium
• D. Cobalt

Answer 1

The correct option is B

Potassium

Potassium plays an important role in the opening and closing of stomata. According to the potassium pump theory, the movement of potassium ions across the cell membranes of the guard cells of the stomata leads to changes in the osmotic pressure of the surrounding cells. This, in turn, changes the turgor pressure of the guard cells causing the closing and opening of the stomata.