Question

Element involved in stomatal regulation, its opening and closing is

• A. Zinc
• B. Magnesium
• C. Potassium
• D. Iron

Answer 1

The correct option is C Potassium

Stomata open and closes due to water and ion movement. When the light falls on the parts of the plant, chloroplast carries out photosynthesis. ATP from photosynthesis powers sodium and potassium pump. Then the K${}^{+}$ ions are pumped (influx of K${}^{+}$) into the guard cells, by creating a concentration gradient and also water enter into the guard cell through osmosis. As a result of this, guard cells swells and stomata open. The reverse process occurs in the closing of stomata, i.e, loss of K${}^{+}$ ions (efflux of K${}^{+}$) by guard cells and water also leave the guard cells by the process osmosis. As a result, guard cells become flaccid and stomata close.

So, the correct answer is option C.