Question

Which one is responsible for opening and closing of stomata?

• A. Rise in pH of guard cells causes hydrolysis of starch
• B. Cytokinins and cAMP are required
• C. Absicisic acid promotes closure
• D. All of the above

Answer 1

Answer: (D)

All of the above

When there is the rise in pH it causes hydrolysis of starch into sugar which accumulates in guard cells which results in the opening of cells. For this mechanism, cytokinins and cAMP are required.

Abscisic acid is the stress hormone which results in the closing of stomata.

So, the correct answer is 'All of the above'.