Question

Which one of the following describes a possible reason for the opening and closing of the guard cells

• A. Stomata open in daylight because photosynthesis occurs in the guard cells producing sugar resulting in higher osmotic pressure
• B. Stomata open in daylight because guard cells have chloroplasts and the epidermal cells do not, and so a differential osmotic pressure arises
• C. Stomata open in daylight because starch is changed to osmotically active substances which increase the turgidity of the guard cells
• D. Stomata close in darkness because the starth produced in daylight by photosynthesis; it is changed into sugars and translocated from the guard cells

Answer 1

Answer: (C)

Stomata open in daylight because starch is changed to osmotically active substances which increase the turgidity of the guard cells