Question

In the mechanism of opening of stomata, the important factor is

• A. Turgidity of the guard cells
• B. Chlorophyll content of the guard cells
• C. Hormone content of the subsidiary cells
• D. Protein content of the epidermal cells

Answer 1

The correct option is A Turgidity of the guard cells

The guard cells are produced in pairs containing a gap between them that forms a stomatal pore. The stomatal pores are largest when water is freely available and the guard cells are turgid and closed when water availability is critically low. Photosynthesis depends on the diffusion of Carbon dioxide (CO₂) from the air through the stomata into the mesophyll tissues. Oxygen (O₂), produced as a byproduct of photosynthesis, exits the plant via the stomata. When the stomata are open, water is lost by evaporation and must be replaced via the transpiration stream with water taken up by the roots.