Question

Stomatal opening is affected by

• A. Nitrogen concentration, carbon dioxide concentration and light
• B. Carbon dioxide concentration, temperature and light
• C. Nitrogen concentration, light and temperature
• D. Carbon dioxide concentration, nitrogen concentration and temperature

Answer 1

The correct option is B Carbon dioxide concentration, temperature and light

Carbon dioxide is an effective anti-transpirant. A little rise in CO₂ concentration induces partial closure of stomata. It higher concentration results in complete closure of stomata. Light affects the rate of transpiration in two ways-firstly by controlling the stomatal opening and secondly by affecting the temperature. Increase in temperature increases the rate of transpiration.