Question

Transpiration in plants will be lowest when

• A. There is high humidity in the atmosphere
• B. High wind velocity
• C. There is excess of water in the soil
• D. Environmental conditions are very dry

Answer 1

Answer: (A)

There is high humidity in the atmosphere

Transpiration is loss of water in vapour form through stomata. Rate of transpiration depends on a number of factors, like carbon dioxide concentration, temperature, light, humidity etc. The most important factor which governs rate of transpiration is the vapour pressure gradient, which exists between leaf mesophyll and atmosphere. Thus, more the humidity lesser the rate of transpiration and vice versa.