Question

Which among the following has an adverse effect on the rate of transpiration?
I. Increase in relative humidity
II. Increase in atmospheric temperature
III. Increase in water uptake
IV. Increase in wind velocity
V. Decrease in light intensity

• A. I and II
• B. II and III
• C. II and IV
• D. I and V

Answer 1

The correct option is D I and V

• When relative humidity is high, the rate of transpiration decreases because the atmosphere is more saturated with moisture. It retards the diffusion of water vapour from intercellular spaces to the outer atmosphere through stomata.

•Transpiration increases with an increase in atmospheric temperature and vice-versa.

• An increase in the amount of available soil water increases the rate of transpiration.

•The rate of transpiration increases with the wind velocity because it removes moisture from the vicinity of the transpiring parts of the plants.

•The decrease in light intensity causes a decrease in the rate of transpiration.

So the correct option is " increase in relative humidity and a decrease in light intensity ".