Question

As light intensity increases, rate of transpiration _______.

• A. increases
• B. decreases
• C. remains same
• D. remains unaffected

Answer 1

The correct option is A increases

Light is one of the environmental factors affecting the rate of transpiration. During the day, stomata is open to facilitate the inward entry of carbon dioxide for the process of photosynthesis. Alongside, it also poses a greater risk of higher water loss compared to the night time when the photosynthetic activity has stopped.
As the intensity of light increases, the ambient temperature will be higher. In such case more evaporation will take place and hence the water loss will be higher.
Other external factors affecting the transpiration rate are: Atmospheric pressure, $CO2$ level, wind velocity and temperature.