Briefly explain how the rate of transpiration is affected by
(a) Intensity of light
(b) Humidity of the atmosphere.
a)- Intensity of ligiht plays a major role in transpiration.Transpiration rate increases by an increase in light intensity.
Now the rate of transpiration can be affected by several factors: The opening and closing of the stomata by the guard cells (stomatal rhythm)- In light, guard cells take up water by osmosis and become turgid.
b)-Relative humidity: As the relative humidity of the air surrounding the plant rises the transpiration rate falls. It is easier for water to evaporate into dryer air than into more saturated air. Wind and air movement: Increased movement of the air around a plant will result in a higher transpiration rate