AP BIOLOGY

Detailed explanation-1: -The rate of transpiration Increases with the intensity of sunlight, high temperature, dry air, the velocity of wind, the high water content of the leaf. The rate of transpiration decreases with the closure of stomata, high humidity, high atmospheric carbon dioxide level, the low water content of leaf, shedding of leaf.

Detailed explanation-2: -As the relative humidity of the air surrounding the plant rises the transpiration rate decreases. It is easier for water to evaporate into dryer air than into more saturated air.

Detailed explanation-3: -At high atmospheric humidity, transpiration is low. This is because the rate of transpiration is directly proportional to the saturation deficit. It is dependent on the gradient of vapor pressure. Thus, the higher the humidity, the lower the rate of transpiration.