Question

By which of the following processes does water evaporate from the surface of the leaf?
A. Transpiration
B. Evaporation
C. Condensation
D. Both A and B

Answer 1

Transpiration is defined as the process by which water evaporates from the tiny pores called as stomata present on the surface of the leaf.

Complete step by step answer:
Transpiration, as we know, is defined as the loss of water from the surface of leaves and its vaporization in the atmosphere.
In plants, water is removed from the tiny pores present on the surface of the leaf through the process of transpiration. This water goes into the atmosphere and forms vapor. The process of transpiration is more active during the time when there is no or minimal solar radiation or heat energy for evaporation to take place.
However, during midday time, the water is lost from the surface of the leaf through the process of evaporation too. This is because of the availability of sufficient solar radiation during the day time which is not so evident during night time. Moreover, it can be seen that transpiration is just a replaceable process for evaporation. When the plant gets favorable solar radiation, the process of loss of water takes place through the evaporation. Whereas during night time, when the solar radiation is minimal or not that sufficiently high for evaporation to take place, then the process of transpiration dominates over evaporation.

The correct option is D) Both A and B.

Note:
It should be noted that transpiration is just a subset of the process of evaporation. Thus, the plants can lose water through both the processes depending upon the amount of solar radiation available for the plant.