Question

Rate of transpiration is related to
A. Light and temperature
B. Light, temperature, atmospheric humidity and wind
C. Light, temperature and wind
D. Soil and temperature

Answer 1

Hint: The plants regulate the rate of the transpiration by opening and closing the stomata. However, there are a number of external factors that affect the rate of transpiration.

Complete answer:
The climatic features that influence the rate of the transpiration is light, relative humidity, temperature, availability of water, and also wind.
Distinctly, these are the environmental factors which disturb the process of photosynthesis and the plant growth and processes of development.
The high humidity results in decreasing the transpiration rate.
If there is an increase in the temperature then its effects reflect in the increasing of the evaporation and also in the transpiration.
The wind also increases transpiration and evaporation, wind removes the water vapour from the leaves increasing water vapour pressure gradient.
The light helps to increase in the transpiration rate, by causing the stoma to open.
The wider stomata faster the diffusion process of water vapour out of the leaf.
Therefore, the correct answer is option (B).

Additional information:
The transpiration is the process in which the plant roots absorb water and then release the water in the form of the vapour through the leaves.
The transpiration is an important factor in the water cycle as it is one of the major sources of the water into the atmosphere.
The plants transpire more rapidly in the light than in the dark.
This is largely because the light stimulates the opening of the stomata.
The light also speeds up the transpiration by warming the leaf.
The plants transpire more rapidly at higher temperatures because the water evaporates more rapidly as the temperature rises.

Note:
The rate of transpiration can be calculated by measuring the distance travelled by an air bubble in a capillary tube over the given period of time.
The faster the bubble moves, the greater the rate of water uptake, and so the greater the assumed rate of the transpiration.