Question

Assertion
When the ambient temperature is high and soil contains excess water, the plants tend to lose water in the form of droplets from lenticels.
Reason
Root pressure regulates the rate of loss of water from lenticels.
A. Both Assertion and reason are correct and Reason is the correct explanation for Assertion.
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
C. Assertion is correct but Reason is incorrect.
D. Assertion is incorrect but reason is correct.

Answer 1

Ambient temperature is something related to normal temperature present in the surrounding. Plants lose maximum water via transpiration through the plant leaves, they lose water to remain cool or for pumping several minerals and water to the leaves for photosynthesis.

Complete answer:
In plants, lenticels are present on roots or stem of the plants, rough in texture and cork-like structure on young branches. They are small openings in the bark of branches. Water evaporation from lenticels of the plants is termed as lenticular transpiration. Though they are not present in all plants, a small amount of water loss takes place through lenticels in the form of water vapours.
Assertion: As mentioned when ambient temperature increases and soil having excess water then the plants start losing water in the form of water droplets.
Root pressure (which is a lesser force) is the osmotic pressure within the cells of a root system. It is an essential part of mainly small plants when transpiration is not significant at times e.g, night times as transpiration does not occur at night. Root pressure needs metabolic energy, which manages the active uptake of mineral ions from the soil to root. Root pressure regulates the rate of loss of water via lenticels.
Reason: As mentioned root regulates the rate of water from lenticels.
So, as we have discussed the correct option is B because both assertion and reason are correct but reason does not explain the assertion.

Note: Transpiration keeps the cell turgid or rigid, cools the leaves surface, uptakes minerals or water which is essential for photosynthesis. Whereas transpiration does not occur at night so root pressure is important at that time.