Question

In some plants, the leaves droop down during day, while become normal during night
A. Due to temporary wilting
B. Permanent wilting
C. Both A and B
D. None of the above

Answer 1

Hint: As we know that if the plants do not get enough water, their leaves will start to droop or wilt. The edges also curl and the leaves often turn yellow, too. This is a defensive mechanism, since a plant will get rid of any surface area that would lose water to the atmosphere by shedding leaves.

Complete answer:
We have to remember that the minimum level of water in the soil required by the plant to not wilt is known as the permanent wilting point or wilting point. A plant wilts when the soil water content falls to this or any smaller point and can no longer recover its turgidity when put for 12 hours in a saturated atmosphere.
As we know that when the rate of transpiration is greater than the rate of water absorption, temporary wilting is induced and so the cells of the leaves lose their turgor. However, by watering plants or when the transpiration rate drops during the night period, the turgidity of the leaf cells can be preserved.
It is a situation in which, during transpiration, the amount of water lost from the plant is greater than the amount of water absorbed from the soil. It's the loss of the rigidity of the plants' non-woody sections.
So, the correct answer is “Option A”.

Note:
As we know that when plants don't take delivery of enough water, their leaves set in motion to droop, or wilt. Habitually the edges curl and the leaves turn yellow, too. This is a resistance mechanism, because detaching leaves helps a plant get rid of some exterior area that would lose water to the atmosphere. It's simple to want to augment watering to cure droopy leaves, but sometimes this makes the situation worse. Overwatering a plant can result in roots to rot and stop oxygen from reaching them.