Please explain: 1.seeds when soaked in water imbibe, why? 2.leaves that appear wilted in the day recover?

Question

at night, why? 3. a man supplied excess fertilizer and watered the grass well ; after some times the leaves turns brown why?

Answer 1

1.seeds when soaked in water imbibe, why?

The seed has a small apperture called as micropyle through which the water enters into the seed. Sometimes the seed coat is also permeable to water.

2.leaves that appear wilted in the day recover?at night, why?

During the day due to bright sunlight the rate of transpiration is more than the rate of water absorption. Therefore the leaves wilt. During the evening and night, the rate of transpiration is reduced and that of absorption is more. Therefore the leaves regain the water content and look fresh.

3. a man supplied excess fertilizer and watered the grass well ; after some times the leaves turns brown why?

The excess fertilizers affect the rate of absorption of water and   the metabolic processes so the leaves turn brown.