Question

Why do plants absorb excess water from the soil, which is finally lost by transpiration?

Answer 1

Plants absorb more water because they know they will loose most of the water they have absorbed during transpiration. If they absorb less water they will loose all their water during transpiration leaving no water for metabolic processes. Transpiration is a necessary process because it creates a transpiration pull for the upward movement of water and minerals, so, plants does not stop it.