Mechanism of Absorption of Water

Water absorption by roots can also be classified by a different criterion altogether: whether the living cells of the root have to spend metabolic energy to bring the water in. On this basis, there are two broad modes of absorption — passive absorption, which needs no energy input from the root and is instead driven by events happening in the leaves, and active absorption, which is powered directly by the metabolic activity of the root's own living cells. In practice, both mechanisms operate in the same plant, but …