Absorption by Roots — Biology STD 10 — Question

In land plants most of the water is absorbed through the roots. Roots are suited for absorbing water in the following ways :
(i) Surface area of roots : Roots are branched extensively, ending in millions of root tips. Numerous root hairs are present in the root hair zone of the root tip. Therefore, all together the roots of plants provide tremendous surface area which facilitates absorption of water.
(ii) Root hair contains cell sap of a concentration higher than that of the surrounding water. This characteristic is an important requirement to draw in the water from outside.
(iii) Root hairs have thin walls : Root hairs are an extension of the epidermal cell of the root. The cell wall is thin and allows the movement of water molecules and dissolved substances freely in and out. The cell membrane is thin but semi-permeable, i.e., it allows water molecules to pass through but not the larger molecules of the dissolved salts.