Absorption of Water by Root Hairs

Root hairs are thin, elongated, cylindrical outgrowths of epidermal cells that are present in the region of maturation of the root. They increase the surface area of the root, which aids in the absorption of water and minerals from the soil.

The process of water absorption by root hairs involves the following steps:

1. Active Transport: The concentration of minerals in the soil is lower than that in the root hair cells. Hence, the minerals move into the root hair cells by active transport, which requires energy in the form of ATP.

2. Osmosis: The movement of water across a semi-permeable membrane from a region of high concentration to a region of low concentration is called osmosis. Water moves into the root hair cells by osmosis, as the concentration of water in the soil is higher than that in the root hair cells.

3. Root Pressure: The root cells actively take up ions from the soil, which creates a concentration gradient that causes water to move into the root cells. This movement of water creates a pressure called root pressure, which aids in the movement of water up the plant.

4. Transpiration: The loss of water from the leaves of the plant in the form of water vapour is called transpiration. This loss of water creates a negative pressure gradient that pulls water up the plant from the roots.

Thus, root hairs play a crucial role in the absorption of water by plants. They increase the surface area of the root, which aids in the absorption of water and minerals from the soil. The process of water absorption by root hairs involves active transport, osmosis, root pressure, and transpiration.