Question

What is root hair? Why is it important?

Answer 1

The root hairs are extensions of the epidermal cells of the roots. They have a freely permeable cell wall and a semipermeable cell membrane. The concentration of cell sap is higher than the surrounding soil water as it contains more solute. The root hairs are suitable for water absorption in three main ways: 1. The root hairs increase the surface area for absorption of water. 2. The root hair cell sap is of higher concentration than the surrounding soil water promoting water absorption. 3. The cell wall of root hair allows the passage of all types of molecules through it and the cell membrane allows the passage of solvent molecules (water molecules), thus facilitating the absorption of water through the root hairs in plants.