Question

What are the mechanisms by which root hairs absorb water from the soil? (3 Marks)

Answer 1

The mechanisms by which root hairs absorbs water from soil are:
1. Diffusion is the movement of molecules (solid, liquid or gas) from a region of higher concentration to a region of lower concentration. Water and minerals move into the root hair cells by diffusion when their concentration in the soil is higher than their concentration in the cell sap of the root hair cells.(1 Mark)
2. Osmosis is the movement of solvent molecules through a semipermeable membrane from a region of higher concentration to a region of lower concentration. The solution with less solute and more solvent is called a dilute solution while a solution with more solute and less solvent is called a concentrated solution. (1 Mark)
3.In active transport, the movement of minerals takes place from a region of lower concentration to a region(soil) of higher concentration(cells). Active transport requires ATP to carry molecules across a membrane.(1 Mark)