Question

Water is absorbed by root hairs when

• A. Concentration of salt in the soil is high.
• B. Concentration of solute in cell sap is high.
• C. They are separated from soil by permeable membrane.
• D. The plant is rapidly respiring.

Answer 1

Answer: (B)

Concentration of solute in cell sap is high.

Water flows from a region of higher water potential to a region of lower water potential. It is absorbed by roots when concentration of solute in cell sap is higher because then water potential inside the root hair cells will be lower than the water potential in surrounding soil solution.