Question

Water will be absorbed by the root hairs when:

• A. The concentration of salts in the soil is high.
• B. The concentration of solutes in the cell sap is high.
  
• C. The plant is rapidly respiring.
  
• D. They are separated from the soil by a semi-permeable membrane.

Answer 1

The correct option is B

The concentration of solutes in the cell sap is high.

Root hairs contain cell sap of higher concentration than that of the surrounding soil water. There is less water potential inside the cell and high water potential in the soil. This difference sets off osmosis and outside water diffuses into the root hair. From the root hair water continues to enter the cells and finally reaches the xylem vessels.