Question

Passive absorption of water from the soil by the root is mainly effected by

• A. Typical tissue organisation
• B. Respiratory activity of root
• C. Tension on cell sap due to transpiration
• D. None of the above

Answer 1

Answer: (C)

Tension on cell sap due to transpiration

According to the transpiration pull theory, loss of water from aerial parts due to transpiration is a passive physical process and the loss of water generates the pulling force. The tension in cell sap due to transpiration ultimately pulls water in the plants.

Water is present as a continuous column in vascular tissues due to cohesive and adhesive forces. The loss of water due to transpiration is equal to the amount of water absorbed from the soil. More the transpiration loss of water, more the absorption of water from the soil and vice versa.

So, the correct answer is option C.