Question

Cohesion force existing amongst water molecules contributes to

• A. Plasmolysis
• B. Ascent of sap
• C. Osmosis
• D. Translocation

Answer 1

The correct option is B Ascent of sap

Cohesion force is the strong force of attraction which exist between the same molecules. Cohesive force of water is due to the hydrogen bond between the water molecules. It allows the liquid molecules to resist separation. It contributes in ascent of sap due to the following phenomena.

1) The rate of transpiration is high.

2) The water is lost from guard cell which leads to decrease in the water potential of guard cell as compared to the surrounding cell.

3) To stabilize the water potential in the guard cell water rushes from the neighboring cell which creates a cohesion pull in the xylem vessels to pull the water up to the guard cell.

So, the correct answer is option B.