Question

Which of the following contributes most to water transport from the ground to the leaves of a tall tree?

• A. Breakdown of ATP
• B. Capillary rise of water in xylem
• C. Cohesion of water and transpiration pull
• D. Root pressure

Answer 1

The correct option is C

Cohesion of water and transpiration pull

Water molecules have high-cohesion among themselves and high adhesion forces act between them and the walls of the xylem vessels. Thus, a continuous column of water is formed in the xylem. Transpiration i.e., evaporation of water molecules from the cells of the leaf creates a suction force (transpiration pull) which pulls water in the xylem vessels.