Botany - Transport in Plants Question with Solution | TestHub

Transpiration pull

- Transpiration pull plays a major role in the transport of water in most of the plants.

- Transpiration-driven ascent of xylem sap depends upon following physical properties of water:

1.  Cohesion: It is the force of attraction between the water molecules.

2.  Adhesion: It is the force of attraction between the water molecules and the polar surface of xylem vessels.

3.  Surface tension: In comparison to the gas phase, water molecules are more attracted in the liquid phase. Because of the above properties, water possesses high tensile strength (ability to resist a pulling force) and high capillarity (ability to rise in thin tubes).