Question

How does ascent of sap occur in tall trees?

Answer 1

The ascent of sap is the transport of the water and the inorganic minerals in the plant in the upward direction from the roots to the leaves. The transpiration pull theory is the most acceptable theory for the ascent of sap. It states that transpiration creates a pressure which pulls the sap upwards. Adhesion and cohesion forces actively participate in transportation. Cohesive force between exist between the water molecules. There is adhesion force between water and xylem elements. The force created due to loss of water due to transpiration helps in the conduction of water in tall trees.