Question

Will the ascent of sap be possible without the cohesion and adhesion of the water molecules? Explain.

Answer 1

In plants, the ascent of sap involves factors like root pressure, capillary action, adhesion-cohesion and transpiration. The movement of water up to the base of the stem is resulted only by root pressure. Water can raise only a few centimetres by capillary action so it is effective only in herbs. When there is a water column underneath which is to be pulled only then transpiration pull works. Hence, without adhesion-cohesion of water molecules ascent of sap is not possible.