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