Discuss the factors responsible for ascent of xylem sap in plants.
Explanation The ascent of sap in the xylem tissue of plants is a phenomenon that describes the upward movement of water and minerals from the root to the crown. The factors that affect the ascent of xylem sap in plants are: Transpiration pull is mainly responsible for the ascent of xylem sap in plants. Surface tension is responsible for the greater attraction between water molecules in liquid phase than in gaseous phase. Adhesion- Attraction of water molecules to polar surfaces like the tracheary elements helps in ascent of xylem sap. Cohesion – Mutual attraction between water molecules also help in ascent of sap. Adhesion – Attraction of water molecules to polar surfaces help in ascent of xylem sap. Capillarity –Ability of water to rise in thin tubes is known as capillary action, which helps in ascent of sap via xylem tissues. Opinion: Ascent of sap takes place due to the pumping activity of the cells of xylem parenchyma which are living that provide water and minerals to all parts of the plant. Final Answer Transpiration, surface tension, adhesion-cohesion, capillary action help in the ascent of xylem sap in the plants.
