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Difference between active and passive absorption? |
| Answer» Active absorption1. It occurs due to the activity of roots and particularly root hairs2.it is due to osmotic and non osmotic mechanisms.3. In active absorption the osmotic process involves diffusion pressure deficit(DPD) of the cells. The root hairs have more DPD as compared to soil solution and therefore, water is taken in. Water is still absorbed if soil solution has greater DPD, But under expenditure of metabolic energy.4. Evidences in support of active water absorption are root pressure, bleeding and guttation.Passive absorption1. The passive absorption occurs due to the activity of upper part of plant, such as shoot and leaves.2. Passive absorption is due to the process of active transpiration in the upper part.3. The passive absorption occurs due to the tension created in the xylem sap by transpiration pull.4. Evidences in support of passive water absorption can be given by cutting the roots under water. The absorption of water still occurs if all the roots are removed. | |