1. Name the process being studied in the above experiment.
2. Explain the process mentioned in (a) above
3. Why is oil placed over water?
4. What do we observe with regard to the level of water when this set up is placed in (1) bright sunlight (2) humid conditions (3) windy day?
5. Mention any three adaptations found in plants to foster the process mentioned in (a) above
Answers:
- Water absorption by plant roots through osmosis is the process involved in the above experiment.
- Take a test tube (A) filled with water. Remove a small leafy plant (such as balsam) from the soil and its roots are strong. Root the test tube soon. Add a few drops of oil to the test tube to prevent any water loss from evaporation. Mark the water level. In a day or two, you will find that the water level in the test tube (A) is dropping, which indicates that the water lost in the test tube is absorbed by the roots.
- To prevent any water loss by evaporation, oil is placed over water in the test tube.
- Bright sunlight: This setting when placed in the bright sun, the water level in the test tube appears small compared to its initial marking. Because the transpiration rate is very high.
Humid conditions: This setting when placed in a humid state, the water level in the test tube decreases from its initial mark, but at a much lower level. Because the transpiration rate decreases.
Windy day: This setting when set on a windy day, as the transpiration rate increases significantly so the water level in the test tube appears to decrease rapidly from its initial measurement.
• The large surface area provided by rootlets and root hairs
• The loss of leaves
• Root hairs with thin walls