1. Name the phenomenon being demonstrated.
2. What is the purpose of putting oil in the test tube?
3. What is the purpose of the spring balance in the set-up?
4. Would it make a difference if the experimental set-up is kept in bright sunshine?
Answers:
1. Transpiration
2. To prevent the water loss by evaporation, oil is used in the test tube.
3. The purpose of the spring balance in the set is to measure the change in the weight of the set. A small aquatic plant can be measured before and after a certain period of time. The surface of the soil and the pot should be completely covered to prevent evaporation from outside the plant. Water loss in the plant is because of the process of transpiration.
4. Transpiration rate will increase as a difference in the set up when kept in the bright sunshine.