Question

The diagram below represents a process in plants. The setup was placed in bright sunlight. Answer the following questions.

1. Name the physiological process depicted in the diagram. Why was oil added to the water?
2. When placed in bright sunlight for four hours, what do you observe in regard to the initial and final weight of the plant? Give a suitable reason for your answer.
3. What happens to the level of water when this setup is placed in humid and windy conditions?
4. Mention any three adaptations found in plants to overcome the process mentioned in- 1.
5. Define the term ‘guttation’.

Answer 1

1. The physiological process depicted and the reason for the addition of oil to water:

• Transpiration is the process depicted in the diagram. Transpiration is the biological process by which water is lost in the form of water vapor from the aerial parts of the plants.
• Oil was added in the experiment to prevent the evaporation of water.

2. Observation of the initial and final weight of the plant:

• When placed for 4 hours under sunlight, the final weight of the plant recorded is less than the initial weight.
• The reason for this is the loss of water from the aerial parts of the plant due to transpiration.

3. Level of water in humid and windy conditions:

• In humid conditions, there is no change in the water level.
• On the other hand, in windy conditions, the water level drops.

4. The three adaptations are-

• Presence of sunken stomata in case of Nerium.
• Narrowing of leaves to reduce transpirational area.
• A fewer number of stomata.

5. Guttation:

• It is the loss of water in form of droplets from the pores called hydathodes present on the margins of the plant.