Question

An apparatus, as shown below, was set up to investigate a physiological process in plants. The setup was kept in sunlight for two hours. Droplets of water were then seen inside the bell jar. Answer the questions that follow:

1. Name the process being studied.
2. Explain the process named above in Q.3(a)(i).
3. Why was the pot covered with a plastic sheet?
4. Suggest a suitable control for this experiment.
5. Mention two ways in which this process is beneficial to plants.
6. List three adaptations in plants to reduce the above mentioned process.

Answer 1

1. Transpiration
2. Transpiration is a process during which water is lost in the form of water vapour through the aerial parts of the plant.
3. The pot is covered with a plastic sheet to prevent the evaporation of water from the soil.
4. Place an empty, dry bell jar in the sunlight.
5. 1. It creates a cooling effect.
   2. It helps in the ascent of sap by creating a suction force.
   3. It helps in the distribution of water and mineral salts.
6. Adaptations to reduce excessive transpiration:
   1. Leaves reduced in size or to spines
   2. Sunken stomata
   3. Leaves with thick cuticle