Question

Given alongside is the diagram of an experimental set-up:

1. What is the objective of this experiment?
2. Will it work satisfactorily? Give reason.
3. What alteration(s) will you make in it for obtaining expected result?
4. Would you take any steps before starting the experiment? Describe this step and explain its necessity.

Answer 1

1. To demonstrate the importance of carbon dioxide in photosynthesis.
2. No, the experiment will not work satisfactorily, as the beaker contains lime water and not potassium hydroxide to absorb CO­₂.
3. Place potassium hydroxide in the beaker instead of lime water.
4. The plant must be kept in complete darkness for 48 hours in order to destarch its foliage prior to commencing the experiment. The reason for this is that the experiment will yield false results if the plant is not destarched, as the leaf deposited in the beaker may contain starch that was previously stored, even if no starch is produced during the experiment.