Question

Explain the experiment conducted by you to prove that CO2
is
necessary for photosynthesis.

Answer 1

Explanation:

To prove the necessity of carbon dioxide in photosynthesis do the following steps:

• Insert a part of the leaf of a destarched plant into a conical flask containing potassium hydroxide.

(Potassium hydroxide solution absorbs the carbon dioxide gas from the air present in the glass bottle.)

• Leave the plant in sunlight.

• After few hours, perform a starch test to this and another leaf of the same plant.

Observation-

1. Leaf exposed to the atmosphere are bluish black.
2. Leaf exposed to KOH does not change to blue-black colour

Result- Starch is present in the green part of the leaf.

Conclusion- Presence of starch proves that CO2 is necessary for photosynthesis.