Question

Write an experiment to show that carbon dioxide is necessary for photosynthesis.​

Answer 1

Answer:

Take two healthy potted plants.

Keep them in dark for 2-3 days, so that all the carbon dioxide fixed till that gt used up by the plant.

Take the plants and keep both in two separate closed bell jar containers that are air-tight. In one of the jar, keep an open beaker containing potassium hydroxide (KOH) solution along with the plant. KOH can absorb carbon dioxide, so the jar containing KOH is devoid of carbon dioxide.

Keep both the jars in sunlight for 4 hours.

Pluck the leaves from plants in both jars and remove chlorophyll by boiling in ethanol.

Apply iodine solution over the leaves. The leaves of the plant present in the jar without KOH solution turns blue-black color, as the starch in the leaves reacts with iodine. But, the leaves of the plant in the jar with KOH does not change color as in the absence of carbon dioxide the plant cannot produce starch.