Desacribe an experiment to prove that carbon dioxide is essential for photosynthesis ?

Take two healthy potted plants. Keep them in a dark room for 2-3 days. Now place each plant in a separate glass. Get a cup containing potassium hydroxide by the side of the plants (the potassium hydroxide is used to absorb carbon dioxide). COver both plants with separate jars. Seal the jars so that the set-up-is-air-tight. Keep the plants in sunlight for two hours. Gently pluck a leaf from each plant. remove the chlorophyll from the leaves by boiling them in alcohol. Wash the leaves with water and then pour iodine solution over them.

We can conclude that the photosynthesis cannot be carried out without carbon dioxide. the leaf from the plant (which was the jar containing potassium hydroxide, which absorbed the carbon dioxide) turns blue black on iodine solution showing that starch is presented in this lead.

so this shows that carbon dioxide is necessary for the processs of photosynthesis to take place

Where’s the selection?