Question

Explain the experiment to show that chlorophyll is necessary for photosynthesis​

Answer 1

Answer:

In the presence of starch iodine solution will turn into blue-black color and in the absence of starch iodine added to leaf will turn into brown color. ... So iodine added in this region will change into brown color. Thus this experiment proves chlorophyll is necessary for leaves to prepare starch through photosynthesis

Answer 2

Explanation:

Destarch a potted plant by putting it in complete darkness for two days. Fill partly a wide-mouthed bottle with a strong solution of caustic potash and fit a split cork on its mouth. Insert about half of the portion of a leaf of the destarched plant into the bottle through the split cork. Place the whole apparatus in light after applying grease on the upper portion of split cork, and test the leaf for starch after about 10 hours. Positive test of starch shown by the portions of the leaf present outside the bottle indicates that photosynthesis process is continuously going on there because all the essential requirements, i.e., light, chlorophyll, water and CO2 are readily available to this portion.

That the chlorophyll is also an essential requirement for photosynthesis can be shown by testing starch in a variegated leaf. Only green portions of the leaf show positive starch test.