Experiment to show that Light is essential for Photosynthesis

Experiment to show that Light is essential for Photosynthesis:

Requirements: A potted plant with green leaves, Black paper, Alcohol, Iodinesolution, and clips, (the plant should kept in dark for a long time before experiment). .

Procedure: Cover both side of a leaf with black paper and clip so that Sunlightcannot reach inside. Then let the pot with the plant be kept in Sunlight. After one hour tear the leaf off and boil in alcohol so that the leaf becomes chlorophyll free. Now let the leaf be immersed in iodine solution.

Observation: On taking out from the iodine solution it will be seen that all thearea except the covered area became blue (deep violet or black)

Conclusion: Carbohydrate react with iodine solution turns to blue (deep violetor black). Sunlight did not reach the area covered with black paper; photosynthesis did not occur there, that is carbohydrate did not produce. As carbohydrate did not produce there the area did not turn blue (deep violet or black). Thus it is proved that Sunlight is essential for photosynthesis so to say for manufacture of carbohydrate.