Describe and explain any color change in the leaf.

After adding the iodine there was no color change in the area covered by tinfoil. The part of the leaf that had not been covered with tinfoil, however, turned blue/black indicating the presence of starch. The starch, which is a storage product, is only accumulated when the plant is engaged in photosynthesis.The part of the leaf which had been deprived of light will obtain food from other parts of the plant but will not be able to carry on photosynthesis itself.