Question

Take a potted plant with broad leaves take two strips of black paper and cut out a small square and the centres cover a part of two leaves with these papers and Secure them with paper clips figure 1.9 keep the plant in sunlight for 25 days observe the difference in the colour of the covered and the uncovered for persons on the leaf perform iodine test on this leaf did the two parts so different results now Tech 2nd leaf remove the strip and expose the covered path to the sunlight for 223 day and do the iodine test again describe your observation NCERT question answer

Answer 1

The surface area of the leaf that is not getting any light for the duration of the experiment will want to conserve its resources. One of the valuable resources a plant has is its chlorophyll pigment. This is what gives the plant leaves a green color. I predict that the surface area that is covered will lose its chlorophyll and hence lose its green pigment. Since its more difficult for the plant to recycle the other pigments (the carotenoids), a yellow pigment will remain, much like what we see in fall leaves. In the square area that is exposed to the sun light I predict no change. The result will be a yellow leaf with a green square on it.