This activity involves studying the process of photosynthesis in a plant with variegated leaves. Here's a step-by-step explanation of what happens during the experiment:
1. Placing the plant in a dark room for three days depletes the starch stored in the leaves since photosynthesis cannot occur without light.
2. When the plant is exposed to sunlight for about six hours, it starts photosynthesizing again, producing starch in the green areas of the leaves.
3. By plucking a leaf, marking the green areas, and tracing them on a sheet of paper, you can visualize where photosynthesis is happening.
4. Boiling the leaf in water followed by immersion in alcohol removes the chlorophyll, the green pigment responsible for photosynthesis, from the leaf.
5. Heating the alcohol in a water bath causes the chlorophyll to dissolve and come out of the leaf, resulting in a change in leaf color.
6. When the leaf is dipped in a dilute solution of iodine, it reacts with any starch present in the leaf, turning the areas where starch is present blue-black.
7. Comparing the color of the leaf after the iodine treatment with the tracing done initially allows you to see where starch has been synthesized through photosynthesis.
By following these steps, you can observe the relationship between light, chlorophyll, starch production, and photosynthesis in plants with variegated leaves.
