NCERT Class 7 Chapter 1 Nutrition in Plants Suggested projects and activities
This activity asks us to cover a part of the leaf with black paper, compare the colour with uncovered part and test with iodine solution.
The covered part of the leaf become light green and pale colour. When we test them with iodine, the covered part does not turn blue.
When we cover a part of the leaf with paper, it can not photosynthesise and produce starch. With the passage of time chlorophyll of the covered part translocate to other parts. As a result, the covered part becomes light green and pale. Iodine solution turns blue with starch. Since the covered part does not contain starch it does not turn blue.
This experiment demonstrates that sunlight is necessary for photosynthesis. For more details, you can visit this experiment.
2. Visiting a greenhouse farm.
A greenhouse farm is an artificial chamber that keeps plants warmer than the outside. For this, the chamber is made of glass or plastic that allow solar radiation but prevent its escape. Desired temperature and humidity are carefully controlled by fans and irrigation. This helps the vegetation to grow which is not possible in that area
3. Growing a sweet potato in water.
Sweet potato can be grown into water. For this, we dip a sweet potato into water. Within a few weeks, it sprouts and stem arise from it.