Answer:
Photosynthesis is the process through which green plants (mainly) transform solar energy into useful chemical energy. Plants require energy to grow, reproduce, and defend themselves. Excess photosynthetic energy is stored in plant tissue as starch. Starch is a powdery white material. It stores glucose, which plants utilize for energy. The presence of starch in a leaf is conclusive proof of photosynthesis. This is due to the fact that starch production necessitates photosynthesis.
Explanation:
1. Place one of the plants in a dark room for 24 hours; place the other one on a sunny windowsill.
2. Wait 24 hours.
3. Fill the beaker or jar with ethyl alcohol.
4. Place the beaker or jar in a saucepan full of water.
5. Heat the pan until the ethyl alcohol begins to boil.
6. Remove from the heat.
7. Dip each of the leaves in the hot water for 60 seconds, using tweezers. 8. Drop the leaves in the beaker or jar of ethyl alcohol for two minutes (or until they turn almost white).
9. Set them each in a shallow dish.
10. Cover the leaves with some iodine solution and watch.
The hot water kills the leaf, while the alcohol degrades the chlorophyll, removing the leaf's green hue. When iodine is applied to the leaves, one will turn blue-black and the other will turn reddish-brown. Iodine is a starch indicator that becomes blue-black when it comes into contact with it. The leaf that was exposed to light turns blue-black, indicating that it has been photosynthesising and making starch.
