Answer:
1. Oxygen
2. Glucose
3.Light energy
Step-by-step explanation:
1. Oxygen is not needed by the plant for photosynthesis.
It is a by-product of photosynthesis. Instead Carbondioxide is needed.
2. The glucose produced does not stay solely in the plant, part of it is used up by the plant while others stores in edible parts of the plant that men use as food.
3. The light energy converts H2O to 4H+ and 4OH- needed in the synthesis of carbohydrate and release of Oxygen.