"Oxygen is a waste product of photosynthesis." Comment.

Oxygen is the product of photosynthesis. Though some of this oxygen may be used by the leaf itself for respiration, the major remaining portion of oxygen produced by photosynthesis is given out by the stomata into the atmosphere. But we cannot call this a waste product, as it is the one molecule very living organism needs for respiration.

Oxygen is produced by green plants by photosynthesis, most of which diffuses into the atmosphere. All other living organisms like birds, animals, and humans, depend on this for their survival. In respiration, all organisms take in oxygen and give out CO₂. Thus, oxygen cannot be considered as a waste product as it serves many useful purposes.