In photosynthesis, the oxygen released into the atmosphere comes from

Question

Accepted Answer

A. water (H₂O), split during light reactions

Isotope tracing with ¹⁸O-labelled water confirms: the oxygen released comes from H₂O.
The light reaction's photolysis splits water into H⁺, electrons, and O₂.
CO₂ becomes the carbon backbone of glucose, but its oxygen ends up in the water products, not in the released gas.

Answer

CO₂ split during dark reactions

Answer

glucose, the final product

Answer

atmospheric N₂ recycled by the chloroplast

In photosynthesis, the oxygen released into the atmosphere comes from

Keep practising Photosynthesis in Higher Plants