Question

What happens in the dark reaction of photosynthesis?

• A. Formation of ATP
• B. Evolution of Oxygen
• C. Evolution of Hydrogen
• D. PGAL synthesis

Hint:

Dark reaction fixes CO\textsubscript{2} and synthesizes PGAL for sugar formation.

Answer 1

The Correct Option is D

The dark reaction, also known as the Calvin cycle, occurs in the stroma of chloroplasts and does not require light directly. It synthesizes PGAL (phosphoglyceraldehyde), a three-carbon sugar, by fixing atmospheric CO\textsubscript{2} using ATP and NADPH produced during the light reactions.
- ATP formation and oxygen evolution occur during light reactions.
- Hydrogen evolution is not part of photosynthesis.