Dark reaction of photosynthesis occurs in:

Correct option is B

· Dark Reaction: Also known as the Calvin Cycle, it occurs in the stroma of the chloroplast.
· While light-dependent reactions take place in the grana and produce ATP and NADPH, the stroma hosts the dark reaction, where carbon fixation occurs.
· Key Points About Stroma:
· It is the fluid-filled matrix of chloroplasts.
· Site of enzyme-mediated reactions for glucose synthesis.
· Utilizes ATP and NADPH produced in light reactions to fix CO₂.
· Key Steps of the Calvin Cycle:
4. Carbon Fixation: CO₂ is fixed into a 5-carbon sugar, RuBP.
4. Reduction: ATP and NADPH are used to reduce the fixed carbon.
4. Regeneration: RuBP is regenerated.
· Other Options Explained:
· Grana: Site of light-dependent reactions.
· Ribosomes: Involved in protein synthesis.
· Golgi bodies: Involved in protein and lipid modification.
· Therefore, the stroma (Option B) is the correct answer.