Which organelle is the site of photosynthesis in plant cells?

• A. Chloroplast
• B. Mitochondrion
• C. Nucleus
• D. Vacuole

Answer: (A)

Photosynthesis in plant cells happens in chloroplasts, organelles that contain chlorophyll to capture light energy. Inside these chloroplasts, light-dependent reactions use the light-absorbing pigments to generate ATP and NADPH, which then power the synthesis of sugars in the Calvin cycle located in the stroma. This makes chloroplasts the specialized site where light energy is converted into chemical energy and stored as sugar. The mitochondrion is the powerplant of the cell for respiration, not photosynthesis, while the nucleus houses genetic material and the vacuole stores water and maintains turgor. So the chloroplast is the correct site of photosynthesis.