Which organelle performs photosynthesis in plant cells?

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

Answer: (C)

Photosynthesis in plant cells occurs in chloroplasts, organelles that capture light energy and convert it into chemical energy stored as sugar. Chloroplasts contain chlorophyll, the pigment that absorbs light, and have internal structures called thylakoid membranes where the light-dependent reactions take place, producing ATP and NADPH. The surrounding fluid, the stroma, hosts the Calvin cycle, which uses carbon dioxide to synthesize glucose. This combination lets the plant build energy-rich sugars from light, water, and CO2 while releasing oxygen. Other organelles have different roles: ribosomes make proteins, the nucleus stores genetic material and directs activities, and mitochondria carry out cellular respiration to generate ATP from sugars, not to capture light for photosynthesis.