What is the role of chloroplasts and what pigment drives the light-absorbing process?

• A. Chloroplasts store genetic information; chlorophyll is a storage pigment.
• B. Chloroplasts perform photosynthesis; chlorophyll is the primary pigment absorbing light.
• C. Chloroplasts digest waste; chlorophyll is not involved in light absorption.
• D. Chloroplasts produce ATP through cellular respiration; chlorophyll absorbs heat.

Answer: (B)

Chloroplasts are the sites where photosynthesis happens in plant cells. They capture light energy and use it to convert carbon dioxide and water into glucose, releasing oxygen in the process. The pigment that drives light absorption is chlorophyll, the main light-absorbing molecule in the chloroplasts’ thylakoid membranes. This energy absorption powers the light-dependent reactions, which produce ATP and NADPH to fuel the production of sugars in the Calvin cycle. The other statements mix up roles or say chlorophyll absorbs heat, which isn’t correct—chlorophyll captures light energy, not heat.