How does photosynthesis contribute to the carbon cycle?

• A. Plants release CO2 into the atmosphere
• B. Plants remove CO2 from the atmosphere to make glucose, and release oxygen
• C. Plants convert oxygen into carbon dioxide
• D. Plants store carbon in the ground only after death

Answer: (B)

Photosynthesis pulls carbon dioxide from the air and uses sunlight to build glucose, so carbon moves from the atmosphere into plant tissues and oxygen is released. This is a key part of the carbon cycle because it stores carbon in living matter and fuels, rather than letting it stay in the air. Later, carbon can return to the atmosphere when plants respire or decay, or it can become part of the soil and, over long timescales, fossil fuels.

Other options don’t fit because plants aren’t releasing CO2 during photosynthesis (they’re taking it in); they don’t convert oxygen into carbon dioxide during this process (oxygen is produced); and carbon is stored in living plants and debris as well as after death, not only underground.