Which process removes carbon dioxide from the atmosphere and stores it as organic matter?

• A. Respiration releases CO2 into the atmosphere
• B. Decomposition releases CO2
• C. Photosynthesis removes CO2 from the atmosphere and stores it as organic matter
• D. Combustion releases energy

Answer: (C)

Photosynthesis is the process that removes carbon dioxide from the atmosphere and stores carbon in organic matter. Plants, algae, and some bacteria use light energy to drive a reaction that converts CO2 and water into organic molecules like glucose, releasing oxygen in the process. This puts carbon into plant biomass and soils, creating stores of organic carbon that can persist for varying lengths of time. Other processes in the carbon cycle—such as respiration, decomposition, and combustion—release CO2 back into the air rather than storing it. So, photosynthesis is the key mechanism that makes atmospheric CO2 become part of living matter and long-term carbon stores.