Which process moves carbon from the atmosphere to plants?

• A. Photosynthesis moves carbon from the atmosphere to plants.
• B. Respiration moves carbon from plants to the atmosphere.
• C. Weathering moves carbon from rocks to water.
• D. Combustion removes carbon from the atmosphere.

Answer: (A)

Photosynthesis moves carbon from the atmosphere to plants. In this process, plants use sunlight to convert carbon dioxide from the air and water from the soil into organic sugars like glucose. The carbon in CO2 becomes part of the plant’s tissues—leaves, stems, and roots—and can then pass through the food web as plants are eaten. This is the key way atmospheric carbon is captured and stored in living matter. While plants do respire and release CO2, the initial transfer of carbon from air to plant biomass happens through photosynthesis. The other processes described—respiration releasing carbon back to the atmosphere, weathering moving carbon from rocks into water, and combustion releasing carbon into the atmosphere—do not move carbon from the air into plants in the same way.