What role does sunlight play in the carbon cycle?

• A. It drives photosynthesis in plants, converting carbon dioxide and water into glucose and oxygen.
• B. It stores energy in the soil as minerals.
• C. It warms the atmosphere directly.
• D. It is used by animals for respiration.

Answer: (A)

Sunlight provides the energy that drives photosynthesis. In photosynthesis, plants use light energy to convert carbon dioxide and water into glucose, with oxygen released as a byproduct. This stores carbon in plant biomass and starts the movement of carbon through the ecosystem. When organisms eat plants and later respire or when they decompose, carbon dioxide is released back into the air, continuing the cycle. So the role of sunlight is to power the transformation of atmospheric carbon dioxide into organic matter, which is why this option best explains the carbon cycle.