Which statement best describes aerobic cellular respiration?

• A. A process that uses nitrogen as the final electron acceptor.
• B. A process that occurs only in anaerobic conditions.
• C. A series of enzyme-controlled chemical reactions in which oxygen reacts with glucose to produce carbon dioxide and water, releasing energy in the form of ATP; includes glycolysis, the Krebs cycle, and the electron transport system.
• D. The light-independent reactions of photosynthesis.

Answer: (C)

The main concept here is that aerobic cellular respiration turns glucose into ATP by using oxygen through a coordinated sequence of enzyme-driven steps. In this process, glucose is broken down and electrons are transferred through pathways that ultimately use oxygen as the final electron acceptor, producing carbon dioxide and water as waste products while capturing energy in ATP. The pathway includes glycolysis in the cytoplasm, the Krebs cycle, and the electron transport chain, where most of the ATP is generated.

This description matches the idea that oxygen is essential for the final step of electron transport, that energy is released and stored as ATP, and that the full sequence involves glycolysis, the Krebs cycle, and the electron transport system. The other statements conflict with this understanding: oxygen isn’t used as a final electron acceptor in a process that would only occur without oxygen, and the light-independent reactions of photosynthesis are a separate process entirely.