Final answer:
The aerobic system begins with glycolysis, requires oxygen, and produces carbon dioxide as a by-product. Its efficiency is limited by the availability of oxygen.
Step-by-step explanation:
The aerobic system begins with glycolysis, does use oxygen, and leaves carbon dioxide as a toxic by-product. The limiting factor in aerobic respiration is the availability of oxygen. In aerobic respiration, the final electron acceptor in the electron transport chain is an oxygen molecule. If oxygen is not present, organisms may resort to processes like fermentation ('anaerobic respiration') to regenerate NAD* from NADH, which is essential for glycolysis to proceed. However, fermentation produces less ATP and more toxic by-products such as ethanol or lactic acid compared to aerobic respiration.