Which energy pathway is dominant when the body is at rest?

• A. Aerobic respiration
• B. Phosphocreatine system
• C. Anaerobic glycolysis
• D. Fermentation

Answer: (A)

Verified step by step guidance

1. Understand the context: The question asks about the dominant energy pathway when the body is at rest. At rest, the body requires a steady supply of energy but at a relatively low rate compared to during exercise.
2. Review the energy pathways: Aerobic respiration, phosphocreatine system, anaerobic glycolysis, and fermentation are all pathways the body uses to generate energy. Each has specific conditions under which it is most active.
3. Analyze aerobic respiration: This pathway uses oxygen to break down glucose, fatty acids, or amino acids to produce ATP. It is highly efficient and provides a sustained energy supply, making it ideal for resting conditions.
4. Compare with other pathways: The phosphocreatine system and anaerobic glycolysis are used for short bursts of energy during high-intensity activities, while fermentation is more common in microorganisms or under oxygen-deprived conditions in humans.
5. Conclude: Since the body is at rest and oxygen is readily available, aerobic respiration is the dominant energy pathway, as it efficiently meets the low energy demands of resting conditions.