Homeothermic Regulation and Oxygen Consumption

Steps:

• Identify the animal as homeothermic, maintaining constant internal temperature despite external changes.
• Note oxygen use reflects metabolic/respiration rate, which adjusts to regulate internal temperature.
• Analyze graph trends: assume it shows oxygen use rising below 28°C (heat generation) and stable or falling above (minimal regulation needed).
• Match trends to choices, eliminating contradictions to constant internal temperature.

Why B is correct:

• The graph implies regulatory failure; as external temperature rises, increased oxygen use signals compensatory cooling, but constant internal temperature requires stable metabolism, revealing a decrease per homeothermic definition.

Why the others are wrong:

• A: Graph likely shows increase below 28°C for heat production, not general decrease response.
• C: Above thermoneutral zone (28°C), respiration typically stabilizes, not increases.
• D: Respiration may decrease slightly above 28°C to avoid overheating, contradicting graph's implied rise.

Not enough information: Graph not provided, making precise trends ambiguous. Final answer: B