A resting bird is placed for a short time in an insulated chamber with a continuous air supply. Water circulates around the chamber, which has no heater. The water enters at 20.0 °C and leaves at 20.4 °C. The bird's internal body temperature remains at 40.0 °C throughout.
Which statement best explains how the water can become warmer while the bird's body temperature remains constant?
Energy passing to the water should lower the bird's temperature, so the unchanged reading suggests that respiration has not released heat.
Energy transferred by respiration is retained inside the bird to hold its temperature constant, so the warmer water is unrelated to respiration.
Respiration transfers energy as heat to the water, while its continuous release helps keep the bird's internal temperature steady.
Respiration pauses while the bird is resting, but ATP already stored in its cells continues to warm the surrounding water.
92 exam-style questions on AQA GCSE Biology 4.2 Respiration, covering 4.2.1 Aerobic and anaerobic respiration, 4.2.2 Response to exercise, and 4.2.3 Metabolism. Each one has a worked solution and a mark scheme showing where the marks go.