A researcher investigates how recovery conditions affect cooling after exercise.
The same person completes an identical exercise test on three different days. At the end of each test, the person's core body temperature is 38.4 ∘C38.4\ ^\circ\mathrm{C}38.4 ∘C. The person then sits and recovers for 30 minutes.
The table shows the results.
| condition | air temperature in ∘C^\circ\mathrm{C}∘C | skin temperature at start of recovery in ∘C^\circ\mathrm{C}∘C | relative surface blood flow during the first 10 minutes in arbitrary units | mass of sweat evaporated in 30 minutes in kg | core body temperature after 30 minutes in ∘C^\circ\mathrm{C}∘C |
|---|---|---|---|---|---|
| A | 18 | 34 | 8 | 0.18 | 37.3 |
| B | 28 | 34 | 8 | 0.18 | 37.8 |
| C | 18 | 34 | 3 | 0.18 | 37.7 |
Calculate the decrease in core body temperature during recovery in condition A.
Using the data, explain why condition A produced a greater decrease in core body temperature than both condition B and condition C.
In a fourth recovery, the air temperature, starting skin temperature and surface blood flow are the same as in condition A. Only 0.06 kg of sweat evaporates.
Explain how the core body temperature after 30 minutes is likely to compare with the value in condition A.
78 exam-style questions on Edexcel GCSE Biology 7.3 Homeostasis and thermoregulation, covering 7.3.1 Importance of a constant internal environment, 7.3.2 Importance of homeostasis, 7.3.3a Thermoregulation via the skin and hypothalamus, and 7.3.3b Vasoconstriction and vasodilation in thermoregulation. Each one has a worked solution and a mark scheme showing where the marks go.