A student constructs a model of shivering using a container of warm water, a temperature probe, a controller and a small heater. The water represents blood, and the heater represents the transfer of energy as heat from contracting muscles. The probe only displays the water temperature and the heater runs continuously.
Which modification would allow the model to show a coordinated homeostatic response?
Link the probe to the controller so that the heater switches on only when the water temperature rises above the normal range.
Add a second probe so that the water temperature is displayed at two different places in the container.
Replace the heater with a more powerful heater that runs continuously so that the water warms up faster.
Link the probe to the controller so that the heater switches on only when the water temperature falls below the normal range.
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.