A student constructs a model of heat loss through the skin. Warm water in a reservoir represents blood. A variable-speed pump moves the water through tubing beneath a metal sheet, representing blood flow through capillaries near the skin surface. A temperature probe in the reservoir sends readings to a controller that can change the pump speed. The air around the metal sheet is cooler than the water.
Which sequence would allow the model to show a coordinated homeostatic response to a rise in the temperature of the water?
The probe detects a rise, the controller decreases the pump speed and less warm water flows beneath the sheet.
The probe detects a rise, the controller leaves the pump speed unchanged and only stores the temperature reading.
The probe detects a fall, the controller increases the pump speed and more warm water flows beneath the sheet.
The probe detects a rise, the controller increases the pump speed and more warm water flows beneath the sheet.
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.