Problem 1: Explain the requirement for regulation of the internal environment by reference to some named homeostatic systems.
Problem 2: Explain negative and positive feedback in a homeostatic control mechanism, and the involvement of organ(s) in this mechanism.
Positive and negative feedback mechanism including in marathon.
Problem 3: Explain the role of skin in thermoregulation
Problem 4: Analyse the roles of hormones (4) including insulin.