The figure shows the parts of an automatic control system in the human body.
Figure: An automatic control system that returns an internal condition to its optimum level

Name the parts labelled A, B and C.
Give one example of a coordination centre in the human body.
The effector in this control system is a gland. Describe what a gland does when it responds.
40 exam-style questions on AQA GCSE Biology 5.1 Homeostasis, covering 5.1 Homeostasis. Each one has a worked solution and a mark scheme showing where the marks go.