GCSE Combined Science revision · Biology: homeostasis, inheritance and ecology

Homeostasis

The idea

Homeostasis is the regulation of internal conditions, such as blood glucose concentration, body temperature and water levels, to keep cells working. Control systems have receptors that detect stimuli, coordination centres (the brain, spinal cord and pancreas) that process the information, and effectors (muscles or glands) that bring about responses. Control can be nervous or hormonal.

Identify the receptor.
Identify the coordination centre.
Identify the effector and its response.

Watch out Effectors are muscles or glands; receptors detect the change.

See it worked

Worked example

Name the three parts of a control system in the right order.

The receptor detects the change.
The coordination centre processes the information, and the effector responds.

Answer Receptor, coordination centre, effector

Your turn

Question 1Calculator allowed1 mark

Which is an effector?

Question 2Calculator allowed1 mark

Which condition is controlled by homeostasis?

Question 3Calculator allowed3 marks

Explain why homeostasis is important.

Write your answer, then see a model answer

Stable conditions.
Enzyme and cell function.

Answer It keeps internal conditions, such as temperature and glucose concentration, stable so that enzymes and cells work at their best.

In past papers

8 official questions in 8 papers since 2018. The latest:

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