Explain why homeostasis is important for the normal functioning of the body.

AQA GCSE Biology (8461) — 4.5.1 Homeostasis · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Homeostasis is the regulation of internal conditions of a cell or organism.
It maintains optimum conditions for enzyme activity, metabolic reactions and cell function.
It responds to internal and/or external changes or stimuli.
Negative‑feedback cycles reverse a change and restore optimum levels.

Examiner tips

Use the exact terminology from the mark scheme – ‘homeostasis’, ‘negative feedback’. Show the link between regulation and enzyme activity. Explain the response to stimuli and the role of feedback. Keep the answer concise to fit the 4‑mark limit.

Common mistakes

Using vague terms such as ‘balance’ instead of ‘homeostasis’. Omitting the role of negative feedback or the link to enzyme activity.

Mark scheme (4 marks)

Homeostasis is the regulation of internal conditions of a cell or organism
To maintain optimum conditions for enzyme activity / metabolic reactions / cell function
In response to internal and/or external changes / stimuli
Negative feedback cycles are used to reverse a change and restore optimum levels

Key terms in this question

homeostasis