What does the microorganisms and health module cover?

This module covers Unit 2 sections 2.8 to 2.10: the types of microorganism and their useful roles in food and biotechnology, how pathogens cause disease and the body's defences, immunity and vaccination, and medicines including antibiotics, antibiotic resistance, and the effects of alcohol and tobacco.

Which exam assesses this module?

These topics are part of Unit 2 Body Systems, Genetics, Microorganisms and Health, a written paper worth 40 percent of the GCSE. Foundation tier lasts 1 hour 30 minutes and Higher tier lasts 1 hour 45 minutes. Expect structured and longer questions, including processes such as the immune response or making a food product.

Why do antibiotics not work against viruses?

Antibiotics kill bacteria or stop them reproducing, for example by damaging their cell walls. Viruses are different: they are not cells and reproduce inside the body's own cells, so antibiotics have no effect on them. This is why a viral infection such as a cold cannot be treated with antibiotics, and why overusing antibiotics is harmful.

What practicals are linked to this module?

Prescribed practical work includes culturing microorganisms using aseptic technique, for example investigating the effect of antibiotics or antiseptics on bacterial growth using agar plates and zones of inhibition. You learn the aseptic methods that prevent contamination and how to measure and compare the clear zones.

How should I revise this module?

Learn the microorganism types and the conditions they need, the food-production processes, and the body's first and second lines of defence. Make sure you can explain phagocytosis, antibodies and how a vaccine creates memory cells, and the difference between bacteria and viruses for antibiotics. Practise the antibiotic-resistance explanation and CCEA past-paper questions.

Northern IrelandBiology

CCEA GCSE Biology: Microorganisms and health overview

An overview of the microorganisms and health module of CCEA GCSE Biology (Unit 2 sections 2.8 to 2.10), mapping microorganisms and biotechnology, defence against disease, vaccination and the immune system, and medicines, antibiotics and drugs, and how they are examined.

Generated by Claude Opus 4.87 min readCCEA 6568 Unit 2.8 to 2.10Updated 2026-06-14

Reviewed by: AI editorial process; not yet individually human-reviewed

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What this module covers
How it is examined
How to study it

This module is about microbes, disease and how we treat it. It covers Unit 2 sections 2.8 to 2.10 and is examined on the Unit 2 written paper. This page maps the topics and links to a focused answer page for each.

What this module covers

Microorganisms and biotechnology: The types of microorganism, the conditions they need to grow, their useful roles in food production, biotechnology and aseptic technique. Start with Microorganisms and biotechnology.
Defence against disease: Pathogens and how they spread, the body's first-line defences, and the role of white blood cells in phagocytosis and antibody production. See Defence against disease.
Vaccination and the immune system: Memory cells and long-term immunity, how a vaccine works, and herd immunity. See Vaccination and the immune system.
Medicines, antibiotics and drugs: How antibiotics work and why not against viruses, antibiotic resistance, medical versus recreational drugs, and the effects of alcohol and tobacco. See Medicines, antibiotics and drugs.

How it is examined

These topics appear on Unit 2, worth 40% of the GCSE. Expect structured questions on microorganisms and food production, pathogens and defences, the immune response and vaccination, and antibiotics and resistance, plus a longer answer such as how a vaccine makes a person immune.

How to study it

Learn the microorganism types and the conditions they need, then the body's first and second lines of defence. Make sure you can explain phagocytosis, antibodies and how a vaccine makes memory cells, and why antibiotics work on bacteria but not viruses. Rehearse the antibiotic-resistance explanation (it links to natural selection), then work through CCEA past papers and finish with the module quiz.

Sources & how we know this

CCEA GCSE Biology specification — CCEA (2017)