Infection and response: GCSE Combined Science
Pathogens, named diseases, human defences, vaccination, antibiotics and how new drugs are tested
The short version
Know the four pathogen types with named examples, body defences, vaccines, antibiotics vs painkillers, and how new drugs are tested.
Key idea
Grade 2–3: Colds spread through coughs and sneezes. Washing hands helps.
Grade 5–6: I can name virus/bacterium/fungus/protist with one example each and a spread method (air, water, contact, vector, sex, food).
Grade 9: Prevention matches the route: condoms for gonorrhoea, hygiene for salmonella, mosquito nets for malaria, vaccination for measles. HIV attacks white blood cells — immune system fails (AIDS).
Go a bit deeper
Grade 2–3: Each disease has a way it spreads and a way we try to stop it.
Grade 5–6: I can sort the spec list into the four groups.
Grade 9: I use the plant examples on a Combined paper without mixing TMV (virus) with black spot (fungus).
Worked example
Worked example
Grade 2–3: Colds spread through coughs and sneezes. Washing hands helps. Grade 5–6: I can name virus/bacterium/fungus/protist with one example each and a spread method (air, water, contact, vector, sex, food). Grade 9: Prevention matches the route: condoms for gonorrhoea, hygiene for salmonella, mosquito nets for malaria, vaccination for measles. HIV attacks white blood cells — immune system fails (AIDS).
Lessons in this topic
- Communicable disease
- Viral, bacterial, fungal and protist disease
- Human defence systems
- Vaccination
- Antibiotics and painkillers
- Drug development
In the app each lesson is video (when we have a real YouTube id) then intro, learn and summary steps.
What the examiner wants
Name the pathogen type for each disease, explain antibody specificity, interpret vaccine graphs, and describe clinical trials (placebo, double-blind, peer review).
Try these questions
Cover the answers and have a go first. Worked solutions are underneath.
A pathogen is...
Which disease is caused by a virus?
Malaria is caused by a...
Stomach acid helps defend against pathogens by...
Common mistakes
- Viruses are not cells and are not killed by antibiotics. “Malaria is a virus” is a 0.
- Antibodies are not antibiotics. One is made by you; the other is a medicine for bacteria.
- Vaccines do not contain a full live measles infection in the MMR sense students fear — Combined: inactive/dead/weakened or antigens. They do not treat an infection you already have the way antibiotics treat bacteria.
- “The bacteria become immune” is sloppy. People become immune; bacteria become resistant.
Answers and working
Frequently asked questions
Is GCSE Infection and response on Combined Science and Triple?
Infection and response is on Combined Science and on Triple Biology. Progress is shared in the ReviseEasy app.
Which exam board is this Infection and response page for?
The ideas are board-agnostic for AQA, Edexcel, OCR, WJEC and CCEA. Paper lengths and question numbers differ — check your specification.
Is Infection and response Foundation or Higher?
The core ideas appear on both tiers. Higher papers add extra application and some HT-only detail, marked in lessons with a Higher badge.
Learn, try, get feedback, fix the mistake
Open the stepped lesson, then the quiz with hints. Required-practical and calculation questions use the same method you will need in the paper.
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