How to Revise IGCSE Biology Topic 10: Diseases and Immunity
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Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Key point
Know pathogen types and transmission routes. Understand phagocytes, lymphocytes, antibodies, and memory cells. Explain vaccination and herd immunity. Understand why antibiotic resistance develops.
Topic 10 covers how diseases are transmitted, the body's defence mechanisms, the immune response (antibodies and memory cells), vaccination, and antibiotic resistance. These are highly topical and commonly tested.
Priority 1: Types of pathogen and transmission
Four types: bacteria, viruses, fungi, and protoctists. Transmission routes: direct contact, droplet infection, contaminated food/water, vectors (e.g. Mosquitoes for malaria). Know specific diseases: cholera (bacteria, water-borne), malaria (protoctist, mosquito vector), HIV/AIDS (virus, body fluids).
Priority 2: Body defences and immune response
First line: skin, mucus, stomach acid. Immune response: phagocytes engulf and digest pathogens. Lymphocytes produce specific antibodies that bind to antigens on the pathogen surface. After infection, memory cells remain: if the same pathogen returns, the response is faster and stronger (secondary immune response).
Priority 3: Vaccination and antibiotic resistance
Vaccines contain dead or weakened pathogens that stimulate the immune system to produce memory cells without causing disease. Herd immunity protects unvaccinated individuals when enough of the population is immune.
Antibiotics kill bacteria, not viruses. Overuse and misuse of antibiotics leads to resistant strains (e.g. MRSA) through natural selection.
Frequently asked questions
Why can't antibiotics treat viral infections?
Viruses reproduce inside host cells and lack the structures (cell walls, ribosomes) that antibiotics target. An antibiotic would have to destroy the host cell to reach the virus.
Put the guide into practice
Questions and practical resources
Use a fresh question to check whether the idea can be applied without prompts.