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Cambridge O Level Biology 5090

Human systems

Disease and immunity

Connect pathogen transmission, body defences, antibodies, vaccination and public-health control.
5090 syllabus routeConcept · skill · exam language

What to know

Build the topic around four anchors.

  1. 01Pathogens and transmission
  2. 02Physical and chemical barriers
  3. 03Antibodies and lymphocytes
  4. 04Vaccination and community protection

Exam skills

What the paper asks you to do

  • Suggest transmission controls from evidence
  • Explain vaccination as a sequence
  • Distinguish antibiotics from antibodies

Common mistakes

Where marks disappear

  • Using antibiotics for viral disease
  • Saying vaccines directly kill pathogens
  • Confusing an antigen with an antibody

Structured practice

Answer these without looking back.

For each prompt, write the biological chain clearly enough that every mark-worthy link is visible.

  1. 01Explain how vaccination creates protection.
  2. 02Suggest controls for a water-borne pathogen.
  3. 03Compare antibody and antigen.

Continue learning

Read the connected explanation.

See how barriers, inflammation, phagocytes, antibodies and T cells cooperate—and where immune memory comes from.

Next topicExcretion

This independent teaching resource follows the Cambridge O Level Biology 5090 syllabus direction and is not endorsed by Cambridge International Education.