Explain how white blood cells protect the body against disease.

WJEC GCSE Biology (Wales) — 1.4.1 Blood and circulation · Explain · 4 marks · View as Markdown

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

Model answer (4 marks)

White blood cells protect the body by (1) engulfing and digesting pathogens through phagocytosis.
(2) Producing antibodies that recognise specific antigens on pathogens.
(3) Antibodies neutralise or destroy the pathogens by binding to them.
(4) Some white blood cells produce antitoxins that neutralise toxins released by pathogens.

Examiner tips

Use the exact terms ‘phagocytosis’, ‘antibodies’, ‘antigens’, and ‘antitoxins’. Show the causal link: production of antibodies → binding to antigens → neutralisation. Keep each point short and separate with numbers or bullets.

Common mistakes

Confusing antibodies with white blood cells; they are produced by white blood cells but are not the cells themselves. Omitting the word ‘antigens’ when describing antibody action. Using vague phrases like ‘fight infection’ instead of specific mechanisms.

Mark scheme (4 marks)

White blood cells can engulf and digest pathogens / microorganisms (phagocytosis)
White blood cells produce antibodies
Antibodies destroy / neutralise specific pathogens / attack antigens on the pathogen's surface
White blood cells produce antitoxins that neutralise toxins produced by pathogens

Key terms in this question

white blood cells