White blood cells and blood clottingSpec B9.4.4
In short
Lymphocytes make antibodies and phagocytes engulf pathogens; clotting converts soluble fibrinogen to insoluble fibrin, forming a mesh that seals a wound.
Roles of blood clotting
When the skin is cut, blood clots to prevent blood loss and to prevent the entry of pathogens into the body. The clot dries to form a scab.
Quick check
List the four components of blood.
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Red blood cells, white blood cells, platelets and plasma.
What is the function of haemoglobin?
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To transport oxygen in the red blood cells.
Supplement State two roles of blood clotting.
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Prevents blood loss and prevents entry of pathogens.
Written and checked against the Cambridge IGCSE Combined Science (0653) specification · Updated October 2026