Immunity

Question 1

Outline phagocytosis.

Answer 1

1. Phagocyte recognises the foreign antigen on a pathogen.
2. Cytoplasm of phagocyte moves round the pathogen, engulfing it.
3. The pathogen is now contained in a phagocytic vacuole in the cytoplasm.
4. The lysosome fishes with the vacuole. Its lysozymes break down the pathogen.
5. Phagocyte now presents pathogen’s antigens to activate other immune cells