Immunity and the evolutionary raceEdexcel International A Level Biology: Mind map

Exam questions on Immunity and the evolutionary race

1. A baby is breast-fed and receives antibodies from her mother in the milk. At eight weeks old she is also given her first dose of a vaccine against whooping cough.
   Distinguish between active and passive immunity.2 marks
2. A traveller is bitten by a dog in a region where rabies occurs. At the clinic he is immediately injected with ready-made rabies antibodies, and is then given a course of rabies vaccine over the following weeks.
   Explain why the injected antibodies give the traveller only short-term protection.2 marks
3. Influenza viruses accumulate mutations in the genes for their surface antigens, so a new strain appears every few years. Each year a new influenza vaccine has to be produced against the strains most likely to be circulating.
   Explain why a person who has recovered from influenza one year may become ill again when a new strain appears.3 marks