Biology 9700 · AS & A Level · Antibodies and vaccination
Antibodies and vaccination — practice question
Malaria is an illness caused by the parasite Plasmodium. This parasite has a complicated life cycle, and part of that cycle takes place in the gut of the female mosquito, which transmits the disease. Fig. 5.1 illustrates part of the malarial parasite’s life cycle. In vaccine trials for malaria, the parasites were destroyed using radioactivity and then injected into volunteers. This approach gave some protection against malaria.
(a)[3]
Explain why the parasites were destroyed with radioactivity rather than by using high temperatures.
(b)[3]
Using Fig. 5.1, explain why the researchers chose the parasite form injected by mosquitoes rather than the form that leaves the liver.
(c)[5]
The volunteers injected with the killed parasites produced antibodies, and these gave some protection against the disease.
Outline the sequence of events after the parasites are injected that leads to antibody production.
Worked solution & mark scheme
This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Vaccines include antigens that are proteins or glycoproteins” …