CAIE A Level Biology 9700 · Immunity
A patient is infected with a novel virus (Virus X) and recovers after 10 days. One year later, the same patient is re-infected with the same strain of Virus X. This time, the infection is cleared within 48 hours and the patient shows no symptoms.
Explain why the secondary immune response is faster and more effective than the primary immune response.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
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