A-LevelBiologyImmunityOct/Nov 2019Paper 1 Q381 Mark
Immune response to a vaccination against a virus can be assessed by making three measurements: 1 the concentration of anti-virus antibody in the blood 2 the time taken to increase the antibody concentration significantly after a booster vaccination 3 the number of virus-specific lymphocytes per cm³ blood. What describes the immunity of an individual when the values of 1, 2 and 3 are all low ten years after vaccination?
Aactive immunity due to the presence of memory cells
Blow immunity due to the absence of antibodies
Clow immunity due to the absence of memory cells
Dpassive immunity due to the presence of antibodies
✓ Correct Answer
The correct answer is A: active immunity due to the presence of memory cells
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
🎯 Mark Scheme Breakdown
Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.
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