Quick revision: every question with its correct answer. For the full explanation, open the test and tap View Solution.
4.4 Immunological Memory — Test 1
Q1. Immunological memory is the basis of:✓ A faster, stronger response on re-exposure to the same antigen
Q2. Compared with the primary response, the secondary (memory) antibody response shows:✓ Shorter lag, higher titre, higher affinity, mainly IgG
Q3. Memory B cells differ from naive B cells in that they:✓ Respond faster and often carry class-switched, high-affinity receptors
Q4. Long-term serum antibody levels are maintained largely by:✓ Long-lived plasma cells in the bone marrow
Q5. Central memory T cells differ from effector memory T cells in that central memory cells:✓ Home to lymph nodes and have high proliferative potential
Q6. The principle behind a vaccine booster dose is to:✓ Re-stimulate memory cells for a stronger, higher-affinity response
Q7. The lag phase of the secondary response is shorter than the primary because:✓ Memory cells are already expanded and primed
Q8. Original antigenic sin describes the tendency of the immune system to:✓ Preferentially use memory from a first exposure when meeting a related variant
Q9. Memory cells are generated mainly during which phase of an immune response?✓ After clonal expansion, surviving the contraction phase
Q10. A key reason memory responses are of higher affinity is:✓ Memory B cells arise from affinity-matured germinal-centre cells
Q11. Which cells provide rapid, immediate effector function in peripheral tissues on re-infection?✓ Effector memory and tissue-resident memory T cells
Q12. Vaccination establishes protection primarily by generating:✓ Long-lived memory lymphocytes (and antibody)
Q13. Why does specific IgM, rather than IgG, suggest a recent/acute infection?✓ IgM dominates the primary response before class switching
Q14. Survival of memory T cells in the absence of antigen depends largely on:✓ Cytokines such as IL-7 and IL-15
Q15. In a typical antibody response curve, the secondary response differs by showing:✓ A steeper rise to a much higher plateau of IgG
Q16. Memory generation generally requires which kind of antigen for robust B-cell memory?✓ T-dependent (protein) antigens
Q17. Heterologous (cross-reactive) memory can sometimes provide:✓ Partial protection against a related but different pathogen
Q18. The contraction phase that follows clonal expansion serves to:✓ Remove most effector cells, leaving a stable memory pool
Q19. Why can some vaccines (e.g. measles) confer lifelong immunity?✓ They induce durable memory cells and long-lived plasma cells
Q20. The most widely accepted theory of antibody production is:✓ Clonal selection theory
Q21. A person exposed to a brand-new cold virus feels unwell for one to two weeks mainly because:✓ No memory cells exist yet, so the slower primary response is needed
Q22. Which cells are chiefly responsible for a rapid secondary immune response?✓ Memory cells
Q23. Immunological memory means that:✓ A second exposure to the same antigen produces a faster, stronger response
Q24. On re-exposure to a virus, prior mild illness now prevents sickness mainly due to:✓ Memory B (and T) cells formed after the first exposure
Q25. An antigen given only once (no booster) shows a low antibody titre weeks later mainly because:✓ Without re-exposure, a strong secondary (memory) response is not triggered
Q26. Match each feature with the response it best describes and select the correct option.✓ A-ii, B-iii, C-iv, D-i