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2.5 T & B Lymphocyte Subsets β Test 1
Q1. Helper T cells are identified by the surface marker:β CD4
Q2. Cytotoxic T cells are identified by the surface marker:β CD8
Q3. Th1 cells, driven by IL-12, secrete IFN-Ξ³ and primarily promote:β Cell-mediated immunity (macrophage activation, CTL help)
Q4. Th2 cells, driven by IL-4, promote:β Humoral immunity, IgE and eosinophil responses (anti-helminth/allergy)
Q5. Th17 cells, induced by IL-6 and TGF-Ξ², secrete IL-17 and are important for:β Defence against extracellular bacteria and fungi (neutrophil recruitment)
Q6. Regulatory T cells (Tregs), defined by FoxP3, function to:β Suppress immune responses and maintain self-tolerance
Q7. Follicular helper T (Tfh) cells specialise in:β Helping B cells in germinal centres (affinity maturation, class switching)
Q8. B cells are identified by surface markers such as:β CD19 and CD20
Q9. Plasma cells are the effector form of B cells specialised for:β Secreting large amounts of antibody
Q10. Memory cells differ from naive lymphocytes in that memory cells:β Respond faster and more strongly on re-exposure to antigen
Q11. The master transcription factor for Th1 cells is:β T-bet
Q12. The master transcription factor for regulatory T cells is:β FoxP3
Q13. The B-cell receptor (BCR) is essentially:β Membrane-bound immunoglobulin (with IgΞ±/IgΞ² for signalling)
Q14. Unlike the TCR, the BCR can:β Recognise native, unprocessed antigen directly
Q15. The two signals a B cell typically needs for a T-dependent response are:β Antigen via the BCR plus help from a helper T cell (e.g. CD40L)
Q16. The CD3 complex is a marker found on:β All T cells (associated with the TCR)
Q17. A reduced CD4:CD8 ratio (e.g. in advanced HIV) reflects:β Loss of CD4 helper T cells
Q18. Helper T cells are essential because they:β Coordinate and amplify responses of B cells, CTLs and macrophages
Q19. B-1 cells differ from conventional B-2 cells in that B-1 cells:β Produce 'natural' antibodies (often IgM) with broad specificity, largely T-independently
Q20. A key difference between T and B cells is that:β T cells mature in the thymus and B cells mature in the bone marrow
Q21. Which cell interacts with both the humoral and cell-mediated immune responses?β The helper T (TH) cell
Q22. CD4 and CD8 are best described as:β Cell-surface glycoproteins (clusters of differentiation) marking T-cell subsets
Q23. Match each lymphocyte subset with its defining feature and select the correct option.β A-ii, B-iv, C-i, D-iii