Quick revision: every question with its correct answer. For the full explanation, open the test and tap View Solution.
5.5 The T-Cell Receptor (TCR) β Test 1
Q1. The most common T-cell receptor on circulating T cells is composed of:β An Ξ± and a Ξ² chain
Q2. Unlike antibodies, the TCR recognises antigen as:β A peptide presented on an MHC molecule
Q3. The TCR transmits its signal through the associated:β CD3 complex
Q4. TCR diversity is generated by mechanisms most similar to:β Antibody V(D)J recombination (without somatic hypermutation)
Q5. In TCR gene rearrangement, the Ξ² chain is analogous to the immunoglobulin:β Heavy chain (uses V, D and J)
Q6. The CD4 co-receptor on helper T cells binds to:β A conserved region of MHC class II
Q7. The CD8 co-receptor on cytotoxic T cells binds to:β A conserved region of MHC class I
Q8. Ξ³Ξ΄ T cells differ from Ξ±Ξ² T cells in that they:β Often recognise antigen without classical MHC restriction
Q9. The proximal kinase recruited to phosphorylated CD3/ΞΆ ITAMs during TCR signalling is:β ZAP-70
Q10. The pre-T-cell receptor (pre-TCR) checks for a productive rearrangement of the:β Ξ² chain (pairing with a pre-TΞ± chain)
Q11. The most variable, antigen-contacting loops of the TCR are encoded largely by:β The CDR3 region at the V(D)J junction
Q12. Compared with antibodies, the affinity of the TCR for peptideβMHC is generally:β Lower, which is compensated by co-receptors and adhesion molecules
Q13. Superantigens activate large numbers of T cells by binding:β MHC class II and the TCR VΞ² region outside the peptide groove
Q14. The Ξ±Ξ² TCR's recognition of 'peptide plus self-MHC' is established during:β Positive selection in the thymus
Q15. The TCR is a member of which protein family?β The immunoglobulin superfamily
Q16. The TCR has how many antigen-binding sites per receptor?β One
Q17. Adhesion molecules such as LFA-1 binding ICAM-1 are important in T-cell activation because they:β Stabilise the contact (immunological synapse) between T cell and APC
Q18. Recognition of lipid antigens by some T cells (e.g. NKT cells) is mediated by:β CD1 molecules
Q19. A functional difference between the TCR and the BCR is that the TCR:β Is never secreted and only recognises processed peptideβMHC
Q20. The ligand recognised by the Ξ³Ξ΄ T-cell receptor is typically:β Phospholipid/non-peptide antigens
Q21. MHC restriction is absent in:β Ξ³Ξ΄ T-cell receptors
Q22. Match each component with its role and select the correct option.β A-ii, B-iii, C-iv, D-i