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3.1 Antigens & Immunogens β Test 1
Q1. An antigen is best defined as a substance that:β Is recognised and bound by an antibody or lymphocyte receptor
Q2. A substance that can react with antibody but cannot by itself induce an immune response is a:β Hapten
Q3. The ability of a molecule to induce an immune response is termed:β Immunogenicity
Q4. Which property generally increases immunogenicity?β Large molecular size and chemical complexity
Q5. A substance added to a vaccine to enhance the immune response to the antigen is a(n):β Adjuvant
Q6. T-dependent antigens require which cell for an effective antibody response?β Helper T cells
Q7. A typical T-independent antigen is a:β Bacterial polysaccharide
Q8. Foreignness is required for immunogenicity because:β The immune system is normally tolerant to self-antigens
Q9. Superantigens are distinctive because they:β Activate very large numbers of T cells non-specifically
Q10. A conjugate vaccine improves the polysaccharide response chiefly by:β Linking the polysaccharide to a carrier protein to recruit T-cell help
Q11. Which class of biomolecule is usually the strongest immunogen?β Proteins
Q12. A hapten becomes immunogenic when it is:β Coupled to a carrier macromolecule
Q13. Antigens that share identical or similar epitopes can lead to:β Cross-reactivity
Q14. The dose and route of antigen administration affect:β Whether immunity or tolerance develops
Q15. Heterophile antigens are antigens that:β Are shared among phylogenetically unrelated species
Q16. Which of the following is an example of an autoantigen?β Double-stranded DNA in systemic lupus erythematosus
Q17. Particulate antigens (e.g. cells, bacteria) are generally:β More immunogenic than soluble monomers
Q18. Alloantigens are antigens that:β Differ between members of the same species
Q19. A tolerogen is an antigen that:β Induces specific immunological unresponsiveness
Q20. Which organism is also called a 'mosaic antigen'?β Virus
Q21. To be immunogenic, a molecule generally must be:β Foreign, of high molecular weight (>1000 Da) and chemically complex
Q22. Haptens are:β Antigenic but not immunogenic by themselves
Q23. A hapten becomes immunogenic when complexed with a:β Carrier protein
Q24. A homopolymer such as poly-Ξ³-D-glutamic acid (MW ~50,000) is not immunogenic mainly because of:β Low chemical complexity
Q25. Which class of molecule is generally the least immunogenic?β Nucleic acids (DNA/RNA)
Q26. Which of the following can act as immunogens (capable of activating an immune reaction)?β Bacteria, carriers and haptenβcarrier complexes
Q27. Penicillin can induce antibody only after binding a serum protein. Here penicillin acts as a ___ and the serum protein as a ___:β Hapten; carrier
Q28. An example of a thymus-independent antigen is:β Bacterial lipopolysaccharide (LPS)
Q29. Adjuvants enhance immune responses by:β Aiding antigen delivery to lymph nodes, prolonging release and stimulating innate receptors
Q30. In the ABO blood group system, the antigenic determinants are:β Carbohydrate (oligosaccharide) in nature
Q31. Match each term with its correct description and select the correct option.β A-ii, B-i, C-iv, D-iii