Antigens Chat Questions (PDF)

Which of the following is a characteristic of T-independent antigens? A) They can be degraded easily B) They require the assistance of CD4+ T cells to activate B cells C) They have a polymeric structure with repeated antigenic determinants D) They are typically proteins with multiple antigenic deter...

Which of the following is a characteristic of T-independent antigens? A) They can be degraded easily B) They require the assistance of CD4+ T cells to activate B cells C) They have a polymeric structure with repeated antigenic determinants D) They are typically proteins with multiple antigenic determinants Correct answer: C What is the primary feature of superantigens? A) They bind speci cally to TCRs and MHC molecules of CD8+ T cells B) They induce a monoclonal immune response C) They activate a large number of T cells non-speci cally D) They exclusively activate B cells Correct answer: C Which of the following molecules are most likely to serve as autoantigens in autoimmunity? A) Viral antigens B) Altered self-antigens C) Bacterial antigens D) Polysaccharides Correct answer: B Haptens are considered incomplete antigens because: A) They cannot bind to MHC molecules B) They cannot induce an immune response on their own C) They bind only to T cells D) They cause rapid degradation Correct answer: B Which of the following factors is least likely to a ect the immunogenicity of an antigen? A) The size of the antigen B) The foreignness of the antigen C) The route of administration D) The age of the antigen Correct answer: D Which type of antigen is most likely to stimulate a polyclonal activation of lymphocytes? A) Haptens B) Superantigens C) T-independent antigens D) Endogenous antigens Correct answer: B Which of the following characteristics is true for most protein antigens? A) They are usually T-independent antigens B) They are weakly immunogenic unless conjugated with lipids C) They are primarily T-dependent antigens D) They stimulate only a monoclonal B cell response Correct answer: C What role do adjuvants play in vaccine formulations? A) They prevent degradation of antigens B) They stimulate polyclonal B cell activation C) They enhance the immune response to an antigen D) They reduce the immunogenicity of an antigen Correct answer: C Which type of antigen is most likely to require a carrier protein to induce an immune response? A) Endogenous antigens B) T-independent antigens C) Haptens D) Viral antigens Correct answer: C What characteristic makes particulate antigens more immunogenic than soluble antigens? A) They have more antigenic determinants B) They are more easily phagocytosed and processed by antigen-presenting cells C) They are typically larger in size D) They stimulate both B cells and T cells Correct answer: B Which of the following routes of antigen administration is rarely used for vaccines? A) Intradermal B) Intravenous C) Subcutaneous D) Intramuscular Correct answer: B Why are denatured antigens more immunogenic than their native counterparts? A) Denaturation destroys immunogenic epitopes B) Denaturation exposes more antigenic determinants C) Native antigens are recognized as self by the immune system D) Denatured antigens are easier to degrade Correct answer: B Which of the following is NOT an example of an exogenous antigen? A) Inhaled pollen B) Viral antigen C) Bacterial toxin D) Tumor antigen Correct answer: D Which of the following is a structural characteristic of T-dependent antigens? A) They contain repeating antigenic determinants B) They consist mainly of lipids and polysaccharides C) They require the presence of helper T cells for activation of B cells D) They can activate B cells without T cell assistance Correct answer: C How do superantigens di er from regular antigens in T cell activation? A) They activate only antigen-speci c T cells B) They require CD8+ T cells for activation C) They bind to the variable domain of the β-chain of TCRs D) They induce a weak immune response Correct answer: C Which of the following is the most immunogenic macromolecule? A) Lipids B) Nucleic acids C) Proteins D) Polysaccharides Correct answer: C Which of the following would be classi ed as an endogenous antigen? A) Ingested bacterial antigen B) Self-antigen altered during tumorigenesis C) Antigen from inhaled pollen D) Parasitic antigen in the gut Correct answer: B Autoantigens di er from foreign antigens in that: A) Autoantigens are recognized as self and do not induce an immune response B) Autoantigens are associated with allergic reactions C) Autoantigens are derived from endogenous molecules D) Autoantigens are rapidly degraded by immune cells Correct answer: C Which of the following is a key property of antigens that in uences their immunogenicity? A) Foreignness B) Solubility C) Neutral charge D) Ability to form antigen-antibody complexes Correct answer: A A polysaccharide vaccine is most likely to act as a: A) T-dependent antigen B) T-independent antigen C) Hapten D) Superantigen Correct answer: B Which type of antigenic determinant is most likely to activate a polyclonal response? A) T-independent antigen B) T-dependent antigen C) Hapten D) Superantigen Correct answer: D Which of the following would decrease the immunogenicity of an antigen? A) Denaturation of the antigen B) Increasing the foreignness of the antigen C) Administration of an adjuvant D) Small molecular size Correct answer: D What happens when a hapten binds to a larger carrier molecule? A) It loses its immunogenicity B) It can induce an immune response C) It becomes a T-independent antigen D) It activates cytotoxic T cells Correct answer: B Which of the following factors increases the likelihood that an antigen will induce an immune response? A) Being a lipid B) Small size C) High complexity D) Solubility Correct answer: C Which type of antigen is derived from microbial agents and is responsible for activating the immune system in infections? A) Endogenous antigens B) T-independent antigens C) Exogenous antigens D) Superantigens Correct answer: C What is a common characteristic of T-independent antigens? A) They degrade quickly B) They activate helper T cells C) They consist of repeating units D) They are mostly proteins Correct answer: C Which antigen type is most closely associated with autoimmunity? A) T-independent antigen B) Superantigen C) Autoantigen D) Hapten Correct answer: C Which of the following factors might in uence whether a particular antigen will be recognized as immunogenic in di erent individuals? A) Physical size of the antigen B) Genetic di erences in MHC molecules C) Foreignness of the antigen D) The route of administration Correct answer: B Which of the following routes of vaccine administration might be used to prevent respiratory infections? A) Subcutaneous B) Intradermal C) Intranasal D) Intravenous Correct answer: C Why do proteins tend to be highly immunogenic compared to other macromolecules? A) They have greater molecular complexity B) They are more likely to be soluble C) They do not degrade easily D) They have fewer antigenic determinants Correct answer: A Which of the following best describes a superantigen's interaction with T cells? A) It binds only to the α-chain of T cell receptors B) It speci cally activates a single type of T cell receptor C) It induces activation by binding to the variable domain of the β-chain of TCR D) It requires MHC class I interaction for activation Correct answer: C