Immunology Q&A PDF

Immunology (Deja review) Q&A. What cells mediate innate immunity? a) Monocytes/macrophages, neutrophils, and natural killer (NK) cells b) B cells and T cells c) Plasma cells and dendritic cells d) Only neutrophils Answer: a) Monocytes/macrophages, neutrophils, and natural killer (NK) cells 2. What...

Immunology (Deja review) Q&A. What cells mediate innate immunity? a) Monocytes/macrophages, neutrophils, and natural killer (NK) cells b) B cells and T cells c) Plasma cells and dendritic cells d) Only neutrophils Answer: a) Monocytes/macrophages, neutrophils, and natural killer (NK) cells 2. What cells mediate humoral immunity? a) T lymphocytes b) NK cells c) B lymphocytes d) Macrophages Answer: c) B lymphocytes 3. What cells mediate cell-mediated immunity? a) B lymphocytes b) T lymphocytes c) NK cells d) Macrophages Answer: b) T lymphocytes 4. What interacts with the T-cell receptor (TCR) of an immature T cell to signal differentiation into a single-positive cell? a) Interaction with major histocompatibility complex I (MHC I) or MHC II b) Interaction with dendritic cells c) Interaction with B cells d) Interaction with macrophages Answer: a) Interaction with major histocompatibility complex I (MHC I) or MHC II 5. In what organ does T-cell differentiation occur? a) Bone marrow b) Thymus c) Spleen d) Lymph nodes Answer: b) Thymus 6. What cells function as professional antigen-presenting cells (APCs)? a) Monocytes, NK cells, and T cells b) Neutrophils, eosinophils, and basophils c) Dendritic cells, macrophages, and B cells d) Plasma cells, mast cells, and NK cells Answer: c) Dendritic cells, macrophages, and B cells 7. What is the source of antigens presented by MHC-I molecules? a) Extracellular proteins b) Intracellular proteins c) Secreted cytokines d) Free-floating antibodies Answer: b) Intracellular proteins 8. Which cells possess MHC-I molecules? a) Only APCs b) All nucleated cells c) Neutrophils and macrophages d) B cells and plasma cells Answer: b) All nucleated cells 9. Which T-helper line elicits a more effective response against intracellular pathogens, such as Mycobacterium tuberculosis? a) Th1 cells b) Th2 cells c) Tc cells d) Treg cells Answer: a) Th1 cells 10. By what two main methods do CD8+ cells kill virus-infected, graft, and tumor cells? a) Phagocytosis and cytokine release b) Lyse infected cells or induce apoptosis c) Neutralization and agglutination d) Opsonization and antigen presentation Answer: b) Lyse infected cells or induce apoptosis 11. What is the role of MHC-I molecules on allogeneic donor cells in graft rejection? a) They suppress immune responses b) They are recognized by Tc cells, which kill the grafted cells c) They prevent antibody formation d) They enhance tolerance Answer: b) They are recognized by Tc cells, which kill the grafted cells 12. Which mature immune cell has receptors for whole, unprocessed antigens and does not require MHC presentation? a) T cells b) NK cells c) Dendritic cells d) B cells Answer: d) B cells 13. Where does B-cell differentiation occur? a) Thymus b) Bone marrow c) Spleen d) Lymph nodes Answer: b) Bone marrow 14. What is the predominant antibody released in the initial stages of the primary humoral response? a) IgG b) IgA c) IgE d) IgM Answer: d) IgM 15. What would be different about the T cells in a patient with DiGeorge syndrome? a) They would lack memory T cells b) They would differentiate abnormally due to thymic hypoplasia c) They would overproduce cytokines d) They would lack surface receptors Answer: b) They would differentiate abnormally due to thymic hypoplasia 16. What immune cell kills infected cells lacking MHC-I proteins? a) B cells b) NK cells c) T-helper cells d) Macrophages Answer: b) NK cells 17. What is the major histocompatibility complex (MHC) also known as? a) Human antigen markers b) Immune regulatory proteins c) Human leukocyte antigen (HLA) complex d) Adaptive immunity markers Answer: c) Human leukocyte antigen (HLA) complex 18. What is the importance of MHC classes I and II proteins? a) To stimulate B-cell maturation b) To regulate cytokine production c) To enable T cells to recognize foreign antigens d) To inhibit immune cell differentiation Answer: c) To enable T cells to recognize foreign antigens 19. What are the two main functions of innate immunity? a) Target intracellular pathogens and produce antibodies b) Provide a first line of defense and stimulate adaptive immunity c) Direct phagocytosis and cytokine release d) Produce memory cells and regulate inflammation Answer: b) Provide a first line of defense and stimulate adaptive immunity 20. Which system is able to respond to a broader array of foreign motifs, innate or adaptive immunity? Why? a) Innate immunity; because it recognizes highly specific antigens b) Adaptive immunity; because it produces memory cells c) Adaptive immunity; because it has broader specificity d) Innate immunity; because it recognizes conserved patterns Answer: d) Innate immunity; because it recognizes conserved patterns 21. Which system is better at discriminating self from nonself, innate or adaptive immunity? a) Innate immunity b) Adaptive immunity c) Both systems equally d) Neither system Answer: a) Innate immunity 22. Name the three principal effector cells of the innate immune system apart from epithelial cells. a) Monocytes/macrophages, neutrophils, and NK cells b) Plasma cells, B cells, and T cells c) Mast cells, basophils, and eosinophils d) Cytotoxic T cells, Th1 cells, and dendritic cells Answer: a) Monocytes/macrophages, neutrophils, and NK cells 23. How do NK cells identify infected cells? a) By detecting foreign antibodies b) By identifying abnormal cytokine levels c) By the absence of host MHC-I molecules d) By recognizing PAMPs (pathogen-associated molecular patterns) Answer: c) By the absence of host MHC-I molecules 24. How do NK cells kill infected cells? a) Phagocytosis and antigen presentation b) Perforins and granzymes to induce apoptosis c) Neutralization and complement activation d) Cytokine release and inflammation Answer: b) Perforins and granzymes to induce apoptosis 25. Deficiencies of NK cells predispose to what types of infections? a) Extracellular bacterial infections b) Intracellular infections, including viruses c) Autoimmune diseases d) Allergic reactions Answer: b) Intracellular infections, including viruses 26. Microbial pathogens entering the nasopharynx will most likely encounter which immunoglobulin isotype? a) IgG b) IgM c) IgA d) IgE Answer: c) IgA 27. What two immune processes does IgE mediate? a) Allergy and Type II hypersensitivity b) Helminth immunity and allergy/anaphylaxis c) Autoimmune response and complement activation d) B-cell differentiation and antibody production Answer: b) Helminth immunity and allergy/anaphylaxis 28. What is the most abundant antibody in serum? a) IgA b) IgM c) IgG d) IgE Answer: c) IgG 29. What antibody is produced in the largest amounts? a) IgG b) IgM c) IgA d) IgE Answer: c) IgA 30. What antibody has the highest avidity (overall strength)? a) IgG b) IgA c) IgM d) IgE Answer: c) IgM 31. What is the immunoglobulin isotype primarily produced by the fetus? a) IgG b) IgA c) IgM d) IgE Answer: c) IgM 32. Define antibody-mediated cell cytotoxicity (ADCC). What two cells utilize ADCC? What isotypes are involved in each case? a) The process by which antibodies induce complement activation; NK cells via IgG and eosinophils via IgA b) The process by which Fc receptors on a cell bind the Fc portion of antigen-bound antibodies, resulting in the inactivation of that cell; NK cells via IgG and eosinophils via IgE c) The process by which T cells directly kill infected cells; CD8+ T cells via IgE and NK cells via IgA d) The process by which macrophages ingest pathogens; B cells via IgG and T cells via IgM Answer: b) The process by which Fc receptors on a cell bind the Fc portion of antigen-bound antibodies, resulting in the inactivation of that cell; NK cells via IgG and eosinophils via IgE 33. Name two molecules that result in direct opsonization. a) IgE and C3b b) IgM and C3a c) IgG and C3b d) IgA and C4b Answer: c) IgG and C3b 34. Humoral immunity and cell-mediated immunity are the two branches of adaptive immunity. What mediates humoral immunity? What are the targets of humoral immunity? a) T cells; intracellular pathogens b) B cells and antibodies; extracellular pathogens, certain intracellular pathogens, and toxins c) Macrophages; tumor cells and viruses d) NK cells and T cells; fungi and bacteria Answer: b) B cells and antibodies; extracellular pathogens, certain intracellular pathogens, and toxins 35. What are key differences between primary and secondary responses? What accounts for these differences? a) Primary responses are quicker but less specific; secondary responses are slower due to initial exposure. b) Primary responses are characterized by IgG only, while secondary responses include IgM production. c) Primary responses have a longer lag period and are characterized by IgM followed by low amounts of IgG; secondary responses are faster and have larger amounts of IgG due to memory B cells. d) There is no difference between primary and secondary responses. Answer: c) Primary responses have a longer lag period and are characterized by IgM followed by low amounts of IgG; secondary responses are faster and have larger amounts of IgG due to memory B cells. 36. What type of cell stimulates B-cell clonal expansion, isotype switching, affinity maturation, and differentiation into memory B cells? a) CD8+ cytotoxic T cells b) CD4+ helper T cells c) B cells d) Dendritic cells Answer: b) CD4+ helper T cells 37. What are the two types of cells that may become activated B cells? a) T-helper cells and cytotoxic T cells b) Plasma cells and memory B cells c) T-regulatory cells and macrophages d) NK cells and dendritic cells Answer: b) Plasma cells and memory B cells 38. What are the two types of naive Th cells? a) Th1 and Th2 b) Th17 and Th22 c) Treg and Th1 d) CD4+ and CD8+ Answer: a) Th1 and Th2 39. What are the functions of macrophages? a) Present antigens, produce cytokines, and perform phagocytosis b) Secrete antibodies, activate complement, and present antigens c) Perform apoptosis and cell lysis d) Produce antibodies and mediate allergic reactions Answer: a) Present antigens, produce cytokines, and perform phagocytosis 40. Persons with a deficiency in cell-mediated immunity are prone to which types of infections? a) Extracellular infections and autoimmune diseases b) Fungal and viral infections, Mycobacterium, and intracellular organisms c) Parasitic infections and hypersensitivity reactions d) Allergies and autoimmune conditions Answer: b) Fungal and viral infections, Mycobacterium, and intracellular organisms 41. Cell-mediated immunity (CMI) and humoral immunity are the two aspects of adaptive immunity. What mediates CMI? a) B cells b) T-helper cells (CD4+), cytotoxic T cells (CD8+), macrophages, and NK cells c) Macrophages and dendritic cells d) T cells and antibodies Answer: b) T-helper cells (CD4+), cytotoxic T cells (CD8+), macrophages, and NK cells 42. Cell-mediated immunity is mainly directed against what two major types of cells? a) Extracellular microorganisms and viruses b) Cells with intracellular microorganisms and aberrant endogenous cells such as cancer cells c) Fungal cells and helminths d) Cancer cells and T cells Answer: b) Cells with intracellular microorganisms and aberrant endogenous cells such as cancer cells 43. Which types of infections are persons with a deficiency in cell-mediated immunity prone to? a) Allergies and autoimmune diseases b) Extracellular bacterial infections c) Fungal infections, viruses, Mycobacterium, and other intracellular organisms d) Parasitic infections Answer: c) Fungal infections, viruses, Mycobacterium, and other intracellular organisms 44. Which of the hypersensitivity reactions are antibody-mediated? a) Type I, Type II, and Type III b) Type II, Type III, and Type IV c) Type I and Type IV d) Type III and Type IV Answer: a) Type I, Type II, and Type III 45. Which of the hypersensitivity reactions is cell-mediated? a) Type I b) Type II c) Type III d) Type IV Answer: d) Type IV 46. What antibody mediates type I reactions? a) IgA b) IgM c) IgE d) IgG Answer: c) IgE 47. What antibodies mediate types II and III reactions? a) IgA and IgM b) IgG and IgM c) IgG and IgE d) IgA and IgE Answer: b) IgG and IgM 48. What are type I reactions also referred to as? a) Immediate hypersensitivity b) Cytotoxic hypersensitivity c) Immune complex hypersensitivity d) Delayed-type hypersensitivity Answer: a) Immediate hypersensitivity 49. What are the two phases of type I hypersensitivity reactions? a) Primary and secondary b) Early and late c) Immediate and late d) Acute and chronic Answer: c) Immediate and late 50. What are the symptoms of the immediate phase of type I reactions? a) Fever, rash, and hypotension b) Edema, erythema, wheal and flare reaction in the skin, itching, and runny nose c) Fatigue, muscle pain, and headache d) Erythema, pain, and swelling in joints Answer: b) Edema, erythema, wheal and flare reaction in the skin, itching, and runny nose 51. What are the symptoms of the late phase of type I reactions? a) Edema and induration, wheezing b) Fever and lethargy c) Erythema and itchiness d) Hypotension and fatigue Answer: a) Edema and induration, wheezing 52. What are the common clinical manifestations of type I hypersensitivity reactions? a) Skin: urticaria (hives), eczema; Airways: rhinitis, asthma; Eyes: conjunctivitis b) Skin: blistering, redness; Airways: coughing, chest tightness; Eyes: dryness c) Skin: ulcers, rashes; Airways: wheezing, shortness of breath; Eyes: swelling d) Skin: bruising; Airways: chest pain; Eyes: tearing Answer: a) Skin: urticaria (hives), eczema; Airways: rhinitis, asthma; Eyes: conjunctivitis 53. What is the most severe form of type I hypersensitivity reactions? a) Contact dermatitis b) Systemic anaphylaxis c) Chronic asthma d) Rhinitis Answer: b) Systemic anaphylaxis 54. What are some common causes of anaphylaxis? a) Peanuts, bee venom, drugs, and latex allergy b) Dust, pet dander, and mold c) Bacterial infections, vaccinations, and food allergies d) Vaccines, medication, and insect bites Answer: a) Peanuts, bee venom, drugs, and latex allergy 55. What are type II hypersensitivity reactions also known as? a) Antibody-mediated cytotoxic reactions b) Immune complex-mediated reactions c) IgE-mediated reactions d) Delayed-type hypersensitivity reactions Answer: a) Antibody-mediated cytotoxic reactions