Module 2 Questions Part 4 PDF

### **1. What is the primary function of neutrophils in innate immunity?** a\) Antibody production\ b) Phagocytosis and destruction of pathogens\ c) Release of histamine\ d) Defense against parasitic infections\ e) Recognition of self-antigens **Answer:** b) Phagocytosis and destruction of pathoge...

### **1. What is the primary function of neutrophils in innate immunity?** a\) Antibody production\ b) Phagocytosis and destruction of pathogens\ c) Release of histamine\ d) Defense against parasitic infections\ e) Recognition of self-antigens **Answer:** b) Phagocytosis and destruction of pathogens ### **2. What happens to monocytes when they leave the bloodstream?** a\) They become macrophages.\ b) They transform into B cells.\ c) They lyse infected cells.\ d) They secrete antibodies.\ e) They release cytokines. **Answer:** a) They become macrophages. ### **3. Which leukocyte releases histamine and promotes inflammation?** a\) Basophils\ b) Eosinophils\ c) Neutrophils\ d) Monocytes\ e) Natural killer cells **Answer:** a) Basophils ### **4. What is the function of mast cells in immunity?** a\) Promote inflammation through chemical release\ b) Directly lyse tumor cells\ c) Phagocytize pathogens\ d) Produce memory T cells\ e) Transport oxygen **Answer:** a) Promote inflammation through chemical release ### **5. Which cell defends against parasitic infections and participates in allergic responses?** a\) Neutrophils\ b) Basophils\ c) Eosinophils\ d) Macrophages\ e) Natural killer cells **Answer:** c) Eosinophils ### **6. What do natural killer (NK) cells target?** a\) Parasitic infections\ b) Tumor and virus-infected cells\ c) Extracellular bacteria\ d) Autoimmune antibodies\ e) Histamine-secreting cells **Answer:** b) Tumor and virus-infected cells ### **7. What is the role of macrophages in the immune response?** a\) Produce cytokines\ b) Present antigens to T cells\ c) Destroy pathogens by phagocytosis\ d) Promote tissue repair\ e) All of the above **Answer:** e) All of the above ### **8. Which cells are most effective in the later stages of infection and tissue repair?** a\) Neutrophils\ b) Macrophages\ c) Basophils\ d) Mast cells\ e) NK cells **Answer:** b) Macrophages ### **9. What triggers chemotaxis in leukocytes?** a\) Attraction to high oxygen levels\ b) Attraction to chemotactic factors from microbes\ c) High concentration of antibodies\ d) Increased blood pressure\ e) Increased interstitial fluid **Answer:** b) Attraction to chemotactic factors from microbes ### **10. Which leukocyte is the first to respond to infection?** a\) Eosinophils\ b) Basophils\ c) Neutrophils\ d) Mast cells\ e) Monocytes **Answer:** c) Neutrophils ### **11. What process involves the engulfing and destruction of pathogens by neutrophils?** a\) Opsonization\ b) Chemotaxis\ c) Phagocytosis\ d) Co-stimulation\ e) Anergy **Answer:** c) Phagocytosis ### **12. Which immune response is characterized by redness, heat, swelling, and pain?** a\) Systemic inflammation\ b) Local inflammation\ c) Adaptive immunity\ d) Passive immunity\ e) Antibody-mediated immunity **Answer:** b) Local inflammation ### **13. What is the role of pyrogens in the immune response?** a\) Promote fever\ b) Destroy pathogens\ c) Enhance antibody production\ d) Suppress inflammation\ e) Increase lymphocyte proliferation **Answer:** a) Promote fever ### **14. What distinguishes systemic from local inflammation?** a\) Presence of fever and widespread vascular permeability\ b) Increased localized swelling\ c) Lack of neutrophil recruitment\ d) Decreased blood flow\ e) Absence of redness and heat **Answer:** a) Presence of fever and widespread vascular permeability ### **15. What type of molecule acts as an antigen in the immune response?** a\) Lipids only\ b) Proteins and polysaccharides\ c) DNA only\ d) Water molecules\ e) Fatty acids **Answer:** b) Proteins and polysaccharides ### **16. What is the function of helper T cells?** a\) Directly destroy infected cells\ b) Promote B cell activation and antibody secretion\ c) Release histamine\ d) Inhibit cytotoxic T cells\ e) Transport oxygen to tissues **Answer:** b) Promote B cell activation and antibody secretion ### **17. What is the role of regulatory T cells?** a\) Enhance inflammation\ b) Promote tolerance to self-antigens\ c) Produce antibodies\ d) Activate mast cells\ e) Secrete pyrogens **Answer:** b) Promote tolerance to self-antigens ### **18. What is an epitope?** a\) A part of an antibody\ b) A small region on an antigen recognized by the immune system\ c) A cytokine that activates T cells\ d) A surface molecule on NK cells\ e) A receptor on macrophages **Answer:** b) A small region on an antigen recognized by the immune system ### **19. Which cell type is involved in both innate and adaptive immunity?** a\) Basophils\ b) NK cells\ c) Macrophages\ d) Neutrophils\ e) Mast cells **Answer:** c) Macrophages ### **20. Which type of MHC molecule presents endogenous antigens?** a\) MHC Class I\ b) MHC Class II\ c) MHC Class III\ d) HLA-A\ e) HLA-B **Answer:** a) MHC Class I ### **21. What type of immunity results from vaccination?** a\) Passive natural immunity\ b) Active artificial immunity\ c) Passive artificial immunity\ d) Active natural immunity\ e) Innate immunity **Answer:** b) Active artificial immunity ### **22. Which immunoglobulin is the first to respond during the primary immune response?** a\) IgG\ b) IgA\ c) IgM\ d) IgE\ e) IgD **Answer:** c) IgM ### **23. What is the primary function of IgE antibodies?** a\) Neutralize bacterial toxins\ b) Activate complement proteins\ c) Mediate allergic responses\ d) Cross the placenta\ e) Bind to pathogens **Answer:** c) Mediate allergic responses ### **24. What occurs during the secondary immune response?** a\) Rapid antibody production due to memory cells\ b) Delayed response to antigens\ c) IgM is the predominant antibody produced\ d) No antibody production occurs\ e) Increased fever production **Answer:** a) Rapid antibody production due to memory cells ### **25. What type of T cells are involved in lysing virus-infected cells?** a\) Helper T cells\ b) Regulatory T cells\ c) Cytotoxic T cells\ d) Memory T cells\ e) Plasma cells **Answer:** c) Cytotoxic T cells ### **26. What type of immunity protects against intracellular antigens such as viruses?** a\) Innate immunity\ b) Cell-mediated immunity\ c) Antibody-mediated immunity\ d) Passive immunity\ e) Artificial immunity **Answer:** b) Cell-mediated immunity ### **27. Which cytokine is most critical for the proliferation of helper T cells?** a\) Interferon-alpha\ b) Interleukin-1\ c) Interleukin-2\ d) Tumor necrosis factor\ e) Histamine **Answer:** c) Interleukin-2 ### **28. Which immune process eliminates self-reactive lymphocytes?** a\) Positive selection\ b) Negative selection\ c) Chemotaxis\ d) Opsonization\ e) Clonal selection **Answer:** b) Negative selection ### **29. What is the primary function of MHC Class II molecules?** a\) Display self-antigens to regulatory T cells\ b) Present exogenous antigens to helper T cells\ c) Bind to antibodies for antigen destruction\ d) Activate cytotoxic T cells\ e) Promote innate immune responses **Answer:** b) Present exogenous antigens to helper T cells ### **30. Which cell type produces antibodies?** a\) Helper T cells\ b) Cytotoxic T cells\ c) Plasma cells\ d) NK cells\ e) Mast cells **Answer:** c) Plasma cells ### **31. What type of immune response is associated with clonal selection?** a\) Innate immunity\ b) Adaptive immunity\ c) Passive immunity\ d) Humoral immunity only\ e) Systemic inflammation **Answer:** b) Adaptive immunity ### **32. What is the function of opsonization in the immune response?** a\) Activate helper T cells\ b) Coat pathogens to enhance phagocytosis\ c) Release pyrogens to cause fever\ d) Neutralize toxins in the bloodstream\ e) Stimulate antibody production **Answer:** b) Coat pathogens to enhance phagocytosis ### **33. What is the main role of clonal selection in adaptive immunity?** a\) Eliminate self-reactive lymphocytes\ b) Produce large numbers of antigen-specific lymphocytes\ c) Trigger the release of histamine\ d) Neutralize bacterial toxins\ e) Initiate the inflammatory response **Answer:** b) Produce large numbers of antigen-specific lymphocytes ### **34. Which immunoglobulin can cross the placenta to provide passive immunity?** a\) IgA\ b) IgE\ c) IgD\ d) IgG\ e) IgM **Answer:** d) IgG ### **35. What occurs when a helper T cell is activated?** a\) It directly kills infected cells.\ b) It produces cytokines to activate other immune cells.\ c) It secretes antibodies.\ d) It differentiates into NK cells.\ e) It suppresses regulatory T cells. **Answer:** b) It produces cytokines to activate other immune cells. ### **36. What type of immunity involves receiving antibodies from another individual?** a\) Active natural immunity\ b) Active artificial immunity\ c) Passive natural immunity\ d) Passive artificial immunity\ e) Adaptive immunity **Answer:** d) Passive artificial immunity ### **37. What type of antigen is typically presented by MHC Class I molecules?** a\) Bacterial toxins\ b) Viral proteins synthesized inside a cell\ c) Allergens\ d) Fungal antigens\ e) Exogenous antigens **Answer:** b) Viral proteins synthesized inside a cell ### **38. What process is required for cytotoxic T cells to destroy virus-infected cells?** a\) Activation by MHC Class I molecules\ b) Activation by MHC Class II molecules\ c) Phagocytosis\ d) Clonal deletion\ e) Cytokine suppression **Answer:** a) Activation by MHC Class I molecules ### **39. What type of hypersensitivity is IgE primarily associated with?** a\) Type I (allergic reactions)\ b) Type II (cytotoxic reactions)\ c) Type III (immune complex reactions)\ d) Type IV (delayed hypersensitivity)\ e) Autoimmune reactions **Answer:** a) Type I (allergic reactions) ### **40. Which complement protein is involved in the formation of the membrane attack complex (MAC)?** a\) C1\ b) C3\ c) C5\ d) C9\ e) C2 **Answer:** d) C9 ### **41. What is the function of IL-4 in adaptive immunity?** a\) Activate cytotoxic T cells\ b) Promote differentiation of B cells into plasma cells\ c) Stimulate macrophages to phagocytize pathogens\ d) Inhibit helper T cell proliferation\ e) Suppress inflammation **Answer:** b) Promote differentiation of B cells into plasma cells ### **42. Which immune response is faster and stronger due to memory cells?** a\) Primary immune response\ b) Secondary immune response\ c) Innate immune response\ d) Passive immune response\ e) Systemic inflammation **Answer:** b) Secondary immune response ### **43. What is the primary function of IgA antibodies?** a\) Mediate allergic responses\ b) Provide immunity at mucosal surfaces\ c) Activate complement proteins\ d) Neutralize toxins in the bloodstream\ e) Promote systemic inflammation **Answer:** b) Provide immunity at mucosal surfaces ### **44. What is the mechanism by which B cells recognize antigens?** a\) Phagocytosis\ b) Binding of antigens to surface immunoglobulin receptors\ c) Interaction with MHC Class I molecules\ d) Activation by cytokines\ e) Endocytosis of antigens **Answer:** b) Binding of antigens to surface immunoglobulin receptors ### **45. Which process eliminates lymphocytes that bind to self-antigens?** a\) Positive selection\ b) Negative selection\ c) Clonal expansion\ d) Phagocytosis\ e) Cytokine suppression **Answer:** b) Negative selection ### **46. What type of immunity is provided by a rabies vaccine?** a\) Active natural immunity\ b) Passive artificial immunity\ c) Active artificial immunity\ d) Passive natural immunity\ e) Innate immunity **Answer:** c) Active artificial immunity ### **47. What is the role of the constant region of an antibody?** a\) Bind to antigens\ b) Recognize self-antigens\ c) Activate complement and attach to immune cells\ d) Neutralize bacterial toxins\ e) Inhibit inflammatory responses **Answer:** c) Activate complement and attach to immune cells ### **48. What type of immunity involves helper T cells activating cytotoxic T cells and B cells?** a\) Innate immunity\ b) Cell-mediated immunity\ c) Humoral immunity\ d) Passive immunity\ e) Active natural immunity **Answer:** b) Cell-mediated immunity ### **49. Which immune system cell is responsible for suppressing immune responses?** a\) Helper T cells\ b) Cytotoxic T cells\ c) Regulatory T cells\ d) NK cells\ e) Plasma cells **Answer:** c) Regulatory T cells ### **50. What type of immune disorder involves the immune system attacking its own cells?** a\) Allergic reaction\ b) Autoimmune disease\ c) Immunodeficiency\ d) Hypersensitivity\ e) Innate immune response **Answer:** b) Autoimmune disease