STUDY QUESTIONS MICRO 310 Multiple Choice Questions 1. Which of the following is a physical barrier in the nonspecific defense of a mammalian host? A. Inflammation B. Phagocytosis C. Fever D. Mucous membranes 2. Substances that are recognized as foreign and provoke immune responses are called A. Antibodies B. Antigens C. Infective agents D. Inducers 3. Macrophage A. Are derived from monocytes B. Have receptors for compounds released by the immune system that coat microorganisms and enhance phagocytosis C. Spread throughout the body of animals and take up residence in specific tissues D. All of the choices 4. Acquired immunity refers to the type of specific immunity that A. Develops after exposure to a specific pathogen B. Involves the participation of lymphocytes C. Involves a memory aspect D. All of the choices 5. Which of the following is (are) way(s) that the complement system aids in the defensive responses of an organism? A. Lysis of antibody coated gram-negative bacteria B. Attract phagocytic cells C. Activation of phagocytic cells D. All of these are ways that the complement system aids in the defensive responses of an organism 6. Dendritic cells A. Play an important role in the development of allergies and hypersensitivity B. Contain granules with histamine and other pharmacologically active substances that contribute to the inflammatory response C. Are capable of recognizing specific pathogen-associated molecular patterns and play an important role in non-specific resistance D. Are mainly important in the defense against protozoan and helminth parasites 7. Opsonizing antibodies must be against __________ components if they are to effectively stimulate phagocytosis. A. Surface B. Internal C. Protein D. Polysaccharide 8. Which of the following releases histamine? A. Mast cells B. Basophils C. Plasma cells D. Mast cells and basophils E. None of the choices 9. Lymphocytes are comprised of which of the following cell types? A. T cells B. B cells C. Natural killer cells D. All of the choices E. T cells and B cells 10. Macrophages are derived from A. Granulocytes B. Basophils C. Neutrophils D. Monocytes 11. Cytokines A. Cause lysis of invading microorganisms B. Play key roles in both specific and non-specific immunity C. Are required for regulation of the immune response D. Play key roles in both specific and non-specific immunity and are required for regulation of the immune response 12. Which of the following cell types migrates to the lymphoid tissue after encountering pathogens in the skin or the mucous membranes? A. Mast cells B. Dendritic cells C. Macrophages D. None of the choices 13. A mature activated B cell is called a(n) A. Plasma cell B. Dendritic cell C. Natural killer cell D. Spleen cell 14. The lungs are protected from microorganisms by A. The mucociliary blanket B. Lysozyme in mucus C. Phagocytic action of alveolar macrophages D. All of the choices 15. Under normal circumstances, which of the following is (are) normally sterile environments in mammals? A. Kidneys B. Ureters C. Urinary bladder D. All of these 16. Phagocytosis leads to destruction of engulfed pathogens by which of the following mechanisms? A. Lysosomal mediated hydrolysis B. Production of bacteriocins C. Complement fixation D. All of the choices 17. Which of the following is considered to be a biological defense mechanism? A. Skin B. Fever C. Gastric acid D. Indigenous microbiota 18. Which of the following is used to help protect the lungs from infection? A. Turbulent airflow deposits airborne pathogens on sticky mucosal surfaces B. The mucociliary blanket moves trapped organisms away from the lungs by ciliary action C. Coughing and sneezing forcefully expel organisms away from the lungs D. All of the choices 19. Microorganisms are actively cleared from the trachea, bronchi, bronchiols and alveoli by A. Continuous outward movement of mucus B. The action of ciliated epithelial cells C. Alveolar macrophages D. Two of the choices E. All of the choices 20. Pathogen associated molecular patterns (PAMPs) include A. Lipopolysaccharide B. Peptidoglycan C. Phospholipids of the cytoplasmic membrane D. Two of the choices E. All of the choices 21. T cells produce and secrete factors which do not directly interact with invading microorganisms but which augment the body's defense mechanisms. These molecules are called A. Antibodies B. Cytokines C. Immunogens D. Augmetins 22. Antibodies A. Can bind to an immunogen B. Can target the immunogen for destruction C. Are part of the nonspecific immune response D. Both can bind to an immunogen and can target the immunogen for destruction E. Both can bind to an immunogen and are part of the nonspecific immune response 23. Acquired immunity refers to the type of specific immunity that A. Develops after exposure to antigen B. Can result from transfer of antibodies from one individual to another C. Can be induced by natural or artificial means D. All of the choices 24. The humoral immune response defends against A. Bacteria B. Bacterial toxins C. Viruses D. All of the choices 25. T cells attack A. Host cells that have been parasitized by microorganisms B. Transplanted tissue cells from one host to another C. Cancer cells D. All of the choices 26. Class I major histocompatibilty complex molecules are found on ____________ cells. A. All nucleated B. Antigen-presenting C. All anucleated D. None of the choices 27. The inability of a virus to bind to its target cell as a result of antibody binding to the virus is referred to as A. Toxin neutralization B. Adherence prevention C. Viral neutralization D. Cytotoxicity 28. Class II major histocompatibilty complex molecules are found on all of the following types of cells except A. T cells B. B cells C. Macrophages D. Dendritic cells 29. The humoral immune response differs from the cell-mediated immune response in that only in the humoral immune response is there A. Secretion of antibody B. A precommitted lymphocyte C. A clonal selection mechanism D. The development of memory cells 30. The immune system normally discriminates between __________ antigens. A. Self and nonself B. B and T cells C. Humoral and cell-mediated D. Primary and secondary response 31. Which of the following is a characteristic associated with secondary antibody responses? A. Shorter lag phase B. Higher antibody titer C. Higher antibody affinity D. All of the choices 32. A vaccination is a good example of A. Naturally acquired passive immunity B. Naturally acquired active immunity C. Artificially acquired active immunity D. Artificially acquired passive immunity 33. Cytotoxic T lymphocytes are distinguished from other lymphocytes by the presence of A. CD8 B. CD4 C. CD19 D. All of the choices 34. Which type of antigen-presenting cell is particularly good at stimulating naïve T cells? A. Macrophages B. B cells C. Dendritic cells D. All three are equally proficient 35. When a presented antigen fragment interacts with the T cell receptor of a helper T cell, the co-receptor that must also participate to finalize recognition is A. CD4 B. CD8 C. MHC I D. All of these 36. The secondary immune response is typically stronger than the primary response because __________ during the secondary response. A. All classes of immunoglobulins are active B. Both B and T cells are activated C. The antigen is weakened by the primary response D. A larger population of lymphocytes reactive to antigen has developed 37. One plasma cell can synthesize more than __________ antibody molecules per hour. A. 10,000 B. 100,000 C. 1,000,000 D. 10,000,000 38. Which type of hypersensitivity is IgE-mediated? A. Type IV B. Type III C. Type II D. Type I True / False Questions 39. T-cell receptors can only recognize antigens on the surfaces of antigen-presenting cells; they cannot bind free antigen. T 40. Each antigen has one antigenic determinant site or epitope. F 41. If the clonal selection theory is correct, there exists at least one lymphocyte capable of synthesizing an antibody specific to each antigen prior to exposure to the antigen. T 42. T cells are so named because they mature in the thyroid. F 43. Inflammation is a nonspecific defensive reaction to a tissue injury. T 44. The skin surface (epidermis) is a very favorable environment for colonization by microorganisms. F 45. Body temperature is a physiological barrier against certain microorganisms. T 46. The lymph nodes lie at the junctions of lymphatic vessels where they filter out microbes and antigens from the lymph. T 47. The mucociliary blanket is found in the digestive system of mammals. F 48. Defensins act against bacteria and fungi by permeabilizing cell membranes. T 49. An intraepidermal lymphocyte migrates to a lymph node and matures into a dendritic cell after phagocytosing an antigen. F Fill in the Blank Questions 50. Opsonization is a process by which microorganisms or other particles are coated by serum components, preparing them for recognition and ingestion by phagocytic cells. 51. Interferons are a group of cytokines produced by some eukaryotic cells in response to a viral infection. 52. The spleen is a large organ in the abdominal cavity that specializes in filtering the blood and trapping blood-borne microorganisms and antigens. 53. A class of pathogen recognition receptors that function exclusively as signaling receptors are known as the toll-like receptors.