DAMB 711 Microbiology
Final Exam A 100 points May 18, 2004
Your name (Print Clearly):
_____________________________________________
1. The enzymes that catalyze gene rearrangements on chromosomes that carry the genetic code for immunoglobulins are:
A. superoxide dismutases B. RAG 1 and RAG 2 C. recombinases D. rearrangeases
2. Statement 1: A particulate antigen will be a better immunogen, because it will tend to be
chemically complex. Statement 2: A particulate antigen will be a better immunogen, because it will likely be taken up by antigen presenting phagocytes. Statement 3: A particulate antigen is likely to have a low molecular weight; therefore, it will not be a strong immunogen.
A. Statement 1 is true. B. Statement 2 is true. C. Statement 3 is true.
D. Statements 1 and 2 are true. E. All of the statements are true.
3. Viruses that resist killing by lipid soluble disinfectants are: A. Covered with a membrane
B. Hydrophilic viruses C. Hydrophobic viruses D. Both A and C
4. Bacteria will stain either Gram positive or Gram negative based on the structure of their: A. capsule
B. S-layer C. cell wall D. flagellum
E. outer membrane
5. A bacterium that has a chemotactic response to a nutrient must have a: A. flagellum
B. fimbriae C. teichoic acids D. LPS
6. All of the following are examples of nonspecific immunity except: A. TDTH lymphocytes
B. The intact epithelium C. Complement in serum D. Phagocytosis
E. The pH of the stomach.
7. The first host cell to respond to invasion by a microbial cell will be: A. the polymorphonuclear neutrophil
8. Of the following cells, which one does not have an antigen binding receptor? A. naïve B lymphocyte
B. plasma cell
C. clonal B lymphocyte D. memory B lymphocyte
9. The signal transduction receptor on the T lymphocyte is: A. CD3
B. CD28 C. CD40 D. CD154 E. CTLA-4
10. C3a, C4a and C5a are released into the tissues upon complement activation. What is the most likely outcome of their release?
A. antigen immobilization
B. histamine release by mast cells and phagocyte chemotaxis C. opsonization of antigens and innocent bystander lysis
D. chemotaxis into the area by phagocytes.
11. In an immune response, the cytokine, ______, released by TH lymphocytes is a
_______________ growth factor. A. IL- 8, B lymphocyte B. IL-1, macrophage C. IL-2, T and B lymphocyte D. IFNγ, B lymphocyte
Questions 12 through 16, below, list structures in Gram positive and Gram negative cells. On your
answer sheet, mark:
A if it is a Gram positive structure B if it is a Gram negative structure
17. Which of the following disinfectants is not the proper concentration? A. 0.5 to 15 % phenol
B. 0.05 to 0.5 % chlorine as sodium hypochlorite C. 0.1% available iodine
D. 70% alcohol E. 2% glutaraldehyde
18. The presence of pathogenic bacteria in the blood is: A. bacteremia
B. toxemia C. septicemia D. viremia
19. An antigen that must be linked to a protein carrier in order to have immunogenic properties is a/an:
A. heterophile antigen B. hapten
C. autoantigen D. isoantigen
20. An example of an antigen that activates B cells by cross linking a number of the B cell receptors is:
A. an allergen
B. a T-independent antigen, like LPS C. a hapten, like nickel or penicillin D. a heterologous antigen
21. In a cross reaction in which an antibody against Escherichia coli reacts with a bacterium of a different species such as Shigella sonnei, the cross reacting antigen is a:
A. heterologous antigen B. isoantigen
C. heterophile antigen D. homologous antigen
22. The variable and constant regions of a TCR heavy chain will be encoded by the genes: A. VJC
B. VDJC C. VJ
D. VDJCμ,Cδ,Cγ1,Cγ2,Cγ3,Cγ4,Cα,Cε
23. Which of the following statements about the MHC Class II receptor is incorrect? A. It will display endogenous antigen to the TCR.
B. It will be important to immune defense against bacteria.
24. Which of the following is an oxygen dependent chemical that can kill bacteria in the phagolysosome? A. lactoferrin B. lysozyme C. acid hydrolases D. hydrogen peroxide E. LPS binding protein
25. The classical complement pathway is most likely to be activated by: A. lipopolysaccharide
B. an antigen complexed to IgM, IgG1, IgG2 or IgG3 C. a B lymphocyte that has not been exposed to antigen D. Both B and C.
26. The alternative complement pathway is most likely to be activated by: A. lipopolysaccharide
B. an antigen complexed to IgG4
C. a B lymphocyte that has not been exposed to antigen D. Both A and C.
27. In hematopoiesis, the myeloid lineage of blood cells includes all except the following: A. mast cells
B. monocytes C. lymphocytes D. dendritic cells E. neutrophil
28. The lymphocyte that is not specific to antigen is the: A. natural killer cell
B. B cell C. THELPER cell
D. activated macrophage E. eosinophil
29. The fixed macrophages in the connective tissue are the: A. mesangial cells
B. microglial cells C. histiocytes D. Kupffer cells E. serosal cells
30. The immunoglobulins that are found in mother’s milk: A. IgA and IgE
31. In the dental operatory, the people at highest risk for infection due to cross-contamination are: A. the dental staff.
B. the patients. C. the community
D. the dental staffs’ family
32. Component of the bacterial cell wall that imparts rigidity: A. cellulose
B. chitin
C. peptidoglycan D. silica
E. None of the above
33. Properdin is necessary to stabilize the C3 convertase of the: A. alternative complement pathway
B. classical complement pathway C. mannose binding lectin pathway D. all of the above
34. Interaction between these B-lymphocyte and T-lymphocyte receptors will cause the T cell to stop secreting IL-2.
A. CD40 and CD28 B. B7 and CD28 C. B7 and CTLA-4 D. B7 and CD154 E. CD40 and CD154
35. Interaction between these B-lymphocyte and T-lymphocyte receptors will stimulate the T cell to secrete IL-2. A. CD40 and CD28 B. B7 and CD28 C. B7 and CTLA-4 D. B7 and CD154 E. CD40 and CD154
36. One of the following antigen/antibody reactions is quantitative and sensitive to nanogram amounts of test material. Which one?
A. immunofluorescence B. immunoelectrophoresis
C. enzyme linked immunosorbent assay (ELISA) D. Ouchterlony gel double diffusion
37. A young child develops a severe headache with a high fever. Within 10 days, titers of the child’s serum show a significant rise in IgM. The IgM is specific to the bacterium, Neisseria meningitidis, which is one cause of meningitis. This is characteristic of a:
A. primary humoral immune response B. delayed type hypersensitivity
C. secondary humoral immune response D. antibody dependent cell cytotoxicity E. CD8+ Tc lymphocyte response
38. A cytokine that is released by T- helper lymphocytes and then causes a generalized inflammatory response with fever is:
A. IL-4 B. IFNγ C. TNFα D. TNFβ
39. Delayed type hypersensitivity is the most common immune response to and causes the characteristic lesions of:
A. tuberculosis B. viral pathogens
C. contact dermatitis (poison ivy) D. A and C.
40. An activated macrophage is the effector cell in: A. humoral immunity
B. the delayed type hypersensitivity response C. CD8+ T-lymphocyte response
D. ADCC
41. This/these cytokine(s) will promote differentiation of a THO progenitor cell to a TH1
cell.
A. IL-4 and IL-2
B. IL-12, IFNγ and IL-18 C. IL-2, IFNγ and TNFβ D. IL-4
42. The cells that secrete cytokine(s) that stimulate differentiation of a THO progenitor cell to a TH1
cell are responding to _________________ and they are ____________________________.
43. An “effector” CD8+ TC lymphocyte that encounters the antigen for which it is specific
will not require costimulation from a CD4+ TH lymphocyte before it can kill the cell
harboring the antigen. A. The statement is true. B. The statement is false.
44. Eighty- five to ninety per cent of the world’s population has been infected with the Cytomegalovirus. For this reason new born babies will usually have serum antibody to the virus. What type of immunity is this?
A. artificially acquired active immunity B. naturally acquired active immunity C. artificially acquired passive immunity D. naturally acquired passive immunity
45. An individual who survives a case of diphtheria will not contract the disease again. Which type of immunity is protecting this person?
A. artificially acquired active immunity B. naturally acquired active immunity C. artificially acquired passive immunity D. naturally acquired passive immunity
46. What type of immunity will immunization with an attenuated bacterium convey? A. artificially acquired active immunity
B. naturally acquired active immunity C. artificially acquired passive immunity D. naturally acquired passive immunity
47. Horse serum containing antibodies to the diphtheria toxin (antitoxin) is used to treat
diphtheria. What kind of immunity is this?
A. artificially acquired active immunity B. naturally acquired active immunity C. artificially acquired passive immunity D. naturally acquired passive immunity
48. Th2 lymphocytes can inhibit proliferation of Th1 lymphocytes by secreting this/these cytokine(s). A. IL-12 and IL-10
49. The proper interaction between the following cells and receptors is necessary to initiate a cell mediated immune response.
A. Antigen Presenting Cell (APC) with MHC Class I; TCR of a CD4+ T-lymphocyte; TCR of a CD8+ T-lymphocyte
B. APC with MHC Class II; TCR of a CD4+ T-lymphocyte; IgM of a B-lymphocyte
C. APC with MHC II; TCR of a CD4+ T-lymphocyte; APC with MHC I; TCR of a CD8+ T-lymphocyte
D. Fc receptors on a CD8+ Tc lymphocytes; antibody on a target cell.
50. This/these cytokine(s) will promote differentiation of a THO progenitor cell to a TH2
cell.
A. IL-4 and IL-2
B. IL-12, IFNγ and IL-18 C. IL-2, IFNγ and TNFβ D. IL-4
51. In one form of cell mediated immunity (CMI), antigen displayed on a target cell MHC Class I receptor is recognized by a TCR receptor on the effector cell. The effector cell that participates in this activity is a ___________ and the type of CMI is ___________.
A. either a killer or natural killer cell: antibody dependent cell mediated cytotoxicity B. CD8+ T lymphocyte: cell mediated cytotoxicity
C. CD4+ T lymphocyte: antibody dependent cell mediated cytotoxicity D. Macrophage: delayed type hypersensitivity (DTH)
52. A unit of measurement used to describe the size of viruses: A. nanometer (10-9 meters)
B. a micrometer (10-6 meters) C. a millimeter (10-3 meters) D. a meter
53. A common disadvantage with all heat sterilization techniques is: A. materials are wet after sterilization
B. metals may be dulled and corroded C. water based liquids may evaporate
54. Areas of the body that are either sterile or have few microorganisms include: A. dental pulp, skin and oropharynx
B. dental pulp, colon and oral cavity
C. dental pulp, mucous membranes and bladder D. dental pulp, kidneys and cerebral spinal fluid
55. A component of the first line of defense that competes with transient microflora for space and nutrients
A. normal (indigenous) flora B. sebaceous secretions C. macrophages
56. A nonspecific immune factor that is found in host secretions and attacks the bacterial cell wall: A. histamine
B. transferrin C. lactoferrin D. lysozyme
57. The inflammatory cytokines that cause fever are: A. IL-1, IFNγ and IL-6
B. IL-1, TNFα and IL-6 C. histamine, IL-1 and IL-6 D. PGE2, TNFα and IL-6
58. Cytokines released in inflamed tissue may cause up-regulation (increased production) of integrins (LFA1) on a phagocytic cell surface and ICAMs on endothelial cells. These receptors interact to mediate this phagocytic activity:
A. margination
B. opsonization
C. chemotaxis
59. A number of sites in which differentiation in response to specific antigens takes place: A. primary lymphoid organs
B. secondary lymphoid organs C. integrins
D. high endothelial venules
60. The immune response to most blood-borne pathogens will occur in the ________; the immune response to most antigens draining from the tissues into the lymphatics will occur in the _______________; the immune response to most antigens entering through the mucosal epithelium will occur in the _______________.
A. spleen; bone marrow; MALT B. MALT; spleen; bone marrow
C. Peyer’s patches; lymph nodes; thymus D. spleen; lymph nodes; MALT
61. What is the best description (or example) of a germinal center? A. Kupffer cells in the liver
B. secondary follicles of lymphoid tissue containing antigen stimulated, actively dividing B lymphocytes and plasma cells
C. area where lymphocyte circulation passes from lymph to blood
D. primary follicles of lymphoid tissue with high concentrations of B lymphocytes that have not been exposed to antigen
62. An isotype switch is possible because rearranged (clonal) B cell DNA of an Ig heavy chain: A. will have genes for all heavy chain constant regions
B. will have genes for only μ and δ constant heavy chains C. will have more than one V but only one D and one J gene
63. In an immune response, antigen stimulated B lymphocytes may undergo an isotype switch and then proliferate to produce plasma cells and memory B lymphocytes. The
receptor(s) on the memory B lymphocytes:
A. undergo a change in antigen specificity following the isotype switch B. will still be mIgD and mIgM
64. Cytokines that induce a B cell class switch to IgE synthesis are ____________________ produced by________________
A. IL-2, IFNγ, and TNFβ: TH2 lymphocytes
B. IL-4, IL-5, IL-10, IL-13: TH2 lymphocytes
C. IL-2, IFNγ, and TNFβ: TH1 lymphocytes
D. IL-4, IL-5, IL-10, IL-13: TH1 lymphocytes
65. A cytokine that is released by T-lymphocytes and that induces expression of MHC Class II molecules.
A. IL-4 B. IFNγ C. TNFα D. TNFβ
66. MHC molecules are not tolerant. A. The statement is true. B. The statement is false.
67. The antigen presenting cell whose “specialty” is presentation of soluble proteins for example, bacterial toxins:
A. macrophage
B. dendritic cell
C. B lymphocyte
68. The proper conditions for sterilization in a conventional autoclave are: A. 160O C for 2 hours
B. 132O C, 20 to 40 psi for 20 minutes C. 121O C, 15 psi for 15 to 20 minutes D. 134 O C, 15 or 30 psi for 3.5 to 5 minutes
69. In a delayed type hypersensitivity response, this cytokine is secreted by macrophages to stimulate proliferation of a population of antigen specific TDTH helper cells.
A. IL-8
B. TNFα
C. IL-12
70. Major roles of helper, CD4+, T lymphocytes in the immune response include all except the following:
A. directing the specificity of the response through MHC Class II dependent recognition of antigen epitopes
B. selection of effector mechanisms against antigens and target cells C. differentiating into an effector lymphocyte and killing the target cell D. secretion of cytokines that aid in the proliferation of the appropriate effector cells
71. Which of the following describes the initiation of an antibody dependent cell mediated cytotoxicity (ADCC) response?
A. The MHC Class I of the target cell binds the TCR of a CD8+ T cell.
B. The KIR (Killer Inhibitory Receptor) on the natural killer (NK) cell binds antigen presented on a cancer cell.
C. Antibody bound to antigen on the target cell is recognized and bound by Fc receptors on an effector killer (K) or natural killer (NK) cell.
D. Tumor antigens displayed on the target cell are bound to MHC Class I receptors on the NK cell.
72. Interaction between the B lymphocyte receptor, CD40, and the T lymphocyte receptor, CD154 induces:
A. an immunoglobulin class switch B. signal transduction
C. cell to cell adhesion D. T lymphocyte proliferation E. IgE secretion
73. The cytokine that is secreted by macrophages and induces neutrophil chemotaxis: A. IL-4
74. The genes that encode for the Class II MHC molecules are: A. HLA-A, HLA-B, HLA-DP
B. DP, DQ, DR
C. HLA-A, HLA-B, HLA-C D. VDJ
75. The following describes the sequence of target cell killing by an antigen specific CD8+ cytotoxic T lymphocyte. Which step is not part of that sequence?
A. Upon contact with a cell bearing the MHC Class I antigen for which it is specific, the CD8+ cytotoxic T lymphocyte will release Ca2+, perforins and polymerizing enzymes. B. The Ca2 and polymerizing enzymes organize the perforin subunits into structures that form pores in the target cell membrane.
C. Fc receptors on the CD8+ Tc lymphocytes bind to antibody on the target cell.
D. The CD8+ Tc lymphocyte releases granzymes which enter the target cell through the perforin pores and induce apoptosis.
E. The target cell dies from apoptosis
76. When antigen presenting (dendritic) cells in the thymus present “self antigen” on their MHC Class I and Class II receptors to the TCRs of differentiating, maturing T
lymphocytes, those lymphocytes that bind self antigen either undergo apoptosis or become anergic.
A. This is an example of positive selection. B. This is an example of negative selection.
77. One of the following is not a mechanism that antibodies would use to eliminate or protect the host against a pathogenic microorganism.
A. aggregation (clumping) of antigens to make them easier to remove through phagocytosis, swallowing or peristalsis
B. neutralization of toxins and other harmful soluble factors
C. opsonization
D. perforation of a target cell membrane
78. An immune response occurs in which: 1) B lymphocytes of the IgG isotype are activated; 2) IgG levels are 10 to 100 fold higher than a previous response to the same antigen; 3) IgM is not detected before IgG and IgG persists in serum for several months. This is a(an):
A. allergic response
B. primary immune response C. secondary immune response
D. antibody dependent cell mediated cytotoxicity
E. cell mediated immunity with a cytotoxic Tc lymphocyte effector
79. Which of the following types of immunity will be long-term immunity (last for several years)? A. passive
B. active
The macrophage and the T-helper lymphocyte both control a number of immune functions. In questions 80 through 82, below, answer:
A. if it is a macrophage function
B. if it is a T-helper lymphocyte function
C. if the actions of both cells are needed to complete the activity 80. antigen presentation
81. tissue reorganization
82. selection of an effector mechanism
83. In antigen presentation the cell that responds to a specific epitope is the: A. antigen presenting cell
B. T-helper cell C. cytotoxic T cell
84. Infection with vaccinia virus results in vaccinia-specific CD8+ T cells in the host. If these
vaccinia virus-specific CD8+ T cells are subsequently removed from the individual and tested in vitro in laboratory experiments, which of the following cells will they kill?
A. vaccinia-infected cells expressing MHC class II molecules from any individual B. influenzae-infected cells expressing the same MHC class I molecules as the host C. uninfected cells expressing the same MHC class I molecules as the host
Short Answer: Your Name __________________________________________________ 85. (3 points) In question 84, above, explain why you chose your answer.
86. In a delayed type hypersensitivity response (DTH), what is the action of each of the following cytokines?
TNFβ − IFNγ −
IL-2 –
MCP (macrophage chemotactic factor) –
What cell releases these cytokines?
What stage of DTH is this occurring in?
What cells and antigen receptors are mediating this stage of DTH?
Why is it called delayed type hypersensitivity?
