Medical Lab Science: Summative Review + Answers

MEDICAL LABORATORY SCIENCE SUMMATIVE EXAM REVIEW QUESTIONS #01 +ANSWERS & RATIONALIZATIONS 1. 2. 3. 4. 5. 6. 7. 8. pH that keeps most microorganisms from growing: a. 5.6 b. 6.5 c. 7.2 d. 8.0 Primary function of the eosinophil: a. Phagocytosis b. Suppression of the inflammatory response c. Reacting in acute, systemic hypersensitivity reactions d. Antigen recognition Interferons (IFN) have been demonstrated to act as: a. Immunomodulators b. Antiviral agents c. Antineoplastic agents d. All of these → Interferons The process of inflammation is characterized by all of the following except: a. Increased blood supply to the area b. Migration of white blood cells c. Decreased capillary permeability d. Appearance of acute-phase reactants Acute-phase reactants are produced primarily by: a. Endothelial cells b. Epithelial cells c. Fibroblasts d. Hepatocytes (liver parenchymal cells) The acute phase reactant that has the fastest response time and can rise 100x is: a. Alpha-1 antitrypsin b. Haptoglobin c. C-reactive protein d. Ceruloplasmin Measurement of CRP levels can be used for all of the following except: a. Monitoring drug therapy with antiinflammatory agents b. Tracking the normal progress of surgery c. Diagnosis of a specific bacterial infection d. Determining active phases of rheumatoid arthritis In plasma, this acute phase reactant is associated with HDL cholesterol, and it is thought to play a role in metabolism of cholesterol: a. CRP b. Ceruloplasmin c. Haptoglobin d. Serum amyloid 9. Hypochlorite and hydroxyl ions damage _______ irreversibly, occur in the oxygen-dependent phase of phagocytosis. a. DNA b. Carbohydrate c. Lipid d. Protein 10. Neutrophil phagocytosis and particle ingestion are associated with an increase in oxygen utilization called respiratory burst. What are the two most important products of this biochemical reaction? a. b. c. Hydrogen peroxide and superoxide anion Lactoferrin and NADPH oxidase Cytochrome b and collagenase d. Alkaline phosphatase and ascorbic acid 11. Which is the most significant agent formed in the phagolysosome for the killing of microorganisms? a. Proteolytic enzymes b. Hydroxyl radicals c. Hydrogen peroxide d. Superoxides 12. Which is the most significant agent formed in the phagolysosome for the elimination of microorganisms? a. Proteolytic enzymes b. Hydrogen ions c. Hypochlorite ions d. Superoxides 13. A DPT vaccination is an example of: a. Active humoral-mediated immunity b. Passive humeral-mediated immunity c. Cell-mediated immunity d. Immediate hypersensitivity → DPT vaccination - contains antigen 14. Which of the following cell surface molecules is classified as an MHC class II antigen? a. HLA-A b. HLA-B c. HLA-C d. HLA-DR → HLA-A, B, C are MHC class I ag 15. Antigen receptors on T lymphocytes bind HLA class II molecules with the help of which accessory molecule? a. CD2 b. CD3 c. CD4 d. CD8 16. What molecule on the surface of most T cells recognizes antigen? a. IgT b. MHC protein c. CD3 d. TcR 17. The main function of T cells in the immune response is to: a. Produce cytokines that regulate both innate and adaptive immunity b. Produce antibodies c. Participate actively in phagocytosis d. Respond to target cells without prior exposure 1 18. Which cluster of differentiation (CD) marker appears during the first stage of T-cell development and remains present as an identifying marker for T cells? a. CD1 b. CD2 c. CCD3 d. CD4 or CD8 19. Which cluster of differentiation is most specific identifying marker for mature T cells? a. CD1 b. CD2 c. CD3 d. CD4 or CD8 20. Less expensive to perform and is of historic significance, because this represents the first means of T-cell identification: a. Monoclonal antibodies b. Flow cytometry c. Rosette test d. None of these 21. This T cell defect is a congenital anomaly that represents faulty embryogenesis, which results in aplasia of the parathyroid and thymus glands: a. DiGeorge syndrome b. Ataxia telangiectasia c. Bruton agammaglobulinemia d. Wiskott-Aldrich syndrome 22. In testing for DiGeorge’s syndrome, what type of laboratory analysis would be most helpful in determining the number of mature T cells? a. Complete blood count b. Nitroblue tetrazolium (NBT) test c. T-cell enzyme assays d. Flow cytometry 23. A transplant patient began to show signs of rejection 8 days after receipt of the transplanted organ, and the organ was removed. What immune elements might be found in the rejected organ? a. Antibody and complement b. Primarily antibody c. Macrophages d. T cells 24. Patients at risk for graft-versus-host disease (GVHD) include each of the following, EXCEPT recipients of: a. Bone marrow transplants b. Lung transplants c. Liver transplants d. Irradiated leukocytes 25. Marginal B cells remain in the: a. Bone marrow b. Lymph nodes c. Spleen d. Thymus → Marginal B cells remain in the spleen in order to respond quickly to any blood-borne pathogens they may come into contact with. → Follicular B cells migrate to lymph nodes and other secondary organs 26. Which of the following is the most common humoral immune deficiency disease? a. Bruton agammaglobulinemia b. Selective IgA deficiency c. IgG deficiency d. Wiskott-Aldrich syndrome 27. An 18-month-old boy has recurrent sinopulmonary infections and septicemia. Bruton’s X-linked immunodeficiency syndrome is suspected. Which test result would be markedly decreased? a. Serum IgG, IgA, and IgM b. Total T-cell count c. Both B- and T-cell counts d. Lymphocyte proliferation with phytohemagglutinin stimulation 28. Macrophages produce which of the following proteins during antigen processing? a. IL-1 and IL-6 b. γ-Interferon c. IL-4, IL-5, and IL-10 d. Complement components C1 and C3 29. Which of the following best describes a hapten? a. Not able to react with antibody b. Antigenic only when coupled to a carrier c. Has multiple determinant sites d. A large chemically complex molecule 30. Haptenic determinant will react with: a. Both T cells and antibody b. T cells but not antibody c. Neither T cells nor antibody d. Antibody but not T cells 31. A synonym for an antigenic determinant is: a. Immunogen b. Epitope c. Binding site d. Polysaccharide 32. Unique amino acid sequence that is common to all immunoglobulin molecules of a given class in a given species: a. Isotype b. Allotype → Minor variations of these sequences that are present in some individuals but not others c. Idiotype → Variable portions of each chain unique to a specific antibody molecule d. Any of these 33. Antibody class/isotype and antibody subclass are determined by major physiochemical differences and antigenic variation found primarily in the: a. Constant region of heavy chain b. Constant region of light chain c. Variable regions of heavy and light chains d. Constant regions of heavy and light chains 34. Antibody allotype is determined by the: a. Constant region of heavy chain b. Constant region of light chain c. Variable regions of heavy and light chains d. Constant regions of heavy and light chains 35. Antibody idiotype is dictated by the: a. Constant region of heavy chain b. Constant region of light chain c. Variable regions of heavy and light chains d. Constant regions of heavy and light chains 36. The ratio of kappa to lambda light chain-producing cells in normal individuals is: a. 1:1 b. 2:1 c. 3:1 d. 4:1 2 37. All of the following are functions of immunoglobulins EXCEPT: a. Neutralizing toxic substances b. Facilitating phagocytosis through opsonization c. Interacting with TC cells to lyse viruses d. Combining with complement to destroy cellular antigens 38. Treatment of IgG with papain results in how many fragments from each immunoglobulin molecule? a. 2 → Pepsin = F(ab)2 + Fc b. 3 → Papain = 2 Fab + Fc c. 4 d. 5 39. Which of the following immunoglobulins is present in the highest concentration in normal human serum? a. IgM b. IgG c. IgA d. IgE → Immunoglobulins from highest to lowest concentration: IgG > IgA > IgM > IgD > IgE 40. The key structural difference that distinguishes immunoglobulin subclasses is the: a. Number of domains b. Stereometry of the hypervariable region c. The sequence of the constant regions d. Covalent linkage of the light chains → Immunoglobulin subclasses differ from each other in their Fe regions; this is the reason that the different classes have different biological function. 41. The subclasses of IgG differ mainly in: a. Type of L chain b. Arrangement of disulfide bonds c. Ability to act as opsonins d. Molecular weight 42. Which lgG subclass is most efficient at crossing the placenta? a. lgG1 b. lgG2 c. lgG3 → best for complement d. lgG4 43. Which antibody is best at agglutination and complement fixation? a. IgA b. IgG c. IgD d. IgM → Immunoglobulins from most effective to least effective in agglutination and complement fixation: IgM > IgG3 > IgG1 > IgG2 44. Which of the following statements about IgM is false? a. Composed of five basic subunits b. More efficient in the activation of the complement cascade and agglutination than IgG c. Predominant in an initial antibody response d. Predominant in a secondary (anamnestic) response 45. Which best describes the role of the SC of IgA? a. A transport mechanism across endothelial cells b. A means of joining two IgA monomers together c. An aid to trapping antigen d. Enhancement of complement fixation by the classical pathway 46. Which represents the main function of IgD? a. Protection of the mucous membranes b. Removal of antigens by complement fixation c. Enhancing proliferation of B cells d. Destruction of parasitic worms 47. All of the following are immunologic functions of complement EXCEPT: a. Induction of an antiviral state b. Opsonization → C3b c. Chemotaxis → C5a d. Anaphylatoxin formation → C4a, C3a, C5a 48. Which region determines whether an immunoglobulin molecule can fix complement? a. VH b. CH c. VL d. CL 49. Which of the following statements is false about an anamnestic response versus a primary response? a. Has a shorter lag phase b. Has a longer plateau c. Antibodies decline more gradually d. IgM antibodies predominate → Anamnestic response aka memory/booster/secondary response 50. In a secondary (anamnestic) response, all the following characteristics are correct EXCEPT: a. IgG is the predominant antibody type b. It has a shorter lag phase c. The antibody titer is lower d. It has a more gradual decline in antibody response 3