Harr’s Medical Laboratory Science Review PART (CHAPTER REVIEW) Flashcards
- From the following, identify a specific component of the adaptive immune system that is formed in response to antigenic stimulation:
A. Lysozyme
B. Complement
C. Commensal organisms
D. Immunoglobulin (Ig)
D. Immunoglobulin (Ig)
- Which two organs are considered the primary lymphoid organs in which immunocompetent cells originate and mature?
A. Thyroid and Peyer patches
B. Thymus and bone marrow
C. Spleen and mucosal-associated lymphoid tissue (MALT)
D. Lymph nodes and thoracic duct
B. Thymus and bone marrow
- What type of B cells is formed after antigen stimulation?
A. Plasma cells and memory B cells
B. Mature B cells
C. Antigen-dependent B cells
D. Receptor-activated B cells
A. Plasma cells and memory B cells
- T cells travel from bone marrow to the thymus for maturation. What is the correct order of the maturation sequence for T cells in the thymus?
A. Bone marrow to the cortex; after thymic education, released back to peripheral circulation
B. Maturation and selection occur in the cortex; migration to the medulla; release of mature T cells to secondary lymphoid organs
C. Storage in either the cortex or medulla; release of T cells into the peripheral circulation
D. Activation and selection occur in the medulla; mature T cells are stored in the cortex until activated by antigen
B. Maturation and selection occur in the cortex; migration to the medulla; release of mature T cells to secondary lymphoid
organs
- Which cluster of differentiation (CD) marker is the most specific identifying marker for mature T cells?
A. CD1
B. CD2
C. CD3
D. CD4 or CD8
C. CD3
- Which markers are found on mature, peripheral helper T cells?
A. CD1, CD2, CD4
B. CD2, CD3, CD8
C. CD1, CD3, CD4
D. CD2, CD3, CD4
D. CD2, CD3, CD4
- Which T cells express the CD8 marker and act specifically to kill tumors or virally infected cells?
A. Helper T cells
B. Suppressor T cells
C. Cytotoxic T cells (TC cells)
D. Regulator T cells
C. Cytotoxic T cells (TC cells)
- How are TC cells and natural killer (NK) cells similar?
A. Require antibody to be present
B. Effective against virally infected cells
C. Recognize antigen in association with human leukocyte
antigen (HLA) class II markers
D. Do not bind to infected cells
B. Effective against virally infected cells
- What is the name of the process by which phagocytic cells are attracted to a substance, such as a bacterial peptide?
A. Diapedesis
B. Degranulation
C. Chemotaxis
D. Phagotaxis
C. Chemotaxis
- All of the following are immunologic functions of complement except:
A. Induction of an antiviral state
B. Opsonization
C. Chemotaxis
D. Anaphylatoxin formation
A. Induction of an antiviral state
- Which complement component is found in both the classic and alternative pathways?
A. C1
B. C4
C. Factor D
D. C3
D. C3
- Which region of the Ig molecule can bind antigen?
A. Fragment antigen binding (Fab)
B. Fragment crystallizable (Fc)
C. Constant light (CL)
D. Constant heavy (CH)
A. Fragment antigen binding (Fab)
- Which Ig(s) help(s) initiate the classic complement pathway?
A. IgA and IgD
B. IgM only
C. IgG and IgM
D. IgG only
C. IgG and IgM
- How is complement activity destroyed in vitro?
A. Heating serum at 56°C for 30 minutes
B. Keeping serum at room temperature of 22°C for 1 hour
C. Heating serum at 37°C for 45 minutes
D. Freezing serum at 0°C for 24 hours
A. Heating serum at 56°C for 30 minutes
- What is the purpose of C3a, C4a, and C5a, the split products of the complement cascade?
A. To bind with specific membrane receptors of lymphocytes and cause release of cytotoxic substances
B. To cause increased vascular permeability, contraction of smooth muscle, and release of histamine from basophils
C. To bind with membrane receptors of macrophages to facilitate phagocytosis and the removal of debris and foreign
substances
D. To regulate and degrade membrane cofactor protein after activation by C3 convertase
B. To cause increased vascular permeability, contraction of smooth muscle, and release of histamine from basophils
- Which region determines whether an Ig molecule can fix complement?
A. Variable heavy (VH)
B. Constant heavy (CH)
C. Variable light (VL)
D. Constant light (CL)
B. Constant heavy (CH)
- Which Ig class(es) has (have) a J-chain?
A. IgM
B. IgE and IgD
C. IgM and surface IgA (sIgA)
D. IgG3 and IgA
C. IgM and surface IgA (sIgA)
- Which Ig appears first in the primary immune response?
A. IgG
B. IgM
C. IgA
D. IgE
B. IgM
- Which immunoglobulin appears in highest titer in the secondary response?
A. IgG
B. IgM
C. IgA
D. IgE
A. IgG
- Which Ig can cross the placenta?
A. IgG
B. IgM
C. IgA
D. IgE
A. IgG
- Which Ig cross-links mast cells to release histamine?
A. IgG
B. IgM
C. IgA
D. IgE
D. IgE
- 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
D. HLA-DR
- All of the following are functions of Igs 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
C. Interacting with TC cells to lyse viruses
- Which of the following are products of HLA class III genes?
A. T-cell immune receptors
B. HLA-D antigens on immune cells
C. Complement proteins C2, C4, and factor B
D. Ig VL regions
C. Complement proteins C2, C4, and factor B
- Which MHC class of molecule is necessary for antigen recognition by CD4-positive T cells?
A. Class I
B. Class II
C. Class III
D. No MHC molecule is necessary for antigen recognition
B. Class II
- Toll-like receptors (TLRs) are found on which cells?
A. T cells
B. Dendritic cells
C. B cells
D. Large granular lymphocytes
B. Dendritic cells
- What molecule on the surface of most T cells recognizes antigen?
A. IgT, a four-chain molecule that includes the tau heavy chain
B. MHC protein, a two-chain molecule encoded by the HLA region
C. CD3, consisting of six different chains
D. T-cell receptor (TcR), consisting of two chains: α-chain and β-chain
D. T-cell receptor (TcR), consisting of two chains: α-chain and β-chain
- TcR is similar to Ig molecules in that it:
A. Remains bound to the cell surface and is never secreted
B. Contains V and C regions on each of its chains
C. Binds complement
D. Can cross the placenta and provide protection to a fetus
B. Contains V and C regions on each of its chains
- 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
A. IL-1 and IL-6
- A superantigen, such as toxic shock syndrome toxin-1 (TSST-1), bypasses the normal antigen-processing stage by binding to and cross-linking:
A. A portion of an Ig molecule and complement component C1
B. TLRs and an MHC class 1 molecule
C. A portion of an Ig and a portion of a TcR
D. A portion of a TcR and an MHC class II molecule
D. A portion of a TcR and an MHC class II molecule
- T-regulator cells, responsible for controlling autoimmune antibody
production, express which of the following phenotypes?
A. CD3, CD4, CD8
B. CD3, CD8, CD25
C. CD3, CD4, CD25
D. CD8, CD25, CD56
C. CD3, CD4, CD25
- The interaction between individual antigen and antibody molecules depends on several types of bonds, such as ionic bonds, hydrogen bonds, hydrophobic bonds, and van der Waals forces. How is the strength of this attraction characterized?
A. Avidity
B. Affinity
C. Reactivity
D. Valency
B. Affinity
- A laboratory is evaluating an enzyme-linked immunosorbent assay (ELISA) for detecting an antibody to cyclic citrullinated peptide (CCP), which is a marker for rheumatoid arthritis (RA). The laboratory includes serum from healthy volunteers and from patients with other connective tissue diseases in the evaluation. These specimens determine which factor of the assay?
A. Sensitivity
B. Precision
C. Bias
D. Specificity
D. Specificity
- The detection of precipitation reactions depends on the presence of
optimal proportions of antigen and antibody. A patient’s sample contains a large amount of antibody, but the reaction in a test system containing antigen is negative. What has happened?
A. Performance error
B. Low specificity
C. A shift in the zone of equivalence
D. Prozone phenomenon
D. Prozone phenomenon
- The positive and negative control values for an ELISA procedure are below their acceptable ranges. What is the most likely cause?
A. Decay of the positive and negative controls
B. Incomplete washing following specimen addition
C. Overly long incubation times
D. Decay of the antibody–enzyme conjugate
D. Decay of the antibody–enzyme conjugate
- What is the interpretation when an Ouchterlony plate shows crossed lines between wells 1 and 2 (antigen is placed in the center well and antisera in wells 1 and 2)?
A. No reaction between wells 1 and 2
B. Partial identity between wells 1 and 2
C. Nonidentity between wells 1 and 2
D. Identity between wells 1 and 2
C. Nonidentity between wells 1 and 2
- A weightlifter taking many supplements is tested monthly for
thyroid-stimulating hormone (TSH) in a direct capture assay, which uses a streptavidin–biotin indicator system. She has had normal TSH levels for the past 3 months on specimens collected in the late evening. This month she comes in right after breakfast for her blood draw. The TSH level is three times her previous level. What may be the cause of this difference?
A. Diurnal variation in TSH levels
B. Exogenous biotin in her system from a supplement taken that morning
C. Reduced thyroid function caused by an unidentified pathology
D. Pipetting error
B. Exogenous biotin in her system from a supplement taken that morning
- What comprises the indicator system in an indirect ELISA for detecting antibody?
A. Enzyme-conjugated antibody + chromogenic substrate
B. Enzyme conjugated antigen + chromogenic substrate
C. Enzyme + antigen
D. Substrate + antigen
A. Enzyme-conjugated antibody + chromogenic substrate
- What outcome results from improper washing of a tube or well after adding the enzyme–antibody conjugate in an ELISA system?
A. Result will be falsely decreased
B. Result will be falsely increased
C. Result will be unaffected
D. Result is impossible to determine
B. Result will be falsely increased
- What would happen if the color reaction phase is prolonged in one
tube or well of an ELISA test?
A. Result will be falsely decreased
B. Result will be falsely increased
C. Result will be unaffected
D. Impossible to determine
B. Result will be falsely increased
- The absorbance of a sample measured by ELISA is greater than
the highest standard. What corrective action should be taken?
A. Extrapolate an estimated value from the highest reading
B. Repeat the test using a standard of higher concentration
C. Repeat the assay using one half the volume of the sample
D. Dilute the test sample
D. Dilute the test sample
- A patient was suspected of having a lymphoproliferative disorder. After several laboratory tests were completed, the patient was found to have an IgMκ paraprotein. In what sequence should the laboratory tests leading to this diagnosis have been performed?
A. Serum protein electrophoresis (SPE) followed by immunofixation electrophoresis (IFE)
B. Ig levels, followed by SPE
C. Total lymphocyte count, followed by Ig levels
D. Ig levels, followed by urine protein electrophoresis
A. Serum protein electrophoresis (SPE) followed by immunofixation electrophoresis (IFE)