CIULLA: IMMUNOSEROLOGY EXAM QUESTIONS WITH CORRECT ANSWERS |LATEST UPDATE
100% SOLVED| GRADED A+
1. Which of the following statements about the test for C-reactive protein (CRP) is true?
A. It correlates with neutrophil phagocytic function
B. It is an indicator of ongoing inflammation
C. It is diagnostic for rheumatic fever
D. Levels decrease during heart disease B. CRP is an acute-phase reactant. Although it is
elevated in inflammation, its presence is not diagnostic for any one disease, such as rheumatic
fever. It does not correlate with antibody levels or with neutrophil phagocytic function. CRP
levels are sometimes elevated during heart disease.
2. In the classical pathway of complement activation,
A. C3 is activated by binding C-reactive protein
B. The sequence of activation is C1, C2, C3, C4
C. C1q is activated by the presence of a single Fab region
D. Activation by antibody requires one IgM or two IgG molecules D. Complement attaches to
the Fc portion of the antibody molecule. At least two Fc binding sites are required for Clq to
attach. Therefore, activation requires two IgG molecules or a single molecule of IgM, which is a
pentamer. The C proteins were named in order of discovery. The correct reaction sequence is
Cl, C4, C2, C3. As the last step of this reaction sequence, C3 is split into C3a and C3b.
3. The alternative complement pathway:
A. Can be activated by bacterial capsule polysaccharides
,B. Uses C5b as a C3 convertase
C. Bypasses steps C3 through C5
D. Is inactivated by properdin A. The alternative pathway for complement activation is a
more nonspecific defense mechanism, in that it does not require the presence of antibody for
activation. It can be activated by a variety of substances, including complex polysaccharides
found in bacterial capsules and cell walls. These materials activate C3 directly. Properdin
protein stabilizes some of the active complement proteins, and C4b2a is a C3 convertase.
4. A cut on a person's finger becomes contaiminated with the bacterium Stephyloccus aureus.
The first response by the immune system consists of activity of:
A. B cells
B. Monocytes
C. Neutrophils
D. T cells C. The first response to invading bacteria is mounted by the innate immune
system. The innate immune system, although it lacks the specificity of the adaptive immune
system, is nonetheless effective at handling many invading bacteria. The first response by the
innate immune system consists of an influx of neutrophils into the tissue invaded by bacteria.
Monocytes and macrophages, although they are phagocytic cells and part of the innate
immune system, play only a minor role in the initial response to bacterial invasion.
5. Incompatible blood transufsions are examples of:
A. Type I hypersensitivity reactions
B. Type II hypersensitivity reactions
C. Type III hypersensitivity reactions
,D. Type IV hypersensitivity reactions B. Incompatible blood transfusions are examples of a
type II hypersensitivity reaction. These reactions are characterized as the antigen being a part
of a cell. Antibody binds to the antigen, complement is activated, and the red blood cells are
lysed.
6. A soluble antigen and soluble antibody reacting to form an insoluble product describes:
A. Agglutination reactions
B. Heterophile reactions
C. Labeled reactions
D. Precipitation reactions D. Precipitation reactions involve both soluble antigens and
antibodies. These reactions are typically detected in agarose gels. With agglutination reactions,
one of the reactants is soluble and the other is insoluble. A reactant is made insoluble by
combining with a carrier particle such as latex beads.
7. Which of the following is an example of a treponemal antigen test used for the diagnosis of
syphilis?
A. CRP
B. RPR
C. VDRL
D. FTA-ABS D. The fluorescent treponemal antibody absorbance (FTA-ABS) test is often used
as a confirmatory test for syphilis. Treponema pallidum subsp. pallidum, the causative agent of
syphilis, is the source of the antigen. The rapid plasma reagin (RPR) and Venereal Disease
Research Laboratory (VDRL) are diagnostic tests for syphilis that use nontreponemal antigen. C-
reactive protein (CRP) is not involved in syphilis testing.
, 8. A serum sample is positive for HBsAg. This results indicates that the person from whom the
serum was taken:
A. Had a hepatitis B infection in the past but overcame the infection
B. Has either active or chronic hepatitis B infection
C. Was immunized recently against the hepatitis B virus
D. Is no infectious for the hepatitis B virus B. Hepatitis B surface antigen (HBsAg) is a marker
for active or chronic infection by the hepatitis B virus; it indicates ongoing viral replication. A
person positive for this marker is infectious. If the person had overcome a past infection, he or
she would have antibody to the surface antigen (anti-HBs) but not the surface antigen.
Immunization causes formation of anti-HBs antibody, and the surface antigen would not be
present in serum
9. What is the indicator system used in the complement fixation test?
A. Sensitized sheep red blood cells
B. Fluorescent-labeled antihuman globulin
C. Enzyme-labeled antihuman globulin
D. Guinea pig complement A. The first step in the complement fixation test, the test system,
involves the reaction of antibody in the patient's serum to the corresponding antigen in the
presence of guinea pig complement. If antibody-antigen binding occurs, complement will bind
to the immune complexes. The second step is the addition of sensitized sheep red blood cells
(the indicator system). If complement bound to the immune complexes in the first step, it is not
available to lyse the sensitized red blood cells. If antibody was not present in the patient
sample, complement will not bind to the immune complexes, and it will be free to lyse the
sensitized cells.
100% SOLVED| GRADED A+
1. Which of the following statements about the test for C-reactive protein (CRP) is true?
A. It correlates with neutrophil phagocytic function
B. It is an indicator of ongoing inflammation
C. It is diagnostic for rheumatic fever
D. Levels decrease during heart disease B. CRP is an acute-phase reactant. Although it is
elevated in inflammation, its presence is not diagnostic for any one disease, such as rheumatic
fever. It does not correlate with antibody levels or with neutrophil phagocytic function. CRP
levels are sometimes elevated during heart disease.
2. In the classical pathway of complement activation,
A. C3 is activated by binding C-reactive protein
B. The sequence of activation is C1, C2, C3, C4
C. C1q is activated by the presence of a single Fab region
D. Activation by antibody requires one IgM or two IgG molecules D. Complement attaches to
the Fc portion of the antibody molecule. At least two Fc binding sites are required for Clq to
attach. Therefore, activation requires two IgG molecules or a single molecule of IgM, which is a
pentamer. The C proteins were named in order of discovery. The correct reaction sequence is
Cl, C4, C2, C3. As the last step of this reaction sequence, C3 is split into C3a and C3b.
3. The alternative complement pathway:
A. Can be activated by bacterial capsule polysaccharides
,B. Uses C5b as a C3 convertase
C. Bypasses steps C3 through C5
D. Is inactivated by properdin A. The alternative pathway for complement activation is a
more nonspecific defense mechanism, in that it does not require the presence of antibody for
activation. It can be activated by a variety of substances, including complex polysaccharides
found in bacterial capsules and cell walls. These materials activate C3 directly. Properdin
protein stabilizes some of the active complement proteins, and C4b2a is a C3 convertase.
4. A cut on a person's finger becomes contaiminated with the bacterium Stephyloccus aureus.
The first response by the immune system consists of activity of:
A. B cells
B. Monocytes
C. Neutrophils
D. T cells C. The first response to invading bacteria is mounted by the innate immune
system. The innate immune system, although it lacks the specificity of the adaptive immune
system, is nonetheless effective at handling many invading bacteria. The first response by the
innate immune system consists of an influx of neutrophils into the tissue invaded by bacteria.
Monocytes and macrophages, although they are phagocytic cells and part of the innate
immune system, play only a minor role in the initial response to bacterial invasion.
5. Incompatible blood transufsions are examples of:
A. Type I hypersensitivity reactions
B. Type II hypersensitivity reactions
C. Type III hypersensitivity reactions
,D. Type IV hypersensitivity reactions B. Incompatible blood transfusions are examples of a
type II hypersensitivity reaction. These reactions are characterized as the antigen being a part
of a cell. Antibody binds to the antigen, complement is activated, and the red blood cells are
lysed.
6. A soluble antigen and soluble antibody reacting to form an insoluble product describes:
A. Agglutination reactions
B. Heterophile reactions
C. Labeled reactions
D. Precipitation reactions D. Precipitation reactions involve both soluble antigens and
antibodies. These reactions are typically detected in agarose gels. With agglutination reactions,
one of the reactants is soluble and the other is insoluble. A reactant is made insoluble by
combining with a carrier particle such as latex beads.
7. Which of the following is an example of a treponemal antigen test used for the diagnosis of
syphilis?
A. CRP
B. RPR
C. VDRL
D. FTA-ABS D. The fluorescent treponemal antibody absorbance (FTA-ABS) test is often used
as a confirmatory test for syphilis. Treponema pallidum subsp. pallidum, the causative agent of
syphilis, is the source of the antigen. The rapid plasma reagin (RPR) and Venereal Disease
Research Laboratory (VDRL) are diagnostic tests for syphilis that use nontreponemal antigen. C-
reactive protein (CRP) is not involved in syphilis testing.
, 8. A serum sample is positive for HBsAg. This results indicates that the person from whom the
serum was taken:
A. Had a hepatitis B infection in the past but overcame the infection
B. Has either active or chronic hepatitis B infection
C. Was immunized recently against the hepatitis B virus
D. Is no infectious for the hepatitis B virus B. Hepatitis B surface antigen (HBsAg) is a marker
for active or chronic infection by the hepatitis B virus; it indicates ongoing viral replication. A
person positive for this marker is infectious. If the person had overcome a past infection, he or
she would have antibody to the surface antigen (anti-HBs) but not the surface antigen.
Immunization causes formation of anti-HBs antibody, and the surface antigen would not be
present in serum
9. What is the indicator system used in the complement fixation test?
A. Sensitized sheep red blood cells
B. Fluorescent-labeled antihuman globulin
C. Enzyme-labeled antihuman globulin
D. Guinea pig complement A. The first step in the complement fixation test, the test system,
involves the reaction of antibody in the patient's serum to the corresponding antigen in the
presence of guinea pig complement. If antibody-antigen binding occurs, complement will bind
to the immune complexes. The second step is the addition of sensitized sheep red blood cells
(the indicator system). If complement bound to the immune complexes in the first step, it is not
available to lyse the sensitized red blood cells. If antibody was not present in the patient
sample, complement will not bind to the immune complexes, and it will be free to lyse the
sensitized cells.
