PCB 4233 Quiz 1-12 Exam MC Questions
With Correct Answers
8. Yersinia pestis, the causative agent of the bubonic plague, has multiple
| | | | | | | | | | | |
mechanisms of immune evasion. This Gram-negative bacterium is transmitted
| | | | | | | | |
from fleas (body temperature 26 deg C) to humans (body temperature 37 deg C)
| | | | | | | | | | | | | |
by flea bites. Studies have shown that the lipopolysaccharide (LPS) produced by Y.
| | | | | | | | | | | |
|pestis grown at 37 deg C is about 10-fold less potent at stimulating TLR4 signaling
| | | | | | | | | | | | | |
|than is the Y. pestis LPS from bacteria grown at 26 deg C. When these two forms
| | | | | | | | | | | | | | | | |
of Y. pestis LPS are compared for their abilities to induce responses from human
| | | | | | | | | | | | | |
macrophages, one would expect that the 26 deg C Y. pestis LPS would result in:
| | | | | | | | | | | | | |
A. Increased production of antimicrobial peptides
| | | | |
B. Increased production of TNF-a and IL-6
| | | | | |
C. Reduced production of IL-10
| | | |
D. Increased activation of the inflammasome
| | | | |
E.Reduced production of Type 1 interferons - CORRECT ANSWER✔✔-B. Increased
| | | | | | | | | |
production of TNF-a and IL-6 | | | |
1. An infant with recurrent bacterial and fungal infections is suspected to have an
| | | | | | | | | | | | |
immunodeficiency disease. Within two days after exposure to a pathogen, the | | | | | | | | | | |
organisms have |
proliferated to dangerous levels requiring immediate systemic antibiotic
| | | | | | | |
treatment. It is | |
unlikely that this infant has a defect in B or T lymphocyte responses to the
| | | | | | | | | | | | | | |
infection because: |
,A. Systemic infections of bacteria and fungi are usually cleared by the spleen.
| | | | | | | | | | | |
B. Bacteria and fungi do not require B cell or T cell responses for their clearance.
| | | | | | | | | | | | | | |
C. Bacteria and fungi are not efficiently transported to draining lymph nodes to
| | | | | | | | | | | | |
initiate adaptive |
immune responses. |
D. The defective immune response occurs too rapidly following infection to be
| | | | | | | | | | | |
due to a defect
| | |
in B or T lymphocytes responses.
| | | | |
E. Adaptive immune responses require dendritic cells to take up and degrade
| | | | | | | | | | | |
pathogens. - CORRECT ANSWER✔✔-D. The defective immune response occurs
| | | | | | | | |
too rapidly following infection to be due to a defect
| | | | | | | | |
in B or T lymphocytes responses.
| | | | |
2. In patients with lymphomas, the cancer cells invade the bone marrow and
| | | | | | | | | | | | |
destroy the |
environment required for normal hematopoiesis. This leads to bone marrow
| | | | | | | | | |
failure, which |
disrupts the production of hematopoietic cell lineages. All of the following cell
| | | | | | | | | | | |
types would be | |
affected by this EXCEPT: | | |
A. Red blood cells
| | |
B. Endothelial cells
| |
C. Lymphocytes
|
D. Dendritic cells
| |
E. Neutrophils - CORRECT ANSWER✔✔-B. Endothelial cells
| | | | | |
,3. Epithelial surfaces provide the first line of defense against infection by the use
| | | | | | | | | | | | | |
of several types
| |
of mechanisms. What is a chemical way to fend off pathogens?
| | | | | | | | | |
A. Secretion of antimicrobial peptides by epithelial cells
| | | | | | |
B. Joining of epithelial cells by tight junctions
| | | | | | |
C. Production of mucus, tears, or saliva in the nose, eyes, and oral cavity
| | | | | | | | | | | | |
D. Movement of mucus by cilia
| | | | |
E. Peristalsis in the gastrointestinal tract - CORRECT ANSWER✔✔-A. Secretion of
| | | | | | | | | | |
antimicrobial peptides by epithelial cells
| | | |
4. Neutrophil secret defensins, which are:
| | | | |
A. Enzymes
|
B. Glycolipids
|
C. Short amphipathic peptides
| | |
D. Carbohydrates
|
E. Reactive oxygen species (ROS) - CORRECT ANSWER✔✔-C. Short amphipathic
| | | | | | | | | |
peptides
5. Which of the following statements is TRUE of lysozyme?
| | | | | | | | |
A. Lysozyme is a cytoplasmic organelle
| | | | |
B. Lysozyme activates complement
| | |
C. Lysozyme is a protease
| | | |
D. Lysozyme splits peptidoglycan
| | |
, E. Lysozyme is released by mast cells - CORRECT ANSWER✔✔-D. Lysozyme splits
| | | | | | | | | | | |
peptidoglycan
6. True or False: The classical and lectin pathways of complement activation
| | | | | | | | | | | |
converge at the step
| | |
of C3 activation. Moreover, the initiating steps of each pathway use protein
| | | | | | | | | | | |
components and |
enzymatic mechanisms that share high similarity with each other. - CORRECT
| | | | | | | | | | |
ANSWER✔✔-TRUE
7. Which one of the following is NEITHER a C3 convertase NOR a C5 convertase?
| | | | | | | | | | | | | |
A. C4b2a3b
|
B. C3bBb
|
C. C4b2a
|
D. C3(H2O)Bb
|
E. C1q, C1r and C1s - CORRECT ANSWER✔✔-E. C1q, C1r and C1s
| | | | | | | | | | |
8. The membrane attack complex consists of
| | | | | |
A. C4b2a
|
B. (C3b)2Bb
|
C. C5b, 6, 7, 8, 9
| | | | |
D. C3a or C5a
| | |
E. MASP-1, -2, and -3 - CORRECT ANSWER✔✔-C. C5b, 6, 7, 8, 9
| | | | | | | | | | | |
With Correct Answers
8. Yersinia pestis, the causative agent of the bubonic plague, has multiple
| | | | | | | | | | | |
mechanisms of immune evasion. This Gram-negative bacterium is transmitted
| | | | | | | | |
from fleas (body temperature 26 deg C) to humans (body temperature 37 deg C)
| | | | | | | | | | | | | |
by flea bites. Studies have shown that the lipopolysaccharide (LPS) produced by Y.
| | | | | | | | | | | |
|pestis grown at 37 deg C is about 10-fold less potent at stimulating TLR4 signaling
| | | | | | | | | | | | | |
|than is the Y. pestis LPS from bacteria grown at 26 deg C. When these two forms
| | | | | | | | | | | | | | | | |
of Y. pestis LPS are compared for their abilities to induce responses from human
| | | | | | | | | | | | | |
macrophages, one would expect that the 26 deg C Y. pestis LPS would result in:
| | | | | | | | | | | | | |
A. Increased production of antimicrobial peptides
| | | | |
B. Increased production of TNF-a and IL-6
| | | | | |
C. Reduced production of IL-10
| | | |
D. Increased activation of the inflammasome
| | | | |
E.Reduced production of Type 1 interferons - CORRECT ANSWER✔✔-B. Increased
| | | | | | | | | |
production of TNF-a and IL-6 | | | |
1. An infant with recurrent bacterial and fungal infections is suspected to have an
| | | | | | | | | | | | |
immunodeficiency disease. Within two days after exposure to a pathogen, the | | | | | | | | | | |
organisms have |
proliferated to dangerous levels requiring immediate systemic antibiotic
| | | | | | | |
treatment. It is | |
unlikely that this infant has a defect in B or T lymphocyte responses to the
| | | | | | | | | | | | | | |
infection because: |
,A. Systemic infections of bacteria and fungi are usually cleared by the spleen.
| | | | | | | | | | | |
B. Bacteria and fungi do not require B cell or T cell responses for their clearance.
| | | | | | | | | | | | | | |
C. Bacteria and fungi are not efficiently transported to draining lymph nodes to
| | | | | | | | | | | | |
initiate adaptive |
immune responses. |
D. The defective immune response occurs too rapidly following infection to be
| | | | | | | | | | | |
due to a defect
| | |
in B or T lymphocytes responses.
| | | | |
E. Adaptive immune responses require dendritic cells to take up and degrade
| | | | | | | | | | | |
pathogens. - CORRECT ANSWER✔✔-D. The defective immune response occurs
| | | | | | | | |
too rapidly following infection to be due to a defect
| | | | | | | | |
in B or T lymphocytes responses.
| | | | |
2. In patients with lymphomas, the cancer cells invade the bone marrow and
| | | | | | | | | | | | |
destroy the |
environment required for normal hematopoiesis. This leads to bone marrow
| | | | | | | | | |
failure, which |
disrupts the production of hematopoietic cell lineages. All of the following cell
| | | | | | | | | | | |
types would be | |
affected by this EXCEPT: | | |
A. Red blood cells
| | |
B. Endothelial cells
| |
C. Lymphocytes
|
D. Dendritic cells
| |
E. Neutrophils - CORRECT ANSWER✔✔-B. Endothelial cells
| | | | | |
,3. Epithelial surfaces provide the first line of defense against infection by the use
| | | | | | | | | | | | | |
of several types
| |
of mechanisms. What is a chemical way to fend off pathogens?
| | | | | | | | | |
A. Secretion of antimicrobial peptides by epithelial cells
| | | | | | |
B. Joining of epithelial cells by tight junctions
| | | | | | |
C. Production of mucus, tears, or saliva in the nose, eyes, and oral cavity
| | | | | | | | | | | | |
D. Movement of mucus by cilia
| | | | |
E. Peristalsis in the gastrointestinal tract - CORRECT ANSWER✔✔-A. Secretion of
| | | | | | | | | | |
antimicrobial peptides by epithelial cells
| | | |
4. Neutrophil secret defensins, which are:
| | | | |
A. Enzymes
|
B. Glycolipids
|
C. Short amphipathic peptides
| | |
D. Carbohydrates
|
E. Reactive oxygen species (ROS) - CORRECT ANSWER✔✔-C. Short amphipathic
| | | | | | | | | |
peptides
5. Which of the following statements is TRUE of lysozyme?
| | | | | | | | |
A. Lysozyme is a cytoplasmic organelle
| | | | |
B. Lysozyme activates complement
| | |
C. Lysozyme is a protease
| | | |
D. Lysozyme splits peptidoglycan
| | |
, E. Lysozyme is released by mast cells - CORRECT ANSWER✔✔-D. Lysozyme splits
| | | | | | | | | | | |
peptidoglycan
6. True or False: The classical and lectin pathways of complement activation
| | | | | | | | | | | |
converge at the step
| | |
of C3 activation. Moreover, the initiating steps of each pathway use protein
| | | | | | | | | | | |
components and |
enzymatic mechanisms that share high similarity with each other. - CORRECT
| | | | | | | | | | |
ANSWER✔✔-TRUE
7. Which one of the following is NEITHER a C3 convertase NOR a C5 convertase?
| | | | | | | | | | | | | |
A. C4b2a3b
|
B. C3bBb
|
C. C4b2a
|
D. C3(H2O)Bb
|
E. C1q, C1r and C1s - CORRECT ANSWER✔✔-E. C1q, C1r and C1s
| | | | | | | | | | |
8. The membrane attack complex consists of
| | | | | |
A. C4b2a
|
B. (C3b)2Bb
|
C. C5b, 6, 7, 8, 9
| | | | |
D. C3a or C5a
| | |
E. MASP-1, -2, and -3 - CORRECT ANSWER✔✔-C. C5b, 6, 7, 8, 9
| | | | | | | | | | | |
