IMM250F Past Midterm test
Choose the one best or most appropriate answer
Lectures 1, 2, 3 (Innate Immunity)
1. What was the important contribution to microbiology of Anton Van Leeuwenhoek in
the 1600s?

A. He was the first to observe microorganisms
B. He disproved the theory of spontaneous generation of microorganisms
C. He was the first to show that a disease could be caused by a microorganism
D. He was the first to describe the process of fermentation
Ans. A

2. Which of the following early contributors to the development of immunology is
paired up properly with his or her accomplishment?

A. Louis Pasteur: demonstrated that cowpox vaccination can protect from
smallpox
B. Paul Ehrlich: identified lymphocytes as the cells mediating adaptive immunity
C. MacFarlane Burnet: proposed the side-chain theory of antibodies which
suggested that multiple antigen receptors are expressed on immune cells
D. Robert Koch: developed techniques to grow pure bacterial cultures
Ans. D

3. In the late 1890s, ‘cellularists’ and ‘humoralists’ were intensively arguing about the
key components driving the immune response. What was a crucial finding that led
the humoralists to dominate the field in the following 50 years?

A. The demonstration of the Germ Theory of disease
B. The discovery that cell-free serum could transfer immunity from an immunized
animal to a non-immunized one
C. The discovery of the tuberculin reaction
D. The determination of the antibody structure
Ans. B

4. Phagocytes were discovered by:

A. Ilya Metchnikoff
B. Louis Pasteur
C. Emil von Behring
D. Robert Koch
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Ans. A

5. The clonal selection theory explains:

A. That one given lymphocyte expresses multiple antigen receptors with different
specificity
B. That antigens influence the generation of antigen receptors during lymphocyte
development
C. How the immune response to an antigen increases the number of lymphocytes
specific for that antigen
D. The increase in blood neutrophils observed during bacterial infections
Ans. C

6. The researcher that postulated the existence of ‘pattern recognition receptors’ on
innate cells was:

A. Susumu Tonegawa
B. Ilya Metchnikoff
C. Charles Janeway
D. Ralph Steinman
Ans. C

7. An example of a preformed chemical barrier is

A. Mucus
B. Lysozyme
C. Tight junctions in epithelial cells
D. Cilia in the respiratory tract
Ans. B

8. Which of the following does not describe defensins?

A. They disrupt pathogen membranes by penetrating them and disrupting their
integrity
B. They function as opsonins
C. They are amphipathic, that is they have hydrophobic and hydrophilic regions
D. They are contained in neutrophil granules
Ans. B

9. Why did Barry Marshall drink a pure culture of Helicobacter pylori?

A. To demonstrate the H. pylori is the cause of gastric cancer
B. To demonstrate an association between H. pylori infection and gastric ulcers
C. To demonstrate that gastric ulcers are caused by stress rather than bacterial
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infections
D. A and B are both correct
Ans. B

10. Virulence factors can be transferred from pathogenic to non-pathogenic bacterial
strains that are part of the normal flora. An example of a commensal bacterial
species that has turned into a pathogenic strain is:

A. E. coli 0157:H7
B. M. tuberculosis
C. Group A S. pyogenes
D. All opportunistic bacterial species
Ans. A

11. Which of the following is correct about lectin receptors?

A. They recognize microbial carbohydrates
B. They are expressed on phagocytes
C. They can be classified as pattern recognition receptors
D. All of the above is correct
Ans. D

12. A protein-protein interaction domain present both in TLR-4 and MyD88 is:

A. CARD
B. TIR
C. Leucine rich repeat (LRR)
D. Immunoglobulin-like domain
Ans. B

13. To which cellular location would you expect NFB to move in macrophages that
have been stimulated with LPS?

A. To the cytoplasm
B. To phagosomes
C. To the nucleus
D. To the cell membrane
Ans. C

14. What is the function of CD14 with respect to LPS recognition?

A. It is an accessory protein that allows the transport of newly synthesized TLR-4
onto the cell membrane
B. It is a cytosolic protein that binds LPS that has been internalized via TLR-4/MD-2
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C. It acts as an adaptor in the TLR-4 signaling pathway
D. It is expressed on the cell membrane and shuttles LPS to the vicinity of TLR-
4/MD-2
Ans. D

15. TLR-3 detects viruses found in:

A. Cytosol
B. Extracellular space
C. Endosomes
D. All of the above
Ans. C

16. Which of the following is not a systemic cytokine?

A. TNF
B. IL-1
C. IL-6
D. IL-8
Ans. D

17. Find the unmatched pair with respect to immune function

A. Interferons: protection from viral infections
B. ROS: killing of engulfed pathogens
C. Mast cells: acute phase response
D. Selectins: role in leukocyte extravasation
Ans. C

18. All of the following can be a consequence of the formation of NETs with the
exception of

A. Killing of microbes contained in phagolysosomes
B. Death of neutrophils
C. Trapping of microbes at sites of infection
D. Extracellular microbial killing
Ans. A

19. ‘Rolling’ of neutrophils on endothelial cells is mediated by:

A. Selectins expressed on endothelial cells
B. Integrins expressed on leukocytes
C. Chemokines such as CXCL-8 (IL-8)
D. TNF
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Ans. A

20. With regard to NADPH oxidase, which of the following statements in not correct?
A. It is the enzyme involved in the respiratory burst that follows the engagement of
phagocytic receptors
B. Individuals with mutations of NADPH oxidase subunits suffer repeated infections
because of defective killing of phagocytosed pathogens
C. It is constitutively expressed as a complex of 5 subunits in unstimulated cells
D. It controls the formation of reactive oxygen species
Ans. C

21. A clinical indicator of inflammation is:

A. Decreased concentration of C3b
B. Increased concentration of C-reactive protein
C. Decreased concentration of MBL
D. All of the above
Ans. B

22. Which of the following molecules can function both as complement initiators and as
opsonins?

A. C3b
B. C-reactive protein
C. MBL
D. All of the above
Ans. D

23. Which of the following complement proteins is not part of the membrane attack
complex?

A. C5a
B. C5b
C. C6
D. C7
Ans. A

24. The lectin and the classical pathway are similar because:

A. The same component initiates the complement cascade
B. The same enzyme cleaves C4 and C2
C. They lead to the formation of the same C3 convertase
D. They both involve recognition of an antigen/antibody complex as a trigger for
complement activation
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Ans. C


Lectures 3, 5 (Adaptive Immunity)
25. Select the property that applies only to pathogens:

A. Replicate in (or on) a host
B. Infect host cells
C. Cause disease in a host with normal immune function
D. Are transmitted between individuals of a given species
Ans. C

26. Which of the following represents the correct sequence of host immune defenses as
encountered by a pathogen?

A. Innate responses; physical barriers; adaptive responses
B. Physical barriers; innate responses; adaptive responses
C. Adaptive responses; physical barriers; innate responses
D. Physical barriers; adaptive responses; innate responses
Ans. B

27. Which class of biological molecules can be bound by an immunoglobulin?

A. Proteins
B. Carbohydrates
C. Lipids
D. All of the above
Ans. D

28. Which of the following is a characteristic of the constant region of a T cell receptor?

A. Mediates antigen binding
B. Anchors the receptor in the T cell membrane
C. Interacts with MHC molecules
D. Structurally diverse amongst all T cell receptors
Ans. B

29. Secondary lymphoid tissues are where:
A. Lymphocyte precursors become mature
B. Inflammation occurs during re-infection with a given pathogen
C. Lymphocytes become activated by antigen
D. Gene rearrangement takes place
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Ans. C

30. Which of the following is a feature of antigen recognition by B cells?

A. Their antigen receptors are never secreted
B. Their antigen receptors recognize a fragment of protein in combination with an
MHC molecule
C. Their receptors each have two identical antigen binding sites
D. They recognize pattern associated molecular structures (PAMPs) that are unique
to a particular pathogen
Ans. C

31. The term ‘lymphocyte repertoire’ refers to:

A. The range of antigen receptor specificities found in a lymphocyte population
B. The variety of effector functions that result from an adaptive immune response
C. Antigen receptor specificities found on a given lymphocyte
D. The collection of daughter cells produced when a lymphocyte divides after
activation
Ans. A

32. The rearrangement of gene segments that occurs randomly in B cell receptor genes
and T cell receptor genes:

A. Occurs during clonal expansion of B cells and T cells
B. Involves rapid genetic mutation after lymphocytes become activated
C. Allows the mature lymphocyte population to recognize an enormous diversity of
antigens
D. Occurs in the DNA of all cells in the body
Ans. C

33. A naïve lymphocyte:
A. Does not yet express antigen receptors
B. Is not yet considered mature
C. Has not yet been activated by antigen
D. Is found only in primary lymphoid tissues
Ans. C

34. How does the secondary (memory) immune response differ from the primary
immune response?

A. It is mediated by the adaptive immune system rather than the innate immune
system
B. It is less antigen-specific
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C. It is slower and weaker
D. It is faster and stronger
Ans. D

35. Which of the following is not required for full activation of a naïve lymphocyte?

A. Migration into an inflammatory site
B. Costimulatory signalling
C. Cytokines
D. Recognition of specific antigen
Ans. A


36. After engagement of its pattern recognition receptors what happens to a dendritic
cell to enable its role in naïve T cell activation?

A. Expression of MHC class I molecules begins
B. Increased uptake of antigens
C. Expression of the B7 molecule
D. PAMP-induced proliferation
Ans. C


37. Which of the following are not typically found within secondary lymphoid tissues?

A. Naïve lymphocytes
B. Hematopoietic stem cells
C. Dendritic cells
D. Antigen
Ans. B


38. Lymph consists of fluid that:

A. Is taken up from tissues by lymphatic capillaries
B. Carries antigens and mature dendritic cells to lymph nodes
C. Is secreted by lymphocytes
D. Both A and B are correct
Ans. D


39. Lymphocyte recirculation refers to the process by which naïve lymphocytes
constantly move back and forth:

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A. Between primary lymphoid tissues and secondary lymphoid tissues
B. Between blood and various primary lymphoid tissues
C. Between blood and various secondary lymphoid tissues
D. Between inflammatory sites and secondary lymphoid tissues
Ans. C