1
Which of the following statements is true of the INNATE immune system?
Choose one answer.
a. Its response generally involves the production of antibodies.
b. Its response generally involves macrophages.
c. It provides a tailored response to specific pathogens.
d. It is responsible for the medical efficacy of vaccines.
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Question 2
Mycobacterium tuberculosis, the pathogen that causes tuberculosis, is a bacterium that grows and replicates within the vesicles of macrophages. In macrophages with this infection, which of the following would you expect to see?
Choose one answer.
a. Macrophages releasing excessive amounts of cytokines
b. Macrophages expressing peptides associated with MHC I molecules at their surface
c. Macrophages expressing peptides associated with MHC II molecules at their surface
d. Macrophages expressing CD4 co-receptors at their surface
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Question 3
When you get a cold, you might notice that you have swollen glands, lumps of swelling on either side of the base of your jaw. What immunological activity causes this?
Choose one answer.
a. An influx of mast cells to the affected area
b. The rapid proliferation of natural killer cells within lymph nodes
c. The expansion of lymph fluid within lymph nodes
d. The rapid proliferation of B cells within lymph nodes
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Question 4

You have a viral infection. Although you might have an increase in lymphocytes generally, which type of lymphocyte would you expect to be the most abundant and effective, and why?

Choose one answer.
a. Cytotoxic T cells, because they recognize the antigens displayed by cells infected with viruses
b. TH1 cells, because their presence is required in order to stimulate B cells to recognize the infection
c. B cells, because they would be proliferating and secreting large amounts of antibodies
d. TH2 cells, because their presence is required in order to stimulate B cells to recognize the infection
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Question 5
In American football, many players will sometimes tackle and pile up on a single player from the opposing team in order to immobilize this player. This technique is most similar to which role of antibodies?
Choose one answer.
a. Complement activation
b. Opsonization
c. Neutralization
d. Antigen recognition
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Question 6
Which of the following statements regarding vaccines is true?
Choose one answer.
a. Vaccines are produced in cows, which is where the term vaccine comes from.
b. Edward Jenner discovered that cowpox can be used as a vaccine against smallpox.
c. Despite our efforts to perfect the smallpox vaccine, the disease is still not eradicated.
d. Louis Pasteur developed a cholera vaccine, which works against rabies.
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Question 7

Which of the following types of immune-system cells respond immediately to bacterial infections and release chemokines and cytokines?

Choose one answer.
a. Macrophages
b. Neutrophils
c. Eosinophils
d. Cytotoxic T cells
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Question 8
We are lucky to have both an innate and an adaptive immune system, because each type of system helps us in different ways and each one has advantages and disadvantages. What is one disadvantage of the adaptive immune system?
Choose one answer.
a. It lacks specificity.
b. It can only be used once against any specific pathogen.
c. It can only be initiated when the thymus is triggered to release certain activators.
d. It can take several days for an initial response to take effect.
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Question 9
Inflammation involves heat, pain, redness, and swelling. The increased blood flow and leaking of fluid from blood vessels near the site of an infection are responsible for which of the following aspects of inflammation?
Choose one answer.
a. Heat and redness
b. Swelling
c. Pain
d. Both A and B
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Question 10
Which of the following types of immune-system cells are known as inflammatory cells and recruit to infected areas in large numbers, where they engulf bacteria and other microorganisms?
Choose one answer.
a. Cytotoxic T Cells
b. Neutrophils
c. Eosinophils
d. Basophils
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Question 11
Blood work shows that a patient has immature T cells in his blood and he lacks mature T cells. In which organ or tissue do you expect to see a problem?
Choose one answer.
a. The spleen
b. The thymus
c. The bone marrow
d. The mucosal lymphoid tissues (MALT)
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Question 12

Which of the following is NOT a principle of the Clonal Selection Theory?

Choose one answer.
a. Each lymphocyte has a single type of receptor with unique specificity.
b. A lymphocyte will be activated to proliferate only when its receptor comes into contact with the specific antigen to which it binds.
c. Receptors with different specificities are produced as the offspring of activated lymphocytes.
d. It postulates that those lymphocytes that respond to self-antigen are selected against (deleted) and are not present as mature lymphocytes.
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Question 13
Mycobacterium tuberculosis, the pathogen that causes tuberculosis, is a bacterium that grows and replicates within the vesicles of macrophages. Which of the following types of immune-system cells are heavily involved in the recognition and destruction of M. tuberculosis?
Choose one answer.
a. Cytotoxic T cells
b. T helper 1 cells
c. T helper 2 cells
d. Basophils
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Question 14

Which of the following is NOT one of the ways in which epithelia function as a first line of immunological defense?

Choose one answer.
a. The epithelia provide a physical barrier to pathogens.
b. Cilia on the epithelial surface capture and display pathogens to immune-system cells.
c. Good bacteria on the epithelial surface prevent pathogens from colonizing it.
d. Many epithelial secretions, like tears and saliva, have antimicrobial properties.
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Question 15

Which complement-system pathway can provide amplification of the other two pathways?

Choose one answer.
a. Classical pathway
b. Mannose-binding (MB) pathway
c. Alternative pathway
d. None of these answers
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Question 16

Which complement-system pathway is initiated with the help of antibodies bound to the surface of a pathogen?

Choose one answer.
a. Classical pathway
b. Mannose-binding (MB) pathway
c. Alternative pathway
d. None of these answers
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Question 17

Which of the following statements about neutrophils is false?

Choose one answer.
a. Neutrophils are members of the first line of defense during an immune reaction.
b. Neutrophils live longer than macrophages after meeting with a pathogen.
c. Neutrophils have scavenger receptors, allowing them to quickly recognize a pathogen.
d. Neutrophils die after one round of phagocytosis, which is the major component of pus.
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Question 18

Which of the following statements about C3b of the complement pathway is false?

Choose one answer.
a. All three complement pathways lead to the breakdown of C3 to C3b and C3a.
b. C3b can act as an opsonin for phagocytes.
c. C3b can lead to the formation of the membrane attack complex.
d. C3b can become iC3b, which is known as the active form.
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Question 19

Complete the following sentence. C3a molecules act as:

Choose one answer.
a. pro-inflammatory mediators.
b. the initial triggers of the classical pathway.
c. membrane-attack proteins.
d. opsonins.
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Question 20

Which of the following statements about Toll-like receptors is false?

Choose one answer.
a. They are part of the vertebrate version of an ancient immunological pathway.
b. They are present on the surface of phagocytes.
c. They are involved solely in the induction of innate immune responses.
d. Some members of the Toll-like receptor family bind to CD14.
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Question 21

Which of the following is true for mammals lacking a receptor for TNF-α ?

Choose one answer.
a. They are resistant to septic shock.
b. Their immune cells cannot extravasate.
c. They are especially susceptible to septic shock.
d. Their immune cells are better able to contain local infections.
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Question 22

Which of the following types of cells would be present first, and in the largest numbers, at the site of a very recent infection?

Choose one answer.
a. Dendritic cells
b. Neutrophils
c. Cytotoxic T cells
d. Basophils
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Question 23

The presence of interferons alpha and beta indicates that the body has been infected with what kind of pathogen?

Choose one answer.
a. A bacterial pathogen
b. A viral pathogen
c. A fungal pathogen
d. Any intracellular pathogen
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Question 24

Complete the following sentence. The presence of interferons alpha and beta will most likely result in or cause:

Choose one answer.
a. the activation of B cells.
b. the activation of naïve monocytes.
c. an increase in the number of B cells.
d. the activation of natural killer cells.
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Question 25

How can the adaptive immune system be so specific during a first response, when it has never seen the pathogen before?

Choose one answer.
a. These cells individually adapt to the infecting pathogen.
b. These cells have many receptors, each with a specific binding site for common patterns only found on pathogens.
c. These cells are numerous clones, each with a unique receptor.
d. Cells from the innate immune system only bring certain types of pathogens to cells of the adaptive immune system.
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Question 26

A protease cleaves an antibody into three fragments. Two of these fragments are identical and are composed of a light polypeptide chain and a heavy polypeptide chain. The third fragment is composed solely of heavy chains. Which of the following statements regarding the identical fragments is true?

Choose one answer.
a. They are the area of the antibody involved in effector interactions.
b. They are also known as Fc fragments.
c. They make up the C domain of the antibody.
d. They are the area of the antibody involved in antigen binding.
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Question 27

If your friend is suffering from severe hay fever, then you will expect an increase in his levels of which immunoglobulin?

Choose one answer.
a. IgE
b. IgG
c. IgD
d. IgA
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Question 28

If you are looking for maternal antibodies in a newborn, what isotype of antibodies should you look for?

Choose one answer.
a. IgE
b. IgG
c. IgD
d. IgM
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Question 29

An antibody isotype that has a high affinity for antigen-binding sites and can diffuse easily into tissues is best suited for what type of immune-system role?

Choose one answer.
a. Mediation of allergic response
b. Activation of complement
c. Activation of mast cells
d. Neutralization of toxins
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Question 30

Which of the following is an example of passive immunization?

Choose one answer.
a. Toxoids, toxin sequences with the toxic portion removed, are injected into a patient to promote an antibody response to bacterial toxins.
b. Maternal antibodies are transported across the placenta into the bloodstream of a fetus.
c. A horse is immunized with venom and its antibodies are injected into a person bitten by a rattlesnake.
d. Secretions like tears and saliva always contain antibodies as a protection against potential infection.
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Question 31
A bacterium in the respiratory tract uses adhesins to bind to host cells and later enter those cells. Given what you know about isotype functions AND locations, which of the following isotypes would prevent this bacterial infection?
Choose one answer.
a. IgA
b. IgM
c. IgE
d. IgG
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Question 32

Which of the following statements about IgM is false?

Choose one answer.
a. It is the first antibody to be secreted by B cells.
b. It has relatively low affinity as a monomer.
c. It is the only antibody that forms dimers.
d. It is a good agglutinating antibody.
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Question 33

Which of the following is NOT a means through which immunoglobulin diversity is achieved?

Choose one answer.
a. Affinity maturation
b. The association of 2 chains (a light and a heavy chain) in forming antigen-binding sites
c. The presence of many different V-regions on an individual’s genome
d. The somatic recombination of V, D, and J segments
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Question 34

Complete the following sentence. Point mutations of the V regions of light- and heavy-chain genes occur at a dramatic rate, leading to the expression of variant B-cell receptors on B cells. This occurrence is known as:

Choose one answer.
a. combinatorial diversity.
b. somatic hypermutation.
c. somatic recombination.
d. hypervariable rearrangement.
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Question 35

Point mutations of the V regions of light- and heavy-chain genes occur at a dramatic rate, leading to the expression of variant B-cell receptors on B cells. Is this occurrence an advantage or a disadvantage for B cells’ function, and why?

Choose one answer.
a. It is a disadvantage, because these variant B-cell receptors are unable to recognize antigens.
b. It is an advantage, because B cells with variant receptors divide more quickly.
c. It is an advantage, because some variant B-cell receptors bind antigen better and are selected for.
d. It is a disadvantage, because B cells with variant receptors, regardless of their functionality, can never secrete antibodies.
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Question 36
Which of the following isotype descriptions is incorrect?
Choose one answer.
a. IgG antibodies are the best at crossing the placenta.
b. IgM antibodies are the best at opsonizing extracellular bacteria.
c. IgA antibodies are mostly in the form of a dimer.
d. IgE are the most problematic during allergic reactions.
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Question 37
Tumor cells can evade the immune system in which of the following ways?
Choose one answer.
a. The tumor cells no longer express mutant proteins.
b. Antibody bound antigens on the tumor cells are endocytosed.
c. The tumor cells secrete factors that directly inhibit T cells.
d. All of these answers
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Question 38

Although MHC I and MHC II signaling pathways are triggered by different pathogens and use different molecules, some of these molecules perform very similar functions. Which of the following statements does NOT describe a similarity in function between molecules in each pathway?

Choose one answer.
a. Proteasomes and proteases both degrade antigen proteins into peptides.
b. Interferons and acids each induce proteasomes and proteases, respectively.
c. The TAP-1:2 complex and the invariant chain each help ensure that MHC molecules and peptides will be present in the same place so that peptide binding can occur.
d. The TAP-1:2 complex and HLA-DO both catalyze the binding of MHC molecules with peptides.
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Question 39

Which MHC class type is found on every nucleated cell in the body and why?

Choose one answer.
a. MHC I, to present self peptides
b. MHC II, to present infecting viruses
c. MHC II, to present both infecting viruses and phagocytosed bacteria
d. MHC I, to present self peptides and viral peptides
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Question 40

Which MHC class type do Antigen Presenting Cells express on their surface?

Choose one answer.
a. MHC I
b. MHC II
c. Neither
d. Both MHC I and MHC II
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Question 41

This molecule is expressed to some degree by almost all nucleated cells:

Choose one answer.
a. MHC I
b. MHC II
c. CD4
d. CD8
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Question 42

Which of the following molecules is usually expressed only by antigen-presenting immune-system cells?

Choose one answer.
a. MHC I
b. MHC II
c. CD4
d. CD8
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Question 43

Which of the following molecules increases the sensitivity of Cytotoxic T cells to antigen 100-fold?

Choose one answer.
a. MHC I
b. MHC II
c. CD4
d. CD8
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Question 44

Which of the following statements about antigen recognition is false?

Choose one answer.
a. The receptors of B and T cells are very similar in structure.
b. The receptors of T cells require co-receptors in order to strongly respond to antigens.
c. The receptors of B and T cells recognize and bind to antigen fragments.
d. Unlike B cells, the receptors of T cells have only one binding site.
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Question 45

The parasite that causes malaria enters red blood cells and is relatively undetected by T cells. Which of the following is a possible reason for its ability to avoid detection by T cells?

Choose one answer.
a. Red blood cells do not express MHC II molecules.
b. Red blood cells do not express MHC I molecules.
c. Red blood cells do not have the cellular machinery to break down antigen proteins.
d. The unique structure of a red blood cell prevents it from being brought into contact with T cells.
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Question 46

You discover a cell type that you believe is involved in immune response and antigen recognition. However, when you place these cells in cultures with whole antigens, they do not respond to them. Knowing about the ways in which lymphocytes respond to antigens, what other experiment should you try before concluding that your suspicion was incorrect?

Choose one answer.
a. Place these cells in a culture with antigen fragments.
b. Place these cells in a culture with T cells.
c. Inject these cells into mice, and observe the resulting level of infection.
d. Place these cells in a culture with antibodies tailored to specific antigens.
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Question 47

Interferon-gamma would increase the response to what type of infection?

Choose one answer.
a. Viral
b. Vesicular parasite
c. Vesicular bacteria
d. All of these answers
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Question 48
Fever is caused by which of the following cytokines?
Choose one answer.
a. IL-1 and IL-6
b. TNFa
c. IL-8 and IL-12
d. Both A and B
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Question 49
Which of the following is used to present self-antigen as a way to monitor proteins produced inside host cells?
Choose one answer.
a. MHC I
b. MHC II
c. Antibodies
d. T cell receptors
.
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Question 50

A researcher finds that some of her mice lack appropriate B cell function; they seem unresponsive to antigens that should stimulate B cells. She discovers that although these mice produce healthy B cells and normal-looking receptors, those receptors are only present within B cells rather than on the B-cell surface. The researcher concludes that these cells are lacking which of the following?

Choose one answer.
a. CD3 complex
b. ζ (zeta) chains
c. Igα and Igβ
d. BCR-3
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Question 51

ZAP-70 phosphorylates LAT and SLP-76; SLP-76 then activates Tec kinases. This signaling cascade occurs in what type of cells?

Choose one answer.
a. B cells
b. T cells
c. Both B and T cells
d. None of these answers
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Question 52

What would be the most direct way to prevent the activation of the transcription factor NFAT?

Choose one answer.
a. Inhibit calcineurin.
b. Inhibit Src-family kinases.
c. Increase the expression of Csk.
d. Inhibit ITAMs.
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Question 53

Complete the following sentence. Antagonist peptides are thought to:

Choose one answer.
a. activate the T-cell receptor.
b. alter the phosphorylation of ζ chains.
c. increase the persistence of some viral infections.
d. increase the responsiveness of T cells to MHC:antigen complexes.
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Question 54

Apoptosis is induced by which of the following signaling pathways?

Choose one answer.
a. NF-κB (Nuclear Factor κB)
b. GPCR (G Protein Coupled Receptor)
c. JAKs (Janus Kinases)
d. TNF (Tumor Necrosis Factor) Family
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Question 55

If you wanted to stop B-cell development in vitro, you would do which of the following?

Choose one answer.
a. Block STAT signaling.
b. Introduce an antibody against IL-7.
c. Introduce bone-marrow stromal cells.
d. All of these answers
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Question 56

Which of the following statements about double-positive thymocytes (T cells) is false?

Choose one answer.
a. The vast majority of them die.
b. They are capable of recognizing a larger repertoire of antigens than single-positive thymocytes.
c. They can be either negatively or positively selected.
d. If they are positively selected, they will not always remain double-positive.
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Question 57

Mouse One has a defect that prevents T lymphocytes from maturing. Mouse Two has a defect that prevents complete thymus development. Neither mouse has mature T cells. What is one way to induce the development of mature T cells in Mouse One?

Choose one answer.
a. Introduce bone-marrow stem cells from Mouse Two into Mouse One.
b. Inject antibodies against defective T cells into Mouse One.
c. Graft thymus from Mouse Two into Mouse One.
d. Inject an antibody against CD4 into Mouse One.
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Question 58

One immature T cell has a weak affinity for the self MHC:self peptide complex, and one has a strong affinity for the complex. The one with weak affinity is positively selected; the one with strong affinity is induced to undergo apoptosis. What is the adaptive immune system trying to avoid?

Choose one answer.
a. Strong reactions against pathogens
b. An autoimmune disease
c. Allergies
d. All of these answers
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Question 59

Why is negative selection of T cells important?

Choose one answer.
a. It ensures that only T cells that respond to MHC signaling mature.
b. It prevents the later activation of immune cells against self peptides.
c. It prevents cells whose receptors respond to MHC I from expressing CD4.
d. It prevents cells whose receptors respond to MHC II from expressing CD8.
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Question 60
Complete the following sentence. Cytokines binding to their receptors change the actions of the receiving cells by:
Choose one answer.
a. changing the out-put of the endoplasmic reticulum.
b. changing the proteasome's location in the cell.
c. changing the gene expression profile of the cell.
d. changing the antigen receptor position on the surface of the cell.
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Question 61
You are fighting off a viral infection. Which of the following interactions will be used to successfully remove this invading virus?
Choose one answer.
a. CD4 T cell interactions with MHC I
b. CD8 T cell interactions with MHC II
c. CD4 T cell interactions with MHC II
d. CD8 T cell interactions with MHC I
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Question 62
You are fighting off an infection caused by extracellular bacteria, Escherichia Coli. Which of the following interactions will be used to successfully remove this invading pathogen?
Choose one answer.
a. CD4 T cell interactions with MHC I
b. CD8 T cell interactions with MHC II
c. CD4 T cell interactions with MHC II
d. CD8 T cell interactions with MHC I
.
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Question 63

A pathogen enters your blood. Assuming that your innate immune system is unable to eliminate it, where would your T cells be presented with this pathogen?

Choose one answer.
a. At the site of infection
b. In Peyer’s patches
c. In the thymus
d. In the spleen
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Question 64

A sample of an individual’s immune-system cells shows normal levels of all cell types except dendritic cells: these are present in very low numbers. Which of the following best describes the effect, if any, that this will have on the individual’s adaptive immune response?

Choose one answer.
a. This will not have an effect; dendritic cells are involved in the innate immune response.
b. This will have a large negative effect; dendritic cells are essential in activating B cells.
c. This will have a large negative effect; dendritic cells are the strongest initiators of T cell activation.
d. This will barely have an effect; dendritic cells are not particularly strong signalers within the immune system.
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Question 65

Which type of T cells needs to remain adhered to target macrophage cells for longer, and why?

Choose one answer.
a. TH1 cells, because it can take hours to manufacture the molecules necessary to induce responses in their targets
b. CD8 T cells, because it can take hours to induce apoptosis
c. TH1 cells, because their target cells only slowly express ligand for their receptors
d. CD8 T cells, because they do not produce sensitizing ligands as CD4 cells do
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Question 66

An individual who has Hyper-IgM syndrome (whose symptoms include an excess of IgM in the plasma and little or no IgG in the plasma) probably has which of the following?

Choose one answer.
a. A mutation in his or her CD8 gene
b. A mutation in his or her gene for the CD40 ligand
c. A mutation in his or her gene for IgE
d. None of these answers
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Question 67

The inhabitants of an isolated island experience an epidemic of a virus. All individuals are infected, and once they recover, the virus is absent for many years. Later, a visitor reintroduces the virus to the island. Only those individuals born after the initial outbreak are infected. What does this tell you about immunological memory?

Choose one answer.
a. It requires repeated exposures to the pathogen to be maintained.
b. It is heritable.
c. It requires a single exposure in order to persist.
d. Both B and C
.
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Question 68

In order to prevent Rh-negative pregnant mothers from having an immunological reaction against their Rh-positive child’s red blood cells, these women are injected with anti-Rh antibodies before they react. Why does this treatment reduce the mothers’ responses to their children’s blood?

Choose one answer.
a. These antibodies remove the majority of Rh-positive red-blood cells before the mothers’ immune cells can recognize them and mount a response.
b. These antibodies act on the mothers’ own B cells and suppress their function.
c. These antibodies bind to B-cell receptors and block the sites that would allow them to recognize Rh-positive blood cells.
d. These antibodies trigger the release of cytokines that block somatic hypermutation.
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Question 69

Why is there no problem with the pregnancy of an Rh-negative mother carrying an Rh-positive child if the mother had never been exposed to Rh previously, when a second pregnancy with another Rh-positive child leads to a miscarriage?

Choose one answer.
a. The Rh-positive blood of the child during the first pregnancy does not enter the mother's blood stream.
b. By the time the mother produces anti-Rh antibodies during the first pregnancy, the womb of the mother is protecting the child.
c. During the second pregnancy, the mother has an allergic reaction against the child.
d. The risk of a miscarriage is the same for the first and second child.
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Question 70

Complete the following sentence. An immune cell that expresses an altered CD45 isoform is a:

Choose one answer.
a. memory CD8 T cell.
b. memory CD4 T cell.
c. memory B cell.
d. naïve B cell.
.
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Question 71

Complete the following sentence. An immune cell that expresses IgG, IgA, or IgE, rather than IgM, on its surface is most likely a:

Choose one answer.
a. memory CD8 T cell.
b. memory CD4 T cell.
c. memory B cell.
d. naïve B cell.
.
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Question 72

Complete the following sentence. The cells responsible for killing virally infected cells and the reason why we are only infected with the chicken pox once are:

Choose one answer.
a. memory CD8 T cells.
b. memory CD4 T cells.
c. memory B cells.
d. naïve B cells.
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Question 73
Which of the following statements about B cell immunological memory is false?
Choose one answer.
a. Affinity maturation occurs for a more specific secondary response.
b. Clonal expansion occurs for a stronger secondary response.
c. Memory B cell clones have an increased sensitivity to the antigen.
d. None of these answers
.
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Question 74
Which of the following statements about T cell immunological memory is false?
Choose one answer.
a. Affinity maturation occurs for a more specific secondary response.
b. Clonal expansion occurs for a stronger secondary response.
c. Memory T cell clones have an increased sensitivity to the antigen.
d. None of these answers
.
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Question 75
Why wouldn't macrophages be kept perpetually activated?
Choose one answer.
a. Activated macrophages cause damage to host tissue.
b. Keeping macrophages active consumes a huge amount of energy.
c. Macrophages are kept perpetually activated.
d. Both A and B
.
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Question 76

Identify the type of host evasion by a pathogen that is described here: an influenza (flu) virus has its RNA genome rearranged and combined with another flu type in a non-human animal species. This rearranged virus now re-infects humans.

Choose one answer.
a. Serotype variety
b. Antigenic drift
c. Antigenic shift
d. Latency
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Question 77

Identify the type of host evasion by a pathogen that is described here: a herpes simplex virus remains present at a low level, in a quiescent state, in neurons, until a stressor triggers the virus to re-infect epithelial cells.

Choose one answer.
a. Serotype variety
b. Antigenic drift
c. Antigenic shift
d. Latency
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Question 78
The risk of infection by Neisseria meningitides bacteria in a normal population is one in two million. The risk of infection by this bacterium in a particular sub-population is one in two hundred. The members of this sub-population have a deficiency in which of the following immune-system components?
Choose one answer.
a. C5-C9
b. CD59
c. CD40
d. B cells
.
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Question 79

Some individuals are resistant to infection by HIV. A mutation in what gene appears to be responsible for this resistance?

Choose one answer.
a. gp120
b. gp41
c. CCR5
d. CXCR4
.
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Question 80

A small group of people who are resistant to infection by HIV appear to have this resistance because they are homozygous for a non-functional variant of a specific immune-system protein. How does this prevent HIV from infecting them?

Choose one answer.
a. It prevents the induction of apoptosis in CD4 T cells.
b. It prevents glycoproteins on the viral envelope from binding and entering CD4 T cells.
c. It induces CD4 T cell activation, which helps to maintain a low viral load.
d. It prevents host proteases from cleaving viral proteins that are required to form the viral envelope.
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Question 81

Which of the following immune responses is involved in reducing viral numbers during HIV infection?

Choose one answer.
a. Seroconversion
b. Actions by CD8 and TH1 cells
c. Actions by dendritic cells and macrophages
d. Both A and B
.
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Question 82

Why can't HIV be cleared by anti-viral drugs?

Choose one answer.
a. HIV never stops accumulating mutations.
b. The HIV viral genome integrates into the T cell genome it infected.
c. HIV infects activated CD4 T cells.
d. All of these answers
.
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Question 83

Complete the following sentence. A friend of yours smells a flower and immediately starts sneezing. In order to annoy him, you immediately diagnose him with the correct immunological term for his condition, which is:

Choose one answer.
a. allergic asthma.
b. allergic rhinitis.
c. allergic conjunctivitis.
d. anaphylaxis.
.
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Question 84

The IgE-triggered inflammatory response to allergens can cause everything from minor tissue damage and annoyance to life-threatening symptoms. So why does this pathway exist?

Choose one answer.
a. Some allergens that are currently harmless were dangerous in our evolutionary history.
b. It is speculated that IgE is a faulty antibody that has survived only because it outcompetes other antibodies in its affinity for mast cells.
c. This pathway is very useful against infections by parasites like flatworms (helminths) and ticks.
d. When triggered by non-allergy antigens, this pathway is the first step in the activation of memory B cells.
.
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Question 85

An individual who had a heart attack was treated with an injection of streptokinase, a bacterial enzyme. Seven days after the injection, the patient began suffering chills, fever, and a rash, as the antibody response within her body formed immune complexes. What is the name of this disease, and what type of disease is it?

Choose one answer.
a. The Arthus reaction, type III hypersensitivity
b. Hemolytic anemia, type II hypersensitivity
c. Serum sickness, type III hypersensitivity
d. Allergic conjunctivitis, type I hypersensitivity
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Question 86

What are the major genes involved in autoimmune diseases?

Choose one answer.
a. HLA genes (genes for the human MHC complex)
b. Genes for the CD40 ligand
c. Genes for the IgE-mediated immune response
d. IDDM genes
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Question 87

Why have whole-organ transplantations become more and more successful over the recent years?

Choose one answer.
a. Doctors have become more adept at perfectly matching HLA types.
b. Doctors have become more adept at perfectly matching minor H antigens.
c. Doctors have made major advancements in immunosuppressive therapies.
d. Doctors have made major advancements in matching MHC class II types.
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Question 88
Which of the following statements about inherited immunodeficiencies is false?
Choose one answer.
a. Low levels of antibody production leads to a decreased ability to clear extracellular bacteria and viruses.
b. A deficiency in T-cell immunity is called SCID, resulting in deficiencies in T-cell memory with retained ability to form B-cell memory.
c. Intracellular bacteria infections persist in patients with mutations in IL-12, IL-12 receptor, or IFNa receptors.
d. Both B and C
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Question 89

Which of the following immunosuppressants would you use if a patient exhibited dangerously high levels of inflammation?

Choose one answer.
a. Azathioprine
b. Prednisone
c. Cyclosporin A or FK506
d. Rapamycin
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Question 90

Fill in the blank. The immunosuppressant cyclophosphamide is part of a family of compounds that were originally developed for warfare; mustard gas, which was used in World War I and had devastating effects, is an example. Although it is less toxic, ____________ is another drug that is cytotoxic and must be administered in low doses or in tandem with other drugs.

Choose one answer.
a. Azathioprine
b. Prednisone
c. Cyclosporin A or FK506
d. Rapamycin
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Question 91

A major type of cancer therapy currently in development involves the use of tumor vaccines. What do these vaccines consist of?

Choose one answer.
a. Monoclonal antibodies that bind to cell-surface tumor antigens
b. Adjuvants along with tumor antigens that have been shown to stimulate a cytotoxic T-cell response
c. Bacterial enzymes that stimulate heightened T-cell proliferation
d. Tumor-specific T cells that have been developed in horses or mice
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Question 92

Which of the following statements is true of herd immunity?

Choose one answer.
a. It refers to the program through which livestock are immunized.
b. It refers to a population in which all members have either been immunized or have natural immunity to a pathogen.
c. It refers to the fact that when a large enough proportion of individuals is immunized, the likelihood of infection to anyone is greatly reduced.
d. It refers to the protection conferred on an immunized individual when in a large group of unvaccinated individuals.
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Question 93

The use of specific epitopes in protein-based vaccines is a current area of study. What is one problem with this approach?

Choose one answer.
a. Epitopes have a strong likelihood of reverting to wild type and becoming highly infectious.
b. Specific epitopes are presented by very specific MCH molecules, and humans vary widely in their MHC complex.
c. Epitope vaccines cannot be given via injection.
d. There are no current problems with this approach; it merely requires more time and money to be made practical.
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Question 94

Which of the following statements regarding oral vaccines is false?

Choose one answer.
a. They are likely to have more practical support, because they are less painful than injections.
b. They mimic the route through which most pathogens naturally enter the body.
c. There is some danger in that they can damage pathogen structure if they are partially digested.
d. They have been shown to be a less-effective means of stimulating immune responses.
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Question 95

Complete the following sentence. Current vaccines for viruses are generally:

Choose one answer.
a. epitope-based protein vaccines.
b. live-attenuated vaccines.
c. vaccines based on killed organisms.
d. DNA vaccinations.
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Question 96

Which of the following statements regarding vaccines using live-attenuated viruses is true?

Choose one answer.
a. They are more effective but also relatively more dangerous.
b. They are less effective but also relatively safer.
c. They are more effective and relatively safer.
d. It is too early to know whether they will be successful.
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Question 97

Which of the following statements about therapeutic vaccinations is true?

Choose one answer.
a. The goal is to change the pattern of the immune response.
b. The goal is to supercharge the immune system with the pathogen's antigens and adjuvant.
c. The goal is to change the isotype of the Ig response.
d. Both A and B
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Question 98

You have developed a vaccine using a bacterial toxoid. You know that this toxoid is involved in immune recognition during bacterial infections, but your vaccine does not stimulate a sufficient immune response. What might you do to improve this?

Choose one answer.
a. Add adjuvants to the vaccine
b. Use the attenuated bacterium of a different pathogen as a vector for the toxoid
c. Use DNA vaccination
d. A and B
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Question 99
How do pathogens evade the immune system?
Choose one answer.
a. Antigen variation
b. Temporary halting of replication
c. Targeted inhibition of parts of the immune system
d. All of these answers
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Question 100
The majority of the antibodies produced during the secondary response are of which isotype?
Choose one answer.
a. IgA and IgM isotypes
b. IgG isotype
c. IgM isotype
d. IgA, IgE, or IgG isotype
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Question 101
Which of the following descriptions of Toll-like receptors (TLRs) is false?
Choose one answer.
a. TLRs are present on antigen-presenting cells.
b. Every TLR is unique; there is one TLR per pathogen.
c. TLRs are one of the initial triggers of the immune system.
d. TLRs trigger the upregulation of co-receptors.
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