Chapter 13 Flashcards by narud anaid

____ results when a gene affecting the immune system mutates, thereby compromising the immune defense against infection.

a. gene conversion
b. epidemics
c. primary immunodeficiency disease
d. secondary immunodeficiency disease
e. seroconversion

c. primary immunodeficiency disease

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A primary immune response against influenza virus produces antibodies that bind to _____.

a. hemagglutinin and neuraminidase
b. variable surface glycoproteins
c. EBNA-1
d. protein toxins
e. gp41 and gp120

a. hemagglutinin and neuraminidase

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The serotypes of Streptococcus pneumoniae differ in their _____.

a. superantigen products
b. ability to fix complement
c. rates of gene conversion
d. capsular polysaccharides
e. variable surface glycoproteins

d. capsular polysaccharides

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All of the following are associated with the ability of influenza virus to escape from immunity except _____.

a. age
b. error-prone replication of its DNA genome
c. co-infection with avian and human influenza viruses
d. recombinant strains
e. the phenomenon of Ôoriginal antigenic sinÕ

b. error-prone replication of its DNA genome

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All of the following use gene conversion to avoid immune detection except _____.

a. Salmonella typhimurium
b. Trypanosome brucei
c. Treponema pallidum
d. Neisseria gonorrhoeae
e. None of the above

c. Treponema pallidum

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Genes encoding _____ rearrange in trypanosomes permitting replication and survival of the pathogen until the host produces an antibody response against the altered gene product.

a. pilin
b. flagellin
c. variable surface glycoproteins (VSGs)
d. hemagglutinin
e. neuraminidase

c. variable surface glycoproteins (VSGs)

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_____ is a strategy used by herpesviruses where replication and the generation of virus-derived peptides are avoided in order to hide from the immune response.

a. latency
b. antigenic shift
c. antigenic drift
d. seroconversion
e. gene conversion

a. latency

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Which of the following statements regarding herpes simplex virus is false?

a. Because sensory neurons express low levels of MHC class I molecules, they provide appropriate sites for viral dormancy.
b. Reactivation of herpesviruses follows stressful incidents.
c. Cold sores develop as a consequence of CD8 T-cell killing.
d. In a person lifetime, periodic episodes of reactivation are common.
e. Herpes simplex virus infects B lymphocytes.

e. Herpes simplex virus infects B lymphocytes.

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Which of the following is not associated with the reactivation of herpesviruses?

a. hormonal fluctuations
b. antibody deficiency
c. bacterial infection
d. immunosuppression
e. ultraviolet radiation

b. antibody deficiency

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Herpesviruses include all of the following except _____.

a. varicella-zoster
b. Epstein-Barr virus
c. herpes simplex virus
d. cytomegalovirus
e. All of the above are herpesviruses

e. All of the above are herpesviruses

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Shingles is associated with infection by _____.

a. Epstein-Barr virus
b. Staphylococcus aureus
c. herpes zoster
d. Candida albicans
e. Listeria monocytogenes

c. herpes zoster

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Superantigens bind to all of the following molecules except _____.

a. CD4
b. MHC class II alpha chain
c. CD28
d. T-cell receptor Vbeta chain
e. B-cell receptor

d. T-cell receptor Vbeta chain

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All of the following are associated with superantigens except _____.

a. effective at minuscule concentrations
b. nonspecific activation of 2-20% of CD8 T cells
c. processing to peptides is not required for T-cell activation
d. massive production of IL-2, IFN-gamma, and TNF-alpha
e. activate alpha:beta T cells

b. nonspecific activation of 2-20% of CD8 T cells

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Staphylococcal superantigen-like protein 7 (SSLP7) produced by Staphylococcus aureus, binds to _____ and thereby prevents the killing of the bacterium by the host immune system during infection.

a. NK-cell activating receptors
b. C5 complement protein and Fc region of IgA
c. B-cell receptor
d. CD8 co-receptor
e. T-cell receptor Vbeta chain

b. C5 complement protein and Fc region of IgA

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Which of the following is not associated with bacterial infection due to a genetic defect in or pathogen-induced subversion of normal phagocytic processes?

a. leukocyte adhesion deficiency
b. chronic granulomatous disease
c. hereditary angioedema
d. Chediak-Higashi syndrome
e. Listeria monocytogenes

c. hereditary angioedema

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Which of these characteristics is not true of IFN-gamma?

a. When it acts on target cells, it enhances the engulfment and killing of bacteria.
b. It is the major activating cytokine of macrophages.
c. It activates the JAK-STAT signal transduction pathway after binding to its cognate receptor.
d. It is secreted by CD8 cytotoxic T cells, CD4 Th1 cells, and NK cells.
e. It is secreted and functions as a monomer but facilitates the dimerization of its receptor.

e. It is secreted and functions as a monomer but facilitates the dimerization of its receptor.

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Dominant mutant forms of IFNgammaR1 exhibit all of the following in heterozygotes except _____.

a. they are recycled by endocytosis more quickly than the normal receptor
b. the cytoplasmic tail is truncated
c. they are able to form stable dimers with the normal form
d. they cause less severe immunodeficiency than do the homozygous recessive forms
e. they are unable to transduce signals when bound to the normal form

a. they are recycled by endocytosis more quickly than the normal receptor

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Individuals with an antibody deficiency are more susceptible to infections by all of the following except _____.

a. Streptococcus pneumoniae
b. Haemophilus influenzae
c. Streptococcus progenies
d. Mycobacterium tuberculosis
e. Staphylococcus aureus

d. Mycobacterium tuberculosis

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All of the following are X-linked immunodeficiencies except _____.

a. WiskottÐAldrich syndrome caused by deficiency of WASP
b. hyper IgM syndrome caused by deficiency of CD40 ligand
c. lymphoproliferative syndrome caused by deficiency of SH2D1A
d. Chediak-Higashi syndrome caused by deficiency of CHS1
e. agammaglobulinemia caused by deficiency of Bruton tyrosine kinase

d. Chediak-Higashi syndrome caused by deficiency of CHS1

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Paroxysmal nocturnal hemoglobinuria is caused by _____.

a. a profound deficiency of neutrophils
b. leukocytosis
c. immune-complex deposition in tissues
d. defects in recruitment of phagocytes to infected tissues
e. complement-mediated lysis of erythrocytes

e. complement-mediated lysis of erythrocytes

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All of the following are associated with hereditary angioedema except _____.

a. possible death by suffocation
b. overproduction of vasoactive C2a fragment and peptide bradykinin
c. hyporesponsiveness of classical complement pathway
d. subepithelial edema
e. C1 inhibitor deficiency

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c. hyporesponsiveness of classical complement pathway

Severe combined immune deficiency (SCID) describes a condition in which neither _____ nor _____ are functional.

a. classical; alternative pathways of complement
b. T-cell-dependent antibody responses; cell-mediated immune responses
c. innate; acquired immune responses
d. MHC class I; MHC class II molecules

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b. T-cell-dependent antibody responses; cell-mediated immune responses

Mutations affecting all of the following except _____ interfere directly with the rearrangement of immunoglobulin and T-cell receptor genes.

a. Artemis
b. purine nucleoside phosphorylase (PNP)
c. DNA-dependent protein kinase (DNA-PK)
d. RAG-1
e. RAG-2

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b. purine nucleoside phosphorylase (PNP)

A deficiency in _____ causes a condition that closely resembles X-linked severe combined immunodeficiency and is characterized by inefficient cytokine signalling.

a. adenosine deaminase (ADA)
b. class II transactivator (CIITA)
c. TAP1 or TAP2
d. RAG1 or RAG2
e. Janus 3 kinase (Jak3)

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e. Janus 3 kinase (Jak3)

80. Patients who lack _____ are very susceptible to infections with intracellular bacteria, including the ubiquitous nontuberculous strains of mycobacteria. a. CD40 ligand b. IL-12 and IFN-gamma receptors c. properdin (factor P) d. CD18 e. IL-1 receptor

b. IL-12 and IFN-gamma receptors

81. Which of the following explains why Streptococcus pneumoniae can infect an individual recurrently? a. Previous infection with S. pneumoniae wears down the immune system over time. b. S.Êpneumoniae is never completely eradicated during an infection and can reactivate if the host is immunocompromised. c. Immune responses against S. pneumoniae are serotype-specific and protect only against strains that possess the same capsular polysaccharide antigens. d. Anti-capsular antibodies are cleared from the host quickly after an active infection. e. The capsular polysaccharide antigens of S. pneumoniae do not induce immunological memory.

c. Immune responses against S. pneumoniae are serotype-specific and protect only against strains that possess the same capsular polysaccharide antigens.

82. Protective antibodies generated in response to influenza virus bind to _____ of the viral envelope. a. hemagglutinin and neuraminidase b. polysaccharides c. variable surface glycoproteins d. superantigens e. gp41 and gp120

a. hemagglutinin and neuraminidase

83. All of the following contribute to new epidemics and the long-term survival of the influenza virus in the human population, except: a. New viral strains possess epitopes not recognized by antibodies made in the previous epidemic. b. The first influenza strain provoking a primary immune response constrains the types of antibodies made during a subsequent encounter with a different strain. c. The virus loses the capacity to express hemagglutinin, thereby rendering neutralizing antibodies useless. d. The RNA genome of the influenza virus is subject to point mutations during viral replication. e. None of the above.

c. The virus loses the capacity to express hemagglutinin, thereby rendering neutralizing antibodies useless.

84. An epidemic affects _____, whereas a pandemic affects _____. a. susceptible individuals; immune individuals b. immune individuals; susceptible individuals c. global populations; local populations d. local populations; global populations

d. local populations; global populations

85. _____ cause(s) mild and limited disease, whereas _____ cause(s) more severe disease and higher mortality. a. Antigenic drift; antigenic shift b. Antigenic shift; antigenic drift c. Epidemics; pandemics d. Pandemics; epidemics

a. Antigenic drift; antigenic shift

86. Which of the following is not a virus that can cause a persistent infection in the host by establishing latency? a. influenza virus b. herpes simplex virus c. varicella-zoster d. Epstein-Barr virus e. human immunodeficiency virus

a. influenza virus

87. Trypanosomes escape from adaptive immunity by altering the type of _____ expressed on the parasite surface. a. neuraminidase b. hemagglutinin c. variable surface glycoprotein (VSG) d. superantigen e. capsular polysaccharide

c. variable surface glycoprotein (VSG)

88. Epstein-Barr virus infects and establishes latency in _____, gaining entry by binding to _____. a. B cells; CR2 b. T cells; CD4 c. T cells; CD8 d. neurons; MHC class I e. B cells; EBNA-1

a. B cells; CR2

89. Which of the following is not used by the herpes simplex virus to subvert host immune responses? a. a virus-encoded Fc receptor b. a virus-encoded complement receptor c. inhibition of MHC class I expression d. inhibition of peptide transport by transporter associated with antigen processing (TAP) e. inhibition of ICAM-1 expression

e. inhibition of ICAM-1 expression

90. Listeria monocytogenes replicates in _____ of macrophages after _____. a. the phagosome; inhibition of fusion of the phagosome with the lysosome b. the cytosol; escaping from the phagosome c. a specialized membrane-bound vesicle; infection of the cell d. extracellular spaces; coating itself with human proteins e. nucleus; fusion with the nuclear membrane

b. the cytosol; escaping from the phagosome

91. Which of the following is not a characteristic of staphylococcal enterotoxins? a. They bind to MHC class I molecules and T-cell receptors. b. They cause T cells to divide and differentiate into effector T cells. c. They stimulate between 2% and 20% of the total T-cell population. d. They cause excessive synthesis and release of cytokines. e. They induce suppression of the immune response by causing T cells to undergo apoptosis.

a. They bind to MHC class I molecules and T-cell receptors.

92. Which of the following statements regarding inherited immunodeficiency diseases is correct? a. Affected individuals are less susceptible to infection. b. Mortality rates are reduced by the administration of antibiotics to affected individuals. c. Most deficiency syndromes are caused by dominant gene defects. d. Women are more likely than men to inherit X-linked immunodeficiencies. e. Extracellular bacterial infections are common in deficiency syndromes with T-cell defects.

b. Mortality rates are reduced by the administration of antibiotics to affected individuals.

93. Individuals with an immunodeficiency affecting B-cell function are more susceptible to infections caused by which of the following pathogens? a. Toxoplasma gondii b. respiratory syncytial virus c. Haemophilus influenzae d. Listeria monocytogenes e. Mycobacterium tuberculosis

c. Haemophilus influenzae

94. Which of the following deficiency syndromes affects T-cell but not B-cell function? a. X-linked agammaglobulinemia b. X-linked hyper IgM syndrome c. X-linked lymphoproliferative syndrome d. X-linked SCID e. X-linked Wiskott-Aldrich syndrome

e. X-linked Wiskott-Aldrich syndrome

95. Chronic granulomatous disease (CGD), a condition resulting in chronic bacterial and fungal infections, is caused by one or more defects in _____, compromising the ability of macrophages to _____. a. CD18; produce cell adhesion molecules b. NADPH oxidase; produce superoxide radical c. CD40 ligand; produce GM-CSF d. C5-C9; defend against Neisseria e. C3; opsonize capsulated bacteria

b. NADPH oxidase; produce superoxide radical

96. A genetic defect in _____ results in the accumulation of toxic levels of nucleotide metabolites and loss of T-cell function. a. NADPH oxidase b. glucose-6-phosphate dehydrogenase c. myeloperoxidase d. SH2D1A e. adenosine deaminase (ADA)

e. adenosine deaminase (ADA)

97. Herpes simplex virus favours neurons for latency because of the low level of _____, which reduces the likelihood of killing by CD8 T cells. a. LFA-3 b. Toll-like receptors (TLRs) c. transporter associated with antigen processing (TAP) d. MHC class I e. MHC class II

d. MHC class I

98. Which statement regarding retrovirus proviruses is false? a. Proviruses form immediately after the RNA genome assembles with viral proteins and infectious virions are produced. b. Proviruses consist of double-stranded DNA. c. Proviruses are flanked by repetitive sequences called long terminal repeats (LTRs). d. The host cell must provide the transcriptional and translational machinery in order for RNA and protein products to be made from proviruses. e. A cDNA intermediate is required in order to produce a provirus.

a. Proviruses form immediately after the RNA genome assembles with viral proteins and infectious virions are produced.

99. The pol gene of HIV produces all of the following except _____. a. Integrase b. protease c. matrix protein d. reverse transcriptase

c. matrix protein

100. For infectious HIV virions to be made, the infected cell must _____. a. be CD4-positive and express functional NFkB b. express low levels of CCR5 c. be latent d. be polyreactive e. be CD8-positive

a. be CD4-positive and express functional NFkB

101. Which of the following is required for fusion of the human immunodeficiency viral envelope with the host cell membrane and subsequent internalization? a. reverse transcriptase b. p120 c. gp41 d. integrase e. protease

c. gp41

102. During infection with HIV, a person is said to undergo seroconversion when _____. a. HIV variants convert from macrophage-tropic to lymphocyte-tropic late in infection b. anti-HIV antibodies are detectable in their blood serum c. cellular transcription favors the production of HIV-encoded RNA d. HIV is transferred from an infected person to an uninfected recipient e. the initial phase of infection is followed by clinical latency

e. the initial phase of infection is followed by clinical latency

103. A patient is diagnosed with AIDS when CD4 T-cell counts _____. a. rise markedly after T-cell activation b. fall below the CD8 T-cell count c. fall below 1000 cells/ul d. fall below 500 cells/ul e. fall below 200 cells/ul

e. fall below 200 cells/ul

104. Reverse transcriptase is a _____ encoded by _____. a. DNA-dependent DNA polymerase; HIV b. DNA-dependent DNA polymerase; influenza virus c. RNA-dependent DNA polymerase; HIV d. RNA-dependent DNA polymerase; influenza virus e. RNA-dependent RNA polymerase; HIV

c. RNA-dependent DNA polymerase; HIV

105. Preferred viral targets for HIV therapy include: a. reverse transcriptase and protease b. matrix protein c. gp120 d. CD4 e. polymerase

a. reverse transcriptase and protease

Chapter 13 Flashcards

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