Exam 2 (Book Questions) (Chapters 6-13)

Question 1

Epitope-specific receptors of T lymphocytes are found

A) as either cytosolic or membrane-bound proteins.

B) in blood plasma, lymph, & other secretory fluids.

C) on the surface of plasma cells.

D) as transmembrane polypeptides.

E) in the nuclear lipid bilayer.

Answer 1

D) as transmembrane polypeptides.

Question 2

Antibodies (immunoglobulins)

A) are synthesized & secreted by both B & T cells.

B) bind to several different epitopes simultaneously.

C) contain 4 different light chain polypeptides.

D) recognize specific epitopes together with self molecules.

E) tag antigens for destruction.

Answer 2

E) tag antigens for destruction.

Question 3

The constant regions of the 5 major types of heavy chains of immunoglobulin molecules dictate the molecule’s

A) epitope.

B) Fab fragment.

C) isotype.

D) tyrosine activation motif.

E) variable domain.

Answer 3

C) isotype.

Question 4

When an immunoglobulin molecule is subjected to cleavage by pepsin, the product(s)

A) are individual heavy & light chains.

B) can no longer bind to antigen.

C) consist of 2 separated antigen-binding fragments.

D) crystallize during storage in the cold.

E) is a dimeric antigen-binding molecule.

Answer 4

E) is a dimeric antigen-binding molecule.

Question 5

In an individual with an immediate hypersensitivity response (allergy) to dust mites, cross-linking of which of the following dust-mite-specific molecules will trigger inflammatory mediator release?

A) Histamine

B) IgA

C) IgE

D) IgG

E) Mast Cells

Answer 5

C) IgE

Question 6

The classical pathway of complement begins with

A) activation of C1.

B) cleavage & activation of C4, C2, & C3.

C) IgA binding to a specific epitope.

D) initiation of membrane attack complex formation.

E) production of C3 convertase.

Answer 6

A) activation of C1.

Question 7

The classical pathway of complement functions to

A) cleave immunoglobulins into Fc fragments.

B) facilitate destruction of microbes.

C) recognize specific epitopes on microbes.

D) regulate lymphocyte development.

E) trigger histamine release.

Answer 7

B) facilitate destruction of microbes.

Question 8

In humans, MHC class II molecules are expressed by

A) all nucleated cells.

B) B cells, dendritic cells, & macrophages.

C) erythrocytes.

D) mast cells.

E) naïve T cells.

Answer 8

B) B cells, dendritic cells, & macrophages.

Question 9

The basic structure of a T cell receptor consists of

A) a membrane-bound alpha-beta or gamma-delta heterodimer.

B) a complex of disulfide-linked heavy & light chains.

C) covalently linked CD3 & CD47 molecules.

D) peptide-MHC complexes.

E) soluble antigen-binding homodimers.

Answer 9

A) a membrane-bound alpha-beta or gamma-delta heterodimer.

Question 10

Migration of a B lymphocyte to specific sites (such as a lymph node) is dependent in part on the use of

A) antibodies.

B) CD8.

C) CD3.

D) complement.

E) selectins.

Answer 10

E) selectins.

Question 11

Which of the following molecules is expressed by a mature T cell that functions as a helper T cell?

A) CD4

B) CD8

C) GlyCAM-1

D) IgA

E) IgG

Answer 11

A) CD4

Question 12

Following cytokine binding to a specific cell-surface receptor, a lymphocyte is stimulated to undergo signaling via the JAK-STAT pathway. In this pathway, which of the following will be induced to translocate to the cell’s nucleus to regulate trancription?

A) JAK

B) Ras

C) SH2-containing adapter proteins

D) STAT dimers

E) tyrosine kinase

Answer 12

D) STAT dimers

Question 13

T-cell receptors, when coexpressed with CD8 molecules, are restricted to recognizing & binding peptide fragments associated with

A) CD3 molecules.

B) CD4 molecules.

C) MHC class I molecules.

D) MHC class II molecules.

E) MHC class III molecules.

Answer 13

C) MHC class I molecules.

Question 14

B lymphocytes synthesize & express immunoglobulin

A) containing multiple epitope specifications.

B) in cytoplasmic phagosomes.

C) in membrane complexes also containing CD3.

D) on their cell membrane surface.

E) only after leaving the bone marrow.

Answer 14

D) on their cell membrane surface.

Question 15

The primary lymphoid organs are those in which

A) adaptive immune responses are usually initiated.

B) filtration devices remove foreign matter.

C) large numbers of circulating leukocytes make contact with one another.

D) lymphocytes undergo their initial differentiation.

E) pattern recognition receptors bind antigens.

Answer 15

D) lymphocytes undergo their initial differentiation.

Question 16

The thymus is the site on initial differentiation for

A) B cells.

B) RBCs.

C) hematopoietic stem cells.

D) NK cells.

E) T cells.

Answer 16

E) T cells.

Question 17

Lymph nodes have 2 main regions: the

A) cortex & medulla.

B) lymph & cortex.

C) reticulum & cortex.

D) lymph & medulla.

E) reticulum & medulla.

Answer 17

A) cortex & medulla.

Question 18

Which of the following molecules is expressed on the surface of mature CD4+ cells?

A) B-cell receptors

B) CD1d

C) CD3

D) CD8

E) CD19

Answer 18

C) CD3

Question 19

Positive selection refers to

A) the ability of sngle positive cells to bind both MHC class I & II.

B) cortical thymocytes’ acquisition of TCR.

C) migration of stem cells to the thymus to become T cells.

D) programmed cell death of single positive T cells.

E) recognition of MHC by CD4+CD8+ thymocytes.

Answer 19

E) recognition of MHC by CD4+CD8+ thymocytes.

Question 20

Which of the following is a primary lymphoid organ?

A) Bone Marrow

B) Lymph Node

C) Peyer’s Patch

D) Spleen

E) Tonsil

Answer 20

A) Bone Marrow

Question 21

The white pulp of the spleen is enriched in

A) RBCs carrying hemoglobin.

B) CD4+CD8+ T cells binding to MHC.

C) natural killer cells recognizing targets.

D) plasma cells secreting immunoglobulin.

E) precursor cells developing into mature B cells.

Answer 21

D) plasma cells secreting immunoglobulin.

Question 22

In a patient who later developed an allergy to a certain antigen, the initial response to the antigen consisted of immunoglobulin of the IgM class. However, over time, antigen-specific IgE came to be predominant. This change from an IgM to an IgE response is caused by

A) affinity maturation.

B) allelic exclusion.

C) isotype switching.

D) junctional diversity.

E) somatic hypermutation.

Answer 22

C) isotype switching.

Question 23

A 2-year-old child exposed to an antigen for the first time already possesses a B cell with immunoglobulin specific for that antigen. This finding is best explained by

A) antigen-independent immunolglobulin gene rearrangements.

B) antigen stimulation of T cell cytokine production.

C) maternally derived antibodies to that antigen.

D) memory B cells that recognize the antigen.

E) somatic hypermutation of immunglobulins.

Answer 23

A) antigen-independent immunolglobulin gene rearrangements.

Question 24

Serum immunoglobulins containing both maternally & paternally derived V_kappa light chains are found within an individual. A given B cell, however, expresses only maternally derived or paternally deroved V_kappa chains but never both. This finding is the result of

A) allelic exclusion.

B) antibody diversity.

C) isotype switching.

D) junctional diversity.

E) random VD & VDJ joining.

Answer 24

A) allelic exclusion.

Question 25

The role of terminal deoxynucleotidyl transferase (TdT) in development of antibody diversity is to

A) add/remove nucleotides of V, D, & J genes.

B) fuse VD & J segments together in heavy chains.

C) increase binding affinity of antibody for antigen.

D) join C_L to C_H1, C_H2, C_H3, or C_H4 domains.

E) transfer V_L alleles from maternal to paternal chromosomes.

Answer 25

A) add/remove nucleotides of V, D, & J genes.

Question 26

When a memory B cell is restimulated by its specific antigen, small point mutations that accumulate in the DNA encoding variable regions of both light & heavy chains may result in

A) antigen-stimulating VDJ joining & new antigen specificity.

B) change from production of IgM to IgG.

C) DNA chromosomal rearrangment & altered antigen specificty.

D) inactivation of either the maternal or paternal V_L & V_H allele.

E) generation of antibody with increased binding affinity to its epitope.

Answer 26

E) generation of antibody with increased binding affinity to its epitope.

Question 27

DiGeorge syndrome is an immune deficiency disease resulting from impaired thymic development. Which of the following is/are affected in patients with DiGeorge syndrome?

A) B cell development only

B) complement only

C) NK cell function

D) T cell development only

E) T cell & B cell functions

Answer 27

E) T cell & B cell functions

Question 28

Negative selection of T cells occurs in the

A) blood vessels.

B) bone marrow.

C) lymph node.

D) spleen.

E) thymus.

Answer 28

E) thymus.

Question 29

T cell precursors, known as prothymocytes, migrate from the bone marrow to the thymus in response to

A) eotactin.

B) IL-4.

C) IL-5.

D) IL-10.

E) lymphotactin.

Answer 29

E) lymphotactin.

Question 30

What will be the fate of an ealry thymocyte that fails to express IL-7 receptors?

A) apoptotic cell death

B) development as a gamma-delta T cell

C) development as a NKT cell

D) failure to traffice to the thymus

E) maturation along the B-cell lineage

Answer 30

A) apoptotic cell death

Question 31

Gamma-delta T cells

A) contain very extensive antigen recognition repertoires.

B) express surface markers that are also characteristic of NK cells.

C) generate memory when recognizing antigen on multiple occasions.

D) migrate preferentially to respiratory organs, skin, & peritoneal cavity.

E) respond more slowly to antigen then do alpha-beta T cells.

Answer 31

D) migrate preferentially to respiratory organs, skin, & peritoneal cavity.

Question 32

NKT cells

A) are usually CD8 single positive cells.

B) bind epitopes presented by MHC class II molecules.

C) express TCRs generated by DNA rearrangement & junctional diversity.

D) recognize carbohydrates & complex proteins.

E) synthesizes immunoglobulin & display it on their cell surfaces.

Answer 32

C) express TCRs generated by DNA rearrangement & junctional diversity.

Question 33

Pre-pro-B cells

A) contain either kappa or lambda light chains.

B) demonstrate surface expression of pseudo-IgM.

C) express Ig-alpha & Ig-beta BCR accessory molecules.

D) have VDJ joining of genes.

E) express surrogate light chains.

Answer 33

C) express Ig-alpha & Ig-beta BCR accessory molecules.

Question 34

In contrast to B-2 cells, B-1 cells

A) appear later in development.

B) function in innate-related immune responses.

C) express more IgD than IgM on their cell surfaces.

D) have a more extensive antigen recognition repertoire.

E) require interaction with T cells for their activation.

Answer 34

B) function in innate-related immune responses.

Question 35

T cells recognize epitopes they have never before encountered by

A) randomly generating enormous numbers of TCRs prior to antigenic encounter.

B) sampling the environment using phagocytosis & pinocytosis.

C) synthesizing immunoglobulins specific for a wide variety of epitopes.

D) selecting widely expressed molecules as TCR ligands.

E) using genomically encoded PRRs.

Answer 35

A) randomly generating enormous numbers of TCRs prior to antigenic encounter.

Question 36

Which of the following naïve cells load peptide fragments into MHC II molecules?

A) CD4+ T cells

B) CD8+ T cells

C) dendritic cells

D) gamma-delta T cells

E) neutrophils

Answer 36

C) dendritic cells

Question 37

Fragments of a cytoplasmic pathogen is presented to T cells by

A) direct engagement of cell surface PRRs.

B) macropinocytosis into gamma-delta T cells.

C) MHC I molecules to CD8+ T cells.

D) phagocytosis & presentation to CD4+ T cells.

E) placement into endocytic vesicles & complexing with MHC II molecules.

Answer 37

C) MHC I molecules to CD8+ T cells.

Question 38

The term immunologic synapse refers to

A) PAMP recognition by PRRs.

B) restriction of CD4+ Tcells to MHC I.

C) selective unresponsiveness of T cells.

D) T cell recognition of soluble molecules.

E) the interface between antigen-presenting cells & T cells.

Answer 38

E) the interface between antigen-presenting cells & T cells.

Question 39

CD4+ T cells that respond to intracellular pathogens by recruiting & activating phagocytic cells are termed

A) antigen-presenting cells.

B) cytotoxic T lymphocytes.

C) Th0 cells.

D) Th1 cells.

E) Th2 cells.

Answer 39

D) Th1 cells.

Question 40

In the presence of microbe-derived lipopolysaccharide,

A) antigen-presenting cells may secrete IL-12.

B) release of cytokines result in leukocyte activation.

C) stimulation of IFM-gamma secretion activates leukocytes.

D) Th0 cells further differentiate into Th1 cells.

E) all of the above

Answer 40

E) all of the above

Question 41

Upon encountering an appropriate pMHC I on an infected cell,

A) B-cell receptors become cross-linked & signaling ensues.

B) CD4+ cells release IL-4.

C) CD8+ cytotoxic T cells destroy he infected cell.

D) naïve Th1 cells secrete cytokines.

E) Th0 cells differentiate into Th2 cells.

Answer 41

C) CD8+ cytotoxic T cells destroy he infected cell

Question 42

Activation of an individual naïve B cell involves binding of membrane-associated epitopes leading to

A) dendritic cell presentation of MHC I.

B) recognition of different epitopes by surface IgD & IgM.

C) signaling from both the B-cell receptor & a CD4+ Th2 cell.

D) ubiquitination & destruction of antigen by proteasomes.

Answer 42

C) signaling from both the B-cell receptor & a CD4+ Th2 cell.

Question 43

Following a motor vehicle accident, a 25-year-old male requiresa blood transfusion. Blood type tests done prior to the transfusion involve the use of IgM antibodies against A & B antigens on RBCs. A positive reaction is an aggregate formation that is known as

A) agglutination

B) complement activation

C) neutralization

D) opsonization

E) precipitin reaction

Answer 43

A) agglutination

Question 44

The process that is synergistically enhanced by the binding of both antibodies & comlement fragments such as C3b by phagocytes is known as

A) agglutination

B) complement activation

C) neutralization

D) opsonization

E) precipitin reaction

Answer 44

D) opsonization

Question 45

The term applied to the interaction of soluble antigen with soluble antibody that results in the formation of insoluble antigen-antibody complexes is

A) agglutination

B) complement activation

C) neutralization

D) opsonization

E) precipitin reaction

Answer 45

E) precipitin reaction

Question 46

The binding of antibodies to microbial epitopes or soluble molecules in a manner that inhibits the ability of these microbes/molecules to bind to host cell surfaces is termed

A) agglutination

B) complement activation

C) neutralization

D) opsonization

E) precipitin reaction

Answer 46

C) neutralization

Question 47

Which of the following antibody isotypes facilitates the sequential binding of the C1, C4, C2, & C3 components of the complement system?

A) !gA & IgD

B) IgA & IgE

C) IgA & IgM

D) IgE & IgG

E) IgG & IgM

Answer 47

E) IgG & IgM

Question 48

A state of T-lymphocyte nonresponsiveness that occurs following pMHC engagement is know as

A) allergy.

B) apoptosis.

C) anergy.

D) autoimmunity.

E) hypersensitivity.

Answer 48

C) anergy.

Question 49

Which of the following cells have been implicated in the prevention of autoimmune responses & in the prevention of some nonself responses?

A) antigen-presenting cells

B) Anergized T cells

C) CD4+CD25+ T_reg cells

D) Follicular dendritic cells

E) Naïve T cells

Answer 49

C) CD4+CD25+ Treg cells

Question 50

Which of the following cells require interaction with both pMHC & a set of costimulatory second signals from an antigen-presenting cell to become activated?

A) Anergized T cells

B) B cells

C) Mast cells

D) Naïve T cells

E) NK cells

Answer 50

D) Naïve T cells

Question 51

The Foxp3 nuclear transcription factor is expressed within

A) B cells.

B) CD4+/CD8+ (DP) thymocytes.

C) CD8+ cytotoxic cells.

D) CD4+CD25+ T regulatory cells.

E) Th2 cells.

Answer 51

D) CD4+CD25+ T regulatory cells.

Question 52

In activated T cells, CD152 (CTLA4)

A) becomes sequestered within the Golgi.

B) binds to the appropriate surface pMHC.

C) induces progression through the cell cycle.

D) stimulates transcription of IL-2 mRNA.

E) begins to move to the membrane & bind CD80/86.

Answer 52

E) begins to move to the membrane & bind CD80/86.

Question 53

A previously healthy 8-month-old girl with fever & wheezing is diagnosed with RSV infection. Assuming that this is the child’s 1st exposure to RSV, which of the following mechanisms will most likely operate to clear the infection?

A) CD4+ T cell-mediated necrosis of infected cells

B) Complement-mediated lysis of infected cells

C) Cytotoxic T cell-induced apoptosis of infected cells

D) MHC I presentation of viral peptides on CD8+ T cells

E) Virus-specific antibodies that neutralize free virus

Answer 53

C) Cytotoxic T cell-induced apoptosis of infected cells

Question 54

In a patient with Salmonella infection, which of the following mechanisms will most likely be the earliest adaptive response for clearing the infection while bacteria are present within intracellular endosomes?

A) Antibody-mediated neutralization of free bacteria

B) Complement-mediated lysis of infected host cells

C) CTL recognition of bacterial peptides presented by MHC II

D) DTH responses generated by CD4+ T cells

E) Type I hypersensitivity mediated by IgE antibodies

Answer 54

D) DTH responses generated by CD4+ T cells

Question 55

A 25-year-old man is exposed to the roundworm Ascaris but does not develop clinical sugns of infection. Which of the following mechanisms is likely to be responsible for his resistance to infection?

A) Antibody-mediated destruction of worm-infected host cells

B) CTL-induced apoptosis of worm-infected cells

C) Complement-mediated lysis

D) IgE-mediated type I hypersensitivity disrupting worm attachment

E) Phagocytosis of worms followed by necrosis of phagocytes

Answer 55

D) IgE-mediated type I hypersensitivity disrupting worm attachment

Question 56

Despite having recovered fully from influenza the previous winter, a 56-year-old man becomes ill after being exposed to a colleague. Which of the following mechanisms permits his reinfection?

A) Neutralizing antibodies against influenza disappear rapidly

B) Insufficient time has passed for T cells to develop memory

C) Intracellular virus particles escape immune surveillance.

D) Type 1 hypersensitivity responses occur on second exposure.

E) Viral variants evade the immune response against the original virus.

Answer 56

E) Viral variants evade the immune response against the original virus.

Question 57

Which of the following describes the state of immunity resulting from a malaria infection?

A) Antibody-mediated neutralization

B) CTL induced apoptosis

C) Complement-mediated lysis

D) DTH mediated clearing

E) Host immunity is evaded by protozoa reproducing within RBCs

Answer 57

E) Host immunity is evaded by protozoa reproducing within RBCs

Question 58

In response to the lipoppolysaccharide from a gram-negative bacterial infection, local host phagocytes release proinflammatory cytokines, including IL-6, which then stimulates hepatic synthesis & release of

A) C-reactive protein

B) chemokines

C) complement

D) immunoglobulins

E) interleukins

Answer 58

A) C-reactive protein

Question 59

Which of the following is the predominant immunoglobulin isotype secreted in the human MALT?

A) IgA

B) IgD

C) IgE

D) IgG

E) IgM

Answer 59

A) IgA

Question 60

Which of the following is characteristic of the mucosal immune system?

A) A vigorous response is made to all nonself-antigens encountered
B) Chronic inflammation makes an inhospitable environment

C) IL-2 & IFN-gamma contribute to a Th1- like environment

D) Secretion of IgG predominates over secretion of IgA.

E) Tolerance to foreign antigens is the norm rather that the exception.

Answer 60

E) Tolerance to foreign antigens is the norm rather that the exception.

Question 61

A 14-month-old boy who has not received any vaccines remains healthy despite his daily association with several other children for the past year at a home day care facility. Which of the following mechanisms best explains why he has not contracted diphtheria, measles, pertussis, or polio?

A) herd immunity

B) genetic drift

C) genetic shift

D) immune evasion

E) tolerance

Answer 61

A) herd immunity

Question 62

Which of the following types of vaccines would most likely evoke the best & most long-lasting protective immune response against rubeola (measles)?
A) attenuated vaccine

B) DNA vaccine

C) extract vaccine

D) killed vaccine

E) recombinant vaccine

Answer 62

A) attenuated vaccine