Multiple Choice Review Flashcards by Samy Lempke

IgM and IgD are co-expressed on naive B cells by a process called

a) isotype switching
b) somatic recombination
c) somatic hypermustation
d) alternative splcing
e) affinity maturation

d) alternative splicing

How well did you know this?

Not at all

Perfectly

The plasma proteins that inhibit the cleavage of C3 in complement activation are:

a) factor B and H
b) factor H and I
d) decay-accelerating factor and factor H
e) decay-accelerating factor and memebrane cofactor protein

b) factor H and factor I

How well did you know this?

Not at all

Perfectly

An opsonin is:

a) a molecule that neutralizes a pathother
b) a molecule that marks a pathogen for further immune system recongition
c) a molecule the is produced in a pro- form the needs to be activated by cleavage
d) a molecule directly involved in destruction of pathogen
e) all

b) a molecule that marks a pathogen for further immune destruction

How well did you know this?

Not at all

Perfectly

which of the following pairs is mismatched?

a) lymphocytes: innate immune response
b) natural killer cell: kills virus-infected cells
c) macrophage: phagocytosis and killing of microorganisms
d) dendritic cells: pathogen presentation to lymphocytes
e) mast cells; inflammatory response

a) lymphocytes: innate immune response

How well did you know this?

Not at all

Perfectly

Which of the following polymerizes to form a transmembrane channel that compromises the integrity of cell membranes?

a) C5
b) C6
c) C7
d) C8
e) C9

How well did you know this?

Not at all

Perfectly

The mutational mechanism that results in production of antibodies that bind antigen with higher affinity is called

a) somatic recombination
b) isotype swithching
c) somatic hypermuition
d) clonal selection
e) antigen processing

c) somatic hypermutation

How well did you know this?

Not at all

Perfectly

During neutrophil homing, which interaction promotes tight binding of the neutrophil to the blood vessel endothelial cells?

a) C3b:CR1\
b) selectin:sialyl-Lewis
c) LFA0ICAM-1
d) TLR4:LPS
e) None

c) LFA-ICAM-1

How well did you know this?

Not at all

Perfectly

which of the following is an acute-phase protein that enhances complement fixation?

a) TNF-a
b) mannose-binding lectin
c) fibriniogen
d) LFA-1
e) CXCL8

b) mannose-binding lectin

How well did you know this?

Not at all

Perfectly

The vesicle formed immediately upon uptake of a pathogen during phagocytosis is referred to as a

a) phagolysosome
b) endosome
c) lysosome
d) phagosome
e) endolysosome

d) phagosome

How well did you know this?

Not at all

Perfectly

Primary lymphoid tissues are the sites where lymphocytes ______, whereas secondary lymphoid tissues are the sites where lymphocytes _____.

a) are stimulated: develop and mature
b) encounter pathogens; undergo apoptosis
c) develop and mature; become stimulated
d) undergo clonal selection; differentiate from hematopoietic stem cells
e) die; are phagocytosed after death

c) develop and mature; become stimulated

How well did you know this?

Not at all

Perfectly

The enzyme in neutrophils responsible for generating a respiratory burst is:

a) lysozyme
b) defensin
c) NADPH oxidase
e) NF-kB

d) NADPH oxidase

How well did you know this?

Not at all

Perfectly

Which of the following mechanisms is NOT a mechanism utilized in immunoglobulin variation?

a) randomness of subunit interaction
b) production of soluble and membrane-bound forms
c) changes in sequence as spliced sites of gene segments
d) gene rearrangement
e) all

b) production of soluble and membrane-bound forms

How well did you know this?

Not at all

Perfectly

a protein epitope formed as a result of continuous amino acids and is not detroyed if the protein denatures is called a _____ epitope.

a) multivalent
b) disocontinuous
c) monovalent
d) completimentarity
e) linear

e) linear

How well did you know this?

Not at all

Perfectly

Which of the following steps is NOT a step in neutrophil homing?

a) tight binding
b) diapedesis
c) respiratory burst
d) rolling adhesion
e) migration

c) repirator burst

How well did you know this?

Not at all

Perfectly

The process by which a pathogen stimulates only those lymphocytes with receptors specific for that pathogen is called:

a) germline recombination
b) somatic recombination
c) clonal selection
d) antigen processing
e) antigen presentation

c) clonal selection

How well did you know this?

Not at all

Perfectly

Which of the following statements about Notch 1 is correct?

a) Notch 1 is expressed on thymic epithelial cells
b) in the absence of Notch 1 expression, T cells can complete their differentiation
c) Notch 1 is an important signaling component in the T-cell receptor complex
d) Notch 1 contains two distinct domains, one which is proteolytically cleaved and becomes a transcription factor in the nucleus
e) all

d) Notch 1 contains two distict domains, one which is proteolytically cleaved and becomes a transcription factor in the nucleus

How well did you know this?

Not at all

Perfectly

Which of the following statements regarding T-cells receptor recognition of antigen is correct?

a) T-cell receptors recognize antigen only as a peptide bound to a MHC molecule
b) T-cell receptors recoginze antigens in their native form
c) T-cell receptors, like B cell immunoglobulins, can recognize carbohydrae, lipid, and protein antigens
d) antigen processing occurs in extracellular spaces
e) none

a) T-cell receptors recognize antigen only as a peptide bound to an MHC molecule

How well did you know this?

Not at all

Perfectly

Developing B cells that fail to make productive D to J heavy-chain rearrangements on both homologous chromosomes

a) die by apoptosis in the bone marrow
b) will rearrange heavy-chain loci multiple times unitl a productive rearrangment is made
c) undergo clonal proliferation
d) upregulate expressio nof transcription factors E2A and EBF
e) all

a) die by apoptosis in the bone marrow

How well did you know this?

Not at all

Perfectly

If a double-negative thymocyte has just completed a productive b-chain gene rearrangement, which of the following describes the immediate next step in the development of this thymocyte?

a) A pre-T-cell receptor is assembled
b) rearrangement of gamma nd delta-chain genes commences
c) expression levels of RAG-1 and RAG-2 are elevated
d) the linked delta-chain genes are eliminated
e) this cell will inevitably differentiate into a committed gamma;delta

a) A pre-T-cell receptor is assembled

MHC molecules have promiscuous binding specificity. This means that

a) a particular MHC molecule has the potential to bind to different peptides
b) when MHC molecules bind to peptides, they are degraded
c) peptides bind with low affinity to MHC molecules
d) MHC molecules can bind to both T-cell and B-cell receptors
e) none of the above

a) a particular MHC molecule has the potential to bind to different peptides

Pro-B cells produce a surrogate light chain, which associates with the u-chain on the cell surface. The surrogate light chain is composed o

a) E2A and EBF
b) Iga and Igb
c) VpreB and lambda5
d) RAG-1 and RAG-2
e) Pax5 and CD19

c) VpreB and lambda5

Double-negative thymocytes initiate rearrangement at the ____ locus (loci) before all other T-cell receptor genes.

a) gamma dn delta
b) beta
c) alpha, gamma, delta
e) beta, gamma, delta

e) beta, gamma, and delta

Which of the following cell types are capable of producing plasma cells that have undergone isotype switching and somatic hypermutation?

a) follicular dendritic cells
b) germinal cells
c) centrocytes
d) stromal cells
e) all

c) centrocytes

An important advantage of having two gene loci (kappa and lambda) for the light chain is

a) that the likelihood of a successful rearrangement of light-chain genes increases
b) that immunoglobulins are homogeneous and not hetero in mature B cells
c) that different effector functions are conferred by the two different light-chain loci
d) that surrogate light-chain transciption cannot compete iwht d and l transcipriton
e) all

a) that the likelihood of a successful rearrangement of light-chain genes increases

Which of the following is the first stage of T-cell receptor gene rearrangement in apha:beta T cells? a) Va ---> Da b) Da--->Ja c) Vb---> Db d) Db--> Jb e) Va---> Ja

d) Db ---> Jb

CD8-positive T-cell subpopulations are specialized to combat ___ pathogens, whereas CD4 positive T-cell subpopulations are specialized to combat ____ pathogens. a) bacterial; viral b) dead; live c) extracellular; intracellular d) intracellular; extracellular e) virulent; attenuated

d) intracellular; extracellular

_____ involves successive rearrangement at the light-chain loci when reactivity to multivalent self antigen occurs during B-cell development a) receptor editing b) somatic hypermutation c) chromosomal translocation d) clonal deletion e) anergy

a) receptor editing

Which immunoglobulin's main function is to mediate sensitization of mast cells? a) IgA b) IgD c) IgE d) IgG e) IgM

c)IgE

One type of bare lymphocyte syndrome is caused by a genetic defect in MHC class II transactivator (CIITA), which results in the inability to synthesize MHC class II and display it on the cell surface. The conseqence of this would be that a) B cells are unable to develop b) CD8 T cells cannot function c) CD4 T cells cannot function d) intracellular infections cannot be eradicated e) peptides cannot be loaded onto MHC molecules in the lumen of the ER

c) CD4 T cells cannot function

Which of the following pertains to the fate of immature B cells that have specificity for monovalent self antigens? a) IgD is retained in the cytosol b) IgM on the cell suface activates th e B cell to become memory c) The cells acquire a state of unresponsiveness called anergy d) the cells have a much longer life span than mature B cells e) The cells die by apoptosis

c) the cells acquire a state of unresponsiveness called anergy

If a T-cell receptor on a double-positive thymocyte binds to a self-peptide:self-MHC class I complex with moderate affinity, the result is a) negative selection and apoptosis b) cell proliferation c) rearrangement of the second beta-chain locus d) positive selection of a CD4-positive T cell e) positive selection of a CD8-positive T cell

e) positive selection of a CD8-positive T cell

Antigen recognition by T cells in the absence of co-stimulation results in a) upregulation of B7 b) expression of the high-affinity IL-2 receptor c) T-cell anergy d) T-cell apoptosis e) phosphorylation of ITAMs

c) T-cell anergy

C3d is a breakdown product of iC3b, which binds to ____ of the B-cell co-receptor. a) factor I b) CR2 c) CD81 d) CD19 e) CR1

b) CR2

Intracytoplasmic bacteria in epithelial cells of the gastrointestinal tract are detected by____ a) poly-Ig receptor b) major basic protein c) MIC proteins d) NOD proteins e) receptors for phosphoantigens

d) NOD proteins

____ of thymocytes is necessary to produce a T-cell repertoire capable of interacting with self-MHC molecules a) postive selection b) negative selection c) apoptosis d) receptor editing e) isotype swithcing

a) positive selection

The co-stimulatory molecule ____ on professional antigen-presenting cells binds ____ on the surface of naive T cells a) DC-SIGN;ICAM-3 b) B7; CD28 c) ICAM-1;LFA-1 d) MHC II: T-cell receptor e) MHC class II: CD4

b) B7; CD28

Antibody-dependent cell-mediated cytotoxicity is carried out by ___ after cross-linking of IgG1 or IgG3 antibodies a) neutrophils b) Nk cells c) macorphages d) dendritic cells e) mast cells

b) NK cells

What would be the outcome if a naive B cell were to stimultaneously bind to pathogen coated with specific antibody made by an effector B cell in a primary immune response using an Fc receptor, and bind to the same pathogen using its b-cell receptor? a) a positive signal leading to the production of low-affinity IgM antibodies b) a positive signal leading to isotype switching and production of IgG, IgA, or IgE c) a positive signal leading to somatic hypermutation and production of high-affinity IgM antibodies d) a negative signal leading to inhibition of the production of low-affinity IgM antibodies e) a negative signal leading to B cell anergy

d) a negative signal leading to inhibition of the production of low-affinity IgM antibodies

____ involves deliberate stimulation of the immune system and induction of protective immunity to a particular disease-causing pathogen by mimicking infection in the absence of disease. a) Variolation b) Attenuation c) Vaccination d) Conjugation e) Herd immunity

c) Vaccination

Binding of the cytokine ___ induces T-cell proliferation and differentiation of activated T cells a) CD4 b) CD28 c) LFA-1 d) IL-2 e) IL-10

d) IL-2

Which of the following is NOT an example of passive transfer of immunity? a) provision of IgA through breast milk b) receiving antivenom after being bitten by snake c) intravenous immunoglobulin therapy for immunocompromised individuals d) antibody production after vaccination e) acquisition of IgG during fetal development

d) antibody production after vaccination

Which of the following describes the characteristics of CD94:NKG2A? a) it is an activating receptor of NK cells b) it binds to HLA-A, HLA-B, nd HLA-c c) it binds to complexes of leader sequences of HLA-A, HLA-B, HLA-C bound to HLA-E d) It is a member of the killer-cell immunoglobulin-like receptor family e) it reconginzes and presents glycolipid to T cells

c) it binds to complexes of leader sequences of HLA-A, HLA-B, HLA-C bound to HLA-E

Cytokine receptors are associated with cytoplasmic protein kinases called ____, which become activated when the cytokine receptos bind to their respecitive cytokines a) ZAP-70 b) STATs c) Lck d) ITAMs e) JAKs

e) JAKs

Mucosal epithelia of the gastrointestinal tract, eyes, nose, throat, the respiratory, urinary, and genital tracs, and th emammary glands are protected by a) IgG b) IgM c) IgE d) monomeric IgA e) dimeric IgA

e) dimeric IgA

Which of the following statements is false? a) Secondary immune responses take the same amount of time as primary immune responses to become effective. b) Immune responses made in mucosal secondary lymphoid tissues do not usually drive an inflammaroty response c) I fan individual acquires a second cold in the same season ith will most likely be caused by a different type of cold virus d) Plasma cells generated in a secondary immune response have longer lifer spands than those made during aprimary immune response

a) Secondary immune responses take the same amount of time as primary immune responses to become effective.