Question 1

Which of the following is a characteristic of B-2 cells?

Accepted Answer

A)  They are sometimes referred to as CD5 B cells.
B)  They comprise only 5% of the B-cell repertoire.
C)  In adults,they are renewed by cell division in the peripheral circulation.
D)  They are located primarily in secondary lymphoid organs.
E)  They are not dependent on T helper cells for activation.F) All of the above
G) D) and E)

Question 2

A defect in which of the following proteins blocks B-cell development at the pre-B-cell stage,resulting in almost no circulating antibodies in individuals with this defect?

Accepted Answer

A)  IL-7 receptor
B)  terminal deoxynucleotidyltransferase (TdT) 
C)  Pax-5
D)  Bruton's tyrosine kinase (Btk) 
E)  CD19.F) A) and D)
G) A) and C) D

Question 3

The consequence of allelic exclusion at the immunoglobulin loci ensures that _____.(Select all that apply.)

Accepted Answer

A)  B-cell receptors have a low-avidity binding
B)  B cells express antigen receptors of a single specificity
C)  hybrid immunoglobulins are formed
D)  all functional copies of a gene are expressed
E)  homogeneous B-cell receptors bind more effectively to antigen.F) A) and D)
G) A) and C) B,E

Question 4

A.Identify properties that are shared by anergic B cells and plasma cells.
B.What key property is different?

Accepted Answer

A.They both have limited life-spans,expr...

Question 5

The circulatory route through a lymphoid tissue for both immature B cells and mature B cells that do not encounter specific antigen is:

Accepted Answer

A)  bloodstream →HEV of lymphoid cortex → primary lymphoid follicle → efferent lymphatic vessel
B)  afferent lymphatic vessel → primary lymphoid follicle →HEV of lymphoid cortex →efferent lymphatic vessel
C)  afferent lymphatic vessel →medullary cords → primary lymphoid follicle →efferent lymphatic vessel
D)  primary lymphoid follicle →HEV of lymphoid cortex →afferent lymphatic vessel →efferent lymphatic vessel
E)  bloodstream →afferent lymphatic vessel → HEV of lymphoid cortex →efferent lymphatic vessel.F) B) and C)
G) A) and E)

Question 6

When producing monoclonal antibodies,why is it important to use as a fusion partner a myeloma cell that is unable to produce its own immunoglobulin?

Accepted Answer

A)  to ensure that allelic exclusion of μ chain occurs normally
B)  to ensure that the antibodies are homogeneous and able to make strong bivalent attachments to multivalent antigens
C)  to ensure that the monoclonal antibodies are not autoreactive
D)  to provide a greater opportunity for making a successful rearrangement at the light-chain locus
E)  to ensure that antibodies are secreted and not membrane-bound.F) B) and E)
G) A) and D)

Question 7

The latest stages of late pro-B-cell development are recognized by the association of a surrogate light chain with a μ chain.The surrogate light chain is composed of

Accepted Answer

A)  E2A and EFB
B)  Igα and Igβ
C)  VpreB and λ5
D)  RAG-1 and RAG-2
E)  Pax-5 and CD19.F) D) and E)
G) All of the above

Question 8

Immunological tolerance in the B-cell repertoire is called _______ tolerance when it develops in primary lymphoid organs,and _______ tolerance when it is induced outside the bone marrow.

Accepted Answer

A)  primary; secondary
B)  apoptotic; anergic
C)  stromal; follicular
D)  receptor-mediated; systemic
E)  central; peripheral.F) A) and B)
G) A) and E)

Question 9

Describe the six functionally distinct phases of B-cell development.

Accepted Answer

1)Repertoire assembly: Bone marrow expre...

Question 10

What is the role of primary lymphoid follicles in eliminating B cells that have antigen receptors specific for soluble self antigen?

Accepted Answer

To survive,circulating B cells must enter primary follicles where survival signals are delivered by cells in the follicles,including follicular dendritic cells (which are the stromal cells of primary lymphoid follicles).Circulating B cells that fail to enter follicles in secondary lymphoid tissues will die in the peripheral circulation with a half-life of about 3 days.B cells with antigen receptors specific for soluble self antigen are generally rendered anergic in the bone marrow or the circulation.Anergic B cells that enter secondary lymphoid organs are held in the T-cell areas adjacent to primary follicles and are not permitted to penetrate the follicle.As a result,they do not receive the necessary stimulatory signal for survival.Instead,anergic B cells will undergo apoptosis in the T-cell zone.This is an efficient cleansing mechanism and serves to delete potentially autoreactive B cells from the circulation.

Question 11

Which of the following is not paired with its correct complement?

Accepted Answer

A)  N nucleotides: more abundant in rearranged heavy-chain genes than in rearranged light-chain genes
B)  second checkpoint in B-cell development: assembly of a functional B-cell receptor
C)  receptor editing: exchange of light chain for one that is not self-reactive
D)  first checkpoint in B-cell development: selection by the pre-B-cell receptor
E)  large pre-B-cell stage: constitutive expression of RAG-1 and RAG-2 proteins.F) B) and E)
G) B) and D)

Question 12

A developing B cell unable to generate a productive rearrangement on any of the four light-chain loci will undergo

Accepted Answer

A)  self-renewal
B)  apoptosis
C)  allelic exclusion
D)  malignant transformation
E)  differentiation into a B-1 cell.F) B) and D)
G) A) and D)

Question 13

Large pre-B cells undergo clonal expansion before the rearrangement of light-chain loci.Which of the following are beneficial consequences of clonal expansion? (Select all that apply.)

Accepted Answer

A)  Autoreactive B cells are eliminated before the expenditure of energy needed to rearrange a functional light-chain gene.
B)  The energy used to make a functional heavy chain is not wasted as a result of the inability to produce a functional light chain.
C)  RAG gene expression is decreased,which in turn signals light-chain rearrangement.
D)  A diverse population of immature B cells is generated that express the same μ chain but a distinct light chain.
E)  Approximately 85% of small pre-B cells will progress to the immature B-cell stage.F) A) and B)
G) B) and D)

Question 14

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

Accepted Answer

A)  that the likelihood of a successful rearrangement of light-chain genes increases.
B)  that immunoglobulins are homogeneous and not heterogeneous in mature B cells.
C)  that different effector functions are conferred by the two different light-chain loci.
D)  that surrogate light-chain transcription cannot compete with κ and λ transcription and enables B-cell development.
E)  all of the above.F) A) and D)
G) B) and E)

Question 15

Which of the following would occur after the production of a functional μ chain as a pre-B-cell receptor?

Accepted Answer

A)  RAG proteins are degraded.
B)  The chromatin structure of the heavy-chain locus is reorganized to prevent gene rearrangement.
C)  Transcription of the RAG1 and RAG2 genes ceases.
D)  There is allelic exclusion of a second μ chain.
E)  All of the above would occur.F) A) and C)
G) All of the above

Question 16

Negative selection of developing B cells ensures that

Accepted Answer

A)  there is not an overabundance of circulating B cells that would compete with other important cell types in the circulation
B)  only antigen-activated B cells leave the bone marrow
C)  clonal expansion of B cells does not occur in the absence of infection
D)  B-cell receptors that bind to normal constituents of the body do not emerge
E)  B cells do not leave secondary lymphoid tissues.F) A) and D)
G) A) and E)

Question 17

Which of the following cell-surface markers differentiates hematopoietic stem cells from other cell constituents in the bone marrow?

Accepted Answer

A)  pre-B-cell receptor
B)  BAFF receptor
C)  CD34
D)  CD4
E)  membrane-bound stem-cell factor (SCF) .F) A) and D)
G) B) and D)

Question 18

Match between columns
                        Premises: Memory B cells are derived from germinal center B cells as immune responses subside. ___
Memory B cells have more stringent requirements for activation than naive B cells do.
Memory B cells possess high-affinity antigen receptors as a consequence of affinity maturation.
Memory B cells have long life spans. 
Memory B cells express only IgM and retain the capacity to switch to the most beneficial isotype during secondary responses.

Accepted Answer

The Answer of True and False is...

Question 19

Which of the following is correctly matched? (Select all that apply.)

Accepted Answer

A)  early pro-B cell: VDJ rearranged
B)  pre-B-cell receptor: VpreBλ5/μu heavy chain
C)  mature B cell: IgM plus IgD
D)  small pre-B cell: VJ rearranged
E)  immature B cell: μ heavy chain plus λ or κ light chain on surface.F) B) and D)
G) A) and B)

Question 20

All hematopoietic stem cells express

Accepted Answer

A)  CD34
B)  CD127
C)  CD19
D)  VpreBλ5
E)  Pax-5F) All of the above
G) B) and E)

Exam 6: The Development of B Lymphocytes

Which of the following is a characteristic of B-2 cells?

Correct Answer
verified

A defect in which of the following proteins blocks B-cell development at the pre-B-cell stage,resulting in almost no circulating antibodies in individuals with this defect?

Correct Answer
verified
D

The consequence of allelic exclusion at the immunoglobulin loci ensures that _____.(Select all that apply.)

Correct Answer
verified
B,E

A.Identify properties that are shared by anergic B cells and plasma cells. B.What key property is different?

Correct Answer
verified
A.They both have limited life-spans,expr...
View Answer

The circulatory route through a lymphoid tissue for both immature B cells and mature B cells that do not encounter specific antigen is:

Correct Answer
verified

When producing monoclonal antibodies,why is it important to use as a fusion partner a myeloma cell that is unable to produce its own immunoglobulin?

Correct Answer
verified

The latest stages of late pro-B-cell development are recognized by the association of a surrogate light chain with a μ chain.The surrogate light chain is composed of

Correct Answer
verified

Immunological tolerance in the B-cell repertoire is called _ tolerance when it develops in primary lymphoid organs,and _ tolerance when it is induced outside the bone marrow.

Correct Answer
verified

Describe the six functionally distinct phases of B-cell development.

Correct Answer
verified
1)Repertoire assembly: Bone marrow expre...
View Answer

What is the role of primary lymphoid follicles in eliminating B cells that have antigen receptors specific for soluble self antigen?

Which of the following is not paired with its correct complement?

Correct Answer
verified

A developing B cell unable to generate a productive rearrangement on any of the four light-chain loci will undergo

Correct Answer
verified

Large pre-B cells undergo clonal expansion before the rearrangement of light-chain loci.Which of the following are beneficial consequences of clonal expansion? (Select all that apply.)

Correct Answer
verified

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

Correct Answer
verified

Which of the following would occur after the production of a functional μ chain as a pre-B-cell receptor?

Correct Answer
verified

Negative selection of developing B cells ensures that

Correct Answer
verified

Which of the following cell-surface markers differentiates hematopoietic stem cells from other cell constituents in the bone marrow?

Correct Answer
verified

Indicate which of the following statements concerning memory B cells are true (T)and which are false (F):

Which of the following is correctly matched? (Select all that apply.)

Correct Answer
verified

All hematopoietic stem cells express

Correct Answer
verified

Exam 6: The Development of B Lymphocytes

Which of the following is a characteristic of B-2 cells?

Correct AnswerverifiedShow Answer

A defect in which of the following proteins blocks B-cell development at the pre-B-cell stage,resulting in almost no circulating antibodies in individuals with this defect?

Correct AnswerverifiedD

The consequence of allelic exclusion at the immunoglobulin loci ensures that _____.(Select all that apply.)

Correct AnswerverifiedB,E

A.Identify properties that are shared by anergic B cells and plasma cells. B.What key property is different?

Correct AnswerverifiedA.They both have limited life-spans,expr...View AnswerShow Answer

The circulatory route through a lymphoid tissue for both immature B cells and mature B cells that do not encounter specific antigen is:

Correct AnswerverifiedShow Answer

When producing monoclonal antibodies,why is it important to use as a fusion partner a myeloma cell that is unable to produce its own immunoglobulin?

Correct AnswerverifiedShow Answer

The latest stages of late pro-B-cell development are recognized by the association of a surrogate light chain with a μ chain.The surrogate light chain is composed of

Correct AnswerverifiedShow Answer

Immunological tolerance in the B-cell repertoire is called _______ tolerance when it develops in primary lymphoid organs,and _______ tolerance when it is induced outside the bone marrow.

Correct AnswerverifiedShow Answer

Describe the six functionally distinct phases of B-cell development.

Correct Answerverified1)Repertoire assembly: Bone marrow expre...View AnswerShow Answer

What is the role of primary lymphoid follicles in eliminating B cells that have antigen receptors specific for soluble self antigen?

Which of the following is not paired with its correct complement?

Correct AnswerverifiedShow Answer

A developing B cell unable to generate a productive rearrangement on any of the four light-chain loci will undergo

Correct AnswerverifiedShow Answer

Large pre-B cells undergo clonal expansion before the rearrangement of light-chain loci.Which of the following are beneficial consequences of clonal expansion? (Select all that apply.)

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following would occur after the production of a functional μ chain as a pre-B-cell receptor?

Correct AnswerverifiedShow Answer

Negative selection of developing B cells ensures that

Correct AnswerverifiedShow Answer

Which of the following cell-surface markers differentiates hematopoietic stem cells from other cell constituents in the bone marrow?

Correct AnswerverifiedShow Answer

Indicate which of the following statements concerning memory B cells are true (T)and which are false (F):

Which of the following is correctly matched? (Select all that apply.)

Correct AnswerverifiedShow Answer

All hematopoietic stem cells express

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified
B,E

Correct Answer
verified
A.They both have limited life-spans,expr...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Immunological tolerance in the B-cell repertoire is called _ tolerance when it develops in primary lymphoid organs,and _ tolerance when it is induced outside the bone marrow.

Correct Answer
verified

Correct Answer
verified
1)Repertoire assembly: Bone marrow expre...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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