Đặng Trần Hoàng
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Mời bà con nhào dzô:
1. B cell differentiation begins with the expression of
a. membrane m chain + surrogate L chain.
b. membrane IgD.
c. Membrane IgM.
d. germline IgM.
e. RAG-1, RAG-2 and TdT.
2. Bone marrow stromal cells
a. are important because they provide physical support for B cells (hence, their name from the Greek word for mattress).
b. are present only in the center of the marrow.
c. present foreign antigen to B cells to stimulate somatic hypermutation .
d. present self antigen on self MHC to B cells for negative selection.
e. secrete cytokines such as IL-7 that signal developing B cells to divide and differentiate.
3. Cell adhesion molecules (CAMs)
a. are found only on bone marrow stromal cells.
b. are specific receptors for cytokines that promote cell-cell binding.
c. function primarily to hold developing B cells in one location until they are fully developed.
d. signal developing B cells to divide and differentiate.
e. signal developing B cells to die because they have bound self.
4. The developmental step that commits a cell to the B lineage is
a. expression of both membrane IgM and IgD.
b. expression of membrane m chain.
c. expression of recombinase enzymes.
d. joining of a VH gene segment to a DH gene segment.
e. joining of a DH gene segment to a JH gene segment
5. Which statement about B cell development is FALSE?
a. Cells which fail to synthesize and express m chains usually die.
b. Each DNA joining event in Ig genes has a 67% probability of resulting in a nonproductive rearrangement.
c. The earliest developing B cell which could be stained with FITC-anti-m chain would be a pro B cell.
d. The earliest developing B cell which could be stained with FITC-anti- k chain would be an immature B cell.
e. The enzyme which can add nucleotides not encoded in the DNA to Ig genes during recombination is TdT.
6. Once H chain genes have been productively rearranged and expressed on the pre-B cell membrane, the next event to occur in the cell is
a. death of cells binding self antigen.
b. expression of membrane IgD.
c. expression of membrane of IgM.
d. proliferation of the pre-B cells.
e. somatic recombination of light chain genes.
7. In a productive rearrangement of Ig DNA, what is produced must be
a. a functional membrane Ig protein chain.
b. a loop of DNA that is then removed.
c. an mRNA for H or L chain.
d. a shorter piece of DNA.
e. successful antibody secretion in response to antigen.
8. Proliferation of large pre-B cells
a. is part of clonal selection.
b. makes the pre-B cells more susceptible to apoptosis following self antigen binding
c. results in production of many B cells with the same antigen specificity.
d. results in the production of many B cells with the same VH chain but different antigen specificities due to different VL regions.
e. requires the presence of RAG-1 and RAG-2.
9. Which of the following statements is TRUE?
a. Isotypic exclusion on individual B cells pertains to expression of a single heavy chain isotype on each mature naive B cell.
b. Pre-B cells must receive a signal from specific antigen binding to pre-B receptor before they can proceed to the next stage in development.
c. Membrane m chain is always expressed with Iga and Igb
d. Membrane m chain is always expressed with VpreB and l5.
e. Transgenic mice for recombined H and L immunoglobulin genes have germline H and L genes in non-B cells.
10. Light chain rescue
a. allows self-specific B cells to repeat somatic recombination of light chain gene segments.
b. is a signal received through binding to the surrogate light chain that rescues the developing B cell from death.
c. results from multiple V-J joining events on a single chromosome until productive rearrangement of light chain occurs or all J segments have been recombined.
d. signals the developing B cell through IgaIgb to begin recombination of light chain gene segments.
e. None of the above is true. ? ?
Mời bà con nhào dzô:1. B cell differentiation begins with the expression of
a. membrane m chain + surrogate L chain.
b. membrane IgD.
c. Membrane IgM.
d. germline IgM.
e. RAG-1, RAG-2 and TdT.
2. Bone marrow stromal cells
a. are important because they provide physical support for B cells (hence, their name from the Greek word for mattress).
b. are present only in the center of the marrow.
c. present foreign antigen to B cells to stimulate somatic hypermutation .
d. present self antigen on self MHC to B cells for negative selection.
e. secrete cytokines such as IL-7 that signal developing B cells to divide and differentiate.
3. Cell adhesion molecules (CAMs)
a. are found only on bone marrow stromal cells.
b. are specific receptors for cytokines that promote cell-cell binding.
c. function primarily to hold developing B cells in one location until they are fully developed.
d. signal developing B cells to divide and differentiate.
e. signal developing B cells to die because they have bound self.
4. The developmental step that commits a cell to the B lineage is
a. expression of both membrane IgM and IgD.
b. expression of membrane m chain.
c. expression of recombinase enzymes.
d. joining of a VH gene segment to a DH gene segment.
e. joining of a DH gene segment to a JH gene segment
5. Which statement about B cell development is FALSE?
a. Cells which fail to synthesize and express m chains usually die.
b. Each DNA joining event in Ig genes has a 67% probability of resulting in a nonproductive rearrangement.
c. The earliest developing B cell which could be stained with FITC-anti-m chain would be a pro B cell.
d. The earliest developing B cell which could be stained with FITC-anti- k chain would be an immature B cell.
e. The enzyme which can add nucleotides not encoded in the DNA to Ig genes during recombination is TdT.
6. Once H chain genes have been productively rearranged and expressed on the pre-B cell membrane, the next event to occur in the cell is
a. death of cells binding self antigen.
b. expression of membrane IgD.
c. expression of membrane of IgM.
d. proliferation of the pre-B cells.
e. somatic recombination of light chain genes.
7. In a productive rearrangement of Ig DNA, what is produced must be
a. a functional membrane Ig protein chain.
b. a loop of DNA that is then removed.
c. an mRNA for H or L chain.
d. a shorter piece of DNA.
e. successful antibody secretion in response to antigen.
8. Proliferation of large pre-B cells
a. is part of clonal selection.
b. makes the pre-B cells more susceptible to apoptosis following self antigen binding
c. results in production of many B cells with the same antigen specificity.
d. results in the production of many B cells with the same VH chain but different antigen specificities due to different VL regions.
e. requires the presence of RAG-1 and RAG-2.
9. Which of the following statements is TRUE?
a. Isotypic exclusion on individual B cells pertains to expression of a single heavy chain isotype on each mature naive B cell.
b. Pre-B cells must receive a signal from specific antigen binding to pre-B receptor before they can proceed to the next stage in development.
c. Membrane m chain is always expressed with Iga and Igb
d. Membrane m chain is always expressed with VpreB and l5.
e. Transgenic mice for recombined H and L immunoglobulin genes have germline H and L genes in non-B cells.
10. Light chain rescue
a. allows self-specific B cells to repeat somatic recombination of light chain gene segments.
b. is a signal received through binding to the surrogate light chain that rescues the developing B cell from death.
c. results from multiple V-J joining events on a single chromosome until productive rearrangement of light chain occurs or all J segments have been recombined.
d. signals the developing B cell through IgaIgb to begin recombination of light chain gene segments.
e. None of the above is true.
? ?
