Reference no: EM1388282

2. Peptide binding diversity is increased by:
A. Multiple MHC alleles in the population.
B. Multiple homologous MHC genes in the genome.
C. Both A and B
D. None of the above
3. The human MHC locus is one of the most polymorphic regions of the
genome. What does this mean? 2 point
A. It has many different genes
B. There are many different alleles of these genes.
C. Sequence variability is low in this region.
D. There are many introns in this region.

4. Which of the following cell types would be LEAST likely to express
MHC class II?
A. B cells
B. T cells
C. Dendritic cells
D. Thymic epithelial cells
E. Vascular endothelial cells
5. Which of the following is the BEST example of self-MHC restriction of
T cells?
A. A T-cell clone is deleted when it binds too tightly to self MHC.
B. A T-cell clone responds more vigorously to a self-peptide than
a foreign peptide.
C. A T-cell clone recognizes foreign MHC.
D. A T-cell clone only recognizes foreign peptides when
presented by self MHC.
E. All of the above

6. Antigen-presenting calls express both class I and class II MHC
molecules on their membranes.
True
False

7. Class III MHC genes encode membrane-bound proteins.
True
False

8. Class II MHC molecules typically bind to longer peptides than do
class I molecules
True
False

9. Under which of the following conditions would T-cell activation be
LEAST likely to occur? 2 points
A. Macrophages are incubated with antigen, then fixed with
paraformaldehyde, then incubated with antigen-specific T cells.
B. Macrophages are fixed with paraformaldehyde, then incubated
with antigen, then incubated with antigen-specific T cells.
C. Macrophages are incubated with digested antigen, then fixed
with paraformaldehyde, then incubated with antigen-specific T
cells.
D. Macrophages are fixed with paraformaldehyde, then incubated
with digested antigen, then incubated with antigen-specific T
cells.
E. Macrophages are incubated with antigen and then incubated
with antigen-specific T cells.

10. Which of the following is an example of cross-presentation?
A. An endogenous peptide being presented on MHC class I
B. An exogenous peptide being presented on MHC class I
C. An endogenous peptide being presented on MHC class II
D. An exogenous peptide being presented on MHC class II
E. A B-cell antigen being presented to a T cell
11. Hematopoietic stem cells cultured in the presence of which
receptor differentiate into T cells rather than B cells?
A. T cells
B. B cells
C. Notch-ligand
D. CD3

12. Which of the following molecules would double-negative T cells
fail to express?
A. CD3
B. CD4
C. MHC class I
D. TAP
E. All of the above

13. At what stage of T cell development is the pre-TCR
expressed?
A. Double negative
B. Double positive
C. Single positive
D. Pro-T cell

14. What happens to autoreactive cells that escape the thymus?
A. They attack self tissues.
B. They can be rendered anergic
C. They negatively regulate other autoreactive cells
D. They require TCR-ligation and costimulation to be activated.
E. All of the above

4. What happens to autoreactive cells that escape the thymus?
A. They attack self tissues.
B. They can be rendered anergic
C. They negatively regulate other autoreactive cells
D. They require TCR-ligation and costimulation to be activated.
E. All of the above

15. At what stage of T cell development is the pre-TCR
expressed?
A. Double negative
B. Double positive
C. Single positive
D. Pro-T cell
E. None of the above

16. In negative selection, cells that receive _____________ signal
through their antigen receptors die.
A. A weak
B. A Strong
C. An Intermediate
D. No

17. What happens to autoreactive cells that escape the thymus?
A. They attack self tissues.
B. They can be rendered anergic.
C. They negatively regulate other autoreactive cells.
D. They require TCR-ligation and costimulation to be activated.
E. All of the above

18. TREGs have been shown to be protective against which of the
following conditions?
A. Inflammatory Bowel Disease
B. Influenza
C. Malaria
D. HIV
E. MRSA 19. Ligation of which of the following cell-surface receptors leads to
cell death?
A. TCR
B. TLR
C. Fas
D. Caspase 8

20. How long does B cell maturation from an HSC to a mature B
cell take?
A. 1-2 Hours
B. 1-2 days
C. 1-2 weeks
D. 1-2 months

21. This type of cell will leave the bone marrow and complete
maturation in the spleen.
A. Common lymphoid progenitor cell
B. Hematopoietic stem cell
C. Immature B cell
D. Pro-B cell
E. Pro-T cell
22. VDJ recombination occurs during which phase of a B cell's
development?
A. Activated B cell
B. Mature B cell
C. Naive B cell
D. Pro-B cell
E. Immature B cell

23. What are two functions of bone marrow stromal cells with
respect to B-cell development?
A. Cytokine expression and traps developing B cells in a specific
location
B. Recruits macrophages to phagocytize self-recognizing B cells
and decreases HSC when no active infection is present
C. Secretes release factors that direct the B cell to the spleen and
expresses necessary cytokines
D. Traps developing B cells in a specific location and recruits red
bloods to bring oxygen to developing B cells

24. All of the following are true regarding B-cell development
EXCEPT:
A. B cells complete maturation in the spleen.
B. B cells are still immature when they leave the bone marrow
C. B cells, like T cells are MHC class restricted
D. Self-reactive B cells may be eliminated through apoptosis
E. Self-reactive B cells may be rendered unreactive (anergic)

25. Individuals of retirement age or older show lower antibody
mediate immune responses due to all of the following reasons
EXCEPT:
A. Increased likelihood of autoimmune disorders.
B. limited HSC production of Pro-B cells
C. Poor antibody response to vaccination
D. Reduced memory-B cell generation
E. Smaller thymus
26. The common lymphoid progenitor cell gives rise to all of the
following cell lines EXCEPT:
A. Dendritic cells
B. Megakaryocytes
C. Natural killer cells
D. Pre-pro-B cells
E. T cell progenitors

27. Which of the following statements regarding HSCs is/are
TRUE
I. HSCs are not self-renewing.
II. HSCs can make copies of themselves.
III. HSCs give rise to one cell lineage.
IV. HSCs are multipotent.
V. HSCs express both Rag 1 and Rag 2 surface markers.
Statement 1 only
Statement I and III only
Statement II and III only
Statement II and IV only

28. At what stage of development does a B cell undergo D-JH
rearrangement?
A. Pre-pro B cell
B. Early pro-B cell
C. Late pro-B cell
D. Late pre-B cell
E. Immature B cell

30. Marginal-zone B cells express:
A. IgD
B. IgG
C. IgM
D. IgE
E. Both B and C

31. Thymocytes Learn MHC restriction in this organ?
A. Bone marrow
B. Thymus
C. Spleen
D. Both A and B
E. Neither of the above

32. Regulatory T cells _____________ regulate Immune
responses?
A. Positively
B. Negatively
33. What introduces a transient hairpin that links the two strands in
the V(D)J coding regions?
Answer
A. TdT
B. Artemis
C. RAG-1/2
D. XRCC4 with DNA ligase IV
E. Ku 70 and Ku 80
34. Apoptosis which results in programmed cell death does not in
duce a local inflammatory response?
True/ False
35. What closes the final nicks in the sugar-phosphate backbone to
generate coding and signal joints?
A. TdT
B. Artemis
C. RAG-1/2
D. XRCC4 with DNA ligase IV
E. Ku 70 and Ku 80

36. Deficiency in RAG-1 and/or RAG-2 can affect the proper
development of which of the following cell types, resulting in
decreased numbers of circulating cells of those types?
B cells
T cells
NK cells
Both A and B

37. Alternative splicing of pre-mRNA accounts for the transition
from membrane-bound IgM to secreted IgM upon activation of a B
cell?
True
False
38. Describe one advantage and one disadvantage of N-nucleotide
addition during the rearrangement of immunoglobulin heavy-chain
gene segment. 2 points
Answer :
39. During DNA rearrangement, gene segments adjacent to the
one-turn RSS can join only with segments adjacent to the one turn
RSS
True
False

40. Because of ___________, the immunoglobulin heavy-chain
genes of only one parental chromosome are expressed per cell. This
process ensures ____________ for B cell. 2 points
41. Match the following structural characteristics with either MHC
class I, class II, or both. 4 points
A. Beta 2-microglobulin
B. Contains two
transmembrane domains
C. Binds 8-10 amino acids
D. Has closed ends on
peptide binding groove