CHAPTER 3
Principles of Adaptive Immunity
Questions
3–1
The _____ region of the and chains of the T-cell receptor forms the pathogen-specific
binding site, whereas the _____ region anchors the molecule on the cell surface:
a. constant; variable
b. effector; constant
c. carboxy-terminal end; amino-terminal end
d. complement; effector
e. variable; constant.
3–2
Which of the following is mismatched?
a. immunoglobulin light chain: VJ
b. T-cell receptor chain: VJ
c. immunoglobulin heavy chain: VJ
d. T-cell receptor chain: VDJ
e. None of the above is mismatched.
3–3
The process of _____ results in the amplification of particular T cells or B cells with
specificity for antigen:
a. germline recombination
b. somatic recombination
c. clonal selection
d. antigen processing
e. antigen presentation.
3–4
A. What molecules do (i) B cells and (ii) T cells use to recognize foreign antigens?
B. Draw simple schematics of these molecules and contrast their different antigen-
recognition properties.
C. Explain how antigen is prepared for T-cell recognition.
3–5
Why are dendritic cells so important in adaptive immune responses? Explain what they
do.
3–6
2
Describe three distinct mechanisms by which antibodies eradicate infection.
3–7
Give four reasons why secondary immune responses are faster and more effective than
primary immune responses.
3–8
Explain how dendritic cells optimize antigen presentation to T cells despite the relatively
limited capacity of any particular MHC molecule to bind different pathogen-derived
peptides.
3–9
Explain what feature of B cells makes them useful as professional antigen-presenting
cells in an immune response.
3–10
Which of the following characteristics distinguishes dendritic cells from macrophages?
a. They are phagocytic.
b. They are leukocytes.
c. They are resident in tissues.
d. They degrade pathogens.
e. They transport antigen from epithelia to draining lymph nodes.
3–11
In most cases, adaptive immune responses rely on the initial activation of _____ in
secondary lymphoid tissue:
a. macrophages
b. T cells
c. B cells
d. dendritic cells
e. epithelium.
3–12
Which of the following is not a characteristic of native antigen recognized by T cells?
a. peptides ranging between 8 and 25 amino acids in length
b. not requiring degradation for recognition
c. amino acid sequences not found in host proteins
d. primary, and not secondary, structure of protein
e. binding to major histocompatibility complex molecules on the surface of antigen-
presenting cells.
3–13
Which of the following statements regarding CD8 T cells is incorrect?
a. When activated, CD8 T cells in turn activate B cells.
b. CD8 is also known as the CD8 T-cell co-receptor.
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c. CD8 binds to MHC molecules at a site distinct from that bound by the T-cell
receptor.
d. CD8 T cells kill pathogen-infected cells by inducing apoptosis.
e. CD8 T cells are MHC class I-restricted.
3–14
Which of the following characteristics permits activated CD8 T cells to destroy any cell
type harboring viable and replicating pathogens such as viruses?
a. The pathogen is located in extracellular spaces.
b. CD8 T cells enable macrophages to kill intracellular pathogens.
c. Pathogen-derived peptides bind MHC class I molecules in endocytic vesicles
found ubiquitously in most cell types.
d. MHC class II molecules are expressed ubiquitously by most nucleated cells.
e. MHC class I molecules are expressed ubiquitously by most nucleated cells.
3–15
_____, _____, and _____ are the three most abundant antibodies in blood:
a. IgA, IgD, and IgE
b. IgA, IgE, and IgG
c. IgA, IgG, and IgM
d. IgE, IgG, and IgM
e. IgD, IgE, and IgM.
3–16
The five isotypes of immunoglobulin differ from each other in their _____:
a. light-chain constant regions
b. heavy-chain constant regions
c. light-chain variable regions
d. heavy-chain variable regions
e. heavy-chain variable and constant regions.
3–17
A circulating B cell that has never before encountered antigen expresses _____ on the
cell surface:
a. IgM and IgD
b. IgM
c. IgD
d. IgM and IgG
e. IgG
f. IgE.
3–18
The antibody transported across mucosal epithelia is _____:
a. IgA
b. IgD
c. IgE
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d. IgG
e. IgM.
3–19
The mutational mechanism that results in the production of antibodies that bind antigen
with higher affinity is called _____:
a. somatic recombination
b. isotype switching
c. somatic hypermutation
d. clonal selection
e. antigen processing.
3–20
The process of _____ results in change in the constant region of the heavy-chain of
antibodies, causing a change in the effector function and transport properties of
antibodies:
a. complement fixation
b. neutralization
c. isotype switching
d. somatic hypermutation
e. somatic recombination.
3–21
A. What is immunological tolerance?
B. What is the general name for the antigens against which the immune system is
normally tolerant?
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Answers
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