Antibodies Flashcards
1. The basic immunoglobulin (Ig) unit is composed of:
A Two identical heavy and two identical light chains
B Two identical heavy and two different light chains
C Two different heavy and two identical light chains
D Two different heavy and two different light chains
E Non-covalently bound polypeptide chains
A Two identical heavy and two identical light chains
2. A fragment antigen binding (Fab) fragment:
A Is produced by pepsin treatment
B Is produced by separation of heavy and light chains
C Binds antigen
D Lacks light chains
E Has no interchain disulfide bonds
C Binds antigen
3. The complementarity determining regions (CDRs):
A Are restricted to light chains
B Are in the constant part of the Ig molecule
C Bind to Fc receptors
D Are concerned in antigen recognition
E Occur at the C-terminal end of the Ig peptide chains
D Are concerned in antigen recognition
4. Which of the following gene clusters do NOT contribute to antigen binding?
A VL
B CL
C VH
D D
E J
B CL
5. Recombination of V, D, and J Ig gene segments:
A Only occurs in mature B-cells
B Only occurs in light chains
C Involves heptamer-spacer-heptamer flanking sequences
D Does not occur until the mRNA stage
E Is effected by recombinase enzymes
E Is effected by recombinase enzymes
6. Ig idiotypes are found:
A In the constant region of the heavy chain
B In the constant region of the light chain
C In the hinge region
D In the variable region of both heavy and light chains
E Only in the light chain
D In the variable region of both heavy and light chains
7. With reference to the variable Ig domain, which of the following statements is FALSE?
A It mediates the secondary consequences of antigen recognition
B It has anti-parallel beta-pleated sheet structures
C It uses beta-turn loops to bind antigen
D It has an extra long beta-turn relative to constant region domains
E It has a typical Ig fold with an intra-chain disulfide bond
A It mediates the secondary consequences of antigen recognition
8. Which of the following statements does NOT apply to IgG?
A Appears early in the primary immune response
B Neutralizes bacterial toxins
C Can fix complement
D Crosses the human placenta
E Opsonizes bacteria
A Appears early in the primary immune response
9. The low affinity FcγRII IgG receptor:
A Has a glycosyl phosphatidylinositol (GPI) anchor
B Binds monomeric IgE
C Avidly binds monomeric IgG
D Binds aggregated IgG
E Is not present on macrophages
D Binds aggregated IgG
10. IgA in seromucus secretions:
A Has no J-chain
B Has no secretory piece
C Is dimeric
D Cannot bind to neutrophils
E Activates the classical complement pathway
C Is dimeric
11. Which of the following statements is TRUE of IgM?
A IgM is usually of high intrinsic affinity
B IgM is most commonly tetrameric
C IgM has the same number of constant domains as IgG
D IgM is a weak bacterial agglutinator
E IgM is the main class of the natural antibodies
E IgM is the main class of the natural antibodies
12. Which of the following statements is TRUE of IgD?
A IgD is pentameric
B IgD is resistant to proteolytic degradation
C IgD is present mainly as a surface receptor on B-cells
D IgD is present with unusual frequency in myelomas
E IgD is abundant in milk
C IgD is present mainly as a surface receptor on B-cells
13. Which of the following statements is TRUE of IgE?
A IgE is abundant in saliva
B IgE binds strongly to mast cells
C IgE cannot bind to macrophages
D IgE activates the complement cascade
E IgE has an insignificant role in worm infestations
B IgE binds strongly to mast cells
14. Which of the following Fc receptors has the highest affinity?
A CD64
B FcγRII
C CD16
D FcϵRI
E CD23
D FcϵRI
15. Cleavage of IgG by papain produces:
A Divalent antigen binding fragments
B Isolated light chains
C Isolated heavy chains
D F(ab′)2
E Fab
E Fab
