Immunology: Immunoglobulin Gene Structure and Diversity MCQ

Immunoglobulin Structure and Genetic Diversity: Multiple Choice Questions

1) Immunoglobulins are produced by plasma cells differentiated from plasma cells and committed towards specific antibodies. 
Which of the following statement is TRUE regarding the genes for these antibodies?
a) The specificity of the antibodies is predetermined by the set of genes before exposure to antigen.
b) The diversity is governed by the set of separate genes i.e. each gene encodes for its specific antibodies.
c) The antibody is encoded by the multi-gene family for the heavy and light chain and its rearrangement confers the diversity.
d) None of the above

2) The light chains of the immunoglobulins are encoded by either kappa or lambda genes. These genes consist of different segments that encode for the variable and constant domain. 
They are:
a) C-J-V
b) V-J-C
c) J-V-C
d) None of the above

3) The heavy chains of the immunoglobulins are encoded by the genes consisting of different DNA segments that encode for the variable, and the constant region. 
They are:
a) C-J-D-V
b) C-D-J-V
c) V-J-D-C
d) V-D-J-C

4) The rearrangement of antibody genes is an orderly process. During the gene expression, which of the following segment undergo the first gene arrangement?
a) The heavy chain constant region that determines the isotype
b) Heavy chain variable region that determines antibody specificity
c) The light chain constant region that provides the backbone
d) Light chain variable region that determines antibody specificity

5) Which of the following is the sequential process of gene arrangement of kappa light chain of antibody?
a) VJ joining --> Transcription --> Alternative RNA splicing --> VJC joining --> Translation
b) Transcription --> VJ joining --> Alternative RNA splicing --> VJC joining --> Translation
c) Transcription --> Alternative RNA splicing --> VJ joining --> VJC joining --> Translation
d) None of the above


6) Which of the following is the sequential process of gene arrangement of the heavy chain of antibodies?
a) Transcription --> DJ- joining --> VDJ joining -->Alternative RNA splicing --> Translation
b) VJ- joining --> VDJ joining -->Transcription --> Alternative RNA splicing --> Translation
c) DJ- joining --> VDJ joining -->Transcription --> Alternative RNA splicing --> Translation
d) None of the above

7) In humans, the gene that encodes for the heavy chain of immunoglobulin is present in chromosomes:
a) 2
b) 14
c) 22
d) None of the above

8) In humans, the genes that encode for the kappa light chain of immunoglobulin is present in chromosome:
a) 2
b) 14
c) 22
d) None of the above

9) In humans, the genes that encode for lambda light chain of immunoglobulin is present in chromosome:
a) 2
b) 14
c) 22
d) None of the above

10) In mice, the genes that encode for the heavy chain of the immunoglobulin is present in chromosome:
a) 6
b) 12
c) 16
d) None of the above

11) The recombination and gene arrangement of the immunoglobulin gene occurs at the site which consists of a unique conserved sequence known as a recombination signal sequence. 
It consists of:
a) GC-rich nucleotide sequence
b) AT-rich nucleotide sequence
c) AG-rich nucleotide sequence
d) Poly A nucleotide sequence

12) The recombination and gene arrangement requires two proteins known as RAG-1 and RAG-2. What is the function of RAG-1 &RAG-2 protein?
a) They catalyze the cleavage of one strand of the DNA
b) They catalyze the cleavage of both strands of the DNA
c) They catalyze the addition of 15 nucleotides in the junction
d) None of the above

13) In membrane-bound IgM molecules, the transmembrane and cytoplasmic segments are encoded by which of the following exons?
a) CH3 & CH4 exons
b) M1 and M2 exons
c) M1 and C1 exons
d) None of the above

14) Which of the following antibodies may be co-expressed by the B-cells?
a) IgM and IgA
b) IgM and IgD
c) IgG and IgD
d) IgG and IgE

15) The assembly of light and heavy chains into disulfide and glycosylated immunoglobulin occurs in the rough endoplasmic reticulum. 
What is the order of assembly for IgM?
a) Assembly of two heavy chains (HH) followed by light chain (LL) and H2L2
b) Assembly of one heavy chain and light (HL) followed by H2L2
c) Assembly of two heavy chains (HH) followed by light chain H2L and H2L2
d) All of the above

16) The assembly of light and heavy chains into disulfide and glycosylated immunoglobulin occurs in the rough endoplasmic reticulum. 
What is the order of assembly for IgG?
a) Assembly of two heavy chains (HH) followed by light chain (LL) and H2L2
b) Assembly of one heavy chain and light (HL) followed by H2L2
c) Assembly of two heavy chains (HH) followed by light chain H2L and H2L2
d) All of the above

17) Which of the following transcription factor binds to the immunoglobulin promoter?
a) E2B
b) Myc
c) Rb2
d) Oct1

18) Chimeric humanized monoclonal antibodies are generated using
a) Hybridoma technology
b) Recombinant DNA technology
c) Southern blot
d) Hyperimmunization

19) Which of the following results in the diversity of the antibodies?
a) Somatic hypermutation
d) Association of light and heavy chain
c) V-D-J joining
d) All of the above

20) Which of the following is true regarding the expression of immunoglobin?
a) The genes from both parents are expressed in a cell
b) The genes from one parent are expressed in a cell
c) The H and L genes are randomly derived from either parent
d) None of the above


Multiple Choice Questions Answers:-
1-c) The antibody is encoded by the multi-gene family for the heavy and light chain and its rearrangement confers the diversity 
2-b) V-J-C
3-d) None of the above
4-b) Heavy chain variable region that determines antibody specificity
5-a) VJ joining --> Transcription --> Alternative RNA splicing --> VJC joining --> Translation
6-c) Transcription --> Alternative RNA splicing --> VJ joining --> VJC joining --> Translation 
7-b) 14 
8-a) 2 
9-c) 22, 
10-b) 12
11-b) AT-rich nucleotide sequence
12-a) They catalyze the cleavage of one strand of the DNA
13-b) M1 and M2 exons
14-b) IgM and IgD 
15-a) Assembly of two heavy chains (HH) followed by light chain (LL) and H2L2 
16-c) Assembly of two heavy chains (HH) followed by light chain H2L and H2L2 
17-d) Oct1
18-b) Recombinant DNA technology
19- d) All of the above
20-b) The genes from one parent are expressed in a cell


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