This set of Immunology Multiple Choice Questions & Answers (MCQs) focuses on “General Organization and Inheritance of MHC”.
1. In humans, what are MHCs called as ___________
a) HHC
b) HLA
c) HAT
d) HPFC
View Answer
Explanation: In humans, MHCs are known as HLAs, Human Leukocyte Antigens. These are present/located and also are controlled by the genes on the short arm of chromosome 6.
2. In mice, what are MHCs called as __________
a) H-1
b) H-2
c) H-3
d) H-4
View Answer
Explanation: In humans, MHCs are known as H-2 complexes, class II like MHCs. The major portion of these are present/located on chromosome 17 where the T complexes are also present.
3. Which order are the three classes of MHCs arranged in?
a) I-II-III
b) II-III-I
c) I-III-II
d) II-I-III
View Answer
Explanation: The three classes of MHCs, i.e., class I, class II and class III are arranged in the order of class II-class III-class I in the short arm of chromosome 6. This arrangement is composed of at least 200 genes.
4. Which order are the three alleles in class I MHCs arranged in?
a) A-B-C
b) B-C-A
c) C-B-A
d) B-A-C
View Answer
Explanation: The three alleles in class I MHCs, i.e., HLA-A, HLA-B and HLA-C are arranged in the order of
HLA-B-HLA-C-HLA-A each one interacting with CD8 molecules.
5. Which order are the three alleles in class II MHCs arranged in?
a) DP-DQ-DR
b) DP-DR-DQ
c) DR-DQ-DP
d) DQ-DR-DP
View Answer
Explanation: The three alleles in class II MHCs, i.e., HLA-DP, HLA-DQ and HLA-DR are arranged in the order of HLA-DP – HLA-DQ – HLA-DR each one interacting with CD4 molecules.
6. β2 microglobulin is on the ____________
a) chromosome 6
b) chromosome 9
c) chromosome 12
d) chromosome 15
View Answer
Explanation: When all the MHC molecules are found on the short arm of chromosome 6, β2 microglobulin is present on chromosome 15 and not in the HLA region. β2 microglobulin acts as a modulator to the lymphocytes.
7. HLA-E,F,G and HLA-DM,DO are called non classical loci.
a) True
b) False
View Answer
Explanation: HLA-E, HLA-F and HLA-G are called non classical loci of class I MHCs and HLA-DM and HLA-DO are called the non classical loci of class II MHCs.
8. Which of the following is the property of MHCs?
a) Polygenic
b) Isotypic
c) Allotypic
d) Idiotypic
View Answer
Explanation: MHC molecules are polygenic. This means that they are the genes with the same function but each one having a different structure and configuration.
9. Do all alleles of MHCs encode proteins?
a) Yes
b) No
View Answer
Explanation: Not all the alleles encode proteins. Some of them lose their function in the process of polymorphism. That is why it is hard to find two individuals with the same HLA genes.
10. MHC molecules exhibit ___________ property.
a) Allelic exclusion
b) Somatic hypermutation
c) Co-dominant expression
d) Clonal expansion
View Answer
Explanation: Expression of MHC molecules is co-dominant because of both the alleles being at the same loci and being expressed at the same time and also being able to present antigens.
Sanfoundry Global Education & Learning Series – Immunology.
To practice all areas of Immunology, here is complete set of 1000+ Multiple Choice Questions and Answers.
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