MIMG C185A Final Exam | Real Expert Questions
and Accurate Solutions with Well-Elaborated
Rationales | 2026 Revised Update | 100% Correct -
UCLA.
SECTION 1: MHC STRUCTURE AND ANTIGEN PRESENTATION
Q1. You work with an inbred (syngeneic) strain of mice called the UCLA mice. Their MHC locus is
organized with specific MHC I and MHC II genes. How many different types of MHC I will the UCLA mice
express on the surface of their APCs?
A) 2
B) 4
C) 6
D) 8
Answer: D) 8
Because the parents are inbred, both maternal and paternal MHC I genes are identical, meaning only the
alleles shown in the locus diagram for Class I will be expressed (including duplicated L genes). The UCLA
mice will express 8 different types of MHC I molecules on their APC surfaces .
Q2. For the same inbred UCLA mouse strain described above, how many different types of MHC II will
these animals express on the surface of their APCs?
A) 0
B) 2
C) 4
D) 8
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,Answer: A) 0
The alpha and beta chains available in the MHC II locus cannot recombine with each other. IA alpha is
only compatible with IA beta, and IE beta is only compatible with IE alpha. Since these compatible pairs
are not both present, no functional MHC II molecules are expressed .
Q3. Based on the UCLA mice's inability to express MHC II, will these animals have normal immune
responses?
A) Yes, because CD8+ T cells are unaffected
B) No, because CD4+ T cells cannot be activated
C) Yes, because B cells can still produce antibodies
D) No, because NK cells are also defective
Answer: B) No, because CD4+ T cells cannot be activated
CD4+ T cells only recognize antigens presented on MHC Class II. Without MHC II expression, CD4+ T cells
will not function. CD8+ T cells will still function since they recognize antigens on MHC Class I.
Q4. Another inbred mouse strain, the Westwood mice, cannot produce TAP1 and TAP2 proteins in any
of their cells. What type of microorganisms will these animals be susceptible to?
A) Extracellular bacteria only
B) Intracellular pathogens (viruses and intracellular bacteria)
C) Parasites only
D) No increased susceptibility
Answer: B) Intracellular pathogens
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,TAP1 and TAP2 are essential for transporting peptides into the ER for loading onto MHC Class I
molecules. Without functional MHC I presentation, CD8+ T cells cannot recognize and kill infected cells,
leading to susceptibility to intracellular pathogens.
Q5. You cross the UCLA and Westwood mice to produce hybrid UCLA/Westwood offspring that express
one allele from each parent. How many different types of MHC I will these hybrid mice express?
A) 4
B) 6
C) 8
D) 16
Answer: C) 8
Despite one allele lacking functional TAP1/2, the hybrid mice inherit functional TAP1/2 from the UCLA
parent. The Westwood mice contribute K, D, and L genes which the UCLA mice already have, so they still
express 8 different types of MHC I.
Q6. How many different types of MHC II will the UCLA/Westwood hybrid mice express?
A) 0
B) 2
C) 3
D) 6
Answer: C) 3
The UCLA strain does not express functional MHC II, but the Westwood strain has both alpha and beta
chains for IA and IE. The hybrid will express MHC II due to this contribution: IA^d and two IE^d types .
Q7. Will the UCLA/Westwood hybrid mice have normal immune responses?
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, A) Yes, they have functional MHC I and MHC II
B) No, they still lack TAP function
C) Yes, but only CD8+ responses
D) No, they lack MHC II
Answer: A) Yes, they have functional MHC I and MHC II
The hybrid mice have functional MHC I complexes (from the UCLA parent supplying TAP1/2) and
functional MHC II complexes (from the Westwood parent). Both CD4+ and CD8+ T cells will be able to
perform their immune functions.
Q8. You have two different male mice: Mouse 1 is homozygous for the k haplotype (Dk, Lk, Kk, IAk, IEk).
You mate Mouse 1 to a female (Mouse 3) that is H-2s (homozygous for s haplotype). You take skin from
a progeny and graft it onto Mouse 1. Will the graft be rejected?
A) No, because the progeny is a close relative
B) Yes, because Mouse 1 lacks the s haplotype
C) No, because all MHC genes are identical
D) Yes, because of blood type incompatibility
Answer: B) Yes, because Mouse 1 lacks the s haplotype
The progeny of Mouse 1 (kk) and Mouse 3 (ss) will be heterozygous (k/s) for the MHC haplotypes.
Mouse 1 is homozygous for the k haplotype and does not express any s haplotype MHC molecules. The
graft will therefore be recognized as foreign and rejected.
Q9. In the same experiment, you graft the skin from the k/s heterozygous progeny onto one of its
siblings. Will the graft be rejected?
A) Yes, because the sibling may have different MHC
4|Page SUCCESS!!!
and Accurate Solutions with Well-Elaborated
Rationales | 2026 Revised Update | 100% Correct -
UCLA.
SECTION 1: MHC STRUCTURE AND ANTIGEN PRESENTATION
Q1. You work with an inbred (syngeneic) strain of mice called the UCLA mice. Their MHC locus is
organized with specific MHC I and MHC II genes. How many different types of MHC I will the UCLA mice
express on the surface of their APCs?
A) 2
B) 4
C) 6
D) 8
Answer: D) 8
Because the parents are inbred, both maternal and paternal MHC I genes are identical, meaning only the
alleles shown in the locus diagram for Class I will be expressed (including duplicated L genes). The UCLA
mice will express 8 different types of MHC I molecules on their APC surfaces .
Q2. For the same inbred UCLA mouse strain described above, how many different types of MHC II will
these animals express on the surface of their APCs?
A) 0
B) 2
C) 4
D) 8
1|Page SUCCESS!!!
,Answer: A) 0
The alpha and beta chains available in the MHC II locus cannot recombine with each other. IA alpha is
only compatible with IA beta, and IE beta is only compatible with IE alpha. Since these compatible pairs
are not both present, no functional MHC II molecules are expressed .
Q3. Based on the UCLA mice's inability to express MHC II, will these animals have normal immune
responses?
A) Yes, because CD8+ T cells are unaffected
B) No, because CD4+ T cells cannot be activated
C) Yes, because B cells can still produce antibodies
D) No, because NK cells are also defective
Answer: B) No, because CD4+ T cells cannot be activated
CD4+ T cells only recognize antigens presented on MHC Class II. Without MHC II expression, CD4+ T cells
will not function. CD8+ T cells will still function since they recognize antigens on MHC Class I.
Q4. Another inbred mouse strain, the Westwood mice, cannot produce TAP1 and TAP2 proteins in any
of their cells. What type of microorganisms will these animals be susceptible to?
A) Extracellular bacteria only
B) Intracellular pathogens (viruses and intracellular bacteria)
C) Parasites only
D) No increased susceptibility
Answer: B) Intracellular pathogens
2|Page SUCCESS!!!
,TAP1 and TAP2 are essential for transporting peptides into the ER for loading onto MHC Class I
molecules. Without functional MHC I presentation, CD8+ T cells cannot recognize and kill infected cells,
leading to susceptibility to intracellular pathogens.
Q5. You cross the UCLA and Westwood mice to produce hybrid UCLA/Westwood offspring that express
one allele from each parent. How many different types of MHC I will these hybrid mice express?
A) 4
B) 6
C) 8
D) 16
Answer: C) 8
Despite one allele lacking functional TAP1/2, the hybrid mice inherit functional TAP1/2 from the UCLA
parent. The Westwood mice contribute K, D, and L genes which the UCLA mice already have, so they still
express 8 different types of MHC I.
Q6. How many different types of MHC II will the UCLA/Westwood hybrid mice express?
A) 0
B) 2
C) 3
D) 6
Answer: C) 3
The UCLA strain does not express functional MHC II, but the Westwood strain has both alpha and beta
chains for IA and IE. The hybrid will express MHC II due to this contribution: IA^d and two IE^d types .
Q7. Will the UCLA/Westwood hybrid mice have normal immune responses?
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, A) Yes, they have functional MHC I and MHC II
B) No, they still lack TAP function
C) Yes, but only CD8+ responses
D) No, they lack MHC II
Answer: A) Yes, they have functional MHC I and MHC II
The hybrid mice have functional MHC I complexes (from the UCLA parent supplying TAP1/2) and
functional MHC II complexes (from the Westwood parent). Both CD4+ and CD8+ T cells will be able to
perform their immune functions.
Q8. You have two different male mice: Mouse 1 is homozygous for the k haplotype (Dk, Lk, Kk, IAk, IEk).
You mate Mouse 1 to a female (Mouse 3) that is H-2s (homozygous for s haplotype). You take skin from
a progeny and graft it onto Mouse 1. Will the graft be rejected?
A) No, because the progeny is a close relative
B) Yes, because Mouse 1 lacks the s haplotype
C) No, because all MHC genes are identical
D) Yes, because of blood type incompatibility
Answer: B) Yes, because Mouse 1 lacks the s haplotype
The progeny of Mouse 1 (kk) and Mouse 3 (ss) will be heterozygous (k/s) for the MHC haplotypes.
Mouse 1 is homozygous for the k haplotype and does not express any s haplotype MHC molecules. The
graft will therefore be recognized as foreign and rejected.
Q9. In the same experiment, you graft the skin from the k/s heterozygous progeny onto one of its
siblings. Will the graft be rejected?
A) Yes, because the sibling may have different MHC
4|Page SUCCESS!!!
