Which of the following is not a function of the innate
immune system?
A. Physical and chemical barriers
B.
Cellular response to infection
C. Activation of adaptive
immunity
D. Production of antibodies
D. Production of antibodies
Why is the MHC necessary for immune function?
A. It produces
cytokines
B. It activates T cells by presenting antigens
C. It allows B cells to recognize soluble antigens
D. It
inhibits adaptive immunity
B. It activates T cells by presenting antigens
Which statement correctly compares BCR and TCR?
A. Both require
MHC to recognize antigen
B. BCRs recognize only MHC-bound
antigens
C. TCRs recognize only MHC-bound antigens
D. TCRs
can recognize soluble antigens
C. TCRs recognize only MHC-bound antigens
What does self-MHC restriction mean?
A. T
cells ignore all self-antigens
B. T cells recognize only foreign
antigens on self-MHC molecules
C. B cells can recognize any
antigen
D. MHC molecules are only found on red blood cells
B. T cells recognize only foreign antigens on self-MHC molecules
MHC Class I molecules present antigens to which type of T cell?
A. CD4+ Helper T cells
B. CD8+ Cytotoxic T cells
C.
Regulatory T cells
D. NK cells
B. CD8+ Cytotoxic T cells
MHC Class II molecules are expressed primarily on:
A. All
nucleated cells
B. Red blood cells
C. Antigen-presenting
cells (APCs)
D. Muscle cells
C. Antigen-presenting cells (APCs)
Which of the following correctly lists the components of MHC
Class I?
A. Alpha (α) chain and Beta chain
B.
Alpha chain and β2 microglobulin
C. Two alpha chains
D.
Two beta chains
B. Alpha chain and β2 microglobulin
The binding groove of the MHC molecule is important
because it:
A. Degrades the antigen
B. Holds and presents
the peptide antigen to T cells
C. Produces cytokines
D.
Activates B cells directly
B. Holds and presents the peptide antigen to T cells
Which of the following accurately describes MHC inheritance?
A.
Only paternal alleles are expressed
B. Only maternal alleles are
expressed
C. Co-dominant expression of both maternal and
paternal alleles
D. Recessive inheritance of one allele
C. Co-dominant expression of both maternal and paternal alleles
What is the heterozygote advantage in MHC
genetics?
A. Having two identical alleles increases immune
diversity
B. Having two different alleles allows presentation of
a wider variety of peptides
C. It decreases peptide
diversity
D. It prevents MHC promiscuity
B. Having two different alleles allows presentation of a wider variety of peptides
The three main functions of the innate immune system are ________, ________, and ________.
Physical and chemical barriers, cellular response to infection, activation of the adaptive immune system
MHC Class I molecules are found on ________ cells and present antigen to ________ T cells.
Nucleated cells; CD8+ cytotoxic T cells
MHC Class II molecules are found on ________ cells and present antigen to ________ T cells.
Antigen-presenting cells (B cells, macrophages, dendritic cells); CD4+ helper T cells
The central dogma of biology is ________ → ________ → ________
DNA → RNA → Protein
The term for multiple versions of a gene is ________, and the resulting protein variants are called ________
Allele; Allotype
The human MHC complex is called ________, and is organized into Classes I, II, and III.
HLA (Human Leukocyte Antigen)
Class I MHC genes include HLA- , HLA-, and HLA-_____
A, B, C
Class II MHC genes include HLA- , HLA-, and HLA-_____.
DP, DQ, DR
A set of alleles usually inherited together is called a _______.
Haplotype
The ability of one MHC molecule to bind multiple peptide antigens is called ________.
Promiscuity
Explain how MHC Class I and II molecules differ in structure and function.
- MHC I: 1 α chain + β2-microglobulin; all nucleated cells; presents to CD8+ cytotoxic T cells.
- MHC II: α + β chains; on APCs (B cells, macrophages, dendritic cells); presents to CD4+ helper T cells.
Describe the process of antigen presentation from pathogen entry to T-cell activation.
Antigen is broken into peptides → loaded onto MHC → MHC–peptide complex displayed on cell surface → recognized by TCR.
Explain the relationship between MHC diversity, promiscuity, and heterozygote advantage.
- Diversity: many MHC variants in a population.
- Promiscuity: one MHC can bind many peptides.
- Heterozygote advantage: more alleles = more peptides recognized.
Why is it important that MHC genes are co-dominantly expressed?
Co-dominance allows both parental alleles to be expressed → broader antigen presentation → stronger immune defense.
What are MHC anchor residues, and why are they more important for Class I molecules?
Anchor residues = peptide amino acids that bind to specific MHC pockets; key for MHC I peptide binding; ensure stable antigen presentation.
A researcher discovers that a group of mice are genetically identical except for one MHC gene. What term describes these mice? Explain how this helps in immunological experiments.
Congenic mice: genetically identical except for one locus; used to study immune responses to specific genes (like MHC).
A patient’s cytotoxic T cells fail to recognize virus-infected cells, but helper T cells function normally. Propose a likely defect and explain your reasoning.
Likely defect in MHC Class I expression → CD8+ T cells not activated; CD4+ T cells unaffected (MHC II still normal).
- If a population has very little MHC polymorphism, what would be the likely consequence for disease resistance?
Reduced MHC polymorphism → weaker immune defense → higher infection rates and less pathogen recognition diversity.