PCB 3233 Immunology Exam 2 Preparation 2026 – UCF
1. Which of the following is a hallmark of the adaptive immune system but not
the innate immune system?
A. Phagocytosis
B. Immunological memory
C. Inflammation
D. Cytokine production
Answer: B
Rationale: Adaptive immunity is characterized by specificity and memory, allowing for a
faster and stronger response upon re-exposure to a pathogen.
2. Where do T cells undergo their primary maturation process?
A. Lymph nodes
B. Bone marrow
C. Spleen
D. Thymus
Answer: D
Rationale: While T cell precursors originate in the bone marrow, they migrate to the
thymus to undergo selection and maturation.
,3. Which class of immunoglobulin is the only one capable of crossing the
placenta to provide passive immunity to a fetus?
A. IgM
B. IgE
C. IgA
D. IgG
Answer: D
Rationale: IgG is the only antibody class that crosses the placenta due to specific neonatal
Fc receptors (FcRn).
4. Which antibody isotype is produced first during a primary immune response?
A. IgM
B. IgA
C. IgE
D. IgG
Answer: A
Rationale: IgM is the first antibody secreted by B cells during the initial exposure to an
antigen before isotype switching occurs.
5. Which cell type is primarily responsible for Antibody-Dependent Cellular
Cytotoxicity (ADCC)?
A. B cells
B. Helper T cells
C. Natural Killer (NK) cells
D. Basophils
Answer: C
Rationale: NK cells use their CD16 (Fc receptor) to bind to antibody-coated target cells and
induce apoptosis.
, 6. MHC Class I molecules are composed of which two components?
A. Alpha chain and Beta-2 microglobulin
B. Alpha chain and Beta chain
C. Alpha chain and Gamma chain
D. Two Beta chains
Answer: A
Rationale: MHC Class I consists of a polymorphic heavy alpha chain and a non-
polymorphic beta-2 microglobulin molecule.
7. MHC Class II molecules are primarily expressed on which types of cells?
A. All nucleated cells
B. Professional Antigen-Presenting Cells (APCs)
C. Red blood cells
D. Neurons only
Answer: B
Rationale: MHC II expression is limited to professional APCs like dendritic cells,
macrophages, and B cells to facilitate helper T cell activation.
8. Which enzyme complex is essential for the V(D)J recombination process in B
and T cell development?
A. DNA Ligase IV
B. RAG-1 and RAG-2
C. Artemis
D. TdT
Answer: B
Rationale: Recombination Activating Genes (RAG-1 and RAG-2) recognize recombination
signal sequences (RSS) to initiate the DNA cleavage required for diversity.
1. Which of the following is a hallmark of the adaptive immune system but not
the innate immune system?
A. Phagocytosis
B. Immunological memory
C. Inflammation
D. Cytokine production
Answer: B
Rationale: Adaptive immunity is characterized by specificity and memory, allowing for a
faster and stronger response upon re-exposure to a pathogen.
2. Where do T cells undergo their primary maturation process?
A. Lymph nodes
B. Bone marrow
C. Spleen
D. Thymus
Answer: D
Rationale: While T cell precursors originate in the bone marrow, they migrate to the
thymus to undergo selection and maturation.
,3. Which class of immunoglobulin is the only one capable of crossing the
placenta to provide passive immunity to a fetus?
A. IgM
B. IgE
C. IgA
D. IgG
Answer: D
Rationale: IgG is the only antibody class that crosses the placenta due to specific neonatal
Fc receptors (FcRn).
4. Which antibody isotype is produced first during a primary immune response?
A. IgM
B. IgA
C. IgE
D. IgG
Answer: A
Rationale: IgM is the first antibody secreted by B cells during the initial exposure to an
antigen before isotype switching occurs.
5. Which cell type is primarily responsible for Antibody-Dependent Cellular
Cytotoxicity (ADCC)?
A. B cells
B. Helper T cells
C. Natural Killer (NK) cells
D. Basophils
Answer: C
Rationale: NK cells use their CD16 (Fc receptor) to bind to antibody-coated target cells and
induce apoptosis.
, 6. MHC Class I molecules are composed of which two components?
A. Alpha chain and Beta-2 microglobulin
B. Alpha chain and Beta chain
C. Alpha chain and Gamma chain
D. Two Beta chains
Answer: A
Rationale: MHC Class I consists of a polymorphic heavy alpha chain and a non-
polymorphic beta-2 microglobulin molecule.
7. MHC Class II molecules are primarily expressed on which types of cells?
A. All nucleated cells
B. Professional Antigen-Presenting Cells (APCs)
C. Red blood cells
D. Neurons only
Answer: B
Rationale: MHC II expression is limited to professional APCs like dendritic cells,
macrophages, and B cells to facilitate helper T cell activation.
8. Which enzyme complex is essential for the V(D)J recombination process in B
and T cell development?
A. DNA Ligase IV
B. RAG-1 and RAG-2
C. Artemis
D. TdT
Answer: B
Rationale: Recombination Activating Genes (RAG-1 and RAG-2) recognize recombination
signal sequences (RSS) to initiate the DNA cleavage required for diversity.
