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IMMUNOLOGY FINAL EXAM QUESTIONS AND CORRECT ANSWERS
LATEST EDITION 2026
Immunology Final Exam — 250 Questions.
1. Which of the following is a primary lymphoid organ where T cells mature?
A. Thymus
B. Spleen
C. Lymph node
D. Tonsil
Rationale: The thymus is the primary lymphoid organ where T cell maturation and selection
occur.
2. Which of the following is a primary lymphoid organ where B cells mature in humans?
A. Bone marrow
B. Thymus
C. Spleen
D. Lymph node
Rationale: B cells mature in the bone marrow in humans.
3. Which immunoglobulin is the first produced in a primary immune response?
A. IgM
B. IgG
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C. IgA
D. IgE
Rationale: IgM is the first antibody produced during a primary immune response.
4. Which immunoglobulin is the most abundant in serum?
A. IgG
B. IgM
C. IgA
D. IgE
Rationale: IgG is the most abundant immunoglobulin in serum.
5. Which immunoglobulin crosses the placenta?
A. IgG
B. IgM
C. IgA
D. IgE
Rationale: IgG crosses the placenta, providing passive immunity to the fetus.
6. Which immunoglobulin is found in secretions such as saliva, tears, and breast milk?
A. IgA
B. IgG
C. IgM
D. IgE
Rationale: IgA is the predominant immunoglobulin in mucosal secretions.
7. Which immunoglobulin is associated with allergic reactions?
A. IgE
B. IgG
C. IgM
D. IgA
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Rationale: IgE binds to mast cells and basophils and mediates type I hypersensitivity.
8. Which immunoglobulin is a monomer on B cell surfaces?
A. IgD
B. IgM
C. IgG
D. IgA
Rationale: IgD is expressed on the surface of mature B cells as a monomer.
9. Which immunoglobulin is a pentamer?
A. IgM
B. IgG
C. IgA
D. IgE
Rationale: IgM circulates as a pentamer, giving it high avidity.
10. Which immunoglobulin is a dimer in secretions?
A. IgA
B. IgG
C. IgM
D. IgE
Rationale: Secretory IgA is a dimer linked by the J chain and secretory component.
11. Which cells produce antibodies?
A. Plasma cells
B. T cells
C. Macrophages
D. Neutrophils
Rationale: Plasma cells are differentiated B cells that produce antibodies.
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12. Which cells are the primary antigen-presenting cells to T cells?
A. Dendritic cells
B. Neutrophils
C. Eosinophils
D. Basophils
Rationale: Dendritic cells are the most potent antigen-presenting cells.
13. Which MHC class presents endogenous antigens to CD8 T cells?
A. MHC class I
B. MHC class II
C. MHC class III
D. CD1
Rationale: MHC class I presents endogenous antigens to CD8 cytotoxic T cells.
14. Which MHC class presents exogenous antigens to CD4 T cells?
A. MHC class II
B. MHC class I
C. MHC class III
D. CD1
Rationale: MHC class II presents exogenous antigens to CD4 helper T cells.
15. Which cells are targeted by HIV?
A. CD4 T cells
B. CD8 T cells
C. B cells
D. Neutrophils
Rationale: HIV infects CD4 T cells via gp120 binding to CD4 and co-receptors.
16. Which cytokine is produced by Th1 cells?
A. IFN-gamma
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IMMUNOLOGY FINAL EXAM QUESTIONS AND CORRECT ANSWERS
LATEST EDITION 2026
Immunology Final Exam — 250 Questions.
1. Which of the following is a primary lymphoid organ where T cells mature?
A. Thymus
B. Spleen
C. Lymph node
D. Tonsil
Rationale: The thymus is the primary lymphoid organ where T cell maturation and selection
occur.
2. Which of the following is a primary lymphoid organ where B cells mature in humans?
A. Bone marrow
B. Thymus
C. Spleen
D. Lymph node
Rationale: B cells mature in the bone marrow in humans.
3. Which immunoglobulin is the first produced in a primary immune response?
A. IgM
B. IgG
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C. IgA
D. IgE
Rationale: IgM is the first antibody produced during a primary immune response.
4. Which immunoglobulin is the most abundant in serum?
A. IgG
B. IgM
C. IgA
D. IgE
Rationale: IgG is the most abundant immunoglobulin in serum.
5. Which immunoglobulin crosses the placenta?
A. IgG
B. IgM
C. IgA
D. IgE
Rationale: IgG crosses the placenta, providing passive immunity to the fetus.
6. Which immunoglobulin is found in secretions such as saliva, tears, and breast milk?
A. IgA
B. IgG
C. IgM
D. IgE
Rationale: IgA is the predominant immunoglobulin in mucosal secretions.
7. Which immunoglobulin is associated with allergic reactions?
A. IgE
B. IgG
C. IgM
D. IgA
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Rationale: IgE binds to mast cells and basophils and mediates type I hypersensitivity.
8. Which immunoglobulin is a monomer on B cell surfaces?
A. IgD
B. IgM
C. IgG
D. IgA
Rationale: IgD is expressed on the surface of mature B cells as a monomer.
9. Which immunoglobulin is a pentamer?
A. IgM
B. IgG
C. IgA
D. IgE
Rationale: IgM circulates as a pentamer, giving it high avidity.
10. Which immunoglobulin is a dimer in secretions?
A. IgA
B. IgG
C. IgM
D. IgE
Rationale: Secretory IgA is a dimer linked by the J chain and secretory component.
11. Which cells produce antibodies?
A. Plasma cells
B. T cells
C. Macrophages
D. Neutrophils
Rationale: Plasma cells are differentiated B cells that produce antibodies.
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12. Which cells are the primary antigen-presenting cells to T cells?
A. Dendritic cells
B. Neutrophils
C. Eosinophils
D. Basophils
Rationale: Dendritic cells are the most potent antigen-presenting cells.
13. Which MHC class presents endogenous antigens to CD8 T cells?
A. MHC class I
B. MHC class II
C. MHC class III
D. CD1
Rationale: MHC class I presents endogenous antigens to CD8 cytotoxic T cells.
14. Which MHC class presents exogenous antigens to CD4 T cells?
A. MHC class II
B. MHC class I
C. MHC class III
D. CD1
Rationale: MHC class II presents exogenous antigens to CD4 helper T cells.
15. Which cells are targeted by HIV?
A. CD4 T cells
B. CD8 T cells
C. B cells
D. Neutrophils
Rationale: HIV infects CD4 T cells via gp120 binding to CD4 and co-receptors.
16. Which cytokine is produced by Th1 cells?
A. IFN-gamma
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