Page 1 of 59
IMMUNOLOGY & SEROLOGY EXAM QUESTIONS AND CORRECT
ANSWERS LATEST EDITION 2026
Immunology & Serology —Questions
Chapter 1: Basic Immunology and Innate Immunity
1. What is the primary function of the immune system?
A) Defense against pathogens
B) Transport of oxygen
C) Blood clotting
D) Hormone production
Answer: A
Rationale: The primary function of the immune system is defense against pathogens, including
bacteria, viruses, fungi, and parasites.
2. What is innate immunity?
A) Non-specific, immediate defense
B) Specific, delayed defense
C) Antibody-mediated defense
D) T-cell mediated defense
Answer: A
Rationale: Innate immunity is non-specific and immediate, providing the first line of defense.
3. What is adaptive immunity?
A) Non-specific, immediate defense
B) Specific, delayed defense
C) Antibody-mediated defense
D) T-cell mediated defense
1|Page
,Page 2 of 59
Answer: B
Rationale: Adaptive immunity is specific and delayed, providing long-lasting protection and
memory.
4. Which cells are the first responders of innate immunity?
A) Neutrophils
B) Lymphocytes
C) Plasma cells
D) Memory cells
Answer: A
Rationale: Neutrophils are the first responders of innate immunity, phagocytosing pathogens.
5. What is the role of macrophages in innate immunity?
A) Phagocytosis and antigen presentation
B) Antibody production
C) Cytokine production only
D) Complement activation
Answer: A
Rationale: Macrophages phagocytose pathogens and present antigens to T cells.
6. What is the role of dendritic cells in innate immunity?
A) Antigen presentation
B) Antibody production
C) Phagocytosis only
D) Complement activation
Answer: A
Rationale: Dendritic cells are the most potent antigen-presenting cells, linking innate and
adaptive immunity.
7. What is the role of natural killer (NK) cells?
A) Kill virus-infected and tumor cells
B) Produce antibodies
C) Phagocytose bacteria
D) Present antigens
Answer: A
Rationale: NK cells kill virus-infected and tumor cells without prior sensitization.
2|Page
,Page 3 of 59
8. What is the role of complement in innate immunity?
A) Opsonization, chemotaxis, and cell lysis
B) Antibody production
C) Antigen presentation
D) Phagocytosis only
Answer: A
Rationale: Complement proteins opsonize pathogens, attract phagocytes (chemotaxis), and
form membrane attack complexes (cell lysis).
9. What is the role of interferons in innate immunity?
A) Antiviral defense
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: Interferons are cytokines that provide antiviral defense by inhibiting viral replication.
10. What is the role of interleukin-1 (IL-1) in innate immunity?
A) Fever and inflammation
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: IL-1 is a proinflammatory cytokine that induces fever and inflammation.
11. What is the role of tumor necrosis factor-alpha (TNF-α) in innate immunity?
A) Inflammation and fever
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: TNF-α is a proinflammatory cytokine that induces inflammation and fever.
12. What is the role of interleukin-6 (IL-6) in innate immunity?
A) Acute-phase response
B) Antibody production
3|Page
, Page 4 of 59
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: IL-6 induces the acute-phase response, including production of C-reactive protein.
13. What is the role of C-reactive protein (CRP) in innate immunity?
A) Opsonization
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: CRP is an acute-phase protein that opsonizes pathogens and activates complement.
14. What is the role of mannose-binding lectin (MBL) in innate immunity?
A) Opsonization and complement activation
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: MBL binds mannose on pathogens, opsonizing them and activating complement.
15. What is the role of toll-like receptors (TLRs) in innate immunity?
A) Recognize pathogen-associated molecular patterns
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: TLRs recognize pathogen-associated molecular patterns (PAMPs) and activate innate
immune responses.
16. What is the role of neutrophils in innate immunity?
A) Phagocytosis
B) Antibody production
C) Antigen presentation
D) Complement activation
4|Page
IMMUNOLOGY & SEROLOGY EXAM QUESTIONS AND CORRECT
ANSWERS LATEST EDITION 2026
Immunology & Serology —Questions
Chapter 1: Basic Immunology and Innate Immunity
1. What is the primary function of the immune system?
A) Defense against pathogens
B) Transport of oxygen
C) Blood clotting
D) Hormone production
Answer: A
Rationale: The primary function of the immune system is defense against pathogens, including
bacteria, viruses, fungi, and parasites.
2. What is innate immunity?
A) Non-specific, immediate defense
B) Specific, delayed defense
C) Antibody-mediated defense
D) T-cell mediated defense
Answer: A
Rationale: Innate immunity is non-specific and immediate, providing the first line of defense.
3. What is adaptive immunity?
A) Non-specific, immediate defense
B) Specific, delayed defense
C) Antibody-mediated defense
D) T-cell mediated defense
1|Page
,Page 2 of 59
Answer: B
Rationale: Adaptive immunity is specific and delayed, providing long-lasting protection and
memory.
4. Which cells are the first responders of innate immunity?
A) Neutrophils
B) Lymphocytes
C) Plasma cells
D) Memory cells
Answer: A
Rationale: Neutrophils are the first responders of innate immunity, phagocytosing pathogens.
5. What is the role of macrophages in innate immunity?
A) Phagocytosis and antigen presentation
B) Antibody production
C) Cytokine production only
D) Complement activation
Answer: A
Rationale: Macrophages phagocytose pathogens and present antigens to T cells.
6. What is the role of dendritic cells in innate immunity?
A) Antigen presentation
B) Antibody production
C) Phagocytosis only
D) Complement activation
Answer: A
Rationale: Dendritic cells are the most potent antigen-presenting cells, linking innate and
adaptive immunity.
7. What is the role of natural killer (NK) cells?
A) Kill virus-infected and tumor cells
B) Produce antibodies
C) Phagocytose bacteria
D) Present antigens
Answer: A
Rationale: NK cells kill virus-infected and tumor cells without prior sensitization.
2|Page
,Page 3 of 59
8. What is the role of complement in innate immunity?
A) Opsonization, chemotaxis, and cell lysis
B) Antibody production
C) Antigen presentation
D) Phagocytosis only
Answer: A
Rationale: Complement proteins opsonize pathogens, attract phagocytes (chemotaxis), and
form membrane attack complexes (cell lysis).
9. What is the role of interferons in innate immunity?
A) Antiviral defense
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: Interferons are cytokines that provide antiviral defense by inhibiting viral replication.
10. What is the role of interleukin-1 (IL-1) in innate immunity?
A) Fever and inflammation
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: IL-1 is a proinflammatory cytokine that induces fever and inflammation.
11. What is the role of tumor necrosis factor-alpha (TNF-α) in innate immunity?
A) Inflammation and fever
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: TNF-α is a proinflammatory cytokine that induces inflammation and fever.
12. What is the role of interleukin-6 (IL-6) in innate immunity?
A) Acute-phase response
B) Antibody production
3|Page
, Page 4 of 59
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: IL-6 induces the acute-phase response, including production of C-reactive protein.
13. What is the role of C-reactive protein (CRP) in innate immunity?
A) Opsonization
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: CRP is an acute-phase protein that opsonizes pathogens and activates complement.
14. What is the role of mannose-binding lectin (MBL) in innate immunity?
A) Opsonization and complement activation
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: MBL binds mannose on pathogens, opsonizing them and activating complement.
15. What is the role of toll-like receptors (TLRs) in innate immunity?
A) Recognize pathogen-associated molecular patterns
B) Antibody production
C) Antigen presentation
D) Phagocytosis
Answer: A
Rationale: TLRs recognize pathogen-associated molecular patterns (PAMPs) and activate innate
immune responses.
16. What is the role of neutrophils in innate immunity?
A) Phagocytosis
B) Antibody production
C) Antigen presentation
D) Complement activation
4|Page
