BI
,OL331/BIOL 331 Module 3
Pathophysiology | Portage |Q&A| 26/27
1. A cell biologist is studying the body's first line of defense against pathogens. Which characteristic
best distinguishes innate immunity from adaptive immunity?
A) It responds immediately and lacks specificity
B) It develops memory after initial exposure
C) It relies on B and T lymphocytes for antigen recognition
D) It requires clonal expansion for effective response
Correct Answer: It responds immediately and lacks specificity
Rationale: Innate immunity provides immediate, non-specific protection against pathogens. Adaptive
immunity is characterized by antigen specificity, immunological memory, and clonal expansion
involving B and T lymphocytes, making those options incorrect descriptions of innate immunity.
2. A researcher is examining the mechanisms by which the innate immune system recognizes
conserved microbial structures. Which receptors are primarily responsible for this recognition?
A) T cell receptors
B) B cell receptors
C) Toll-like receptors
D) Cytokine receptors
,Correct Answer: Toll-like receptors
Rationale: Toll-like receptors (TLRs) are pattern recognition receptors that detect conserved microbial
motifs known as pathogen-associated molecular patterns (PAMPs). T cell and B cell receptors are
components of adaptive immunity, and cytokine receptors bind signaling molecules, making them
incorrect.
3. During an infection, a specific cytokine is released that stimulates inflammation, fever, and liver
production of acute-phase proteins. Which cytokine profile is responsible for these effects?
A) IL-4 and IL-5
B) TNF-α, IL-1, and IL-6
C) IFN-γ and TGF-β
D) IL-10 and IL-12
Correct Answer: TNF-α, IL-1, and IL-6
Rationale: TNF-α, IL-1, and IL-6 are key pro-inflammatory cytokines that initiate fever and the acute-
phase response. IL-4 and IL-5 drive allergic responses, IFN-γ activates macrophages, TGF-β is
immunosuppressive, and IL-10 is anti-inflammatory, making them incorrect.
4. Which innate immune cells are the first to arrive at an infection site and perform phagocytosis?
A) Macrophages
B) Dendritic cells
C) Neutrophils
, D) Natural killer cells
Correct Answer: Neutrophils
Rationale: Neutrophils are the earliest responders to infection, quickly engulfing and destroying
pathogens. Macrophages arrive later, dendritic cells are antigen-presenting cells, and natural killer
cells target infected cells, making them incorrect for this early phagocytic role.
5. Which cytokines are key for antiviral defense in innate immunity?
A) IL-4 and IL-5
B) IFN-α and IFN-β
C) TNF-α and IL-1
D) IL-10 and IL-12
Correct Answer: IFN-α and IFN-β
Rationale: Type I interferons (α, β) inhibit viral replication and activate NK cells, making them central
in antiviral defense. IL-4 and IL-5 drive allergic responses, TNF-α and IL-1 mediate inflammation, and
IL-10 is anti-inflammatory, making them incorrect.
6. Which of the following is NOT a function of the complement system?
A) Opsonization
B) Microbial lysis via membrane attack complex
C) Antibody production
,OL331/BIOL 331 Module 3
Pathophysiology | Portage |Q&A| 26/27
1. A cell biologist is studying the body's first line of defense against pathogens. Which characteristic
best distinguishes innate immunity from adaptive immunity?
A) It responds immediately and lacks specificity
B) It develops memory after initial exposure
C) It relies on B and T lymphocytes for antigen recognition
D) It requires clonal expansion for effective response
Correct Answer: It responds immediately and lacks specificity
Rationale: Innate immunity provides immediate, non-specific protection against pathogens. Adaptive
immunity is characterized by antigen specificity, immunological memory, and clonal expansion
involving B and T lymphocytes, making those options incorrect descriptions of innate immunity.
2. A researcher is examining the mechanisms by which the innate immune system recognizes
conserved microbial structures. Which receptors are primarily responsible for this recognition?
A) T cell receptors
B) B cell receptors
C) Toll-like receptors
D) Cytokine receptors
,Correct Answer: Toll-like receptors
Rationale: Toll-like receptors (TLRs) are pattern recognition receptors that detect conserved microbial
motifs known as pathogen-associated molecular patterns (PAMPs). T cell and B cell receptors are
components of adaptive immunity, and cytokine receptors bind signaling molecules, making them
incorrect.
3. During an infection, a specific cytokine is released that stimulates inflammation, fever, and liver
production of acute-phase proteins. Which cytokine profile is responsible for these effects?
A) IL-4 and IL-5
B) TNF-α, IL-1, and IL-6
C) IFN-γ and TGF-β
D) IL-10 and IL-12
Correct Answer: TNF-α, IL-1, and IL-6
Rationale: TNF-α, IL-1, and IL-6 are key pro-inflammatory cytokines that initiate fever and the acute-
phase response. IL-4 and IL-5 drive allergic responses, IFN-γ activates macrophages, TGF-β is
immunosuppressive, and IL-10 is anti-inflammatory, making them incorrect.
4. Which innate immune cells are the first to arrive at an infection site and perform phagocytosis?
A) Macrophages
B) Dendritic cells
C) Neutrophils
, D) Natural killer cells
Correct Answer: Neutrophils
Rationale: Neutrophils are the earliest responders to infection, quickly engulfing and destroying
pathogens. Macrophages arrive later, dendritic cells are antigen-presenting cells, and natural killer
cells target infected cells, making them incorrect for this early phagocytic role.
5. Which cytokines are key for antiviral defense in innate immunity?
A) IL-4 and IL-5
B) IFN-α and IFN-β
C) TNF-α and IL-1
D) IL-10 and IL-12
Correct Answer: IFN-α and IFN-β
Rationale: Type I interferons (α, β) inhibit viral replication and activate NK cells, making them central
in antiviral defense. IL-4 and IL-5 drive allergic responses, TNF-α and IL-1 mediate inflammation, and
IL-10 is anti-inflammatory, making them incorrect.
6. Which of the following is NOT a function of the complement system?
A) Opsonization
B) Microbial lysis via membrane attack complex
C) Antibody production
