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# MIMG C185A FINAL EXAM
## IMMUNOLOGY PRACTICE QUESTION
BANK
### 2026-2027 ACADEMIC YEAR | 200+
QUESTIONS WITH DETAILED RATIONALES
# SECTION 1: INNATE IMMUNITY & PHYSICAL BARRIERS
## Questions 1-25
### PHYSICAL & CHEMICAL BARRIERS
#### (Questions 1-6)
### Question 1
**Cognitive Level:** Remembering
Which of the following is considered the first line of defense against invading pathogens?
A) Adaptive immunity involving T cells and B cells
B) Innate immunity involving physical barriers, phagocytes, and antimicrobial proteins
C) The complement system only
D) Inflammation mediated by cytokines and chemokines
---
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**Correct Answer: B) Innate immunity involving physical barriers, phagocytes, and
antimicrobial proteins**
**Rationale for Correct Answer:** Innate immunity is the immediate, non-specific defense
present from birth. It includes physical and chemical barriers such as the skin and mucous
membranes, cellular components like phagocytes (neutrophils and macrophages), and soluble
factors such as complement proteins and interferons. This is the most comprehensive and
accurate description of the first line of defense.
**Rationale for Incorrect Answers:**
- **A) Adaptive immunity:** Adaptive immunity involves T cells and B cells that provide
specific, long-lasting immunity but is not the first line of defense; it takes days to develop a
response.
- **C) The complement system only:** The complement system is part of innate immunity, but
it is only one component and not the entire first line of defense.
- **D) Inflammation:** Inflammation is a response to infection or injury, not the primary barrier
against pathogens.
---
### Question 2
**Cognitive Level:** Understanding
Which of the following physical barriers contributes to innate immunity by providing a
mechanical barrier and producing antimicrobial peptides?
A) Mucous membranes
B) Skin
C) Ciliated epithelial cells
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D) Stomach acid
---
**Correct Answer: B) Skin**
**Rationale for Correct Answer:** The skin is the largest organ and serves as the primary
physical barrier against pathogens. It provides a mechanical barrier and produces antimicrobial
peptides such as defensins. The skin's continuous shedding of dead cells also removes attached
microorganisms.
**Rationale for Incorrect Answers:**
- **A) Mucous membranes:** While mucous membranes trap pathogens, they are not the
primary physical barrier and are found in internal surfaces.
- **C) Ciliated epithelial cells:** These cells help move mucus and trapped pathogens out of the
respiratory tract, but they are not the primary physical barrier.
- **D) Stomach acid:** Stomach acid provides a chemical barrier by destroying ingested
pathogens, but it is not a physical barrier.
---
### Question 3
**Cognitive Level:** Applying
A researcher is studying the immune response in mice infected with an extracellular bacterial
pathogen. Which cytokine profile would indicate a protective Th2-biased response?
A) High IFN-γ and TNF-β
B) High IL-4, IL-5, and IL-10
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C) High IL-2 and IL-12
D) High IFN-γ and IL-2
---
**Correct Answer: B) High IL-4, IL-5, and IL-10**
**Rationale for Correct Answer:** Extracellular bacteria are best cleared by antibody-mediated
immunity, which is promoted by Th2 cells. Th2 cells produce IL-4, IL-5, and IL-10. IL-4 drives
B-cell class switching to IgE, IL-5 activates eosinophils, and IL-10 helps dampen excessive
inflammation. A Th2 bias is therefore expected for extracellular bacterial clearance.
**Rationale for Incorrect Answers:**
- **A) High IFN-γ and TNF-β:** This profile indicates a Th1 response, which is associated with
intracellular pathogens where cell-mediated immunity is required.
- **C) High IL-2 and IL-12:** IL-12 promotes Th1 differentiation, and IL-2 is a growth factor
for T cells; this is not a Th2 profile.
- **D) High IFN-γ and IL-2:** This also indicates a Th1 response, not Th2.
---
### Question 4
**Cognitive Level:** Analyzing
A patient with a genetic deficiency in C3 would have which complement-mediated function most
severely impaired?
A) Anaphylatoxin C4a production only
B) Formation of membrane attack complex (MAC) and opsonization
# MIMG C185A FINAL EXAM
## IMMUNOLOGY PRACTICE QUESTION
BANK
### 2026-2027 ACADEMIC YEAR | 200+
QUESTIONS WITH DETAILED RATIONALES
# SECTION 1: INNATE IMMUNITY & PHYSICAL BARRIERS
## Questions 1-25
### PHYSICAL & CHEMICAL BARRIERS
#### (Questions 1-6)
### Question 1
**Cognitive Level:** Remembering
Which of the following is considered the first line of defense against invading pathogens?
A) Adaptive immunity involving T cells and B cells
B) Innate immunity involving physical barriers, phagocytes, and antimicrobial proteins
C) The complement system only
D) Inflammation mediated by cytokines and chemokines
---
,2|Page
**Correct Answer: B) Innate immunity involving physical barriers, phagocytes, and
antimicrobial proteins**
**Rationale for Correct Answer:** Innate immunity is the immediate, non-specific defense
present from birth. It includes physical and chemical barriers such as the skin and mucous
membranes, cellular components like phagocytes (neutrophils and macrophages), and soluble
factors such as complement proteins and interferons. This is the most comprehensive and
accurate description of the first line of defense.
**Rationale for Incorrect Answers:**
- **A) Adaptive immunity:** Adaptive immunity involves T cells and B cells that provide
specific, long-lasting immunity but is not the first line of defense; it takes days to develop a
response.
- **C) The complement system only:** The complement system is part of innate immunity, but
it is only one component and not the entire first line of defense.
- **D) Inflammation:** Inflammation is a response to infection or injury, not the primary barrier
against pathogens.
---
### Question 2
**Cognitive Level:** Understanding
Which of the following physical barriers contributes to innate immunity by providing a
mechanical barrier and producing antimicrobial peptides?
A) Mucous membranes
B) Skin
C) Ciliated epithelial cells
,3|Page
D) Stomach acid
---
**Correct Answer: B) Skin**
**Rationale for Correct Answer:** The skin is the largest organ and serves as the primary
physical barrier against pathogens. It provides a mechanical barrier and produces antimicrobial
peptides such as defensins. The skin's continuous shedding of dead cells also removes attached
microorganisms.
**Rationale for Incorrect Answers:**
- **A) Mucous membranes:** While mucous membranes trap pathogens, they are not the
primary physical barrier and are found in internal surfaces.
- **C) Ciliated epithelial cells:** These cells help move mucus and trapped pathogens out of the
respiratory tract, but they are not the primary physical barrier.
- **D) Stomach acid:** Stomach acid provides a chemical barrier by destroying ingested
pathogens, but it is not a physical barrier.
---
### Question 3
**Cognitive Level:** Applying
A researcher is studying the immune response in mice infected with an extracellular bacterial
pathogen. Which cytokine profile would indicate a protective Th2-biased response?
A) High IFN-γ and TNF-β
B) High IL-4, IL-5, and IL-10
, 4|Page
C) High IL-2 and IL-12
D) High IFN-γ and IL-2
---
**Correct Answer: B) High IL-4, IL-5, and IL-10**
**Rationale for Correct Answer:** Extracellular bacteria are best cleared by antibody-mediated
immunity, which is promoted by Th2 cells. Th2 cells produce IL-4, IL-5, and IL-10. IL-4 drives
B-cell class switching to IgE, IL-5 activates eosinophils, and IL-10 helps dampen excessive
inflammation. A Th2 bias is therefore expected for extracellular bacterial clearance.
**Rationale for Incorrect Answers:**
- **A) High IFN-γ and TNF-β:** This profile indicates a Th1 response, which is associated with
intracellular pathogens where cell-mediated immunity is required.
- **C) High IL-2 and IL-12:** IL-12 promotes Th1 differentiation, and IL-2 is a growth factor
for T cells; this is not a Th2 profile.
- **D) High IFN-γ and IL-2:** This also indicates a Th1 response, not Th2.
---
### Question 4
**Cognitive Level:** Analyzing
A patient with a genetic deficiency in C3 would have which complement-mediated function most
severely impaired?
A) Anaphylatoxin C4a production only
B) Formation of membrane attack complex (MAC) and opsonization
