BIOD 171 Module 6: Exam Portage Learning Questions and
Answers 2026 Practice Set
1. Which of the following is considered a "First Line of Defense" in the innate
immune system?
A) Antibodies
B) T-cells
C) Skin and mucous membranes
D) Plasma cells
Rationale: The first line of defense consists of physical and chemical barriers (like
skin, tears, and stomach acid) that prevent pathogens from entering the body.
2. Which white blood cell is typically the "first responder" to a bacterial infection
and is the primary component of pus?
A) Neutrophils
B) Basophils
C) Eosinophils
D) Monocytes
Rationale: Neutrophils are the most abundant leukocytes and utilize phagocytosis to
destroy invading bacteria at the site of injury.
3. "Opsonization" is a process that enhances phagocytosis by:
A) Killing the bacteria directly
B) Coating the pathogen with proteins (like antibodies or complement) to make it
easier for phagocytes to "grab"
C) Creating holes in the bacterial cell wall
D) Speeding up the heartbeat
Rationale: Opsonins act like "handles" or "red flags" that allow phagocytic cells to
recognize and ingest pathogens more efficiently.
4. Which type of immunity is characterized by "memory" and the ability to
recognize specific antigens?
A) Innate immunity
B) Adaptive immunity
C) Passive immunity
D) Inflammation
,Rationale: Adaptive (Acquired) immunity creates a tailored response to specific
pathogens and retains "memory cells" to respond faster during future exposures.
5. B-cells are primarily responsible for which branch of the adaptive immune
system?
A) Cell-mediated immunity
B) Humoral (antibody-mediated) immunity
C) Innate immunity
D) The Inflammatory response
Rationale: Humoral immunity involves the production of antibodies by plasma cells
(which are derived from activated B-cells) to fight pathogens in body fluids.
6. Which class of antibody is the most abundant in the blood and is the only one
capable of crossing the placenta?
A) IgA
B) IgM
C) IgG
D) IgE
Rationale: IgG provides long-term immunity and protects the fetus via passive immunity
transferred from the mother.
7. "Naturally Acquired Active Immunity" occurs when:
A) An individual is exposed to a live pathogen, gets sick, and recovers
B) An individual receives a vaccine
C) An infant receives antibodies through breast milk
D) An individual receives an injection of antiserum
Rationale: Active means the body produced its own antibodies/memory
cells; Natural means it happened through normal exposure to a disease.
8. MHC Class I molecules are found on:
A) Only B-cells and Macrophages
B) All nucleated cells in the body
C) Only red blood cells
D) Only T-cells
Rationale: MHC I acts as a "self" marker; it allows the immune system (specifically
Cytotoxic T-cells) to identify and kill virally infected or cancerous body cells.
9. Which lymphocyte is responsible for killing virally infected or cancerous cells
directly?
A) Helper T-cell (
, )
B) Cytotoxic T-cell (
)
C) B-cell
D) Memory B-cell
Rationale: Cytotoxic T-cells release perforins and granzymes to induce apoptosis (cell
suicide) in abnormal or infected "self" cells.
10. The five classic signs of "Inflammation" include redness, heat, swelling, pain,
and:
A) Bleeding
B) Shivering
C) Loss of function
D) Numbness
Rationale: Loss of function is the fifth cardinal sign of inflammation, often resulting
from pain and swelling in the affected area.
11. Which immune cell is primarily responsible for releasing "Histamine" during
an allergic reaction?
A) Neutrophil
B) Mast Cell / Basophil
C) Macrophage
D) T-helper cell
Rationale: Mast cells (in tissues) and Basophils (in blood) contain granules filled with
histamine, which triggers vasodilation and itching.
12. "Complement" proteins are part of the innate immune system and work
primarily by:
A) Making the cell grow larger
B) Creating pores in the bacterial membrane (MAC) to cause lysis
C) Producing antibodies
D) Replicating DNA
Rationale: The Membrane Attack Complex (MAC) is the end result of the complement
cascade, which literally "punches holes" in the pathogen.
13. Which class of antibody is found primarily in "Secretions" like tears, saliva,
and breast milk?
A) IgA
B) IgE
Answers 2026 Practice Set
1. Which of the following is considered a "First Line of Defense" in the innate
immune system?
A) Antibodies
B) T-cells
C) Skin and mucous membranes
D) Plasma cells
Rationale: The first line of defense consists of physical and chemical barriers (like
skin, tears, and stomach acid) that prevent pathogens from entering the body.
2. Which white blood cell is typically the "first responder" to a bacterial infection
and is the primary component of pus?
A) Neutrophils
B) Basophils
C) Eosinophils
D) Monocytes
Rationale: Neutrophils are the most abundant leukocytes and utilize phagocytosis to
destroy invading bacteria at the site of injury.
3. "Opsonization" is a process that enhances phagocytosis by:
A) Killing the bacteria directly
B) Coating the pathogen with proteins (like antibodies or complement) to make it
easier for phagocytes to "grab"
C) Creating holes in the bacterial cell wall
D) Speeding up the heartbeat
Rationale: Opsonins act like "handles" or "red flags" that allow phagocytic cells to
recognize and ingest pathogens more efficiently.
4. Which type of immunity is characterized by "memory" and the ability to
recognize specific antigens?
A) Innate immunity
B) Adaptive immunity
C) Passive immunity
D) Inflammation
,Rationale: Adaptive (Acquired) immunity creates a tailored response to specific
pathogens and retains "memory cells" to respond faster during future exposures.
5. B-cells are primarily responsible for which branch of the adaptive immune
system?
A) Cell-mediated immunity
B) Humoral (antibody-mediated) immunity
C) Innate immunity
D) The Inflammatory response
Rationale: Humoral immunity involves the production of antibodies by plasma cells
(which are derived from activated B-cells) to fight pathogens in body fluids.
6. Which class of antibody is the most abundant in the blood and is the only one
capable of crossing the placenta?
A) IgA
B) IgM
C) IgG
D) IgE
Rationale: IgG provides long-term immunity and protects the fetus via passive immunity
transferred from the mother.
7. "Naturally Acquired Active Immunity" occurs when:
A) An individual is exposed to a live pathogen, gets sick, and recovers
B) An individual receives a vaccine
C) An infant receives antibodies through breast milk
D) An individual receives an injection of antiserum
Rationale: Active means the body produced its own antibodies/memory
cells; Natural means it happened through normal exposure to a disease.
8. MHC Class I molecules are found on:
A) Only B-cells and Macrophages
B) All nucleated cells in the body
C) Only red blood cells
D) Only T-cells
Rationale: MHC I acts as a "self" marker; it allows the immune system (specifically
Cytotoxic T-cells) to identify and kill virally infected or cancerous body cells.
9. Which lymphocyte is responsible for killing virally infected or cancerous cells
directly?
A) Helper T-cell (
, )
B) Cytotoxic T-cell (
)
C) B-cell
D) Memory B-cell
Rationale: Cytotoxic T-cells release perforins and granzymes to induce apoptosis (cell
suicide) in abnormal or infected "self" cells.
10. The five classic signs of "Inflammation" include redness, heat, swelling, pain,
and:
A) Bleeding
B) Shivering
C) Loss of function
D) Numbness
Rationale: Loss of function is the fifth cardinal sign of inflammation, often resulting
from pain and swelling in the affected area.
11. Which immune cell is primarily responsible for releasing "Histamine" during
an allergic reaction?
A) Neutrophil
B) Mast Cell / Basophil
C) Macrophage
D) T-helper cell
Rationale: Mast cells (in tissues) and Basophils (in blood) contain granules filled with
histamine, which triggers vasodilation and itching.
12. "Complement" proteins are part of the innate immune system and work
primarily by:
A) Making the cell grow larger
B) Creating pores in the bacterial membrane (MAC) to cause lysis
C) Producing antibodies
D) Replicating DNA
Rationale: The Membrane Attack Complex (MAC) is the end result of the complement
cascade, which literally "punches holes" in the pathogen.
13. Which class of antibody is found primarily in "Secretions" like tears, saliva,
and breast milk?
A) IgA
B) IgE
