Bio 246 Exam 3 Practice | Exam Latest 2026/27
Questions & Answers | Graded A+
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1. Which characteristic best describes the immunoglobulin IgM?
IgM is the most abundant antibody in the bloodstream
IgM is involved in delayed hypersensitivity reactions
IgM is primarily found on the surface of mast cells
IgM is the first antibody produced during the primary immune
response
2. Describe the significance of phagocytosis in the context of the innate
immune response.
Phagocytosis is significant because it allows immune cells to
engulf and eliminate pathogens, thereby providing an immediate
defense against infections.
Phagocytosis is significant because it activates the adaptive immune
response.
Phagocytosis is significant as it helps in the production of
antibodies.
Phagocytosis is significant for the repair of damaged tissues.
3. What is the primary outcome of the resolution of inflammation?
Pathogen elimination
Increased blood flow
Return to homeostasis
Tissue damage
4. What do helper T cells produce to activate other immune cells?
, Cytokines
Histamines
Interferons
Antibodies
5. In a scenario where the membrane attack complex (MAC) is
dysfunctional, what would be the likely consequence for the immune
system's ability to combat infections?
Decreased inflammation response to infections.
Increased susceptibility to infections due to impaired pathogen
elimination.
Enhanced ability to fight infections through increased antibody
production.
No effect on the immune response as other mechanisms compensate.
6. Which of the following is the main function of a Th-1 cell?
Main function is to aid eosinophils and mast cells during a helminth
invasion
Main function is to aid macrophages in fighting intracellular
infections
Main function is to help stimulate b-cell proliferation- Th2 and IL5
Main function is to aid neutrophils in fighting bacteria
7. Which is the 3rd line of defense?
Evolutionary
Adaptive
Innate
Natural
8. If a pathogen evades the cleavage of C5 in the complement system, what
, potential impact could this have on the immune response?
The immune response will only be affected if C3 is also cleaved.
The immune response will be enhanced due to increased levels of C5.
The immune response may be weakened due to the lack of C5a
and C5b, which are essential for activating the complement
cascade.
The immune response will remain unchanged as C5 is not critical.
9. Which components are involved in the formation of the Membrane Attack
Complex (MAC)?
C5b, C6, C7, C8, and C9
C5a, C6, C7, C8, and C9
C1, C2, C3, C4, and C5
C3b, C4, C5, C6, and C7
10. What are the two components that C5 is cleaved into during the
complement activation process?
C6a and C6b
C4a and C4b
C3a and C3b
C5a and C5b
11. Describe how circulation contributes to the effectiveness of the immune
response.
Circulation produces antibodies that neutralize pathogens.
Circulation is responsible for recognizing pathogens in the
bloodstream.
Circulation facilitates the movement of immune cells and
antibodies to infection sites, enhancing the body's ability to
, respond to pathogens.
Circulation only transports nutrients to immune cells.
12. What is the main function of plasma cells?
Recognizing antigens
Phagocytosis
Antigen presentation
Antibody production
13. What is the primary mechanism by which host defense peptides (HDPs)
like defensins act against microbes?
They promote the production of antibodies.
They insert into microbial membranes, destabilizing them and
causing lysis.
They bind to pathogens and neutralize their toxins.
They enhance the activity of phagocytes.
14. What are PAMPs important in the immune system?:
they are presented on MHC proteins once phagocytosed
they are essential for pathogen survival
they allow pathogens to be recognised and targeted for
destruction by the immune system
they are required for pathogen docking and immune reccognition
15. Which immune cells are primarily involved in the process of
phagocytosis?
B cells and T cells
Macrophages and neutrophils
Questions & Answers | Graded A+
Instant Pdf Download
1. Which characteristic best describes the immunoglobulin IgM?
IgM is the most abundant antibody in the bloodstream
IgM is involved in delayed hypersensitivity reactions
IgM is primarily found on the surface of mast cells
IgM is the first antibody produced during the primary immune
response
2. Describe the significance of phagocytosis in the context of the innate
immune response.
Phagocytosis is significant because it allows immune cells to
engulf and eliminate pathogens, thereby providing an immediate
defense against infections.
Phagocytosis is significant because it activates the adaptive immune
response.
Phagocytosis is significant as it helps in the production of
antibodies.
Phagocytosis is significant for the repair of damaged tissues.
3. What is the primary outcome of the resolution of inflammation?
Pathogen elimination
Increased blood flow
Return to homeostasis
Tissue damage
4. What do helper T cells produce to activate other immune cells?
, Cytokines
Histamines
Interferons
Antibodies
5. In a scenario where the membrane attack complex (MAC) is
dysfunctional, what would be the likely consequence for the immune
system's ability to combat infections?
Decreased inflammation response to infections.
Increased susceptibility to infections due to impaired pathogen
elimination.
Enhanced ability to fight infections through increased antibody
production.
No effect on the immune response as other mechanisms compensate.
6. Which of the following is the main function of a Th-1 cell?
Main function is to aid eosinophils and mast cells during a helminth
invasion
Main function is to aid macrophages in fighting intracellular
infections
Main function is to help stimulate b-cell proliferation- Th2 and IL5
Main function is to aid neutrophils in fighting bacteria
7. Which is the 3rd line of defense?
Evolutionary
Adaptive
Innate
Natural
8. If a pathogen evades the cleavage of C5 in the complement system, what
, potential impact could this have on the immune response?
The immune response will only be affected if C3 is also cleaved.
The immune response will be enhanced due to increased levels of C5.
The immune response may be weakened due to the lack of C5a
and C5b, which are essential for activating the complement
cascade.
The immune response will remain unchanged as C5 is not critical.
9. Which components are involved in the formation of the Membrane Attack
Complex (MAC)?
C5b, C6, C7, C8, and C9
C5a, C6, C7, C8, and C9
C1, C2, C3, C4, and C5
C3b, C4, C5, C6, and C7
10. What are the two components that C5 is cleaved into during the
complement activation process?
C6a and C6b
C4a and C4b
C3a and C3b
C5a and C5b
11. Describe how circulation contributes to the effectiveness of the immune
response.
Circulation produces antibodies that neutralize pathogens.
Circulation is responsible for recognizing pathogens in the
bloodstream.
Circulation facilitates the movement of immune cells and
antibodies to infection sites, enhancing the body's ability to
, respond to pathogens.
Circulation only transports nutrients to immune cells.
12. What is the main function of plasma cells?
Recognizing antigens
Phagocytosis
Antigen presentation
Antibody production
13. What is the primary mechanism by which host defense peptides (HDPs)
like defensins act against microbes?
They promote the production of antibodies.
They insert into microbial membranes, destabilizing them and
causing lysis.
They bind to pathogens and neutralize their toxins.
They enhance the activity of phagocytes.
14. What are PAMPs important in the immune system?:
they are presented on MHC proteins once phagocytosed
they are essential for pathogen survival
they allow pathogens to be recognised and targeted for
destruction by the immune system
they are required for pathogen docking and immune reccognition
15. Which immune cells are primarily involved in the process of
phagocytosis?
B cells and T cells
Macrophages and neutrophils
