,BIOD 171 Module 8 | Practice Q&A | 2026/2027 | Microbiology |
Portage Learning
1. The term "antigen" is a combination of which two words?
A) Antibody and pathogen
B) Antibody and generator
C) Antibody and genesis
D) Antibody and gene
Correct Answer: Antibody and generator
Rationale: The word "antigen" is a combination of "antibody" and
"generator." An antigen is any substance that generates an immune
response by stimulating the production of antibodies.
2. Antigens are substances that:
A) Are produced by the immune system to destroy pathogens
B) Are recognized by the immune system and trigger an immune response
C) Directly kill bacteria and viruses
D) Are only found on bacterial cell walls
Correct Answer: Are recognized by the immune system and trigger an
immune response
Rationale: An antigen is any substance that is recognized by the immune
system and triggers an immune response, typically by stimulating antibody
production. Antibodies are the proteins produced in response to antigens.
3. Antibodies are produced by which type of cells?
A) T lymphocytes
,B) B lymphocytes (plasma cells)
C) Macrophages
D) Natural killer cells
Correct Answer: B lymphocytes (plasma cells)
Rationale: Antibodies are proteins produced by B lymphocytes that have
differentiated into plasma cells. Antibodies bind specifically to antigens and
mark them for destruction.
4. Which of the following is NOT a characteristic of an antibody?
A) It is a protein
B) It is produced by plasma cells
C) It directly kills pathogens
D) It binds specifically to an antigen
Correct Answer: It directly kills pathogens
Rationale: Antibodies do not directly kill pathogens. They bind to specific
antigens, neutralizing them, marking them for opsonization, and activating
complement. Direct killing is performed by cytotoxic T cells and phagocytes.
5. The variable region of an antibody is responsible for:
A) Determining the antibody class
B) Antigen binding
C) Activating complement
D) Crossing the placenta
, Correct Answer: Antigen binding
Rationale: The variable region of an antibody is responsible for antigen
binding. The constant region determines the antibody class and mediates
effector functions such as complement activation and opsonization.
6. Which class of antibody is the most abundant in the blood and provides
long-term immunity?
A) IgA
B) IgD
C) IgE
D) IgG
Correct Answer: IgG
Rationale: IgG is the most abundant antibody class in the blood and provides
long-term immunity. It crosses the placenta to provide passive immunity to
the fetus and is involved in opsonization and complement activation.
7. Which class of antibody is the first to be produced during a primary
immune response?
A) IgG
B) IgA
C) IgM
D) IgE
Correct Answer: IgM
Portage Learning
1. The term "antigen" is a combination of which two words?
A) Antibody and pathogen
B) Antibody and generator
C) Antibody and genesis
D) Antibody and gene
Correct Answer: Antibody and generator
Rationale: The word "antigen" is a combination of "antibody" and
"generator." An antigen is any substance that generates an immune
response by stimulating the production of antibodies.
2. Antigens are substances that:
A) Are produced by the immune system to destroy pathogens
B) Are recognized by the immune system and trigger an immune response
C) Directly kill bacteria and viruses
D) Are only found on bacterial cell walls
Correct Answer: Are recognized by the immune system and trigger an
immune response
Rationale: An antigen is any substance that is recognized by the immune
system and triggers an immune response, typically by stimulating antibody
production. Antibodies are the proteins produced in response to antigens.
3. Antibodies are produced by which type of cells?
A) T lymphocytes
,B) B lymphocytes (plasma cells)
C) Macrophages
D) Natural killer cells
Correct Answer: B lymphocytes (plasma cells)
Rationale: Antibodies are proteins produced by B lymphocytes that have
differentiated into plasma cells. Antibodies bind specifically to antigens and
mark them for destruction.
4. Which of the following is NOT a characteristic of an antibody?
A) It is a protein
B) It is produced by plasma cells
C) It directly kills pathogens
D) It binds specifically to an antigen
Correct Answer: It directly kills pathogens
Rationale: Antibodies do not directly kill pathogens. They bind to specific
antigens, neutralizing them, marking them for opsonization, and activating
complement. Direct killing is performed by cytotoxic T cells and phagocytes.
5. The variable region of an antibody is responsible for:
A) Determining the antibody class
B) Antigen binding
C) Activating complement
D) Crossing the placenta
, Correct Answer: Antigen binding
Rationale: The variable region of an antibody is responsible for antigen
binding. The constant region determines the antibody class and mediates
effector functions such as complement activation and opsonization.
6. Which class of antibody is the most abundant in the blood and provides
long-term immunity?
A) IgA
B) IgD
C) IgE
D) IgG
Correct Answer: IgG
Rationale: IgG is the most abundant antibody class in the blood and provides
long-term immunity. It crosses the placenta to provide passive immunity to
the fetus and is involved in opsonization and complement activation.
7. Which class of antibody is the first to be produced during a primary
immune response?
A) IgG
B) IgA
C) IgM
D) IgE
Correct Answer: IgM
