1
BIOL 117 FINAL Questions with Answers (100%
Correct Answers)
How do animals initially prevent infection? Answer: By establishing
barriers that prevent the entry of pathogens.
What role do pattern-recognition receptors play in innate immunity?
Answer: They recognize pathogen-associated molecules to trigger the
innate immune response.
What occurs during the inflammatory response? Answer: White blood
cells endocytose foreign material and release cytokines to recruit more
phagocytic cells.
Which cells are central to the vertebrate adaptive immune response?
Answer: T cells and B cells.
How do T cells and B cells recognize specific antigens? Answer:
Through unique receptors on their surfaces that bind to specific
epitopes.
What process generates the diversity of T-cell and B-cell receptors?
Answer: Gene recombination (rearrangement of gene segments).
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,2
Why can the adaptive immune system respond to so many different
antigens? Answer: Each receptor formed through gene recombination
is slightly different, creating vast diversity.
What does the clonal selection theory explain? Answer: How the most
appropriate immune cells are selected and replicated to control
infection.
How are T cells activated? Answer: When their receptors recognize
epitopes presented on MHC proteins of antigen-presenting cells, along
with secondary signals from cytokines.
How are B cells activated? Answer: By binding free antigens with their
receptors, and often require helper T cell activation for full
differentiation.
Into what do activated B cells typically differentiate? Answer: Plasma
cells and memory cells.
How are extracellular pathogens eliminated? Answer: Through
phagocytosis and substances secreted in the humoral response,
including antibodies.
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, 3
Name three ways antibodies help eliminate pathogens. Answer:
Opsonizing, neutralizing, and agglutinating pathogens, or co-
stimulating complement proteins.
How are intracellular pathogens eliminated? Answer: Through the cell-
mediated response by cytotoxic T cells inducing apoptosis of infected
host cells.
Why does the immune system reject blood transfusions or tissue
transplants? Answer: Due to the presence of nonself molecules (cell-
surface glycoproteins or MHC proteins) or absence of self molecules.
What enables a faster immune response during future infections by the
same pathogen? Answer: Memory lymphocytes produced during a
primary infection or vaccination.
What are allergies? Answer: Abnormal immune responses to harmless
antigens called allergens.
What happens in autoimmune diseases? Answer: Lymphocytes
mistakenly initiate an immune response against the body's own tissues.
© 2025 All rights reserved
BIOL 117 FINAL Questions with Answers (100%
Correct Answers)
How do animals initially prevent infection? Answer: By establishing
barriers that prevent the entry of pathogens.
What role do pattern-recognition receptors play in innate immunity?
Answer: They recognize pathogen-associated molecules to trigger the
innate immune response.
What occurs during the inflammatory response? Answer: White blood
cells endocytose foreign material and release cytokines to recruit more
phagocytic cells.
Which cells are central to the vertebrate adaptive immune response?
Answer: T cells and B cells.
How do T cells and B cells recognize specific antigens? Answer:
Through unique receptors on their surfaces that bind to specific
epitopes.
What process generates the diversity of T-cell and B-cell receptors?
Answer: Gene recombination (rearrangement of gene segments).
© 2025 All rights reserved
,2
Why can the adaptive immune system respond to so many different
antigens? Answer: Each receptor formed through gene recombination
is slightly different, creating vast diversity.
What does the clonal selection theory explain? Answer: How the most
appropriate immune cells are selected and replicated to control
infection.
How are T cells activated? Answer: When their receptors recognize
epitopes presented on MHC proteins of antigen-presenting cells, along
with secondary signals from cytokines.
How are B cells activated? Answer: By binding free antigens with their
receptors, and often require helper T cell activation for full
differentiation.
Into what do activated B cells typically differentiate? Answer: Plasma
cells and memory cells.
How are extracellular pathogens eliminated? Answer: Through
phagocytosis and substances secreted in the humoral response,
including antibodies.
© 2025 All rights reserved
, 3
Name three ways antibodies help eliminate pathogens. Answer:
Opsonizing, neutralizing, and agglutinating pathogens, or co-
stimulating complement proteins.
How are intracellular pathogens eliminated? Answer: Through the cell-
mediated response by cytotoxic T cells inducing apoptosis of infected
host cells.
Why does the immune system reject blood transfusions or tissue
transplants? Answer: Due to the presence of nonself molecules (cell-
surface glycoproteins or MHC proteins) or absence of self molecules.
What enables a faster immune response during future infections by the
same pathogen? Answer: Memory lymphocytes produced during a
primary infection or vaccination.
What are allergies? Answer: Abnormal immune responses to harmless
antigens called allergens.
What happens in autoimmune diseases? Answer: Lymphocytes
mistakenly initiate an immune response against the body's own tissues.
© 2025 All rights reserved
