BIO 420 Final Exam 2025/2026| Real
Exam Questions with Verified Answers|
Already Graded A+
QUESTIONS ANSWERS
Immune deficiency, especially congenital or
What conditions still warrant the use of passive
acquired B-cell defects, toxin or venom exposure
immunization?
with an immediate threat to life, exposure to
pathogens that can cause
death faster than an effective immune response can develop
What is a disadvantage of attenuated vaccines? Live forms can sometimes mutate and revert to a more
virulent form in the host.
Transfer of serum from an immune individual to a susceptible
Which of the following is a form of passive
one, injection of
immunization?
rattlesnake antivenom to a snakebite victim,
infusion of cancer-specific CAR-T cells into a
cancer patient.
Which of the following is a form of active Recovery from an acute viral infection, vaccination
immunization? with attenuated measles virus, vaccination with
the killed polio virus.
What is a strategy for generating an attenuated Growth of a pathogen in abnormal laboratory conditions
vaccine?
What is the main advantage of a killed Safety
versus live vaccine?
What is meant by "herd immunity"? Vaccination of a percentage of individuals to prevent
transmission to others
Page 1
, IFN- secreted by
TH orTC cells
Cytotoxic T
Cell mediated
lymphocytes
(CTLs)
NK cells and macrophages:Has
direct antiviral activity Kill
virus-infected self cells
Kill virus-infected cells by antibody-
dependent cell-mediated
cytotoxicity (ADCC)
Which antibody isotype would be most IgG
useful for combating a systemic (blood-
borne) viral infection?
During severe hemorrhagic viral infections, Steroids inhibit immune cells resulting in less immune pathology
such as can occur during COVID19
infection, treatment with immune
suppressive steroids can reduce symptoms.
Why?
Bacterial infections rely heavily on IgG
antibodies for combating infection. Which
antibody isotype would be most useful for
combating a systemic (blood-borne)
bacterial infection?
Fungal infections often occur at mucosal IgA
surfaces. Which antibody isotype would be
most useful for combating a mucosal
fungal infection?
The most effective way to eliminate IgE
helminth infections is to expel these from the
body. This is often due to mast cell
degranulation resulting in the release of
histamines and muscle contractions that
expel the parasite. Which antibody isotype
would be most useful for combating a
helminth infection?
High doses of antigen
Other than fetal exposure, factors that Long-term persistence of
promote tolerance rather than stimulation of antigen in the host
the immune system by a given antigen Intravenous or oral
Page 2
Exam Questions with Verified Answers|
Already Graded A+
QUESTIONS ANSWERS
Immune deficiency, especially congenital or
What conditions still warrant the use of passive
acquired B-cell defects, toxin or venom exposure
immunization?
with an immediate threat to life, exposure to
pathogens that can cause
death faster than an effective immune response can develop
What is a disadvantage of attenuated vaccines? Live forms can sometimes mutate and revert to a more
virulent form in the host.
Transfer of serum from an immune individual to a susceptible
Which of the following is a form of passive
one, injection of
immunization?
rattlesnake antivenom to a snakebite victim,
infusion of cancer-specific CAR-T cells into a
cancer patient.
Which of the following is a form of active Recovery from an acute viral infection, vaccination
immunization? with attenuated measles virus, vaccination with
the killed polio virus.
What is a strategy for generating an attenuated Growth of a pathogen in abnormal laboratory conditions
vaccine?
What is the main advantage of a killed Safety
versus live vaccine?
What is meant by "herd immunity"? Vaccination of a percentage of individuals to prevent
transmission to others
Page 1
, IFN- secreted by
TH orTC cells
Cytotoxic T
Cell mediated
lymphocytes
(CTLs)
NK cells and macrophages:Has
direct antiviral activity Kill
virus-infected self cells
Kill virus-infected cells by antibody-
dependent cell-mediated
cytotoxicity (ADCC)
Which antibody isotype would be most IgG
useful for combating a systemic (blood-
borne) viral infection?
During severe hemorrhagic viral infections, Steroids inhibit immune cells resulting in less immune pathology
such as can occur during COVID19
infection, treatment with immune
suppressive steroids can reduce symptoms.
Why?
Bacterial infections rely heavily on IgG
antibodies for combating infection. Which
antibody isotype would be most useful for
combating a systemic (blood-borne)
bacterial infection?
Fungal infections often occur at mucosal IgA
surfaces. Which antibody isotype would be
most useful for combating a mucosal
fungal infection?
The most effective way to eliminate IgE
helminth infections is to expel these from the
body. This is often due to mast cell
degranulation resulting in the release of
histamines and muscle contractions that
expel the parasite. Which antibody isotype
would be most useful for combating a
helminth infection?
High doses of antigen
Other than fetal exposure, factors that Long-term persistence of
promote tolerance rather than stimulation of antigen in the host
the immune system by a given antigen Intravenous or oral
Page 2
