MCB 100 Exam 3 IClicker Questions With Complete
Solutions
A commensal E. cali strain usually found as part of the normal
gut microbiota of chickens has a pilin genes (pil1) that is
responsible for attaching and colonizing chicken intestines. A
clinical isolate of the E. coli strain recently isolated from sick
pigs appears to have a new pilin gene (pil2) that allows for
infection in pigs. How would you most directly test this
hypothesis?
a. make a mutation in the pil2 gene and see if the bacterium is
still virulent in chickens, but not in pigs
b. make a mutation in the pil2 gene and see if the bacterium is
still virulent in pigs, but not in chickens
c. make a mutation in the pil1 gene and see if the bacterium is
still virulent in chickens, but not in pigs
d. make a mutation in the pil1 gene and see if the bacterium is
still virulent in both pigs and chickens
e. make a mutation in the pil2 gene and see if the bacterium is
still virulent in both pigs and chickens Correct Answers b
A mosquito bites a person who then develops fever and rash.
What type of transmission would this be?
a. mechanical transmission
b. vehicle transmission
c. zoonotic transmission
d. direct contact transmission
e. biological vector transmission Correct Answers e, c
,According to this graph of cases per capita in the first few
months of 2022, which regions in the united states had the
highest average of cases per capita between February and
march?
a. west
b. midwest
c. south
d. northeast Correct Answers a
At what stage of phagocytosis does the movie end at?
a. adhesion
b. ingestion
c. maturation
d. killing
e. elimination Correct Answers b
Carriers are dangerous because they exhibit all of the following
except:
a. they do not show signs of infection
b. they are symptomatic for infection
c. they are unaware that they are spreading disease
d. they are difficult to identify and quarantine
e. they are more common in a population than most people think
Correct Answers b
Horizontal gene transfer in influenza is more likely to cause
_______?
, a. antigenic drift
b. seasonal influenza strains
c. RNA viruses
d. antigenic shift
e. endemic disease Correct Answers d
How can b-cells become activated to produce antibodies?
a. by marcophages
b. by the complement system
c. by cells that express the MHC-I protein
d. by directly binding to the b-cell receptor
e. by t-cells secreting cytokines Correct Answers e
Inside of which tissue do antibody-producing b-cells mature?
a. tonsils
b. intestines
c. thymus
d. lymph nodes
e. bone marrow Correct Answers e
The immune system will mount a _______ antibody response to
a virus with few antigens present on its surface because the
antibodies generated will bind _______ to the virus than a virus
with few antigens on its surface.
a. more effective / more weakly
b. less effective / equivalently
c. neutral / tighter
d. more effective / more tightly
Solutions
A commensal E. cali strain usually found as part of the normal
gut microbiota of chickens has a pilin genes (pil1) that is
responsible for attaching and colonizing chicken intestines. A
clinical isolate of the E. coli strain recently isolated from sick
pigs appears to have a new pilin gene (pil2) that allows for
infection in pigs. How would you most directly test this
hypothesis?
a. make a mutation in the pil2 gene and see if the bacterium is
still virulent in chickens, but not in pigs
b. make a mutation in the pil2 gene and see if the bacterium is
still virulent in pigs, but not in chickens
c. make a mutation in the pil1 gene and see if the bacterium is
still virulent in chickens, but not in pigs
d. make a mutation in the pil1 gene and see if the bacterium is
still virulent in both pigs and chickens
e. make a mutation in the pil2 gene and see if the bacterium is
still virulent in both pigs and chickens Correct Answers b
A mosquito bites a person who then develops fever and rash.
What type of transmission would this be?
a. mechanical transmission
b. vehicle transmission
c. zoonotic transmission
d. direct contact transmission
e. biological vector transmission Correct Answers e, c
,According to this graph of cases per capita in the first few
months of 2022, which regions in the united states had the
highest average of cases per capita between February and
march?
a. west
b. midwest
c. south
d. northeast Correct Answers a
At what stage of phagocytosis does the movie end at?
a. adhesion
b. ingestion
c. maturation
d. killing
e. elimination Correct Answers b
Carriers are dangerous because they exhibit all of the following
except:
a. they do not show signs of infection
b. they are symptomatic for infection
c. they are unaware that they are spreading disease
d. they are difficult to identify and quarantine
e. they are more common in a population than most people think
Correct Answers b
Horizontal gene transfer in influenza is more likely to cause
_______?
, a. antigenic drift
b. seasonal influenza strains
c. RNA viruses
d. antigenic shift
e. endemic disease Correct Answers d
How can b-cells become activated to produce antibodies?
a. by marcophages
b. by the complement system
c. by cells that express the MHC-I protein
d. by directly binding to the b-cell receptor
e. by t-cells secreting cytokines Correct Answers e
Inside of which tissue do antibody-producing b-cells mature?
a. tonsils
b. intestines
c. thymus
d. lymph nodes
e. bone marrow Correct Answers e
The immune system will mount a _______ antibody response to
a virus with few antigens present on its surface because the
antibodies generated will bind _______ to the virus than a virus
with few antigens on its surface.
a. more effective / more weakly
b. less effective / equivalently
c. neutral / tighter
d. more effective / more tightly
