MCB 100 EXAM 3 QUESTIONS AND ACCURATE
ANSWERS
Which of the following is not a symptom of disease?
a. headache
b. dizziness
c. nausea
d. fever
e. cramps - Answers - D
Which of the following is not a sign of disease?
a. fever
b. dizziness
c. swelling
d. diarrhea
e. rash - Answers - B
What steps should a researcher take to establish a cause-and-effect relationship
between a pathogen and a lethal human illness?
a. identify the causative pathogen
b. obtain the pathogen from the disease outbreak patients
c. infect uninfected people and see if it causes similar disease
d. a, b and c
e. a and b only - Answers - E
Which of the following would make it not possible to satisfy all of Koch's postulates for a
particular microbe?
a. the microbe cannot be isolated in pure culture
b. the microbe only infects nonhuman animals
c. the microbe does not cause the same symptoms in all patients
d. the identity of the microbe is in question
e. the microbe's DNA can be PCR amplified from all tissues where diseases has been
observed - Answers - A
A commensal E. coli strain usually found as part of the normal gut microbe of chickens
has a pillion gene (pil1) that is responsible for attaching and colonizing chicken
intestines. A clinical isolate of this E. coli strain recently isolated from sick pigs appears
to have a new pillion gene (pil2) that now allows for infection in pigs. How could you
must directly test this hypothesis?
a. make a mutation in the pil1 gene and see if the bacterium is still virulent in both pigs
and chickens
, b. make a mutation in the pil2 gene and see if the bacterium is still virulent in both pigs
and chickens
c. make a mutation in the pil2 gene and see if the bacterium is still virulent in chickens,
but not pigs
d. make a mutation in the pil2 gene and see if the bacterium is still virulent in pigs, but
not in chickens
e. make a mutation in the pil1 gene and see if the bacterium is still virulent in chickens,
but not in pigs - Answers -
Carriers are dangerous because they exhibit all of the following except:
a. they do not show signs of infection
b. they are unaware that they are spreading disease
c. they are difficult to identify and quarantine
d. they are symptomatic for infection
e. they are more common in a population that most people think - Answers - D
Which of the following is not a characteristic associate with animal reservoirs?
a. an animal reservoir is naturally infected with the pathogen
b. animal behaviors are more difficult to control than human behaviors
c. animal reservoirs maintain the presence of the pathogen over time
d. an animal reservoir can transmit the disease to a new susceptible host
e. animal reservoirs are easier to eradicate than human reservoirs - Answers - E
Which of the following would be considered a virulence factor of a pathogen?
a. the ability of a virus to become a provirus
b. a surface protein that allows the pathogen to bind to host cells
c. a secondary host that the pathogen can also infect
d. a surface protein that the host immune system recognizes
e. the ability of a fungus to form and release conidia (spores) - Answers - B
A mosquito bites a person who then develops fever and rash. What type of transmission
would this be?
a. biological vector transmission
b. mechanical transmission
c. vehicle transmission
d. zoonotic transmission
e. direct contact transmission - Answers - A
Which of the following is not a general mechanisms of the innate immune response?
a. mechanical movements
b. microbiome
c. antibody production
d. physical barriers
e. chemical production - Answers - C
ANSWERS
Which of the following is not a symptom of disease?
a. headache
b. dizziness
c. nausea
d. fever
e. cramps - Answers - D
Which of the following is not a sign of disease?
a. fever
b. dizziness
c. swelling
d. diarrhea
e. rash - Answers - B
What steps should a researcher take to establish a cause-and-effect relationship
between a pathogen and a lethal human illness?
a. identify the causative pathogen
b. obtain the pathogen from the disease outbreak patients
c. infect uninfected people and see if it causes similar disease
d. a, b and c
e. a and b only - Answers - E
Which of the following would make it not possible to satisfy all of Koch's postulates for a
particular microbe?
a. the microbe cannot be isolated in pure culture
b. the microbe only infects nonhuman animals
c. the microbe does not cause the same symptoms in all patients
d. the identity of the microbe is in question
e. the microbe's DNA can be PCR amplified from all tissues where diseases has been
observed - Answers - A
A commensal E. coli strain usually found as part of the normal gut microbe of chickens
has a pillion gene (pil1) that is responsible for attaching and colonizing chicken
intestines. A clinical isolate of this E. coli strain recently isolated from sick pigs appears
to have a new pillion gene (pil2) that now allows for infection in pigs. How could you
must directly test this hypothesis?
a. make a mutation in the pil1 gene and see if the bacterium is still virulent in both pigs
and chickens
, b. make a mutation in the pil2 gene and see if the bacterium is still virulent in both pigs
and chickens
c. make a mutation in the pil2 gene and see if the bacterium is still virulent in chickens,
but not pigs
d. make a mutation in the pil2 gene and see if the bacterium is still virulent in pigs, but
not in chickens
e. make a mutation in the pil1 gene and see if the bacterium is still virulent in chickens,
but not in pigs - Answers -
Carriers are dangerous because they exhibit all of the following except:
a. they do not show signs of infection
b. they are unaware that they are spreading disease
c. they are difficult to identify and quarantine
d. they are symptomatic for infection
e. they are more common in a population that most people think - Answers - D
Which of the following is not a characteristic associate with animal reservoirs?
a. an animal reservoir is naturally infected with the pathogen
b. animal behaviors are more difficult to control than human behaviors
c. animal reservoirs maintain the presence of the pathogen over time
d. an animal reservoir can transmit the disease to a new susceptible host
e. animal reservoirs are easier to eradicate than human reservoirs - Answers - E
Which of the following would be considered a virulence factor of a pathogen?
a. the ability of a virus to become a provirus
b. a surface protein that allows the pathogen to bind to host cells
c. a secondary host that the pathogen can also infect
d. a surface protein that the host immune system recognizes
e. the ability of a fungus to form and release conidia (spores) - Answers - B
A mosquito bites a person who then develops fever and rash. What type of transmission
would this be?
a. biological vector transmission
b. mechanical transmission
c. vehicle transmission
d. zoonotic transmission
e. direct contact transmission - Answers - A
Which of the following is not a general mechanisms of the innate immune response?
a. mechanical movements
b. microbiome
c. antibody production
d. physical barriers
e. chemical production - Answers - C
