1
BRS Microbiology & Immunology
Questions with 100% Correct Answers
| for Specific Exam Mail
"A pharmaceutical company has developed a new
compound that is well tolerated by the body and inhibits
the sterol ergosterol synthesis. Screening of anti-infectious
agent activity should be directed toward
(A) Bacteria
(B) Chlamydia species
(C) Fungi
(D) Rickettsia species
(E) Viruses"
Ans: The answer is C. Fungi have ergosterol as their
dominant membrane sterol. Mycoplasmas are the only
prokaryotes with sterols in their cytoplasmic membrane,
but they do not synthesize their own sterols.
"50S ribosomal subunits are found in
(A) Bacteria
:
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,2
(B) Fungi
(C) Prions
(D) Protozoa
(E) Viruses"
Ans: The answer is A. Bacteria have 70S ribosomes
composed of 30S and 50S subunits. Fungi and protozoa
have 80S ribosomes, and prions and viruses do not have
ribosomes.
"The normal flora of the large intestine consists mainly of
(A) Bacteria
(B) Fungi
(C) Protozoa
(D) Viruses
(E) No microbial agents"
Ans: The answer is A. Bacteria form the majority of the
normal flora of the large intestine. Other types of human
infectious agents are not usually present except in time of
disease.
:
vPretest - Stuvia US
,3
"The minimal concentration of alcohol necessary to kill
bacteria and enveloped viruses is
(A) 30%
(B) 40%
(C) 50%
(D) 60%
(E) 70%"
Ans: The answer is E. An alcohol concentration of 70% to
95% is necessary to kill bacteria.
"Human obligate intracellular pathogens that depend on
the host cell for ATP production are
(A) Bacteriophages
(B) Mycoplasma species
(C) Prions
(D) Rickettsia species
(E) Viroids"
:
vPretest - Stuvia US
, 4
Ans: The answer is D. Chlamydia and rickettsia are
obligate intracellular pathogens because they depend
on the host cell to provide them with ATP.
"Dimorphism is a characteristic of
(A) Bacteria
(B) Fungi
(C) Prions
(D) Rickettsia species
(E) Viruses"
Ans: The answer is B. Certain species of pathogenic fungi
are dimorphic (i.e., existing as yeast or mold forms
depending on their environment).
"A new infectious agent has been isolated from deer
ticks. It lacks a cell wall but has 70S ribosomes. This agent is
most likely a
(A) Bacterium
(B) Chlamydia species
(C) Mycoplasma species
:
vPretest - Stuvia US
BRS Microbiology & Immunology
Questions with 100% Correct Answers
| for Specific Exam Mail
"A pharmaceutical company has developed a new
compound that is well tolerated by the body and inhibits
the sterol ergosterol synthesis. Screening of anti-infectious
agent activity should be directed toward
(A) Bacteria
(B) Chlamydia species
(C) Fungi
(D) Rickettsia species
(E) Viruses"
Ans: The answer is C. Fungi have ergosterol as their
dominant membrane sterol. Mycoplasmas are the only
prokaryotes with sterols in their cytoplasmic membrane,
but they do not synthesize their own sterols.
"50S ribosomal subunits are found in
(A) Bacteria
:
vPretest - Stuvia US
,2
(B) Fungi
(C) Prions
(D) Protozoa
(E) Viruses"
Ans: The answer is A. Bacteria have 70S ribosomes
composed of 30S and 50S subunits. Fungi and protozoa
have 80S ribosomes, and prions and viruses do not have
ribosomes.
"The normal flora of the large intestine consists mainly of
(A) Bacteria
(B) Fungi
(C) Protozoa
(D) Viruses
(E) No microbial agents"
Ans: The answer is A. Bacteria form the majority of the
normal flora of the large intestine. Other types of human
infectious agents are not usually present except in time of
disease.
:
vPretest - Stuvia US
,3
"The minimal concentration of alcohol necessary to kill
bacteria and enveloped viruses is
(A) 30%
(B) 40%
(C) 50%
(D) 60%
(E) 70%"
Ans: The answer is E. An alcohol concentration of 70% to
95% is necessary to kill bacteria.
"Human obligate intracellular pathogens that depend on
the host cell for ATP production are
(A) Bacteriophages
(B) Mycoplasma species
(C) Prions
(D) Rickettsia species
(E) Viroids"
:
vPretest - Stuvia US
, 4
Ans: The answer is D. Chlamydia and rickettsia are
obligate intracellular pathogens because they depend
on the host cell to provide them with ATP.
"Dimorphism is a characteristic of
(A) Bacteria
(B) Fungi
(C) Prions
(D) Rickettsia species
(E) Viruses"
Ans: The answer is B. Certain species of pathogenic fungi
are dimorphic (i.e., existing as yeast or mold forms
depending on their environment).
"A new infectious agent has been isolated from deer
ticks. It lacks a cell wall but has 70S ribosomes. This agent is
most likely a
(A) Bacterium
(B) Chlamydia species
(C) Mycoplasma species
:
vPretest - Stuvia US
