1|Page
WGU D311 MICROBIOLOGY OBJECTIVE ASSESSMENT EXAM
NEWEST 2026 ACTUAL EXAM| COMPLETE 250 REAL EXAM
QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) ALREADY GRADED A+ (BRAND NEW!!)
A hemagglutination assay is applied to dilutions of a sputum sample
from a person with signs of an upper respiratory infection. When the
scientists evaluated the sputum samples, they did not observe
hemagglutination.
Which microbial cause of upper respiratory infections has been ruled
out?
A. Taenia saginata
B. Rickettsia rickettsii
C. Toxoplasma gondii
D. Influenza virus
D.
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The antibiotic doxycycline works by inhibiting protein synthesis through
binding to the 30S ribosomal subunit.
Why would this antibiotic be ineffective against viruses?
A. Viruses are eukaryotic cells, not prokaryotic cells.
B. Viruses do not have ribosomes.
C. Viruses only have smooth endoplasmic reticula.
D. Viruses have 40S ribosomal subunits.
B
A patient who is immunosuppressed develops skin pustules and itching.
What is a plausible cause of these symptoms?
A. An opportunistic endoparasitic infection
B. An opportunistic bacterial infection
C. An avirulent protozoal infection
D. A highly virulent allergic skin disease
B
A culture of fluid collected from a healthy person via a bronchoalveolar
lavage yielded growth of Staphylococcus aureus; however, a culture of a
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similarly collected sample from a person sneezing and coughing also
yielded growth of Staphylococcus aureus.
How can the same bacteria cause infection and symptoms in one
person but not in another person?
A. Commensal bacteria became opportunistic.
B. Nonpathogenic bacteria became avirulent.
C. Both people must be immunocompromised.
D. One of the samples yielded a false negative result.
A
Why can both cats and people be infected with herpesvirus but not
infect each other?
A. Infectivity must be low for these viruses.
B. Innate immunity differs between species.
C. These viruses are species-specific.
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D. Virus particles are short-lived.
C
Fimbria is a virulence factor of Escherichia coli necessary for an
infection to develop.
Which treatment may be helpful to prevent urinary tract infections
caused by Escherichia coli on the basis of the bacteria's virulence
factor?
A. Probiotic because it interferes with capsule formation by Escherichia
coli
B. Antitoxin because it counters endotoxin released by viable
Escherichia coli
C. Cranberry extract because it interferes with the adherence of
Escherichia coli to the bladder wall
D. Antiparasitic because it prevents antigenic drift common to
Escherichia coli
C
WGU D311 MICROBIOLOGY OBJECTIVE ASSESSMENT EXAM
NEWEST 2026 ACTUAL EXAM| COMPLETE 250 REAL EXAM
QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) ALREADY GRADED A+ (BRAND NEW!!)
A hemagglutination assay is applied to dilutions of a sputum sample
from a person with signs of an upper respiratory infection. When the
scientists evaluated the sputum samples, they did not observe
hemagglutination.
Which microbial cause of upper respiratory infections has been ruled
out?
A. Taenia saginata
B. Rickettsia rickettsii
C. Toxoplasma gondii
D. Influenza virus
D.
,2|Page
The antibiotic doxycycline works by inhibiting protein synthesis through
binding to the 30S ribosomal subunit.
Why would this antibiotic be ineffective against viruses?
A. Viruses are eukaryotic cells, not prokaryotic cells.
B. Viruses do not have ribosomes.
C. Viruses only have smooth endoplasmic reticula.
D. Viruses have 40S ribosomal subunits.
B
A patient who is immunosuppressed develops skin pustules and itching.
What is a plausible cause of these symptoms?
A. An opportunistic endoparasitic infection
B. An opportunistic bacterial infection
C. An avirulent protozoal infection
D. A highly virulent allergic skin disease
B
A culture of fluid collected from a healthy person via a bronchoalveolar
lavage yielded growth of Staphylococcus aureus; however, a culture of a
,3|Page
similarly collected sample from a person sneezing and coughing also
yielded growth of Staphylococcus aureus.
How can the same bacteria cause infection and symptoms in one
person but not in another person?
A. Commensal bacteria became opportunistic.
B. Nonpathogenic bacteria became avirulent.
C. Both people must be immunocompromised.
D. One of the samples yielded a false negative result.
A
Why can both cats and people be infected with herpesvirus but not
infect each other?
A. Infectivity must be low for these viruses.
B. Innate immunity differs between species.
C. These viruses are species-specific.
, 4|Page
D. Virus particles are short-lived.
C
Fimbria is a virulence factor of Escherichia coli necessary for an
infection to develop.
Which treatment may be helpful to prevent urinary tract infections
caused by Escherichia coli on the basis of the bacteria's virulence
factor?
A. Probiotic because it interferes with capsule formation by Escherichia
coli
B. Antitoxin because it counters endotoxin released by viable
Escherichia coli
C. Cranberry extract because it interferes with the adherence of
Escherichia coli to the bladder wall
D. Antiparasitic because it prevents antigenic drift common to
Escherichia coli
C
