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WGU D311 OA FINAL EXAM/ WGU D311 MICROBIOLOGY OBJECTIVE
ASSESSMENT FINAL EXAM NEWEST 2025/2026 ACTUAL EXAM WITH
COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (100%
VERIFIED ANSWERS) |ALREADY GRADED A+| ||PROFESSOR
VERIFIED||
Which type of microscopy produces highly detailed three-
dimensional images of a specimen?
a) Transmission electron microscopy
b) Scanning electron microscopy
c) Phase-contrast microscopy
d) Brightfield microscopy - ANSWER-B
This type of microscope allows one to view the surfaces of larger
objects as well as very small ones. It can create highly detailed
3D images of a specimen
Which method of microscopy uses a laser to scan multiple planes
and produces a three-dimensional image that can be used to
visualize the internal structure of a biofilm?
a) Transmission electron microscopy
b) Brightfield microscopy
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c) Scanning electron microscopy
d) Confocal microscopy - ANSWER-D
This type of microscopy is used to visualize clear images of
biofilms by focusing on one z-plane at a time
Which technique uses a single dye to emphasize particular
structures in the specimen?
a) Differential staining
b) Acid-fast staining
c) Gram staining
d) Simple staining - ANSWER-D
Which bacterial structure determines the different outcomes of the
Gram stain?
a) Endospore
b) Peptidoglycan
c) Capsule
d) Mycolic acid - ANSWER-B
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Bacteria are classified as gram negative or gram positive based
on how many layers of peptidoglycan are in their cell walls
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 - ANSWER-D
Influenza virus uses the adhesin hemagglutinin to spread
infection. If the results are negative, then we know that this URI
isn't influenza
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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. - ANSWER-B
Viruses are acellular and only consist of DNA or RNA
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 - ANSWER-B
This is the most correct because the patient's signs are consistent
with a bacterial skin infection. Opportunistic pathogens can only
WGU D311 OA FINAL EXAM/ WGU D311 MICROBIOLOGY OBJECTIVE
ASSESSMENT FINAL EXAM NEWEST 2025/2026 ACTUAL EXAM WITH
COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (100%
VERIFIED ANSWERS) |ALREADY GRADED A+| ||PROFESSOR
VERIFIED||
Which type of microscopy produces highly detailed three-
dimensional images of a specimen?
a) Transmission electron microscopy
b) Scanning electron microscopy
c) Phase-contrast microscopy
d) Brightfield microscopy - ANSWER-B
This type of microscope allows one to view the surfaces of larger
objects as well as very small ones. It can create highly detailed
3D images of a specimen
Which method of microscopy uses a laser to scan multiple planes
and produces a three-dimensional image that can be used to
visualize the internal structure of a biofilm?
a) Transmission electron microscopy
b) Brightfield microscopy
,2|Page
c) Scanning electron microscopy
d) Confocal microscopy - ANSWER-D
This type of microscopy is used to visualize clear images of
biofilms by focusing on one z-plane at a time
Which technique uses a single dye to emphasize particular
structures in the specimen?
a) Differential staining
b) Acid-fast staining
c) Gram staining
d) Simple staining - ANSWER-D
Which bacterial structure determines the different outcomes of the
Gram stain?
a) Endospore
b) Peptidoglycan
c) Capsule
d) Mycolic acid - ANSWER-B
,3|Page
Bacteria are classified as gram negative or gram positive based
on how many layers of peptidoglycan are in their cell walls
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 - ANSWER-D
Influenza virus uses the adhesin hemagglutinin to spread
infection. If the results are negative, then we know that this URI
isn't influenza
, 4|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. - ANSWER-B
Viruses are acellular and only consist of DNA or RNA
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 - ANSWER-B
This is the most correct because the patient's signs are consistent
with a bacterial skin infection. Opportunistic pathogens can only
