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WGU D311 OA Final Exam/ WGU D311 Microbiology Objective Assessment Final Exam Newest 2025/2026 Actual Exam Complete 260 Questions And Correct Detailed Answers (Verified Answers) |Already Graded A+||Brand New Version!!
What does a phase-contrast microscope use to visualize a specimen?
a) Fluorescence
b) Light
c) X-rays
d) Electrons
Answer; B
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 1 / 4
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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
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 2 / 4
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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
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 3 / 4
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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
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
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