WGU D311
Microbiology
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, D311 Microbiology OA Exam Prep
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,1. Which statement describes prokaryotic cells?
a) Prokaryotic cells are found in coccus form in both pairs and clusters.
b) Prokaryotic cells have multiple rod-shaped chromosomes.
c) Prokaryotic cells are found in chains of rods but not single rods.
d) Prokaryotic cells have a nucleus surrounded by a complex nuclear membrane.
Correct Answer: A
Explanation:
This is correct because prokaryotic cells can form cocus in both pairs and clusters
2. Which statement describes eukaryotic cells?
a) The exoskeletons of eukaryotic cells maintain and support the cells' shapes.
b) The nuclei of eukaryotic cells are surrounded by complex nuclear membranes.
c) The genomes of eukaryotic cells are usually packaged in single circular chromosomes.
d) The organelles of eukaryotic cells are held in place by semipermeable exoskeletons.
Correct Answer: B
3. Which statement describes eukaryotic flagella?
a) Eukaryotic flagella can cover the entire surface of a cell.
b) Eukaryotic flagella are rotating structures.
c) Eukaryotic flagella have twelve pairs of microtubules.
d) Eukaryotic flagella are flexible, whip-like structures.
Correct Answer: D
4. Which statement describes the endomembrane system?
a) It is attached to the smooth endoplasmic reticulum and makes proteins for insertion
into the cell membrane.
b) It includes the Golgi apparatus, lysosomes, and vesicles.
c) It is a system that uses diffusion to transport materials inside of the cell.
, d) It lacks membrane-bound organelles.
Correct Answer: B
5. Which statement accurately describes similarities between protozoa and fungi?
a) Both perform chemosynthesis.
b) Both can be harmful or harmless depending on the context.
c) Both are made of long filaments that form visible colonies.
d) Both move with help from cilia and flagella.
Correct Answer: B
6. Why are algae considered photosynthetic organisms?
a) Algae cell walls are constructed with a material called peptidoglycan.
b) Algae contain substances that can be converted into biofuels.
c) Algae produce chemical energy from the sun's light energy.
d) Algae create waste products that other organisms can use to make energy.
Correct Answer: C
7. Why are plasmids important to the survival of organisms?
a) Plasmids exclusively contain the genes responsible for cellular replication in bacteria.
b) Plasmids can store excess nutrients in the cytoplasm of the cell.
c) Plasmids protect the bacterial genome in a dormant state during unfavorable
environmental conditions.
d) Plasmids carry genetic material, apart from the genome, that can benefit the
organism.
Correct Answer: D
Explanation:
Plasmids often carry genes that can offer beneficial traits such as antibiotic resistance
8. Which statement describes bacteria?
a) Some bacteria are eukaryotes.
, d) Antiviral proteins are produced.
Correct Answer: B
Explanation:
The release of endotoxins from gram negative bacteria triggers the immune system's
inflammatory response. This can lead to fever
22. Which characteristic is true of exotoxins?
a) Exotoxins are produced by only gram-negative bacteria.
b) Exotoxins are stable at high temperatures.
c) Exotoxins are produced by only gram-positive bacteria.
d) Exotoxins can cause cytokine storms.
Correct Answer: D
Explanation:
Exotoxins can trigger immune cells to release cytokines leading to a cytokine storm
23. Which statement describes biofilms?
a) Biofilms contain random collections of microorganisms.
b) Biofilms are always pathogenic to the host.
c) Biofilms form on fomites.
d) Biofilms are highly structured communities.
Correct Answer: D
24. Which step in biofilm formation comes immediately after planktonic cells attach to
a surface?
a) Planktonic cells become sessile.
b) Appendages and the extracellular polymeric substance interact.
c) Sessile cells become planktonic.
d) Planktonic cells colonize new areas.
,44. Gram staining of a urine sample unexpectedly reveals both gram-positive cocci and
gram-negative rods; however, only gram-negative rods are seen in white blood cells
(intracellular). How should these findings be interpreted?
a) The gram-negative bacteria from the sample are pathogenic
b) The gram-positive bacteria from the sample are virulent.
c) The gram-negative bacteria from the sample display commensalism.
d) The gram-positive bacteria from the sample display chemotactic behavior.
Correct Answer: A
Explanation:
Since the gram negative bacteria can be seen within white blood cells, this can indicate
that the pathogen has been targeted by the host's immune system
45. What is a characteristic of rhizospheres?
a) The rhizosphere is where microbes that survive well in extremely acidic conditions
reside.
b) The rhizosphere is where microbes that survive well on humans reside.
c) The rhizosphere is where microbes that survive well in the cold reside.
d) The rhizosphere is where plants release organic compounds that can be metabolized
by microbes into soil.
Correct Answer: D
Explanation:
A rhizosphere is a region of soil who's growth, respiration, and nutrient exchange is
influence by nearby plant roots
46. Microbes that survive well in the cold are called
Correct Answer: Psychrophiles
47. Microbes that survive well in extremely acidic or hot conditions are called
Correct Answer: Extremophiles
, d) Rabies
Correct Answer: D
74. How can adhesins be described?
a) Adhesins are found inside pathogen cells to help break down a host's cells.
b) Adhesins are found on the surface of host cells to recognize foreign cells such as
pathogens.
c) Adhesins are found in portals of entry as a host's defense against pathogens.
d) Adhesins found on the surface of pathogens bind to receptors of host cells.
Correct Answer: D
Explanation:
Adhesins are molecules that help pathogens physically attach themselves to the host.
They are present in bacteria, protozoa, and viruses.
75. Which description indicates a portal of entry?
a) Cellular transport proteins, such as transporters, symporters, and antiporters
b) A mode of pathogen exposure, such as infected animals, food, air, or water
c) A route that a pathogen takes when it shifts from a local infection and spreads
d) Body features through which pathogens can enter host tissue
Correct Answer: D
76. Pathogens produce proteins to prevent the fusion of the phagosome and the
lysosome (phagolysosome). Why does this virulence factor facilitate invasion?
a) It induces the production of adhesions.
b) It allows the pathogen to transport the host cell within its membrane.
c) It prevents the exposure of pathogens to lethal digestive enzymes.
d) It initiates apoptosis or controlled cell suicide of the host cell.
Correct Answer: C
Explanation:
Phagocytes kill pathogens through digestive enzymes present in the lysosome. The
,122. What concentration of alcohol works best?
a) 100%
b) 70% in aqueous solution
c) 25%
d) 50% in aqueous solution
Correct Answer: B
Explanation:
In higher alcohol concentrations, rapid coagulation of surface proteins prevents
effective penetration of cells.
123. What organisms can be disinfected by alcohols?
Correct Answer: Bacteria, fungi, viruses (enveloped only) Can inhibit the process of
sporulation and germination but are not considered sporicidal
124. This group of chemical compounds lower the surface tension of water. They help
to loosen and lift away dirt and microbes from surfaces and skin
Correct Answer: Surfactants
Image placed after Question 124 (source page 25)
125. Are surfactants considered antiseptics or disinfectants? Why?
Correct Answer: No, they do not have the ability to kill or inhibits microbial growth
, c) Wipe away large debris after diluted bleach contacted the surfaces for more than 10
minutes
d) Avoid the surfaces treated with diluted bleach for more than 10 minutes
Correct Answer: B
190. A foodborne pathogen is suspected as a cause of acute onset fever and diarrhea in
people after eating one brand of a packaged salad mix. Which method will mitigate the
future risk of product contamination with this pathogen?
a) Producers only sort, rather than wash, produce prior to packaging.
b) Distributors ensure produce is handled by only their own employees.
c) Transporters carry produce in trucks only after they were used for transporting other
produce.
d) Farmers use water sourced only from a city's water supply for field irrigation.
Correct Answer: D
191. A physician who has been treating a patient with cephalexin for a skin infection
secondary to uncontrolled diabetes mellitus notes that the infection has worsened over
the past 10 days. The physician orders culture and susceptibility testing. Which
pathogen does this physician suspect?
a) Cephalosporin-resistant Pseudomonas aeruginosa
b) Beta-lactam-resistant Aspergillus spp
c) Methicillin-resistant Staphylococcus aureus
d) Penicillin-resistant Ancylostoma spp
Correct Answer: C
192. A physician selects the antibiotic azithromycin for an adult patient with bacterial
pneumonia, based on knowledge of the bacteria that commonly cause pneumonia.
Which public health factor should the physician consider when selecting the antibiotic
for this patient?
a) The Centers for Disease Control and Prevention indicate that azithromycin is an
appropriate antibiotic for pneumonia treatment.
b) The patient has never taken azithromycin, so drug resistance is not a concern.
, Correct Answer: C
229. Which protist is the causative agent of amoebic dysentery?
a) Entamoeba
b) Trypanosoma
c) Paramecium
d) Toxoplasma
Correct Answer: A
230. What is the unicellular form of fungi called?
a) Mycelium
b) Yeast
c) Hyphae
d) Thallus
Correct Answer: B
Explanation:
Yeast are unicellular fungi. Hyphae are the multicellular form. A group of hyphae form
the mycelium. The mold associated with fungi would be the mycelium, which is
composed of hyphae. The thallus is the body of fleshy fungi, like toadstools
231. What is the formal name of the group of sac fungi?
a) Basidiomycota
b) Deuteromycota
c) Zygomycota
d) Ascomycota
Correct Answer: D
232. Which members of fungi can cause deadly toxins?
Correct Answer: Zygomycota Ascomycota Basidiomycota
Microbiology
OA EXAM PREP
Actual Questions with Verified Answers
Pass the Exam with Confidence
What You Will Get:
➢226 OA Exam Questions w/ Answers
➢ OA Definitions,
➢ Concept Reviews
➢ Study Guide
➢ Expert Rationales included.
Take and pass the OA :)
, D311 Microbiology OA Exam Prep
Preview Pages Below
Get the Complete PDF After Purchase
"If you require further clarification or in need of any
study resources, feel free to Message me."
Preview sample - complete PDF available after purchase
,1. Which statement describes prokaryotic cells?
a) Prokaryotic cells are found in coccus form in both pairs and clusters.
b) Prokaryotic cells have multiple rod-shaped chromosomes.
c) Prokaryotic cells are found in chains of rods but not single rods.
d) Prokaryotic cells have a nucleus surrounded by a complex nuclear membrane.
Correct Answer: A
Explanation:
This is correct because prokaryotic cells can form cocus in both pairs and clusters
2. Which statement describes eukaryotic cells?
a) The exoskeletons of eukaryotic cells maintain and support the cells' shapes.
b) The nuclei of eukaryotic cells are surrounded by complex nuclear membranes.
c) The genomes of eukaryotic cells are usually packaged in single circular chromosomes.
d) The organelles of eukaryotic cells are held in place by semipermeable exoskeletons.
Correct Answer: B
3. Which statement describes eukaryotic flagella?
a) Eukaryotic flagella can cover the entire surface of a cell.
b) Eukaryotic flagella are rotating structures.
c) Eukaryotic flagella have twelve pairs of microtubules.
d) Eukaryotic flagella are flexible, whip-like structures.
Correct Answer: D
4. Which statement describes the endomembrane system?
a) It is attached to the smooth endoplasmic reticulum and makes proteins for insertion
into the cell membrane.
b) It includes the Golgi apparatus, lysosomes, and vesicles.
c) It is a system that uses diffusion to transport materials inside of the cell.
, d) It lacks membrane-bound organelles.
Correct Answer: B
5. Which statement accurately describes similarities between protozoa and fungi?
a) Both perform chemosynthesis.
b) Both can be harmful or harmless depending on the context.
c) Both are made of long filaments that form visible colonies.
d) Both move with help from cilia and flagella.
Correct Answer: B
6. Why are algae considered photosynthetic organisms?
a) Algae cell walls are constructed with a material called peptidoglycan.
b) Algae contain substances that can be converted into biofuels.
c) Algae produce chemical energy from the sun's light energy.
d) Algae create waste products that other organisms can use to make energy.
Correct Answer: C
7. Why are plasmids important to the survival of organisms?
a) Plasmids exclusively contain the genes responsible for cellular replication in bacteria.
b) Plasmids can store excess nutrients in the cytoplasm of the cell.
c) Plasmids protect the bacterial genome in a dormant state during unfavorable
environmental conditions.
d) Plasmids carry genetic material, apart from the genome, that can benefit the
organism.
Correct Answer: D
Explanation:
Plasmids often carry genes that can offer beneficial traits such as antibiotic resistance
8. Which statement describes bacteria?
a) Some bacteria are eukaryotes.
, d) Antiviral proteins are produced.
Correct Answer: B
Explanation:
The release of endotoxins from gram negative bacteria triggers the immune system's
inflammatory response. This can lead to fever
22. Which characteristic is true of exotoxins?
a) Exotoxins are produced by only gram-negative bacteria.
b) Exotoxins are stable at high temperatures.
c) Exotoxins are produced by only gram-positive bacteria.
d) Exotoxins can cause cytokine storms.
Correct Answer: D
Explanation:
Exotoxins can trigger immune cells to release cytokines leading to a cytokine storm
23. Which statement describes biofilms?
a) Biofilms contain random collections of microorganisms.
b) Biofilms are always pathogenic to the host.
c) Biofilms form on fomites.
d) Biofilms are highly structured communities.
Correct Answer: D
24. Which step in biofilm formation comes immediately after planktonic cells attach to
a surface?
a) Planktonic cells become sessile.
b) Appendages and the extracellular polymeric substance interact.
c) Sessile cells become planktonic.
d) Planktonic cells colonize new areas.
,44. Gram staining of a urine sample unexpectedly reveals both gram-positive cocci and
gram-negative rods; however, only gram-negative rods are seen in white blood cells
(intracellular). How should these findings be interpreted?
a) The gram-negative bacteria from the sample are pathogenic
b) The gram-positive bacteria from the sample are virulent.
c) The gram-negative bacteria from the sample display commensalism.
d) The gram-positive bacteria from the sample display chemotactic behavior.
Correct Answer: A
Explanation:
Since the gram negative bacteria can be seen within white blood cells, this can indicate
that the pathogen has been targeted by the host's immune system
45. What is a characteristic of rhizospheres?
a) The rhizosphere is where microbes that survive well in extremely acidic conditions
reside.
b) The rhizosphere is where microbes that survive well on humans reside.
c) The rhizosphere is where microbes that survive well in the cold reside.
d) The rhizosphere is where plants release organic compounds that can be metabolized
by microbes into soil.
Correct Answer: D
Explanation:
A rhizosphere is a region of soil who's growth, respiration, and nutrient exchange is
influence by nearby plant roots
46. Microbes that survive well in the cold are called
Correct Answer: Psychrophiles
47. Microbes that survive well in extremely acidic or hot conditions are called
Correct Answer: Extremophiles
, d) Rabies
Correct Answer: D
74. How can adhesins be described?
a) Adhesins are found inside pathogen cells to help break down a host's cells.
b) Adhesins are found on the surface of host cells to recognize foreign cells such as
pathogens.
c) Adhesins are found in portals of entry as a host's defense against pathogens.
d) Adhesins found on the surface of pathogens bind to receptors of host cells.
Correct Answer: D
Explanation:
Adhesins are molecules that help pathogens physically attach themselves to the host.
They are present in bacteria, protozoa, and viruses.
75. Which description indicates a portal of entry?
a) Cellular transport proteins, such as transporters, symporters, and antiporters
b) A mode of pathogen exposure, such as infected animals, food, air, or water
c) A route that a pathogen takes when it shifts from a local infection and spreads
d) Body features through which pathogens can enter host tissue
Correct Answer: D
76. Pathogens produce proteins to prevent the fusion of the phagosome and the
lysosome (phagolysosome). Why does this virulence factor facilitate invasion?
a) It induces the production of adhesions.
b) It allows the pathogen to transport the host cell within its membrane.
c) It prevents the exposure of pathogens to lethal digestive enzymes.
d) It initiates apoptosis or controlled cell suicide of the host cell.
Correct Answer: C
Explanation:
Phagocytes kill pathogens through digestive enzymes present in the lysosome. The
,122. What concentration of alcohol works best?
a) 100%
b) 70% in aqueous solution
c) 25%
d) 50% in aqueous solution
Correct Answer: B
Explanation:
In higher alcohol concentrations, rapid coagulation of surface proteins prevents
effective penetration of cells.
123. What organisms can be disinfected by alcohols?
Correct Answer: Bacteria, fungi, viruses (enveloped only) Can inhibit the process of
sporulation and germination but are not considered sporicidal
124. This group of chemical compounds lower the surface tension of water. They help
to loosen and lift away dirt and microbes from surfaces and skin
Correct Answer: Surfactants
Image placed after Question 124 (source page 25)
125. Are surfactants considered antiseptics or disinfectants? Why?
Correct Answer: No, they do not have the ability to kill or inhibits microbial growth
, c) Wipe away large debris after diluted bleach contacted the surfaces for more than 10
minutes
d) Avoid the surfaces treated with diluted bleach for more than 10 minutes
Correct Answer: B
190. A foodborne pathogen is suspected as a cause of acute onset fever and diarrhea in
people after eating one brand of a packaged salad mix. Which method will mitigate the
future risk of product contamination with this pathogen?
a) Producers only sort, rather than wash, produce prior to packaging.
b) Distributors ensure produce is handled by only their own employees.
c) Transporters carry produce in trucks only after they were used for transporting other
produce.
d) Farmers use water sourced only from a city's water supply for field irrigation.
Correct Answer: D
191. A physician who has been treating a patient with cephalexin for a skin infection
secondary to uncontrolled diabetes mellitus notes that the infection has worsened over
the past 10 days. The physician orders culture and susceptibility testing. Which
pathogen does this physician suspect?
a) Cephalosporin-resistant Pseudomonas aeruginosa
b) Beta-lactam-resistant Aspergillus spp
c) Methicillin-resistant Staphylococcus aureus
d) Penicillin-resistant Ancylostoma spp
Correct Answer: C
192. A physician selects the antibiotic azithromycin for an adult patient with bacterial
pneumonia, based on knowledge of the bacteria that commonly cause pneumonia.
Which public health factor should the physician consider when selecting the antibiotic
for this patient?
a) The Centers for Disease Control and Prevention indicate that azithromycin is an
appropriate antibiotic for pneumonia treatment.
b) The patient has never taken azithromycin, so drug resistance is not a concern.
, Correct Answer: C
229. Which protist is the causative agent of amoebic dysentery?
a) Entamoeba
b) Trypanosoma
c) Paramecium
d) Toxoplasma
Correct Answer: A
230. What is the unicellular form of fungi called?
a) Mycelium
b) Yeast
c) Hyphae
d) Thallus
Correct Answer: B
Explanation:
Yeast are unicellular fungi. Hyphae are the multicellular form. A group of hyphae form
the mycelium. The mold associated with fungi would be the mycelium, which is
composed of hyphae. The thallus is the body of fleshy fungi, like toadstools
231. What is the formal name of the group of sac fungi?
a) Basidiomycota
b) Deuteromycota
c) Zygomycota
d) Ascomycota
Correct Answer: D
232. Which members of fungi can cause deadly toxins?
Correct Answer: Zygomycota Ascomycota Basidiomycota
