WGU D311 MICROBIOLOGY STUDY FOR
OA EXAM QUESTIONS AND ANSWERS
100% PASS
What is a characteristic of rhizospheres? - ANS The rhizosphere is where plants release
organic compounds that can be metabolized by microbes into soil.
Which environment would contain microbes that are psychrophilic? - ANS Glaciers
What is the role of nematodes in soil? - ANS They photosynthesize and fix nitrogen.
Which eukaryote is responsible for producing antibiotics to ward off bacterial competitors? -
ANS Fungi
Which symbiotic relationship is an example of mutualism? - ANS The relationship between
humans and the Escherichia coli colonizing the human gut
Which type of symbiotic relationship exists between the Escherichia coli (E. coli) that inhabit the
human gut and the humans who utilize the vitamin K produced by E. coli? - ANS Mutualism
Which description of resident microbiota is true? - ANS Resident microbiota constantly live
on the human body.
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,Which relationship is exhibited by intestinal Escherichia coli and their human host? -
ANS Mutualism
Which type of disease is transmitted from animals to humans? - ANS Zoonotic diseases
Which type of disease is acquired in hospital settings? - ANS Nosocomial diseases
Which portal of exit can expel the most viral particles? - ANS Respiratory
Which type of disease is sickle cell anemia? - ANS Noninfectious
Which type of transmission occurs when tuberculosis is spread through small particles expelled
by a cough? - ANS Droplet transmission
Which type of transmission occurs when pathogens are spread from mother to child during
breastfeeding? - ANS Vertical direct contact transmission
Which type of transmission occurs when an arthropod carries a viral pathogen inside of its
body? - ANS Biological vector transmission
Which type of transmission occurs through contact with a fomite? - ANS Indirect contact
transmission
Which infected host would be considered a passive carrier? - ANS A healthcare professional
who does not wash their hands after seeing an infected patient
How is Giardia lamblia, the causative agent of giardiasis, transmitted? - ANS Contaminated
food or water
Which organism is the definitive host of Toxoplasma gondii? - ANS Birds
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Which disease is transmitted by animals but not arthropods? - ANS Rabies
How can adhesins be described? - ANS Adhesins found on the surface of pathogens bind to
receptors of host cells.
Which description indicates a portal of entry? - ANS Body features through which pathogens
can enter host tissue
Pathogens produce proteins to prevent the fusion of the phagosome and the lysosome
(phagolysosome).Why does this virulence factor facilitate invasion? - ANS It prevents the
exposure of pathogens to lethal digestive enzymes.
Which action refers to a secondary infection? - ANS An infection by one pathogen enables
another pathogen to cause an infection.
What differentiates signs from symptoms of disease? - ANS Signs are measurable; symptoms
are subjective.
Which procedure does a clinician use to measure a symptom? - ANS Asking patients to rate
pain on a numerical scale
During which stage of an infection does a patient feel the worst? - ANS The period of illness
stage
What defines the end of the incubation period for an infectious disease? - ANS The
appearance of nonspecific signs or symptoms of disease
How does the epidermis help prevent infection and disease? - ANS It provides a harsh
environment for most pathogens and periodically sheds
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
OA EXAM QUESTIONS AND ANSWERS
100% PASS
What is a characteristic of rhizospheres? - ANS The rhizosphere is where plants release
organic compounds that can be metabolized by microbes into soil.
Which environment would contain microbes that are psychrophilic? - ANS Glaciers
What is the role of nematodes in soil? - ANS They photosynthesize and fix nitrogen.
Which eukaryote is responsible for producing antibiotics to ward off bacterial competitors? -
ANS Fungi
Which symbiotic relationship is an example of mutualism? - ANS The relationship between
humans and the Escherichia coli colonizing the human gut
Which type of symbiotic relationship exists between the Escherichia coli (E. coli) that inhabit the
human gut and the humans who utilize the vitamin K produced by E. coli? - ANS Mutualism
Which description of resident microbiota is true? - ANS Resident microbiota constantly live
on the human body.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Which relationship is exhibited by intestinal Escherichia coli and their human host? -
ANS Mutualism
Which type of disease is transmitted from animals to humans? - ANS Zoonotic diseases
Which type of disease is acquired in hospital settings? - ANS Nosocomial diseases
Which portal of exit can expel the most viral particles? - ANS Respiratory
Which type of disease is sickle cell anemia? - ANS Noninfectious
Which type of transmission occurs when tuberculosis is spread through small particles expelled
by a cough? - ANS Droplet transmission
Which type of transmission occurs when pathogens are spread from mother to child during
breastfeeding? - ANS Vertical direct contact transmission
Which type of transmission occurs when an arthropod carries a viral pathogen inside of its
body? - ANS Biological vector transmission
Which type of transmission occurs through contact with a fomite? - ANS Indirect contact
transmission
Which infected host would be considered a passive carrier? - ANS A healthcare professional
who does not wash their hands after seeing an infected patient
How is Giardia lamblia, the causative agent of giardiasis, transmitted? - ANS Contaminated
food or water
Which organism is the definitive host of Toxoplasma gondii? - ANS Birds
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Which disease is transmitted by animals but not arthropods? - ANS Rabies
How can adhesins be described? - ANS Adhesins found on the surface of pathogens bind to
receptors of host cells.
Which description indicates a portal of entry? - ANS Body features through which pathogens
can enter host tissue
Pathogens produce proteins to prevent the fusion of the phagosome and the lysosome
(phagolysosome).Why does this virulence factor facilitate invasion? - ANS It prevents the
exposure of pathogens to lethal digestive enzymes.
Which action refers to a secondary infection? - ANS An infection by one pathogen enables
another pathogen to cause an infection.
What differentiates signs from symptoms of disease? - ANS Signs are measurable; symptoms
are subjective.
Which procedure does a clinician use to measure a symptom? - ANS Asking patients to rate
pain on a numerical scale
During which stage of an infection does a patient feel the worst? - ANS The period of illness
stage
What defines the end of the incubation period for an infectious disease? - ANS The
appearance of nonspecific signs or symptoms of disease
How does the epidermis help prevent infection and disease? - ANS It provides a harsh
environment for most pathogens and periodically sheds
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
