WGU D311 OA FINAL EXAM Updated Question
and Answer (2026/2027) | Verified Practice
Material | A+ Verified
• Why are viruses considered aceilular? -✓✓ They cannot reproduce without a host.
• What is the defining characteristic of eukaryotes? -✓✓ They have a nucleus.
• Which microorganism can cause vaginal yeast Infections and oral thrush? -✓✓ Fungi
• Why can It be difficult to determine the etiologic agent of a disease? -✓✓ Some signs
and symptoms can be caused by many different etiologic agents.
• What kind of staining technique Is the acid-fast stain? -✓✓ differential staining
technique used to distinguish between acid-fast and non-acid-fast bacteria based on the
presence of mycolic acid in their cell walls. The high lipid content of acid-fast organisms,
like Mycobacterium, requires special stains, such as Carbolfuchsin, to penetrate their
waxy cell walls
• A doctor prescribed antibiotics for a patient complaining of runny nose. fever. and
aches and pains. Which type of infection did the doctor suspect? -✓✓ The doctor likely
suspected a bacterial infection because antibiotics are not effective against viral
infections.
• A healthcare professional is treating a patient who developed a yeast infection after
taking antibiotics. What type of medication should be prescribed to this patient? -✓✓
Antifungals
• Which structure promotes motility in Proteus. Shigelia. and Salmonella species. all of
which can cause serious disease in humans? -✓✓ Presence of flagella
• Which bacterial virulence factor allows a strain to resist phagocytosis, increasing the
organism's virulence? -✓✓ Capsule production
• Why is treating Haemophilus influenzae difficult? -✓✓ The capsule is antiphagocytic.
• How do pili aid pathogens in causing disease? -✓✓ They cause pathogens to adhere
to host cells.
• Which virulence factor allows pathogens to penetrate the dermis and invade the body?
-✓✓ Bacterial enzymes
, • A bacterium from a deep-sea hydrothermal vent has been cultured. Which staining
technique should be used to begin the process of species identification? -✓✓ Gram
staining
• What does the presence of a clear area around a cell stained with India ink indicate
about the cell? -✓✓ The cell has a capsule.
• How do basic stains work? -✓✓ The positively charged stain is attracted to the
negatively charged portion of the cell.
• Which staining technique is used to distinguish bacteria based on their ability to
produce structures that can survive extreme heat stress? -✓✓ Endospore stain
• Which aspect of a staining protocol enables dye to penetrate an endospore? -✓✓ Heat
• Why are the relationships between pathogenic microbes and their hosts considered
parasitic? -✓✓ The microbe benefits from the interaction while the host is harmed.
• Which characteristic of dracunculiasis has been pivotal to the success of its
eradication campaign? -✓✓ Dracunculiasis has no animal reservoir.
• Which type of organism would be most likely to grow on food stored in a refrigerator or
freezer? -✓✓ A psychrophile would be most likely to grow on food stored in a
refrigerator or freezer as these microorganisms thrive in cold temperatures.
• Staphylococcus epidermldls is a member of the human resident microbiota and
considered part of the human innate immune system. S. epldermidis uses our dead skin
cells as a source of nutrients. What type of relationship between S. epidermidis and
humans is described above? -✓✓ The type of relationship between Staphylococcus
epidermidis and humans described above is "Commensalism," where one organism (S.
epidermidis) benefits (uses dead skin cells) without harming the other organism
(humans).
Commensalism
• Why is the production of lactic acid by the resident microbe Lactobacillus Important to
human health? -✓✓ Lactic acid is important to human health because it inhibits the
growth of pathogenic yeasts.
• Which type of infections are prevented by proper sterilization of hospital equipment
and healthcare worker handwashing? -✓✓ Nosocomial infections are prevented by
proper sterilization of hospital equipment and healthcare worker handwashing.
and Answer (2026/2027) | Verified Practice
Material | A+ Verified
• Why are viruses considered aceilular? -✓✓ They cannot reproduce without a host.
• What is the defining characteristic of eukaryotes? -✓✓ They have a nucleus.
• Which microorganism can cause vaginal yeast Infections and oral thrush? -✓✓ Fungi
• Why can It be difficult to determine the etiologic agent of a disease? -✓✓ Some signs
and symptoms can be caused by many different etiologic agents.
• What kind of staining technique Is the acid-fast stain? -✓✓ differential staining
technique used to distinguish between acid-fast and non-acid-fast bacteria based on the
presence of mycolic acid in their cell walls. The high lipid content of acid-fast organisms,
like Mycobacterium, requires special stains, such as Carbolfuchsin, to penetrate their
waxy cell walls
• A doctor prescribed antibiotics for a patient complaining of runny nose. fever. and
aches and pains. Which type of infection did the doctor suspect? -✓✓ The doctor likely
suspected a bacterial infection because antibiotics are not effective against viral
infections.
• A healthcare professional is treating a patient who developed a yeast infection after
taking antibiotics. What type of medication should be prescribed to this patient? -✓✓
Antifungals
• Which structure promotes motility in Proteus. Shigelia. and Salmonella species. all of
which can cause serious disease in humans? -✓✓ Presence of flagella
• Which bacterial virulence factor allows a strain to resist phagocytosis, increasing the
organism's virulence? -✓✓ Capsule production
• Why is treating Haemophilus influenzae difficult? -✓✓ The capsule is antiphagocytic.
• How do pili aid pathogens in causing disease? -✓✓ They cause pathogens to adhere
to host cells.
• Which virulence factor allows pathogens to penetrate the dermis and invade the body?
-✓✓ Bacterial enzymes
, • A bacterium from a deep-sea hydrothermal vent has been cultured. Which staining
technique should be used to begin the process of species identification? -✓✓ Gram
staining
• What does the presence of a clear area around a cell stained with India ink indicate
about the cell? -✓✓ The cell has a capsule.
• How do basic stains work? -✓✓ The positively charged stain is attracted to the
negatively charged portion of the cell.
• Which staining technique is used to distinguish bacteria based on their ability to
produce structures that can survive extreme heat stress? -✓✓ Endospore stain
• Which aspect of a staining protocol enables dye to penetrate an endospore? -✓✓ Heat
• Why are the relationships between pathogenic microbes and their hosts considered
parasitic? -✓✓ The microbe benefits from the interaction while the host is harmed.
• Which characteristic of dracunculiasis has been pivotal to the success of its
eradication campaign? -✓✓ Dracunculiasis has no animal reservoir.
• Which type of organism would be most likely to grow on food stored in a refrigerator or
freezer? -✓✓ A psychrophile would be most likely to grow on food stored in a
refrigerator or freezer as these microorganisms thrive in cold temperatures.
• Staphylococcus epidermldls is a member of the human resident microbiota and
considered part of the human innate immune system. S. epldermidis uses our dead skin
cells as a source of nutrients. What type of relationship between S. epidermidis and
humans is described above? -✓✓ The type of relationship between Staphylococcus
epidermidis and humans described above is "Commensalism," where one organism (S.
epidermidis) benefits (uses dead skin cells) without harming the other organism
(humans).
Commensalism
• Why is the production of lactic acid by the resident microbe Lactobacillus Important to
human health? -✓✓ Lactic acid is important to human health because it inhibits the
growth of pathogenic yeasts.
• Which type of infections are prevented by proper sterilization of hospital equipment
and healthcare worker handwashing? -✓✓ Nosocomial infections are prevented by
proper sterilization of hospital equipment and healthcare worker handwashing.
