D311: Microbiology QUESTIONS AND
VERIFIED CORRECT ANSWERS
GRADED A+ [LATEST 2026-2027] 100%
GUARANTEED PASS
Why is treating Haemophilus influenzae difficult? - CORRECT ANSWER-The capsule is
antiphagocytic.
How do pili aid pathogens in causing disease? - CORRECT ANSWER-They cause pathogens to
adhere to host cells.
Which virulence factor allows pathogens to penetrate the dermis and invade the body? -
CORRECT ANSWER-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? - CORRECT ANSWER-Gram
staining
What does the presence of a clear area around a cell stained with India ink indicate about the
cell? - CORRECT ANSWER-The cell has a capsule.
How do basic stains work? - CORRECT ANSWER-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? - CORRECT ANSWER-Endospore stain
Which aspect of a staining protocol enables dye to penetrate an endospore? - CORRECT
ANSWER-Heat
Why are the relationships between pathogenic microbes and their hosts considered parasitic? -
CORRECT ANSWER-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? - CORRECT ANSWER-Dracunculiasis has no animal reservoir.
Which type of organism would be most likely to grow on food stored in a refrigerator or freezer?
- CORRECT ANSWER-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? -
CORRECT ANSWER-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? - CORRECT ANSWER-Lactic acid is important to human health because it inhibits the
growth of pathogenic yeasts.
VERIFIED CORRECT ANSWERS
GRADED A+ [LATEST 2026-2027] 100%
GUARANTEED PASS
Why is treating Haemophilus influenzae difficult? - CORRECT ANSWER-The capsule is
antiphagocytic.
How do pili aid pathogens in causing disease? - CORRECT ANSWER-They cause pathogens to
adhere to host cells.
Which virulence factor allows pathogens to penetrate the dermis and invade the body? -
CORRECT ANSWER-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? - CORRECT ANSWER-Gram
staining
What does the presence of a clear area around a cell stained with India ink indicate about the
cell? - CORRECT ANSWER-The cell has a capsule.
How do basic stains work? - CORRECT ANSWER-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? - CORRECT ANSWER-Endospore stain
Which aspect of a staining protocol enables dye to penetrate an endospore? - CORRECT
ANSWER-Heat
Why are the relationships between pathogenic microbes and their hosts considered parasitic? -
CORRECT ANSWER-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? - CORRECT ANSWER-Dracunculiasis has no animal reservoir.
Which type of organism would be most likely to grow on food stored in a refrigerator or freezer?
- CORRECT ANSWER-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? -
CORRECT ANSWER-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? - CORRECT ANSWER-Lactic acid is important to human health because it inhibits the
growth of pathogenic yeasts.
