BIOD 171 Module 5 Exam Questions and 100 %
Correct Answers Latest 2025: Essential
Microbiology - Portage Learning
Define the concept of universal precautions. - ANSWER any and all samples, whether known or
unknown, are to be treated as potentially hazardous/pathogenic
What would a researcher be certain to note while analyzing a microbial sample? - ANSWER Size
and shape, observable motility, Gram status, any chemical reactions, changes in color in
organism or media, capture/draw any of these characteristics
Which non-selective yet differential agar plate should be used if a Streptococcus sample is
suspected? - ANSWER Blood agar
What disease can result if a patient with streptococcal pharyngitis goes untreated? - ANSWER
rheumatic fever
Streptococcus, E. coli, pseudomonas, and klebsiella are all capable of causing what disease? -
ANSWER septicemia (blood poisoning)
What is a facultative anaerobe? - ANSWER organism that can grow aerobically or an
anaerobically
A bacterial swab is taken from a patient with impetigo and streaked across an MSA plate.
Following incubation at 37C, what will be the color of the agar? - ANSWER from red to yellow
If a patient were suspected to have tuberculosis (TB), which differential stain would you select
and why? - ANSWER Acid fast stain. TB shows a weak Gram stain, acid fast stain for better
visualization
, According to the module, which mycobacterium infection will be treated free of charge by the
World Health Organization (WHO)? - ANSWER leprosy
What are the three main conditions caused by the botulism toxin? - ANSWER foodborne, infant,
wound
Why are infants (< 6 months) more susceptible to botulism? - ANSWER their intestinal tracts are
still maturing and don't yet contain adult microbiota, bacteria can more easily colonize and
produce
What is the mechanism of action of the toxin produced by clostridium tentani (tetanus)? -
ANSWER Acts on inhibitory neurons causing systemic muscle stiffness and spasms. can be
observed in the jaw (lockjaw) or spread systemically to muscles relating to respiratory function.
What Gram-negative bacterium might you come into contact with in a unsanitary hot tub? -
ANSWER Legionella
What are the three forms of plague, and what regions do they affect? - ANSWER Bubonic
(lymph), pneumonic (lungs) and septicemic (blood, all major organs if left untreated)
According to the module, which STD might be best identified via dark-field microscopy? -
ANSWER syphilis (treponema pallidum)
While observing an unknown sample of limited amounts, a researcher must determine the
following observations: 1) the presence of any motility and 2) it's Gram status using the same
sample - the liquid sample can't be divided. Which would you determine first and why? -
ANSWER Motility. It requires a wet mount, Gram staining requires heat fixing the sample which
kills it.
Correct Answers Latest 2025: Essential
Microbiology - Portage Learning
Define the concept of universal precautions. - ANSWER any and all samples, whether known or
unknown, are to be treated as potentially hazardous/pathogenic
What would a researcher be certain to note while analyzing a microbial sample? - ANSWER Size
and shape, observable motility, Gram status, any chemical reactions, changes in color in
organism or media, capture/draw any of these characteristics
Which non-selective yet differential agar plate should be used if a Streptococcus sample is
suspected? - ANSWER Blood agar
What disease can result if a patient with streptococcal pharyngitis goes untreated? - ANSWER
rheumatic fever
Streptococcus, E. coli, pseudomonas, and klebsiella are all capable of causing what disease? -
ANSWER septicemia (blood poisoning)
What is a facultative anaerobe? - ANSWER organism that can grow aerobically or an
anaerobically
A bacterial swab is taken from a patient with impetigo and streaked across an MSA plate.
Following incubation at 37C, what will be the color of the agar? - ANSWER from red to yellow
If a patient were suspected to have tuberculosis (TB), which differential stain would you select
and why? - ANSWER Acid fast stain. TB shows a weak Gram stain, acid fast stain for better
visualization
, According to the module, which mycobacterium infection will be treated free of charge by the
World Health Organization (WHO)? - ANSWER leprosy
What are the three main conditions caused by the botulism toxin? - ANSWER foodborne, infant,
wound
Why are infants (< 6 months) more susceptible to botulism? - ANSWER their intestinal tracts are
still maturing and don't yet contain adult microbiota, bacteria can more easily colonize and
produce
What is the mechanism of action of the toxin produced by clostridium tentani (tetanus)? -
ANSWER Acts on inhibitory neurons causing systemic muscle stiffness and spasms. can be
observed in the jaw (lockjaw) or spread systemically to muscles relating to respiratory function.
What Gram-negative bacterium might you come into contact with in a unsanitary hot tub? -
ANSWER Legionella
What are the three forms of plague, and what regions do they affect? - ANSWER Bubonic
(lymph), pneumonic (lungs) and septicemic (blood, all major organs if left untreated)
According to the module, which STD might be best identified via dark-field microscopy? -
ANSWER syphilis (treponema pallidum)
While observing an unknown sample of limited amounts, a researcher must determine the
following observations: 1) the presence of any motility and 2) it's Gram status using the same
sample - the liquid sample can't be divided. Which would you determine first and why? -
ANSWER Motility. It requires a wet mount, Gram staining requires heat fixing the sample which
kills it.
