Portage Microbiology BIOD171
Exam 5Questions and Answers
100% Pass
Define the concept of universal precautions. -
Answer: Universal precautions means any and all samples, whether known or
unknown, are to be treated as potentially hazardous (or pathogenic) materials.
Question: List at least 3 observations a researcher would be sure to note while
assessing an unknown microbial sample. -
Answer: A lab researcher would be certain to note:
Size and shape
Any observable motility
Gram status (positive or negative)
The presence of any chemical reactions
, Changes in color localized to the organism or the surrounding media
Capture (or draw) images of any of the characteristics described above
Question: While observing an unknown sample of limited amounts, a researcher
must determine the following observations: (1) the presence of any motility and (2)
its Gram status using the same sample—the liquid sample cannot be divided.
Which would you determine first and why? -
Answer: You must determine motility before determining the Gram status.
Motility requires a wet mount, while Gram staining requires heat fixing the sample.
If one were to begin with the Gram stain the heat fixation process would kill the
organism, making any observations regarding motility impossible. The correct
approach would be to place the liquid culture on a glass slide and determine its
motility status. Next, the same liquid culture can be heat fixed and Gram stained.
Question: A facultative anaerobe is a microorganism capable of growth under
what conditions? -
Answer: A facultative anaerobe is capable of growth under aerobic (with oxygen)
and anaerobic (without oxygen) conditions.
Exam 5Questions and Answers
100% Pass
Define the concept of universal precautions. -
Answer: Universal precautions means any and all samples, whether known or
unknown, are to be treated as potentially hazardous (or pathogenic) materials.
Question: List at least 3 observations a researcher would be sure to note while
assessing an unknown microbial sample. -
Answer: A lab researcher would be certain to note:
Size and shape
Any observable motility
Gram status (positive or negative)
The presence of any chemical reactions
, Changes in color localized to the organism or the surrounding media
Capture (or draw) images of any of the characteristics described above
Question: While observing an unknown sample of limited amounts, a researcher
must determine the following observations: (1) the presence of any motility and (2)
its Gram status using the same sample—the liquid sample cannot be divided.
Which would you determine first and why? -
Answer: You must determine motility before determining the Gram status.
Motility requires a wet mount, while Gram staining requires heat fixing the sample.
If one were to begin with the Gram stain the heat fixation process would kill the
organism, making any observations regarding motility impossible. The correct
approach would be to place the liquid culture on a glass slide and determine its
motility status. Next, the same liquid culture can be heat fixed and Gram stained.
Question: A facultative anaerobe is a microorganism capable of growth under
what conditions? -
Answer: A facultative anaerobe is capable of growth under aerobic (with oxygen)
and anaerobic (without oxygen) conditions.
