BIOD 171 Essential Microbiology Module
5 Exam-with 100% verified solutions-
Question 1
Not yet graded / 3 pts
The concept of treating all samples, whether known or unknown, as potentially
hazardous (or pathogenic) materials is known as .
Your Answer:
universal precautions
Universal precautions
Question 2
Not yet graded / 3 pts
List at least 3 observations a researcher would be sure to note while assessing an
unknown microbial sample.
Your Answer:
size and shape, motility, chemical reactions, gram stain, color change
A lab researcher would be certain to note:
1. Size and shape
2. Any observable motility
3. Gram status (positive or negative)
4. The presence of any chemical reactions
5. Changes in color localized to the organism or the surrounding media
6. Capture (or draw) images of any of the characteristics described above
Question 3
Not yet graded / 10 pts
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?
Your Answer:
, The motility should be determined first. Observing motility requires a wet mount. Gram
staining requires heat fixation. Heat fixing would kill the organism and motility would
not be observable.
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 4
Not yet graded / 3 pts
A facultative anaerobe is a microorganism capable of growth under what conditions?
Your Answer:
A facultative anaerobe is capable of growth under aerobic and anaerobic conditions.
A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic
(without oxygen) conditions.
Question 5
Not yet graded / 10 pts
As Streptococcus is catalase negative would it thrive or die in the presence of peroxides?
Why?
Your Answer:
Streptococcus would die in the presence of peroxides because it is not able to break
down the peroxides.
Streptococcus would not survive in the presence of peroxides—it is unable to
breakdown peroxides (catalase negative). Left unchecked, peroxides would damage the
cellular integrity of Strep causing lysis/cell death.
Question 6
pts
Streptococcus is most often streaked onto:
Spirit Blue agar
5 Exam-with 100% verified solutions-
Question 1
Not yet graded / 3 pts
The concept of treating all samples, whether known or unknown, as potentially
hazardous (or pathogenic) materials is known as .
Your Answer:
universal precautions
Universal precautions
Question 2
Not yet graded / 3 pts
List at least 3 observations a researcher would be sure to note while assessing an
unknown microbial sample.
Your Answer:
size and shape, motility, chemical reactions, gram stain, color change
A lab researcher would be certain to note:
1. Size and shape
2. Any observable motility
3. Gram status (positive or negative)
4. The presence of any chemical reactions
5. Changes in color localized to the organism or the surrounding media
6. Capture (or draw) images of any of the characteristics described above
Question 3
Not yet graded / 10 pts
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?
Your Answer:
, The motility should be determined first. Observing motility requires a wet mount. Gram
staining requires heat fixation. Heat fixing would kill the organism and motility would
not be observable.
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 4
Not yet graded / 3 pts
A facultative anaerobe is a microorganism capable of growth under what conditions?
Your Answer:
A facultative anaerobe is capable of growth under aerobic and anaerobic conditions.
A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic
(without oxygen) conditions.
Question 5
Not yet graded / 10 pts
As Streptococcus is catalase negative would it thrive or die in the presence of peroxides?
Why?
Your Answer:
Streptococcus would die in the presence of peroxides because it is not able to break
down the peroxides.
Streptococcus would not survive in the presence of peroxides—it is unable to
breakdown peroxides (catalase negative). Left unchecked, peroxides would damage the
cellular integrity of Strep causing lysis/cell death.
Question 6
pts
Streptococcus is most often streaked onto:
Spirit Blue agar
