PRACTICE TEST EXAM Module 5- Requires Respondus
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Due No due date Points 100 Questions 29 Time Limit 60 Minutes
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Attempt History
Attempt Time Score
LATEST Attempt 1 21 minutes 41 out of 100 *
* Some questions not yet graded
Score for this quiz: 41 out of 100 *
Submitted Dec 31 at 8:57pm
This attempt took 21 minutes.
List at least 3 observations a researcher would be sure to note while assessing
an unknown microbial sample.
Your Answer:
1.) size/shape
2.) motility
3.) change in color
Question 2 Not yet graded / 3 pts
Universal precautions means any and all samples, whether known or
unknown, are to be treated as potentially hazardous (or pathogenic)
materials.
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:
determine first motility
a wet mount
later is a wet mount needs staining . needs a gram status and heat fixing the
heat fixing kills sample and its motility so it wil be unobservable
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
A facultative anaerobe is capable of growth under aerobic (with
oxygen) and anaerobic (without oxygen) conditions.
Your Answer:
conditions of aerobic ( oxygen) and anaerobic ( w/o oxygen)
A facultative anaerobe is a microorganism capable of growth under what
conditions?
Question 4 Not yet graded / 3 pts
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 5 Not yet graded / 10 pts
As Streptococcus is catalase negative would it thrive or die in the presence of
peroxides? Why?
Your Answer:
it would die with peroixide in its present being a catalase negatice not able to
break down the peroxide so it would lead to die and cell lysis if its un treated i
think
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.
Correct!
Streptococcus is most often streaked onto:
Blood agar
Strep is often cultured on Blood agar plates to determine its hemolytic
properties, which aids in the classification (and differentiation) process.
Question 6 2 / 2 pts
Correct!
The Lancefield groupings are used to subdivide beta-hemolytic Strep.
False
True
True or False. The Lancefield groups are used to subdivide antigenic groups of
gamma-hemolytic Streptococcus.
Question 7 2 / 2 pts
Greater than 90% of all human streptococcal infections belong to:
Group C
Question 8 2 / 2 pts
Chocolate agar
Spirit Blue agar
EMB agar
Correct!
Strep. Pharyngitis; beta [Show Less]