Question 1
- / 3 pts
Define the concept of universal precautions.
Your Answer:
this concept means that handlers must be precautious and consider the received samples as hazardous and pathogenic and use PPE ( Personal Protective Equipment) during the process of recognizing the samples Universal precautions means any and all samples, whether known or unknown, are to be treated as potentially hazardous (or pathogenic) materials.
Question 2
- / 3 pts
List at least 3 observations a researcher would be sure to note while assessing an unknown microbial sample.
Your Answer:
1) should evaluate the morphology of the sample based on the size and shape of the organism 2) should consider the precense and absence of the motility under microscope 3) should use staining method and define it is Gream Positive or Gram Negative organism
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
- / 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:
BIOD 171 Essential Microbiology | Portage Learning; Module 5 Exam 1 / 2
the first one is the presence of its motility or not 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
- / 3 pts
A facultative anaerobe is a microorganism capable of growth under what conditions?
Your Answer:
It is capable to growth in both aerobic and anaerobic condition A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic (without oxygen) conditions.
Question 5 10 / 10 pts As Streptococcus is catalase negative would it thrive or die in the presence of peroxides? Why?
Your Answer:
catalase negative cannot breakdown peroxide so it would die 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
- / 2 pts
Streptococcus is most often streaked onto:
EMB agar
Correct!
- / 2