BIOD 171 : MODULE 5 Exam 2026
Questions and Answers
Define the concept of universal precautions. - Correct answer-Universal
precautions means any and all samples, whether known or unknown, are to be
treated as potentially hazardous (or pathogenic) materials.
List at least 3 observations a researcher would be sure to note while assessing an
unknown microbial sample. - Correct answer-1. size and shape
2. gram status
3. any observable motility
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? - Correct answer-You would need to
determine the motility first and then the Gram status. Motility requires a wet mount
and Gram staining requires heat fixing the sample. If you perform a Gram stain
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, first the heat fixation would kill the organism, making it impossible to observe
motility.
A facultative anaerobe is a microorganism capable of growth under what
conditions? - Correct answer-It is capable of growth under both anaerobic and
aerobic conditions
As Streptococcus is catalase negative would it thrive or die in the presence of
peroxides? Why? - Correct answer-It would die. Because it is catalase negative it
wouldn't be able to breakdown peroxides.
Streptococcus is most often streaked onto:
- Chocolate agar
- EMB agar
- Blood agar
- Spirit Blue agar - Correct answer-Blood agar
Strep is often cultured on Blood agar plates to determine its hemolytic properties,
which aids in the classification (and differentiation) process.
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
Questions and Answers
Define the concept of universal precautions. - Correct answer-Universal
precautions means any and all samples, whether known or unknown, are to be
treated as potentially hazardous (or pathogenic) materials.
List at least 3 observations a researcher would be sure to note while assessing an
unknown microbial sample. - Correct answer-1. size and shape
2. gram status
3. any observable motility
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? - Correct answer-You would need to
determine the motility first and then the Gram status. Motility requires a wet mount
and Gram staining requires heat fixing the sample. If you perform a Gram stain
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
, first the heat fixation would kill the organism, making it impossible to observe
motility.
A facultative anaerobe is a microorganism capable of growth under what
conditions? - Correct answer-It is capable of growth under both anaerobic and
aerobic conditions
As Streptococcus is catalase negative would it thrive or die in the presence of
peroxides? Why? - Correct answer-It would die. Because it is catalase negative it
wouldn't be able to breakdown peroxides.
Streptococcus is most often streaked onto:
- Chocolate agar
- EMB agar
- Blood agar
- Spirit Blue agar - Correct answer-Blood agar
Strep is often cultured on Blood agar plates to determine its hemolytic properties,
which aids in the classification (and differentiation) process.
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
