Module 5 Exam Review Questions with
100% Verified Answers (Essential
Microbiology)
, lOMoAR cPSD| 47061011
1. The concept of treating all samples, whether known or unknown, as potentially hazardous
(or pathogenic) materials is known as __________.
a. Universal precautions
2. List at least 3 observations a researcher would be sure to note while assessing an
unknown microbial sample.
a. A lab researcher would be certain to note:
i. Size and shape
ii. Any observable motility
iii. Gram status (positive or negative
iv. The presence of any chemical reactions
v. Changes in color localized to the organism or the surrounding media
vi. Capture (or draw) images of any of the characteristics described above
3. 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?
a. 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.
4. A facultative anaerobe is a microorganism capable of growth under what conditions?
a. A facultative anaerobe is capable of growth under aerobic (with oxygen) and
anaerobic (without oxygen) conditions
5. As Streptococcus is catalase negative would it thrive or die in the presence of peroxides?
Why?
a. 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
6. Streptococcus is most often streaked onto:
a. Chocolate agar
b. EMB agar
c. Blood agar
d. Spirit blue agar
7. True or False. The Lancefield groups are used to subdivide antigenic groups of
gammahemolytic Streptococcus.
a. False - The Lancefield groupings are used to subdivide beta-hemolytic Strep
8. The distinctions for Lancefield subgroupings lie in its: (select all that apply)
a. Hemolytic activity
b. Catalase activity
c. Carbohydrate composition of antigens
i. Carbohydrate composition of antigens present in the cell wall determines
the Lancefield groupings (A, B, C, etc). Note, ALL strep under Lancefield
100% Verified Answers (Essential
Microbiology)
, lOMoAR cPSD| 47061011
1. The concept of treating all samples, whether known or unknown, as potentially hazardous
(or pathogenic) materials is known as __________.
a. Universal precautions
2. List at least 3 observations a researcher would be sure to note while assessing an
unknown microbial sample.
a. A lab researcher would be certain to note:
i. Size and shape
ii. Any observable motility
iii. Gram status (positive or negative
iv. The presence of any chemical reactions
v. Changes in color localized to the organism or the surrounding media
vi. Capture (or draw) images of any of the characteristics described above
3. 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?
a. 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.
4. A facultative anaerobe is a microorganism capable of growth under what conditions?
a. A facultative anaerobe is capable of growth under aerobic (with oxygen) and
anaerobic (without oxygen) conditions
5. As Streptococcus is catalase negative would it thrive or die in the presence of peroxides?
Why?
a. 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
6. Streptococcus is most often streaked onto:
a. Chocolate agar
b. EMB agar
c. Blood agar
d. Spirit blue agar
7. True or False. The Lancefield groups are used to subdivide antigenic groups of
gammahemolytic Streptococcus.
a. False - The Lancefield groupings are used to subdivide beta-hemolytic Strep
8. The distinctions for Lancefield subgroupings lie in its: (select all that apply)
a. Hemolytic activity
b. Catalase activity
c. Carbohydrate composition of antigens
i. Carbohydrate composition of antigens present in the cell wall determines
the Lancefield groupings (A, B, C, etc). Note, ALL strep under Lancefield
