Portage Learning BIOD 171 Module 5
Exam Module 5
1. Define the concept of universal precautions.
Universal precautions means any and all samples, whether known or
unknown, are to be treated as potentially hazardous (or pathogenic)
materials.
2. List at least 3 observations a researcher would be sure to note while
assessing an unknown microbial sample.
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
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?
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 facultative anaerobe is capable of growth under aerobic (with oxygen) and
anaerobic (without oxygen) conditions.
5. True or False. The Lancefield groups are used to subdivide antigenic
groups of alpha-hemolytic Streptococcus.
False. The Lancefield groupings are used to subdivide beta-hemolytic Strep.
6. The distinctions for Lancefield subgroupings lie in its: (select all that
apply)
A. Catalase activity
B. Carbohydrate composition of antigens
C. Hemolytic activity
D. All of the above
B. Carbohydrate composition of antigens present in the cell wall determines
the Lancefield groupings (A, B, C, etc). Note, ALL strep under Lancefield
groupings are (by definition) catalase negative and beta-hemolytic. Thus,
answers A and C cannot be used to subdivide streptococcal species.
7. Rheumatic fever displays hemolytic activity and occurs when is left
untreated.
A. Beta; Strep. Pharyngitis
B. Gamma; Strep. Septicemia
C. Beta; Rheumatic fever
D. Alpha; Strep. Pharyngitis
A. Strep throat (also known as strep. Pharyngitis) can lead to Rheumatic
fever if left untreated and displays beta-hemolytic activity.
8. True or False. Under most circumstances, staphylococcus can be
found in ~80% of human population where it remains non-
symptomatic.
False. Staphylococcus in only found (non-symptomatic) in ~30% of the
human population.
Exam Module 5
1. Define the concept of universal precautions.
Universal precautions means any and all samples, whether known or
unknown, are to be treated as potentially hazardous (or pathogenic)
materials.
2. List at least 3 observations a researcher would be sure to note while
assessing an unknown microbial sample.
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
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?
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 facultative anaerobe is capable of growth under aerobic (with oxygen) and
anaerobic (without oxygen) conditions.
5. True or False. The Lancefield groups are used to subdivide antigenic
groups of alpha-hemolytic Streptococcus.
False. The Lancefield groupings are used to subdivide beta-hemolytic Strep.
6. The distinctions for Lancefield subgroupings lie in its: (select all that
apply)
A. Catalase activity
B. Carbohydrate composition of antigens
C. Hemolytic activity
D. All of the above
B. Carbohydrate composition of antigens present in the cell wall determines
the Lancefield groupings (A, B, C, etc). Note, ALL strep under Lancefield
groupings are (by definition) catalase negative and beta-hemolytic. Thus,
answers A and C cannot be used to subdivide streptococcal species.
7. Rheumatic fever displays hemolytic activity and occurs when is left
untreated.
A. Beta; Strep. Pharyngitis
B. Gamma; Strep. Septicemia
C. Beta; Rheumatic fever
D. Alpha; Strep. Pharyngitis
A. Strep throat (also known as strep. Pharyngitis) can lead to Rheumatic
fever if left untreated and displays beta-hemolytic activity.
8. True or False. Under most circumstances, staphylococcus can be
found in ~80% of human population where it remains non-
symptomatic.
False. Staphylococcus in only found (non-symptomatic) in ~30% of the
human population.
