Portage Learning Microbiology Exam #5
Questions and Guide Answers
100% Verified Graded A+
1. Define the concept of universal precautions (short answer)
Answer: Universal precautions means any and all samples, whether known or unknown, are to be treated
as potentially hazardous (or pathogenic) materials
2. List at lease 3 observations a researcher would be sure to note while assess-ing
and unknown microbial sample (short answer)
Answer: Need to note
1. Size and shape
2. Any observable motility
3. Gram status (positive or negative)
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? (short answer)
Answer: You must determine motility before determining 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? (short answer)
Answer: 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
Answer: False. The Lancefield groups are used to subdivide beta-hemolyt-ic strep
6. The distinctions for Lancefield subgroups lie in its
Answer: (select all that apply)
A. Catalase activity
B. Carbohydrate composition of antigens
Questions and Guide Answers
100% Verified Graded A+
1. Define the concept of universal precautions (short answer)
Answer: Universal precautions means any and all samples, whether known or unknown, are to be treated
as potentially hazardous (or pathogenic) materials
2. List at lease 3 observations a researcher would be sure to note while assess-ing
and unknown microbial sample (short answer)
Answer: Need to note
1. Size and shape
2. Any observable motility
3. Gram status (positive or negative)
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? (short answer)
Answer: You must determine motility before determining 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? (short answer)
Answer: 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
Answer: False. The Lancefield groups are used to subdivide beta-hemolyt-ic strep
6. The distinctions for Lancefield subgroups lie in its
Answer: (select all that apply)
A. Catalase activity
B. Carbohydrate composition of antigens
