BIOD171 / BIOD 171 Module 4
(Latest Update )
Essential Microbiology with Lab |
Questions & Answers | Grade A |
100% Correct - Portage Learning
Question:
True or False: The purpose of the quadrant streak is to expand bacterial
population.
Answer:
False
(The purpose of the quadrant streak is to generate an individual colony so
that a single (pure) bacterial sample can be picked from the plate.)
Question:
To be considered a pure culture, the sample (1) ________ (2) __________ ?
Answer:
1. Can be traced back to a single cell
2. Is free of outside contaminants
,Question:
When performing a quadrant streak, the sample is spread across the plate in
such a way as to form what?
Answer:
A dilution gradient
(The gradient should always contain within it the growth of individual
colonies.)
Question:
In what phase of a dilution streak would you expect to find the highest
concentration of bacteria, P2 or P4?
Answer:
P2
(Phase 2 would contain a higher concentration of bacteria than Phase 4. The
phases rank (from highest to lowest), P1 > P2 > P3 > P4).
Question:
In what phase of a dilution streak would you expect to find the lowest
concentration of bacteria, P2 or P4?
Answer:
P4
, Question:
True or False: When performing a dilution streak, a new (or sterilized) loop
must be used for each phase.
Answer:
True
(Failure to do so would prevent the establishment of a dilution gradient, as
the same bacterial concentration would be spread across both phase regions).
Question:
In order to encourage growth of a slow growing microbe what might a
researcher do during a phase dilution streak?
Answer:
A researcher may either (1) opt to perform only a 3-phase dilution streak or (2)
pass the loop through the previous phase multiple times (as opposed to only
once).
Question:
True or False: To restrict growth of a pathogenic microbe, a researcher might
decrease an incubator from 37 to 25°C.
Answer:
True
(Latest Update )
Essential Microbiology with Lab |
Questions & Answers | Grade A |
100% Correct - Portage Learning
Question:
True or False: The purpose of the quadrant streak is to expand bacterial
population.
Answer:
False
(The purpose of the quadrant streak is to generate an individual colony so
that a single (pure) bacterial sample can be picked from the plate.)
Question:
To be considered a pure culture, the sample (1) ________ (2) __________ ?
Answer:
1. Can be traced back to a single cell
2. Is free of outside contaminants
,Question:
When performing a quadrant streak, the sample is spread across the plate in
such a way as to form what?
Answer:
A dilution gradient
(The gradient should always contain within it the growth of individual
colonies.)
Question:
In what phase of a dilution streak would you expect to find the highest
concentration of bacteria, P2 or P4?
Answer:
P2
(Phase 2 would contain a higher concentration of bacteria than Phase 4. The
phases rank (from highest to lowest), P1 > P2 > P3 > P4).
Question:
In what phase of a dilution streak would you expect to find the lowest
concentration of bacteria, P2 or P4?
Answer:
P4
, Question:
True or False: When performing a dilution streak, a new (or sterilized) loop
must be used for each phase.
Answer:
True
(Failure to do so would prevent the establishment of a dilution gradient, as
the same bacterial concentration would be spread across both phase regions).
Question:
In order to encourage growth of a slow growing microbe what might a
researcher do during a phase dilution streak?
Answer:
A researcher may either (1) opt to perform only a 3-phase dilution streak or (2)
pass the loop through the previous phase multiple times (as opposed to only
once).
Question:
True or False: To restrict growth of a pathogenic microbe, a researcher might
decrease an incubator from 37 to 25°C.
Answer:
True
