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MICROBIOLOGY LAB FINAL EXAM VERSION 3 ACTUAL
EXAM 2025/2026 NEWEST ACTUAL EXAM WITH COMPLETE
QUESTIONS AND VERIFIED ANSWERS |ALREADY GRADED
A+|
Which of the following shows a positive result for the casein
hydrolysis test? - ANSWER-clear zone - subtilis
Observations of colony morphology, cell morphology, and Gram
stain reaction will provide enough data to identify the genus and
species of your unknown environmental isolate. - ANSWER-False
A viable plate count assay is an example of an indirect counting
method for enumerating bacteria. - ANSWER-True
What are the three steps in one cycle of PCR? - ANSWER-Step
1: Denaturation
Step 2: Annealing
Step 3: Extension
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In the molecular identification exercise, what is the purpose of
PCR? - ANSWER-To make lots of copies of the 16S gene of your
unknown environmental isolate
What were the final dilutions of the spread plates in the bacterial
enumeration exercise? - ANSWER-10-3 through 10-6
What does the formation of a dark precipitate in the Kligler's test
mean? - ANSWER-Positive for production of hydrogen sulfide
PCR stands for ______________ ______________
______________ . - ANSWER-polymerase chain reaction
For the acid-fast staining technique, [A] is the positive control
organism, and [B] is the negative control organism. - ANSWER-
Mycobacterium smegmatis
Staphylococcus epidermidis
What will happen to the number of T4 phage particles present in a
sample after all of the Escherichia coli cells have been lysed? -
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ANSWER-Bacteriophage cannot reproduce without host cells, so
the number of T4 phage particles will remain the same
Match each term with the best definition. - ANSWER-Adsoprtion:
The attachment of the bacteriophage to the host cell
Replication: The host cell makes new bacteriophage DNA
Assembly:The host cell produces new bacteriophage
Lysis: The host cell bursts and releases mature bacteriophage
In the bacteriophage exercise... - ANSWER-The T4
bacteriophage infected Escherichia coli strain B
In the molecular identification exercise, gel electrophoresis was
used to visualize the length of your PCR product. - ANSWER-
True
What is the definition of burst size? - ANSWER-The average
number of phage particles released per infected bacterial cell
MICROBIOLOGY LAB FINAL EXAM VERSION 3 ACTUAL
EXAM 2025/2026 NEWEST ACTUAL EXAM WITH COMPLETE
QUESTIONS AND VERIFIED ANSWERS |ALREADY GRADED
A+|
Which of the following shows a positive result for the casein
hydrolysis test? - ANSWER-clear zone - subtilis
Observations of colony morphology, cell morphology, and Gram
stain reaction will provide enough data to identify the genus and
species of your unknown environmental isolate. - ANSWER-False
A viable plate count assay is an example of an indirect counting
method for enumerating bacteria. - ANSWER-True
What are the three steps in one cycle of PCR? - ANSWER-Step
1: Denaturation
Step 2: Annealing
Step 3: Extension
, Page |2
In the molecular identification exercise, what is the purpose of
PCR? - ANSWER-To make lots of copies of the 16S gene of your
unknown environmental isolate
What were the final dilutions of the spread plates in the bacterial
enumeration exercise? - ANSWER-10-3 through 10-6
What does the formation of a dark precipitate in the Kligler's test
mean? - ANSWER-Positive for production of hydrogen sulfide
PCR stands for ______________ ______________
______________ . - ANSWER-polymerase chain reaction
For the acid-fast staining technique, [A] is the positive control
organism, and [B] is the negative control organism. - ANSWER-
Mycobacterium smegmatis
Staphylococcus epidermidis
What will happen to the number of T4 phage particles present in a
sample after all of the Escherichia coli cells have been lysed? -
, Page |3
ANSWER-Bacteriophage cannot reproduce without host cells, so
the number of T4 phage particles will remain the same
Match each term with the best definition. - ANSWER-Adsoprtion:
The attachment of the bacteriophage to the host cell
Replication: The host cell makes new bacteriophage DNA
Assembly:The host cell produces new bacteriophage
Lysis: The host cell bursts and releases mature bacteriophage
In the bacteriophage exercise... - ANSWER-The T4
bacteriophage infected Escherichia coli strain B
In the molecular identification exercise, gel electrophoresis was
used to visualize the length of your PCR product. - ANSWER-
True
What is the definition of burst size? - ANSWER-The average
number of phage particles released per infected bacterial cell
