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MICROBIOLOGY LAB FINAL EXAM VERSION 3 EXAM NEWEST
2025/2026 ACTUAL EXAM WITH COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS (100% VERIFIED ANSWERS)
|ALREADY GRADED A+| ||PROFESSOR VERIFIED||
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
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What will happen to the number of T4 phage particles present in a
sample after all of the Escherichia coli cells have been lysed? -
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
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What is the definition of burst size? - ANSWER-The average
number of phage particles released per infected bacterial cell
In the bacterial transformation exercise, the term transformation
refers to... - ANSWER-The ability of a bacterial cell to pick up
DNA from the environment and to add this new DNA to its
genome
Match the following steps of PCR with the process that occurs
during that step. - ANSWER-Denaturation: DNA unwinds and the
two strands of DNA separate
Annealing: Primers attach to the template DNA
Extension: DNA polymerase adds nucleotides to make a
complimentary strand of DNA
Among the "Top 5" bacteria we use, ______________
______________ has a positive Gram reaction and has coccus-
shaped cells. - ANSWER-Staphylococcus epidermidis
MICROBIOLOGY LAB FINAL EXAM VERSION 3 EXAM NEWEST
2025/2026 ACTUAL EXAM WITH COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS (100% VERIFIED ANSWERS)
|ALREADY GRADED A+| ||PROFESSOR VERIFIED||
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
,2|Page
What will happen to the number of T4 phage particles present in a
sample after all of the Escherichia coli cells have been lysed? -
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
, 3|Page
What is the definition of burst size? - ANSWER-The average
number of phage particles released per infected bacterial cell
In the bacterial transformation exercise, the term transformation
refers to... - ANSWER-The ability of a bacterial cell to pick up
DNA from the environment and to add this new DNA to its
genome
Match the following steps of PCR with the process that occurs
during that step. - ANSWER-Denaturation: DNA unwinds and the
two strands of DNA separate
Annealing: Primers attach to the template DNA
Extension: DNA polymerase adds nucleotides to make a
complimentary strand of DNA
Among the "Top 5" bacteria we use, ______________
______________ has a positive Gram reaction and has coccus-
shaped cells. - ANSWER-Staphylococcus epidermidis
