WGU BIOCHEMISTRY OA EXAMQUESTIONS AND ANSWERS
2025/2026 | COMPLETE QUESTIONS AND CORRECT ANSWERS |
UPDATED VERSION
1. The polymerase chain reaction is a tool used to study protein structure.
True
False - (Answer) -False
Feedback
PCR is a tool used to amplify a specific segment of DNA.
What color is the primer in the following diagram?
Red
Purple
Blue - (Answer) -Red
Feedback
Recall from the section on DNA replication that DNA polymerase needs a primer to
begin DNA synthesis. This requirement means the primers will direct the DNA
polymerase to only synthesize complementary strands of the target DNA. (Note: In
DNA replication, the primers are RNA primers, while PCR generally uses DNA
primers because they are more stable.)
dNTPs are DNA nucleotides used in PCR.
True
False - (Answer) -True
,Feedback
dNTPs stands for deoxynucleotide triphosphates, which are the nucleotides used in
DNA synthesis.
A thermocycler is a machine used for PCR that varies the temperature of a sample.
True
False - (Answer) -True
Feedback
For PCR, in each cycle, the two strands of the duplex DNA are separated by heating,
then the reaction mixture is cooled to allow the primers to anneal (or pair) to their
complementary segments on the DNA. Next, the DNA polymerase directs the
synthesis of the complementary strands. The use of a heat-stable DNA polymerase
eliminates the need to add fresh enzyme after each round of heating (heat inactivates
most enzymes). Hence, in the presence of sufficient quantities of primers and dNTPs,
PCR is carried out simply by cycling through the different temperatures for strand
separation, primer annealing, and DNA synthesis.
The thermocycler is the machine that is used to vary the temperature of the samples.
DNA polymerase is used in DNA replication and in PCR.
True
False - (Answer) -True
Feedback
,Both PCR and DNA replication require DNA polymerase to make new copies of
DNA.
Which of the following changes can NOT be detected using PCR?
Differences in DNA sequence
Epigenetic changes
Deletions
Insertions - (Answer) -Epigenetic changes
Feedback
Epigenetic changes do not affect the sequence of the DNA. PCR is used to look at
the DNA sequence.
Which of the following components is NOT used in PCR?
DNA template
DNA nucleotides
RNA polymerase
Primers - (Answer) -RNA polymerase
Feedback
PCR makes a DNA copy, so DNA polymerase is used.
Assuming there is one copy of the target DNA sequence before PCR, how many
copies of DNA are there after 5 PCR cycles?
, 256
6
65,536
16
32 - (Answer) -32
Feedback
Each cycles double the numbers of DNA copy. Round 1: 1->2. Round 2: 2 ->4.
Round 3: 4 -> 8. Round 4: 8 ->16. Round 5: 16 ->32.
DNA polymerase can synthesize new DNA strands in which direction?
3' to 5'
5' to 3'
any direction
N-terminus to C-terminus - (Answer) -5' to 3'
Feedback
DNA needs a free 3' end to bind to and initiate synthesis of a DNA. It synthesizes in
a 5' to 3' direction.
The following are steps involved in a polymerase chain reaction. Which is the correct
order:
Elongation, denaturation, and annealing
2025/2026 | COMPLETE QUESTIONS AND CORRECT ANSWERS |
UPDATED VERSION
1. The polymerase chain reaction is a tool used to study protein structure.
True
False - (Answer) -False
Feedback
PCR is a tool used to amplify a specific segment of DNA.
What color is the primer in the following diagram?
Red
Purple
Blue - (Answer) -Red
Feedback
Recall from the section on DNA replication that DNA polymerase needs a primer to
begin DNA synthesis. This requirement means the primers will direct the DNA
polymerase to only synthesize complementary strands of the target DNA. (Note: In
DNA replication, the primers are RNA primers, while PCR generally uses DNA
primers because they are more stable.)
dNTPs are DNA nucleotides used in PCR.
True
False - (Answer) -True
,Feedback
dNTPs stands for deoxynucleotide triphosphates, which are the nucleotides used in
DNA synthesis.
A thermocycler is a machine used for PCR that varies the temperature of a sample.
True
False - (Answer) -True
Feedback
For PCR, in each cycle, the two strands of the duplex DNA are separated by heating,
then the reaction mixture is cooled to allow the primers to anneal (or pair) to their
complementary segments on the DNA. Next, the DNA polymerase directs the
synthesis of the complementary strands. The use of a heat-stable DNA polymerase
eliminates the need to add fresh enzyme after each round of heating (heat inactivates
most enzymes). Hence, in the presence of sufficient quantities of primers and dNTPs,
PCR is carried out simply by cycling through the different temperatures for strand
separation, primer annealing, and DNA synthesis.
The thermocycler is the machine that is used to vary the temperature of the samples.
DNA polymerase is used in DNA replication and in PCR.
True
False - (Answer) -True
Feedback
,Both PCR and DNA replication require DNA polymerase to make new copies of
DNA.
Which of the following changes can NOT be detected using PCR?
Differences in DNA sequence
Epigenetic changes
Deletions
Insertions - (Answer) -Epigenetic changes
Feedback
Epigenetic changes do not affect the sequence of the DNA. PCR is used to look at
the DNA sequence.
Which of the following components is NOT used in PCR?
DNA template
DNA nucleotides
RNA polymerase
Primers - (Answer) -RNA polymerase
Feedback
PCR makes a DNA copy, so DNA polymerase is used.
Assuming there is one copy of the target DNA sequence before PCR, how many
copies of DNA are there after 5 PCR cycles?
, 256
6
65,536
16
32 - (Answer) -32
Feedback
Each cycles double the numbers of DNA copy. Round 1: 1->2. Round 2: 2 ->4.
Round 3: 4 -> 8. Round 4: 8 ->16. Round 5: 16 ->32.
DNA polymerase can synthesize new DNA strands in which direction?
3' to 5'
5' to 3'
any direction
N-terminus to C-terminus - (Answer) -5' to 3'
Feedback
DNA needs a free 3' end to bind to and initiate synthesis of a DNA. It synthesizes in
a 5' to 3' direction.
The following are steps involved in a polymerase chain reaction. Which is the correct
order:
Elongation, denaturation, and annealing
