WGU Biochemistry OA Review Questions And
Answers 2022/2023 100%
1. The polymerase chain reaction is a tool used to study protein structure.
True
False
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
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
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
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
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
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
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
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
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
Denaturation, annealing, and elongation
Annealing, elongation, and denaturation
Elongation, annealing, and denaturation
Denaturation, annealing, and elongation
Feedback
PCR uses repeated cycles of temperature to amplify particular DNA segments. In the
first step, the reaction mixture is heated to separate the DNA strands (denaturation).
The reaction is then cooled to allow the DNA primers, which define the sequence to be
amplified, to anneal (base pair) with the template DNA. In the third step, DNA
polymerase extends the DNA primers to create a copy of the target DNA sequence.
Heating the reaction to stop polymerization and separate the DNA strands starts the
cycle over again
Sickle Cell Anemia is inherited in an autosomal recessive pattern. Choose the set
of chromosomes of a person that has inherited the disease. Green boxes
represent normal alleles and yellow boxes represent mutant alleles.
Captionless Image
A. Chromosome 12 (Blue) vs. Chromosome 11 (Red)
B. Chromosome X (Blue) vs. Chromosome Y (Red, Short)
C. Chromosome 11 (Blue) vs. Chromosome 11 (Red w/green stripe)
D. Chromosome 11 (Blue) vs. Chromosome 11 (Red w/yellow stripe)
D. Chromosome 11 (Blue) vs. Chromosome 11 (Red w/yellow stripe)
Feedback
This question depicts chromosomes and asks which pair represents an Autosomal
Recessive inheritance pattern. Each of the chromosomes are pictured carrying an allele
from each parent, which is depicted by a yellow or green box. The green box represents
a normal or dominant allele, while the yellow box represents a mutant or recessive
allele.
, An Autosomal trait will be carried on a numbered chromosome and both chromosomes
should have the same number. An X-linked trait will be carried on an X-chromosome.
This allows us to rule out answer choices A and B.
To inherit a recessive trait, we need to inherit two recessive (or mutant alleles), which
would be shown as two yellow boxes. A dominant trait can be inherited when one or two
dominant alleles are present. Answer choice C depicts an Autosomal Dominant
inheritance, while answer choice D is the correct answer because it depicts an
Autosomal Recessive inheritance pattern.
Hemophilia is an X-linked recessive condition. This means that:
1. A person with at least one normal X chromosome without the hemophilia gene
will not show signs of hemophilia
2. The disease is more common in females
3. Affected men can pass the condition on to sons but not to daughters
4. Women can only pass the condition on to daughters
1. A person with at least one normal X chromosome without the hemophilia gene will
not show signs of hemophilia
Feedback
An X-linked recessive condition is inherited when a female has a recessive allele on
each of her X chromosomes. Males inherit an X-linked recessive condition if they inherit
a recessive allele on their one and only X chromosome. Therefore if a female has a
dominant (or normal) allele on one of her X chromosomes, she will not have the
disease.
Because men only have one X-chromosome, they tend to inherit X-linked conditions
more easily than females.
Men with X-linked recessive conditions do not pass the disease on to their sons,
because they pass a Y chromosome on to their sons. Men will pass an X chromosome
to their daughters.
Women are able to pass an X chromosome on to their son or their daughters.
A woman is homozygous for an abnormal allele on Chromosome 2 that codes for
an autosomal dominant disease. This means that she:
Will have the disease
Will not have the disease
Has one normal gene and one abnormal gene
Can pass on two genes to any daughters and one gene to any son
Will have the disease
Feedback
Homozygous means that the woman will have two copies of the abnormal allele. An
abnormal allele is the allele that can lead to disease. Since the disease is dominant,
Answers 2022/2023 100%
1. The polymerase chain reaction is a tool used to study protein structure.
True
False
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
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
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
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
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
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
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
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
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
Denaturation, annealing, and elongation
Annealing, elongation, and denaturation
Elongation, annealing, and denaturation
Denaturation, annealing, and elongation
Feedback
PCR uses repeated cycles of temperature to amplify particular DNA segments. In the
first step, the reaction mixture is heated to separate the DNA strands (denaturation).
The reaction is then cooled to allow the DNA primers, which define the sequence to be
amplified, to anneal (base pair) with the template DNA. In the third step, DNA
polymerase extends the DNA primers to create a copy of the target DNA sequence.
Heating the reaction to stop polymerization and separate the DNA strands starts the
cycle over again
Sickle Cell Anemia is inherited in an autosomal recessive pattern. Choose the set
of chromosomes of a person that has inherited the disease. Green boxes
represent normal alleles and yellow boxes represent mutant alleles.
Captionless Image
A. Chromosome 12 (Blue) vs. Chromosome 11 (Red)
B. Chromosome X (Blue) vs. Chromosome Y (Red, Short)
C. Chromosome 11 (Blue) vs. Chromosome 11 (Red w/green stripe)
D. Chromosome 11 (Blue) vs. Chromosome 11 (Red w/yellow stripe)
D. Chromosome 11 (Blue) vs. Chromosome 11 (Red w/yellow stripe)
Feedback
This question depicts chromosomes and asks which pair represents an Autosomal
Recessive inheritance pattern. Each of the chromosomes are pictured carrying an allele
from each parent, which is depicted by a yellow or green box. The green box represents
a normal or dominant allele, while the yellow box represents a mutant or recessive
allele.
, An Autosomal trait will be carried on a numbered chromosome and both chromosomes
should have the same number. An X-linked trait will be carried on an X-chromosome.
This allows us to rule out answer choices A and B.
To inherit a recessive trait, we need to inherit two recessive (or mutant alleles), which
would be shown as two yellow boxes. A dominant trait can be inherited when one or two
dominant alleles are present. Answer choice C depicts an Autosomal Dominant
inheritance, while answer choice D is the correct answer because it depicts an
Autosomal Recessive inheritance pattern.
Hemophilia is an X-linked recessive condition. This means that:
1. A person with at least one normal X chromosome without the hemophilia gene
will not show signs of hemophilia
2. The disease is more common in females
3. Affected men can pass the condition on to sons but not to daughters
4. Women can only pass the condition on to daughters
1. A person with at least one normal X chromosome without the hemophilia gene will
not show signs of hemophilia
Feedback
An X-linked recessive condition is inherited when a female has a recessive allele on
each of her X chromosomes. Males inherit an X-linked recessive condition if they inherit
a recessive allele on their one and only X chromosome. Therefore if a female has a
dominant (or normal) allele on one of her X chromosomes, she will not have the
disease.
Because men only have one X-chromosome, they tend to inherit X-linked conditions
more easily than females.
Men with X-linked recessive conditions do not pass the disease on to their sons,
because they pass a Y chromosome on to their sons. Men will pass an X chromosome
to their daughters.
Women are able to pass an X chromosome on to their son or their daughters.
A woman is homozygous for an abnormal allele on Chromosome 2 that codes for
an autosomal dominant disease. This means that she:
Will have the disease
Will not have the disease
Has one normal gene and one abnormal gene
Can pass on two genes to any daughters and one gene to any son
Will have the disease
Feedback
Homozygous means that the woman will have two copies of the abnormal allele. An
abnormal allele is the allele that can lead to disease. Since the disease is dominant,
