WGU Biochemistry Final
Review
1. 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.
2. 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.)
3. dNTPs are DNA nucleotides used in PCR.
True False:
True
Feedback
dNTPs stands for deoxynucleotide triphosphates, which are the nucleotides used in DNA synthesis.
4. 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
, WGU Biochemistry Final
Review
(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.
5. 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.
6. 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.
7. 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.
8. 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
, WGU Biochemistry Final
Review
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.
9. 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.
10.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 elonga- tion
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
11.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)
, WGU Biochemistry Final
Review
D. Chromosome 11 (Blue) vs. Chromosome 11 (Red w/yellow stripe): D. Chro- mosome 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 chro- mosomes 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 boxe
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 inheritanc
pattern.
12.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 i
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, be-
Review
1. 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.
2. 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.)
3. dNTPs are DNA nucleotides used in PCR.
True False:
True
Feedback
dNTPs stands for deoxynucleotide triphosphates, which are the nucleotides used in DNA synthesis.
4. 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
, WGU Biochemistry Final
Review
(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.
5. 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.
6. 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.
7. 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.
8. 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
, WGU Biochemistry Final
Review
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.
9. 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.
10.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 elonga- tion
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
11.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)
, WGU Biochemistry Final
Review
D. Chromosome 11 (Blue) vs. Chromosome 11 (Red w/yellow stripe): D. Chro- mosome 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 chro- mosomes 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 boxe
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 inheritanc
pattern.
12.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 i
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, be-
