WGU Biochemistry
1. DNA replication is , which allows each of the two strands to serve as a for the new strands.
b. semiconservative, template: DNA replication is semiconservative, meaning that each new duplex has one original
(parent) strand and one new strand. Because the two parent strands are separated during replication and the base pairing
is predictable, each parent strand can serve as a template for the new strand synthesis.
2. Which of the following enzymes does NOT assist the DNA polymerase on the lagging strand to overcome
its two problems? (Recall that the DNA polymerase can only make DNA in the 5'->3' direction, and it must
bind a
double-stranded nucleotide polymer before it can start making its own DNA polymer.)
c. Helicase: Helicase unwinds the double stranded DNA to allow for replication, but this is not a problem for the DNA
polymerase.
3. Several components of cigarette smoke, including benzopyrene, insert themselves (intercalate) into the DNA
and lead to several types of mutations such as frameshift mutations, including both insertions and deletion. Which
of the following repair pathways would be used to repair this type of damage?
c. Nucleotide Excision Repair: Nucleotide excision repair is used to repair dele- tions, insertions, and helix-distorting
lesions, such as thymine dimers.
4. Maternal smoking during pregnancy is hazardous yet common in many places. Many studies have associated
prenatal smoking to unhealthy physical and psychological outcomes for the baby. Researchers know that
maternal smoking affects are epigenetic in nature. Which of the following events can be considered epigenetic in
nature?
a. Changes in chromatin structure: Frame shift mutations are a kind of mutations which result from addition of
deletion of a nucleotide base resulting in an altered reading frame and ultimately a different protein, than the one the
gene originally encoded. Frameshift mutations are genetic changes because they alter the DNA sequence, whereas
epigenetic changes do not alter the DNA sequence. Epigenetic changes are modifications to genomic structure (not
sequence) that are caused by the external environment. These environmental factors affect the overall chromatin
structure to allow more or less "access" to the DNA by gene expression machinery to turn the genes "on" or "off". In
other words, epigenetics can alter gene expression without changing the underlying DNA sequences. The changes may
or may not be heritable, depending on the location and circumstances.
1/
22
, WGU Biochemistry
5. Blood type is an example of what type of inheritance?
a. Codominance: The genes that produce the A and B antigen proteins can both be expressed independently, and a
heterozygote (someone with both genes) will be produce both A and B proteins - neither will dominate the other. The is
an example of codominance.
6. What is the expected probability that a child will have an autosomal domi- nant disease if their father is
heterozygous for the allele and their mother is homozygous for the normal allele?
a. 50%: If D is the disease-conferring dominant allele and d is the normal allele, the father has the genotype Dd and the
mother's genotype is dd. Each child can only inherit a d allele from their mother, and they have a 50% chance of
inheriting the D allele from their father. As a result, the expected probability that their child will inherit the disease is
50%.
7. The physical trait of lip protrusion exhibits a characteristic type of in- heritance, as shown by the
pedigree above. What type of inheritance best describes this inheritance pattern?
a. Incomplete dominance: The correct answer is incomplete domin blending of the large and ance. The
small lip protrusion into an intermediate, m edium lip
trusion, as well as the presence of all three variations in the offspring, demonstrate a clear example ofpro-
incomplete
dominance.
8. The normal sequence of a section of the HLA-B27 gene, a genetic marker of the inflammatory disease
Ankylosing spondylitis, is given below. Match each mutation of the sequence to the type of mutation it exhibits. A
genetic code table is provided for your use in answering the question.
5'- CGG CAG AAU UUA -3'
5'- CAG CAG AAU UUA -3' - Missense mutation 5'- CGG CAG
AAA UUU A-3' - Insertion
5'- CGG CAG AAC UUA -3' - Silent mutation 5'- CGG CAG
AAU UA -3' - Deletion
5'- CGG UAG AAU UUA-3' - Nonsense mutation: Silent mutations are those in which the amino acid encoded doesn't
change as a result of the mutation.
Missense mutations are those in which the amino acid encoded changes to a different amino acid as a result of the
mutation.
2/
22
, WGU Biochemistry
Study online at
https://quizlet.com/_2zoopk
Nonsense mutations are those in which the amino acid encoded changes to a stop codon as a result of the mutation,
yielding a smaller protein.
Insertions are the inclusion of extra nucleotides compared to the original sequence. They can result in other mutations, su
as nonsense mutations.
Deletions are the removal of nucleotides compared to the original sequence. They can result in other mutations, such as
nonsense mutations.
9. PCR is a powerful tool that can do all of the following....
b. detect mutations that lead to disease
c. copy small segments of DNA, less than 6kb
d. amplify DNA from samples that have just a few cells: PCR's ability to amplify is powerful, and products can even
be generated from samples with just a few cells. PCR is less reliable for amplifying large segments of DNA greater than
6 kb, though some careful changes to the techniques can allow it.
10.Which of the following is a required "ingredient" in a PCR reaction?
a. DNA nucleotides
b. DNA primers
c. DNA polymerase: The primers used in PCR are made from DNA, rather than RNA. RNA primers are used in DNA
replication inside the cell, but the quick degradation of RNA makes it less useful for PCR reactions. Instead, PCR
reactions contain primers made of DNA to anneal to the region of DNA that will be amplified and serve as a starting
point for DNA polymerase.
11.Which of the following changes can be detected using PCR?
a. Differences in DNA sequence
b. Insertions
c. Deletions: Differences in DNA sequence can be detected since these changes can alter the ability of primers to
anneal to the DNA. They can also be detected by DNA sequencing of the PCR product. Epigenetic changes are not
detectable via PCR because they don't affect the DNA sequence.
12.A small segment of Kevin's green opsin gene is shown below. What would be the resulting mRNA sequence?
Kevin's opsin gene at nucleotide positions 936 to 941.
3/
22
1. DNA replication is , which allows each of the two strands to serve as a for the new strands.
b. semiconservative, template: DNA replication is semiconservative, meaning that each new duplex has one original
(parent) strand and one new strand. Because the two parent strands are separated during replication and the base pairing
is predictable, each parent strand can serve as a template for the new strand synthesis.
2. Which of the following enzymes does NOT assist the DNA polymerase on the lagging strand to overcome
its two problems? (Recall that the DNA polymerase can only make DNA in the 5'->3' direction, and it must
bind a
double-stranded nucleotide polymer before it can start making its own DNA polymer.)
c. Helicase: Helicase unwinds the double stranded DNA to allow for replication, but this is not a problem for the DNA
polymerase.
3. Several components of cigarette smoke, including benzopyrene, insert themselves (intercalate) into the DNA
and lead to several types of mutations such as frameshift mutations, including both insertions and deletion. Which
of the following repair pathways would be used to repair this type of damage?
c. Nucleotide Excision Repair: Nucleotide excision repair is used to repair dele- tions, insertions, and helix-distorting
lesions, such as thymine dimers.
4. Maternal smoking during pregnancy is hazardous yet common in many places. Many studies have associated
prenatal smoking to unhealthy physical and psychological outcomes for the baby. Researchers know that
maternal smoking affects are epigenetic in nature. Which of the following events can be considered epigenetic in
nature?
a. Changes in chromatin structure: Frame shift mutations are a kind of mutations which result from addition of
deletion of a nucleotide base resulting in an altered reading frame and ultimately a different protein, than the one the
gene originally encoded. Frameshift mutations are genetic changes because they alter the DNA sequence, whereas
epigenetic changes do not alter the DNA sequence. Epigenetic changes are modifications to genomic structure (not
sequence) that are caused by the external environment. These environmental factors affect the overall chromatin
structure to allow more or less "access" to the DNA by gene expression machinery to turn the genes "on" or "off". In
other words, epigenetics can alter gene expression without changing the underlying DNA sequences. The changes may
or may not be heritable, depending on the location and circumstances.
1/
22
, WGU Biochemistry
5. Blood type is an example of what type of inheritance?
a. Codominance: The genes that produce the A and B antigen proteins can both be expressed independently, and a
heterozygote (someone with both genes) will be produce both A and B proteins - neither will dominate the other. The is
an example of codominance.
6. What is the expected probability that a child will have an autosomal domi- nant disease if their father is
heterozygous for the allele and their mother is homozygous for the normal allele?
a. 50%: If D is the disease-conferring dominant allele and d is the normal allele, the father has the genotype Dd and the
mother's genotype is dd. Each child can only inherit a d allele from their mother, and they have a 50% chance of
inheriting the D allele from their father. As a result, the expected probability that their child will inherit the disease is
50%.
7. The physical trait of lip protrusion exhibits a characteristic type of in- heritance, as shown by the
pedigree above. What type of inheritance best describes this inheritance pattern?
a. Incomplete dominance: The correct answer is incomplete domin blending of the large and ance. The
small lip protrusion into an intermediate, m edium lip
trusion, as well as the presence of all three variations in the offspring, demonstrate a clear example ofpro-
incomplete
dominance.
8. The normal sequence of a section of the HLA-B27 gene, a genetic marker of the inflammatory disease
Ankylosing spondylitis, is given below. Match each mutation of the sequence to the type of mutation it exhibits. A
genetic code table is provided for your use in answering the question.
5'- CGG CAG AAU UUA -3'
5'- CAG CAG AAU UUA -3' - Missense mutation 5'- CGG CAG
AAA UUU A-3' - Insertion
5'- CGG CAG AAC UUA -3' - Silent mutation 5'- CGG CAG
AAU UA -3' - Deletion
5'- CGG UAG AAU UUA-3' - Nonsense mutation: Silent mutations are those in which the amino acid encoded doesn't
change as a result of the mutation.
Missense mutations are those in which the amino acid encoded changes to a different amino acid as a result of the
mutation.
2/
22
, WGU Biochemistry
Study online at
https://quizlet.com/_2zoopk
Nonsense mutations are those in which the amino acid encoded changes to a stop codon as a result of the mutation,
yielding a smaller protein.
Insertions are the inclusion of extra nucleotides compared to the original sequence. They can result in other mutations, su
as nonsense mutations.
Deletions are the removal of nucleotides compared to the original sequence. They can result in other mutations, such as
nonsense mutations.
9. PCR is a powerful tool that can do all of the following....
b. detect mutations that lead to disease
c. copy small segments of DNA, less than 6kb
d. amplify DNA from samples that have just a few cells: PCR's ability to amplify is powerful, and products can even
be generated from samples with just a few cells. PCR is less reliable for amplifying large segments of DNA greater than
6 kb, though some careful changes to the techniques can allow it.
10.Which of the following is a required "ingredient" in a PCR reaction?
a. DNA nucleotides
b. DNA primers
c. DNA polymerase: The primers used in PCR are made from DNA, rather than RNA. RNA primers are used in DNA
replication inside the cell, but the quick degradation of RNA makes it less useful for PCR reactions. Instead, PCR
reactions contain primers made of DNA to anneal to the region of DNA that will be amplified and serve as a starting
point for DNA polymerase.
11.Which of the following changes can be detected using PCR?
a. Differences in DNA sequence
b. Insertions
c. Deletions: Differences in DNA sequence can be detected since these changes can alter the ability of primers to
anneal to the DNA. They can also be detected by DNA sequencing of the PCR product. Epigenetic changes are not
detectable via PCR because they don't affect the DNA sequence.
12.A small segment of Kevin's green opsin gene is shown below. What would be the resulting mRNA sequence?
Kevin's opsin gene at nucleotide positions 936 to 941.
3/
22
