WGU C785 Final Exam 2 2027
With All The Correct Answers
100+ quiz
1. Which strand of DNA is complementary to mRNA?
A. Coding DNA
B. Template DNA
C. Both DNA strands
D. Neither DNA strand
✅ Correct Answer: B. Template DNA
Rationale: The template DNA strand is used by RNA polymerase as the pattern for synthesizing
mRNA. The mRNA is complementary to the template strand.
2. How do we make protein?
A. Protein → RNA → DNA
B. RNA → DNA → Protein
C. DNA → RNA → Protein
D. DNA → Protein → RNA
✅ Correct Answer: C. DNA → RNA → Protein
Rationale: Genetic information is transcribed from DNA into RNA and then translated from
mRNA into a polypeptide. This sequence is commonly called the central dogma of molecular
biology.
3. Which type of nucleotide sequence is used during translation, and in which direction is it
read?
,A. DNA, 3′ → 5′
B. DNA, 5′ → 3′
C. RNA, 5′ → 3′
D. RNA, 3′ → 5′
✅ Correct Answer: C. RNA, 5′ → 3′
Rationale: Ribosomes read mRNA in the 5′ → 3′ direction during translation. The mRNA codons
determine the sequence of amino acids in the resulting polypeptide.
4. What is the relationship between mRNA and tRNA?
A. tRNA is complementary to the mRNA codon it recognizes.
B. mRNA and tRNA have identical sequences.
C. mRNA produces tRNA through translation.
D. tRNA is complementary to proteins.
✅ Correct Answer: A. tRNA is complementary to the mRNA codon it recognizes.
Rationale: tRNA contains an anticodon that pairs with a complementary codon on mRNA. Each
tRNA carries the amino acid specified by the codon it recognizes.
5. How does mRNA splicing allow multiple proteins to be created from a single gene?
A. It removes all exons from the RNA.
B. It duplicates the gene.
C. Alternative splicing allows different combinations of exons to remain in the mature mRNA.
D. It converts mRNA back into DNA.
✅ Correct Answer: C. Alternative splicing allows different combinations of exons to remain in
the mature mRNA.
Rationale: During RNA processing, introns are removed and exons are joined. Alternative
splicing can join different combinations of exons, allowing one gene to produce multiple protein
variants.
6. Which factors generally increase gene expression?
A. Increased methylation and tightly packed nucleosomes
B. Decreased methylation, increased acetylation, and accessible DNA
,C. Hidden promoters and no transcription factors
D. Tightly packed chromatin and absent RNA polymerase
✅ Correct Answer: B. Decreased methylation, increased acetylation, and accessible DNA
Rationale: Gene expression generally increases when DNA is more accessible to transcription
machinery. Decreased DNA methylation and increased histone acetylation are commonly
associated with more open chromatin.
7. Which factors generally decrease gene expression?
A. Increased methylation and tightly packed nucleosomes
B. Increased acetylation and exposed promoters
C. Widely spaced nucleosomes and active transcription factors
D. Accessible promoters and RNA polymerase
✅ Correct Answer: A. Increased methylation and tightly packed nucleosomes
Rationale: Increased DNA methylation and compact chromatin can reduce access of
transcription machinery to DNA. This generally decreases transcription and gene expression.
8. What should you do to determine what type of mutation occurred between a normal and
mutated DNA/RNA sequence?
A. Compare the sequences, identify the change, and classify the mutation.
B. Compare only the proteins.
C. Ignore nucleotide changes.
D. Count the number of chromosomes.
✅ Correct Answer: A. Compare the sequences, identify the change, and classify the
mutation.
Rationale: First compare the normal and mutated sequences to determine what changed. The
change can then be classified as a substitution, insertion, deletion, or another specific mutation
type.
9. Which are major types of mutations?
A. Silent, missense, nonsense, and frameshift
B. Ionic, covalent, hydrogen, and disulfide
, C. Primary, secondary, tertiary, and quaternary
D. Transcription, translation, replication, and splicing
✅ Correct Answer: A. Silent, missense, nonsense, and frameshift
Rationale: These mutation types describe different effects of DNA sequence changes. A
mutation may have no effect on the amino acid, change an amino acid, create a premature stop
codon, or alter the reading frame.
10. Which DNA damage is associated with each repair pathway?
A. Base excision—single-base damage; nucleotide excision—larger damaged regions; mismatch
—replication errors; HR/NHEJ—double-strand breaks
B. Base excision—protein damage; mismatch—RNA damage
C. HR—only single nucleotide substitutions
D. NHEJ—only mRNA damage
✅ Correct Answer: A. Base excision—single-base damage; nucleotide excision—larger
damaged regions; mismatch—replication errors; HR/NHEJ—double-strand breaks
Rationale: Different repair pathways specialize in different forms of DNA damage. Base excision
repair handles individual damaged bases, nucleotide excision repair removes larger damaged
sections, mismatch repair corrects replication errors, and HR/NHEJ repair double-stranded
breaks.
11. What are the basic steps of excision repair?
A. Recognize damage → remove damaged DNA → replace it → seal the strand
B. Transcribe → translate → fold
C. Replicate → mutate → destroy
D. Separate chromosomes → produce RNA
✅ Correct Answer: A. Recognize damage → remove damaged DNA → replace it → seal the
strand
Rationale: Excision repair identifies damaged DNA and removes the affected section. DNA
polymerase replaces the missing nucleotides, and DNA ligase seals the repaired region.
12. What is the basic process of mismatch repair?
With All The Correct Answers
100+ quiz
1. Which strand of DNA is complementary to mRNA?
A. Coding DNA
B. Template DNA
C. Both DNA strands
D. Neither DNA strand
✅ Correct Answer: B. Template DNA
Rationale: The template DNA strand is used by RNA polymerase as the pattern for synthesizing
mRNA. The mRNA is complementary to the template strand.
2. How do we make protein?
A. Protein → RNA → DNA
B. RNA → DNA → Protein
C. DNA → RNA → Protein
D. DNA → Protein → RNA
✅ Correct Answer: C. DNA → RNA → Protein
Rationale: Genetic information is transcribed from DNA into RNA and then translated from
mRNA into a polypeptide. This sequence is commonly called the central dogma of molecular
biology.
3. Which type of nucleotide sequence is used during translation, and in which direction is it
read?
,A. DNA, 3′ → 5′
B. DNA, 5′ → 3′
C. RNA, 5′ → 3′
D. RNA, 3′ → 5′
✅ Correct Answer: C. RNA, 5′ → 3′
Rationale: Ribosomes read mRNA in the 5′ → 3′ direction during translation. The mRNA codons
determine the sequence of amino acids in the resulting polypeptide.
4. What is the relationship between mRNA and tRNA?
A. tRNA is complementary to the mRNA codon it recognizes.
B. mRNA and tRNA have identical sequences.
C. mRNA produces tRNA through translation.
D. tRNA is complementary to proteins.
✅ Correct Answer: A. tRNA is complementary to the mRNA codon it recognizes.
Rationale: tRNA contains an anticodon that pairs with a complementary codon on mRNA. Each
tRNA carries the amino acid specified by the codon it recognizes.
5. How does mRNA splicing allow multiple proteins to be created from a single gene?
A. It removes all exons from the RNA.
B. It duplicates the gene.
C. Alternative splicing allows different combinations of exons to remain in the mature mRNA.
D. It converts mRNA back into DNA.
✅ Correct Answer: C. Alternative splicing allows different combinations of exons to remain in
the mature mRNA.
Rationale: During RNA processing, introns are removed and exons are joined. Alternative
splicing can join different combinations of exons, allowing one gene to produce multiple protein
variants.
6. Which factors generally increase gene expression?
A. Increased methylation and tightly packed nucleosomes
B. Decreased methylation, increased acetylation, and accessible DNA
,C. Hidden promoters and no transcription factors
D. Tightly packed chromatin and absent RNA polymerase
✅ Correct Answer: B. Decreased methylation, increased acetylation, and accessible DNA
Rationale: Gene expression generally increases when DNA is more accessible to transcription
machinery. Decreased DNA methylation and increased histone acetylation are commonly
associated with more open chromatin.
7. Which factors generally decrease gene expression?
A. Increased methylation and tightly packed nucleosomes
B. Increased acetylation and exposed promoters
C. Widely spaced nucleosomes and active transcription factors
D. Accessible promoters and RNA polymerase
✅ Correct Answer: A. Increased methylation and tightly packed nucleosomes
Rationale: Increased DNA methylation and compact chromatin can reduce access of
transcription machinery to DNA. This generally decreases transcription and gene expression.
8. What should you do to determine what type of mutation occurred between a normal and
mutated DNA/RNA sequence?
A. Compare the sequences, identify the change, and classify the mutation.
B. Compare only the proteins.
C. Ignore nucleotide changes.
D. Count the number of chromosomes.
✅ Correct Answer: A. Compare the sequences, identify the change, and classify the
mutation.
Rationale: First compare the normal and mutated sequences to determine what changed. The
change can then be classified as a substitution, insertion, deletion, or another specific mutation
type.
9. Which are major types of mutations?
A. Silent, missense, nonsense, and frameshift
B. Ionic, covalent, hydrogen, and disulfide
, C. Primary, secondary, tertiary, and quaternary
D. Transcription, translation, replication, and splicing
✅ Correct Answer: A. Silent, missense, nonsense, and frameshift
Rationale: These mutation types describe different effects of DNA sequence changes. A
mutation may have no effect on the amino acid, change an amino acid, create a premature stop
codon, or alter the reading frame.
10. Which DNA damage is associated with each repair pathway?
A. Base excision—single-base damage; nucleotide excision—larger damaged regions; mismatch
—replication errors; HR/NHEJ—double-strand breaks
B. Base excision—protein damage; mismatch—RNA damage
C. HR—only single nucleotide substitutions
D. NHEJ—only mRNA damage
✅ Correct Answer: A. Base excision—single-base damage; nucleotide excision—larger
damaged regions; mismatch—replication errors; HR/NHEJ—double-strand breaks
Rationale: Different repair pathways specialize in different forms of DNA damage. Base excision
repair handles individual damaged bases, nucleotide excision repair removes larger damaged
sections, mismatch repair corrects replication errors, and HR/NHEJ repair double-stranded
breaks.
11. What are the basic steps of excision repair?
A. Recognize damage → remove damaged DNA → replace it → seal the strand
B. Transcribe → translate → fold
C. Replicate → mutate → destroy
D. Separate chromosomes → produce RNA
✅ Correct Answer: A. Recognize damage → remove damaged DNA → replace it → seal the
strand
Rationale: Excision repair identifies damaged DNA and removes the affected section. DNA
polymerase replaces the missing nucleotides, and DNA ligase seals the repaired region.
12. What is the basic process of mismatch repair?
