BIOL180 Lesson 5 Quiz – DNA, RNA, and
Protein Synthesis Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. Which of the following best describes the primary function of DNA in
living organisms?
A. To transport oxygen throughout the body
B. To store and transmit hereditary genetic information
C. To produce energy through cellular respiration
D. To synthesize carbohydrates during photosynthesis
Rationale: DNA serves as the hereditary material that stores genetic
information and passes it from one generation of cells or organisms to the
next. This information directs protein synthesis and regulates cellular
activities.
2. Which nitrogenous base is found in RNA but not in DNA?
A. Adenine
B. Cytosine
C. Guanine
D. Uracil
,Rationale: RNA contains uracil (U) instead of thymine (T). During
transcription, uracil pairs with adenine to form RNA molecules.
3. Which of the following correctly lists the complementary DNA base
pairs?
A. A–C and G–T
B. A–T and C–G
C. A–U and C–G
D. A–G and T–C
Rationale: In DNA, adenine always pairs with thymine, while cytosine pairs
with guanine through hydrogen bonds, maintaining the double-helix
structure.
4. The process by which genetic information in DNA is copied into mRNA
is called:
A. Translation
B. Transcription
C. Replication
D. Mutation
Rationale: Transcription is the process in which RNA polymerase uses a
DNA template to synthesize messenger RNA.
5. Which enzyme is primarily responsible for synthesizing mRNA during
transcription?
A. DNA ligase
B. DNA polymerase
C. RNA polymerase
D. Helicase
Rationale: RNA polymerase binds to DNA, unwinds the double helix locally,
and builds an RNA strand complementary to the DNA template.
, 6. Where does transcription occur in eukaryotic cells?
A. Ribosome
B. Cytoplasm
C. Nucleus
D. Golgi apparatus
Rationale: In eukaryotes, transcription occurs inside the nucleus where
DNA is located before mRNA exits to the cytoplasm.
7. Which RNA molecule carries amino acids to the ribosome during
protein synthesis?
A. mRNA
B. rRNA
C. tRNA
D. snRNA
Rationale: Transfer RNA transports specific amino acids to the ribosome
and matches its anticodon with the mRNA codon.
8. Which RNA molecule forms the structural and catalytic core of
ribosomes?
A. mRNA
B. rRNA
C. tRNA
D. miRNA
Rationale: Ribosomal RNA combines with proteins to form ribosomes and
catalyzes peptide bond formation during translation.
9. During transcription, RNA nucleotides pair with which strand of DNA?
A. Coding strand
B. Template strand
Protein Synthesis Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. Which of the following best describes the primary function of DNA in
living organisms?
A. To transport oxygen throughout the body
B. To store and transmit hereditary genetic information
C. To produce energy through cellular respiration
D. To synthesize carbohydrates during photosynthesis
Rationale: DNA serves as the hereditary material that stores genetic
information and passes it from one generation of cells or organisms to the
next. This information directs protein synthesis and regulates cellular
activities.
2. Which nitrogenous base is found in RNA but not in DNA?
A. Adenine
B. Cytosine
C. Guanine
D. Uracil
,Rationale: RNA contains uracil (U) instead of thymine (T). During
transcription, uracil pairs with adenine to form RNA molecules.
3. Which of the following correctly lists the complementary DNA base
pairs?
A. A–C and G–T
B. A–T and C–G
C. A–U and C–G
D. A–G and T–C
Rationale: In DNA, adenine always pairs with thymine, while cytosine pairs
with guanine through hydrogen bonds, maintaining the double-helix
structure.
4. The process by which genetic information in DNA is copied into mRNA
is called:
A. Translation
B. Transcription
C. Replication
D. Mutation
Rationale: Transcription is the process in which RNA polymerase uses a
DNA template to synthesize messenger RNA.
5. Which enzyme is primarily responsible for synthesizing mRNA during
transcription?
A. DNA ligase
B. DNA polymerase
C. RNA polymerase
D. Helicase
Rationale: RNA polymerase binds to DNA, unwinds the double helix locally,
and builds an RNA strand complementary to the DNA template.
, 6. Where does transcription occur in eukaryotic cells?
A. Ribosome
B. Cytoplasm
C. Nucleus
D. Golgi apparatus
Rationale: In eukaryotes, transcription occurs inside the nucleus where
DNA is located before mRNA exits to the cytoplasm.
7. Which RNA molecule carries amino acids to the ribosome during
protein synthesis?
A. mRNA
B. rRNA
C. tRNA
D. snRNA
Rationale: Transfer RNA transports specific amino acids to the ribosome
and matches its anticodon with the mRNA codon.
8. Which RNA molecule forms the structural and catalytic core of
ribosomes?
A. mRNA
B. rRNA
C. tRNA
D. miRNA
Rationale: Ribosomal RNA combines with proteins to form ribosomes and
catalyzes peptide bond formation during translation.
9. During transcription, RNA nucleotides pair with which strand of DNA?
A. Coding strand
B. Template strand
