,BIOD 210 Module 5 Exam | Q&A | 2026/2027 | Genetics | Portage
Learning
1. Which of the following correctly describes the Central Dogma of molecular
biology?
A) RNA → DNA → Protein
B) DNA → RNA → Protein
C) Protein → RNA → DNA
D) DNA → Protein → RNA
Correct Answer: DNA → RNA → Protein
Rationale: The Central Dogma describes the flow of genetic information from
DNA to RNA (transcription) to protein (translation). This is a foundational
concept in genetics and molecular biology.
2. Which enzyme is responsible for synthesizing RNA during transcription?
A) DNA polymerase
B) Helicase
C) RNA polymerase
D) Ligase
Correct Answer: RNA polymerase
Rationale: RNA polymerase is the enzyme responsible for transcription,
synthesizing RNA from a DNA template. DNA polymerase synthesizes DNA,
helicase unwinds DNA, and ligase joins DNA fragments.
3. True or False: Transcription of DNA into mRNA requires an RNA primer.
A) True
,B) False
Correct Answer: False
Rationale: Unlike DNA polymerases, RNA polymerases can initiate synthesis
de novo; they do not need a pre-existing primer. They bind promoter DNA,
unwind it, and begin adding ribonucleotides using the template strand
directly.
4. During transcription, RNA is synthesized in which direction?
A) 3' to 5'
B) 5' to 3'
C) Both directions
D) It depends on the gene
Correct Answer: 5' to 3'
Rationale: RNA polymerase synthesizes RNA in the 5' to 3' direction, adding
nucleotides to the 3' end of the growing RNA strand. This is the same
directionality as DNA synthesis.
5. The template strand of DNA is read by RNA polymerase in which direction?
A) 3' to 5'
B) 5' to 3'
C) Both directions
D) It depends on the gene
Correct Answer: 3' to 5'
, Rationale: RNA polymerase reads the template strand in the 3' to 5'
direction, synthesizing RNA in the 5' to 3' direction. This is analogous to DNA
replication.
6. Consider the following DNA sequence: 3'-AAC TAC TGT GTA-5'. What is the
complementary RNA sequence?
A) 5'-UUG AUG ACA CAU-3'
B) 3'-UUG AUG ACA CAU-5'
C) 5'-AAC TAC TGT GTA-3'
D) 3'-AAC TAC TGT GTA-5'
Correct Answer: 5'-UUG AUG ACA CAU-3'
Rationale: RNA is synthesized 5'→3' using base-pairing rules (A→U, T→A,
C→G, G→C) on the 3'→5' DNA template. The complementary RNA sequence is
5'-UUG AUG ACA CAU-3'.
7. Translation starts on which end of the mRNA?
A) 3' end
B) 5' end
C) Either end
D) It depends on the gene
Correct Answer: 5' end
Rationale: Translation always initiates at the 5' end of mRNA at the first AUG
start codon, which encodes methionine and establishes the reading frame.
Learning
1. Which of the following correctly describes the Central Dogma of molecular
biology?
A) RNA → DNA → Protein
B) DNA → RNA → Protein
C) Protein → RNA → DNA
D) DNA → Protein → RNA
Correct Answer: DNA → RNA → Protein
Rationale: The Central Dogma describes the flow of genetic information from
DNA to RNA (transcription) to protein (translation). This is a foundational
concept in genetics and molecular biology.
2. Which enzyme is responsible for synthesizing RNA during transcription?
A) DNA polymerase
B) Helicase
C) RNA polymerase
D) Ligase
Correct Answer: RNA polymerase
Rationale: RNA polymerase is the enzyme responsible for transcription,
synthesizing RNA from a DNA template. DNA polymerase synthesizes DNA,
helicase unwinds DNA, and ligase joins DNA fragments.
3. True or False: Transcription of DNA into mRNA requires an RNA primer.
A) True
,B) False
Correct Answer: False
Rationale: Unlike DNA polymerases, RNA polymerases can initiate synthesis
de novo; they do not need a pre-existing primer. They bind promoter DNA,
unwind it, and begin adding ribonucleotides using the template strand
directly.
4. During transcription, RNA is synthesized in which direction?
A) 3' to 5'
B) 5' to 3'
C) Both directions
D) It depends on the gene
Correct Answer: 5' to 3'
Rationale: RNA polymerase synthesizes RNA in the 5' to 3' direction, adding
nucleotides to the 3' end of the growing RNA strand. This is the same
directionality as DNA synthesis.
5. The template strand of DNA is read by RNA polymerase in which direction?
A) 3' to 5'
B) 5' to 3'
C) Both directions
D) It depends on the gene
Correct Answer: 3' to 5'
, Rationale: RNA polymerase reads the template strand in the 3' to 5'
direction, synthesizing RNA in the 5' to 3' direction. This is analogous to DNA
replication.
6. Consider the following DNA sequence: 3'-AAC TAC TGT GTA-5'. What is the
complementary RNA sequence?
A) 5'-UUG AUG ACA CAU-3'
B) 3'-UUG AUG ACA CAU-5'
C) 5'-AAC TAC TGT GTA-3'
D) 3'-AAC TAC TGT GTA-5'
Correct Answer: 5'-UUG AUG ACA CAU-3'
Rationale: RNA is synthesized 5'→3' using base-pairing rules (A→U, T→A,
C→G, G→C) on the 3'→5' DNA template. The complementary RNA sequence is
5'-UUG AUG ACA CAU-3'.
7. Translation starts on which end of the mRNA?
A) 3' end
B) 5' end
C) Either end
D) It depends on the gene
Correct Answer: 5' end
Rationale: Translation always initiates at the 5' end of mRNA at the first AUG
start codon, which encodes methionine and establishes the reading frame.
