ACE BIOL20A MT2 Review Session

What is the difference between the replication origins of prokaryotes and eukaryotes?

• Prokaryotic cells have multiple origins of replication, while eukaryotic cells have a single origin.
• Prokaryotic cells do not have a defined origin of replication.
• Eukaryotic cells do not require an origin of replication.
• Eukaryotic cells have multiple origins of replication, while prokaryotic cells typically have a single origin.

What does the semiconservative model for DNA replication refer to?

• RNA polymerase adds nucleotides to the 3’ end of the RNA transcript using one of the DNA strands as a template.
• The newly synthesized DNA double helix contains one old DNA strand and one new DNA strand.
• A newly synthesized DNA is generated by using a RNA transcript as a template.
• The newly synthesized DNA double helix contains one old DNA template strand and one RNA strand.

Which enzyme is primarily responsible for unwinding the DNA double helix during DNA replication?

• DNA polymerase Ill
• RNA polymerase
• Helicase
• Primase
• Topoisomerase

What is the role of DNA polymerase I during DNA replication?

• Replaces RNA primers with DNA nucleotides.
• Synthesizes the leading strand continuously.
• Synthesizes the RNA primer.
• Joins Okazaki fragments on the lagging strand.

Which of the following is false about proofreading and repairing DNA?

• DNA polymerases can check mismatched bases and correct them during DNA replication.
• DNA damages are repaired by nuclease and ligase.
• If DNA polymerases are unable to catch DNA mismatches, other repair mechanisms will correct mismatches.
• DNA damages are repaired by primase and ligase.

Which of the following statements about the leading strand and the lagging strand is false?

• The lagging strand is synthesized in short segments called Okazaki fragments whereas the leading strand is synthesized continuously.
• The leading strand requires a single RNA primer, while the lagging strand requires multiple primers.
• The leading strand is synthesized away from helicase whereas the lagging strand is synthesized along with helicase.
• Both strands are synthesized in the 5’ to 3’ direction.

Which enzyme is primarily responsible for synthesizing RNA from a DNA template during transcription?

• DNA polymerase III
• Ligase
• Single Strand Binding Protein
• RNA polymerase

Where is the TATA box located?

• At the upstream of transcription start site
• At the transcription start site
• At the upstream of transcription termination site
• At the downstream of transcription start site

Which of the following statements is true about the elongation phase of transcription?

• RNA polymerase reads the DNA template in the 3' to 5' direction.
• RNA is synthesized in the 3' to 5' direction.
• RNA polymerase synthesizes RNA without needing a primer.
• RNA polymerase proofreads the RNA strand as it is synthesized.

Which of the following is not included in mature mRNAs?

• Exons
• UTRs (untranslated regions)
• Introns
• Poly-A  tail
• 5’ CAP