Biol2300 week 2 lecture chapter 9

During DNA replication in bacterial cells, which enzyme is responsible for relieving the torque that builds up ahead of the replication fork?

• DNA gyrase

• DNA polymerase III

• DNA polymerase III

• 
  DNA primase

During homologous recombination via the Holliday model, what event directly follows single-strand nicks to initiate strand invasion?

• 
  Cleavage of the Holliday junction

• Branch migration

• Alignment of homologs

• 
  DNA synthesis

Which of the following is a key difference between eukaryotic and prokaryotic DNA replication?

• 
  Eukaryotic DNA replication occurs in the cytoplasm, while prokaryotic replication occurs in the nucleus.

• Prokaryotic DNA replication involves histone protein reassembly, while eukaryotic replication does not.

• 
  Prokaryotic DNA replication uses multiple origins of replication, whereas eukaryotic replication uses only one.

• Eukaryotic DNA replication requires telomerase to address the ends of linear chromosomes, while prokaryotic replication does not.

During the double-strand break model of homologous recombination, which event occurs immediately after the resection of the two ends, leading to 3' single-stranded tails?

• Strand invasion of one 3' tail into the homologous chromosome

• Ligation of DNA fragments

• Formation of a Holliday junction

• DNA synthesis to fill the gap

Which of the following enzymes is responsible for synthesizing RNA primers on both the leading and lagging strands during DNA replication?

• 
  Helicase

• DNA gyrase

• DNA polymerase III

• Primase

During the Holliday model of homologous recombination, what structure is formed after the process of branch migration?

• Replisome

• 
  D-loop

• Holliday junction

• Telomere

A lab student discovers a bacterial strain with non-functional DNA ligase. What immediate effect would this have on DNA replication?

• Okazaki fragments are not joined together.

• The leading strand is synthesized discontinuously.

• Replication forks stall due to the inability to unwind DNA.

• RNA primers cannot be removed from the lagging strand.

In the Holliday model of homologous recombination, if the Holliday junction is cleaved in the horizontal plane, what type of genetic outcome is produced?

• A crossover product with exchange of genetic material.

• 
  A product where DNA synthesis is prematurely terminated.

• A product with multiple Holliday junctions.

• A non-crossover product with no exchange of genetic material.

In eukaryotic DNA replication, which DNA polymerase is primarily responsible for synthesizing the leading strand?

• DNA polymerase epsilon (ε)

• DNA polymerase alpha (α)

• DNA polymerase gamma (γ)

• DNA polymerase delta (δ)

During homologous recombination, at which specific structure do nucleotide strands pass from one DNA molecule to the other?

• Origin of replication

• Telomere

• Holliday junction

• Replication fork