IB HL DNA replication

What is the function of DNA helicase?

• It breaks hydrogen bonds

• It forms hydrogen bonds

• It breaks phosphodiester bonds

• It forms phosphodiester bonds

Which enzyme relieves pressure on the DNA strand caused by uncoiling?

• DNA helicase

• DNA gyrase

• Single Stranded Binding Proteins

• DNA primase

Name the proteins that prevent separated DNA strands from re-coiling.

What is the purpose of DNA primase?

• Synthesizes a short RNA sequence

• Synthesizes a short DNA sequence

• Replaces the RNA primer with DNA

• Replaces the DNA primer with RNA

Which describes the function of DNA polymerase III?

• Replaces an RNA primer with DNA

• Seals breaks in the sugar-phosphate backbone

• Adds DNA nucleotides to the 3' end of an existing chain

• Adds DNA nucleotides to the 5' end of an existing chain

On which strand are Okazaki fragments created?

• Leading

• Lagging

What is the cause of Okazaki fragments?

• Discontinuous replication

• Continuous replication

• Replication in the same direction as helicase action

• Replication in the opposite direction to helicase action

Which enzyme replaces the RNA primer with DNA?

• DNA polymerase I

• DNA polymerase III

• DNA ligase

• DNA helicase

What do DNA polymerase III and ligase have in common?

• Both create hydrogen bonds

• Both create phosphodiester bonds

• Both break phosphodiester bonds

• Both break hydrogen bonds

What is the name of the fragments created on the lagging strand during DNA replication?