DNA Replication

DNA replication creates two strands of DNA from one. If pink is parental DNA and blue is new DNA - which picture demonstrates the accepted model of DNA replication after the SECOND replication cycle?

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What is the correct order of DNA replication?

• 3, 4, 2, 1
• 3, 1, 4, 2
• 2, 1, 4, 3
• 3, 4, 1, 2

The picture below shows an enzyme unwinding and unzipping DNA.

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​What is the name of this enzyme?

• Helicase

• Ligase

• DNA Pol I

• Topoisomerase

Which enzyme synthesises the new DNA strand?

• DNA Pol I

• DNA Pol III

• Helicase

• Primase

Which letter in the picture below depicts the leading strand in DNA replication?

• A

• C

• B

• None of the above

What is the function of topoisomerase?

• To ligate Okazaki fragments together

• To remove supercoiling in front of replication fork

• To stabilise single-stranded DNA at the replication fork

• To separate the hydrogen bonds between nucleotides

Which is the last step in DNA replication?

• Helicase unwinds the parent DNA strand

• Primase lays down an RNA primer for new nucleotides to be added to

• DNA polymerase builds new strands by bringing in new nucleotides

• Ligase joins together fragments on the lagging strand

Which enzyme creates an RNA primer?

• DNA Pol I

• DNA Pol III

• Ligase

• Primase

Which of the following is correct with respect to DNA replication?

• Helicase stabilises ssDNA

• Ligase creates RNA primers

• DNA Pol I is the main polymerising enzyme

• The lagging strand is made up of Okazaki fragments

What prevents DNA strands from reannealing at the replication fork?

• Single-stranded binding proteins

• Helicase

• Topoisomerase

• Ligase