DNA Replication Practice Quiz

Who discovered the structure of DNA?

Answer: Watson and Crick

What are the four nucleotides that make up the structure of DNA?

Answer: A, T, G, C

How do the bases always match up?

Answer: A=T G=C

What makes up the backbones of DNA?

Answer: Sugar and Phosphate

Name the three enzymes that we discussed in class in regard to DNA Replication.

Answer: DNA Helicase DNA Polymerase DNA Ligase

Write what each of the following enzymes do: DNA Helicase DNA Polymerase DNA Ligase

Answer: DNA Helicase – Unzips the DNA strand, or breaks the hydrogen bonds between bases. DNA Polymerase – Puts in the new bases, in other words matches up A to T and G to C. DNA Ligase – Seals in the gaps and completes the strand.

When nucleotides get added to the new strand, what end to they get added to?

Answer: 3’ end only

What is the shape of DNA?

Answer: Double Helix

DNA Replication is described using two Semi’s, What are they?

Answer: Semi Conservative – Each new cell gets one old strand and one new strand. Semi Discontinuous – there is a lagging strand and a leading strand.

Describe what it means to be semi discontinuous.

Answer:

Show the Enzymes in DNA Replication.

Answer: DNA Polymerase – remember it has two arms (not shown accurately in the picture above, refer to notes). DNA Ligase – fills in the ozaki fragments and completes the strand.

How often does DNA Polymerase make a mistake?

Answer: 1 in every 10,000 base pairs After enzymes double check the strand, a mistake is made 1 in every 1 billion base pairs.

What things can damage DNA?

Answer: Chemicals Sunlight Normal mutations or mistakes in copying

Watch the following Videos to help show the process of DNA Replication. https://www.youtube.com/watch?v=5qSrmeiWsuc https://www.youtube.com/watch?v=v8gH404a3G g https://www.youtube.com/watch?v=FBmO_rmXxIw