Unit 1 Key Area 2: Replication of DNA

Question 1

What is DNA replication?

Answer 1

The process in which DNA makes an identical copy of itself.

Question 2

What happens before cell division?

Answer 2

DNA is replicated by DNA polymerase.

Question 3

What are the requirements for DNA replication? (DEADPool)

Answer 3

DNA template, Enzymes (DNA polymerase), ATP, DNA nucleotides, Primers

Question 4

What is a primer?

Answer 4

A primer is a short sequence of DNA

Question 5

What happens in the first stage of DNA replication? (unwound)

Answer 5

Double helix is unwound by an enzyme

Question 6

What happens in the second stage of DNA replication?

Answer 6

Hydrogen bonds are broken between the bases, unzipping to form two template strands.

Question 7

What happens in the third stage of DNA replication?

Answer 7

Primers bind at the 3’ end of a template strand. On the lag strand primers bind at several sites at 3’ end.

Question 8

What happens in the fourth stage of DNA replication in the leading strand?

Answer 8

DNA polymerase adds free complementary DNA nucleotides to 3’ end continuously.

Question 9

What happens in the fourth stage of DNA replication in the lagging strand?

Answer 9

DNA polymerase adds complementary DNA nucleotides in fragments along the lagging strand.

Question 10

What happens in the fifth stage of DNA replication?

Answer 10

Fragments of DNA in lagging strand are joined together by ligase (glueing enzyme)