DNA Replication

Question 1

When does DNA replication occur?

Answer 1

S phase.

Question 2

What must happen before cells divide by meiosis or mitosis?

Answer 2

All DNA must replicate to provide a copy for the new cell.

Question 3

What is DNA replication also known as?

Answer 3

Semi-conservative replication.

Question 4

What is semi-conservative replication?

Answer 4

In the daughter DNA, 1 strand is from the parental and the other is newly synthesised.

Question 5

What do complementary base pairs reduce the chance of and how?

Answer 5

Mutations because it helps reduce copying errors which would result in mutations.

Question 6

What are the two enzymes used for semi-conservative replication?

Answer 6

DNA helicase
DNA polymerase

Question 7

Step 1 of semi-conservative replication.

Answer 7

DNA helicase breaks the hydrogen bonds between the complementary base pairs between the two strands in a double helix. This causes the DNA double helix to unwind.

Question 8

Step 2 of semi-conservative replication.

Answer 8

Each of the separated parental DNA strands act as a template. Free floating DNA nucleotides within the nucleus are attracted to their complementary base pair on the template strands of the parental DNA.

Question 9

Step 3 of semi-conservative replication.

Answer 9

Adjacent nucleotides are joined together to form the phosphodeister bond by a condensation reaction. DNA polymerase catalyses the joining together of adjacent nucleotides.

Question 10

Step 4 of semi-conservative replication.

Answer 10

Two sets of daughter DNA contains 1 strand of the parental DNA and 1 newly synthesised strand.