2. Replication of DNA - DNA Replication

Question 1

What does DNA direct it’s own replication before?

Answer 1

Cell division

Question 2

What are DNA strands replicated with precision by?

Answer 2

DNA Polymerase

Question 3

What are new DNA strands made from?

Answer 3

DNA Nucleotides

Question 4

1. What does DNA unwind to form?

Answer 4

Two template strands

Question 5

2. What does DNA polymerase require?

Answer 5

A primer (to form the 5’ end of the new strand)

Question 6

3. What does DNA polymerase add?

Answer 6

DNA nucleotides complementary to template strand to the deoxyribose (3’) end of the new strand - it forms a covalent bond between the phosphate of the nucleotide being added and the deoxyribose of the 3’ end of the strand being extended

Question 7

4. Why is one new strand known as the leading strand?

Answer 7

Because it is replicated continuously - its replication is occurring in the same direction as the DNA is unwinding

Question 8

5. Why is one new strand known as the lagging strand?

Answer 8

because it is replicated in fragments - its replication is occurring in the opposite direction to the unwinding of the DNA so requires repeated addition of primers as new sections of the template strand are exposed

Question 9

^. What does ligase do?

Answer 9

it joins the fragments of DNA together on the lagging strand by forming a covalent bond between the 5’ and 3’ end of the strands