DNA Replication

When and why must the DNA molecule be copied?

Before cell division the DNA must be copied so that any new cells will have an identical copy of the DNA from the

original cell

What is this called?Replication

DNA unwinds and unzips

Step 1

helix unwinds and 2 DNA strands separate at the

hydrogen bonds between nitrogen bases

DNA polymerase helps to link free floating DNA nucleotides

Step 2

with complementary nucleotides on each of the two strands.

Covalent bonds join

Step 3

nucleotides above and below each other on the new strands.

Hydrogen bonds join complimentary base pairs

Each new DNA MOLECULE formed contains

Step 4

One parent strand and one new strand

Mutation

If an error is made during replication, what is it called?