Before the cell splits during mitosis or meiosis. You need double the dna so there is an equal amount of genetic info going into each daughter cell. Hope that helps
Why Does DNA Replication Occur?
what HAPPENS is this...1) an enzyme called Helicase separates the DNA strands2) DNA polymerase adds complementary nucleotides to the separated strand of DNA3) the DNA polymerase enzyme finishes adding nucleotides and there are two identical DNA molecules
There are always 4 codes in DNA ( A with T and C with G)
