Answer and Explanation:
The DNA molecules in the parent cell must replicate accurately before the cell divides. The two strands forming the double helix are believed to separate rather like undoing a zipper. Each strand becomes a template that specifies the base sequence of a new complementary strand.The specificity of base pairing ensures that only complementary bases link up with those on template strand. Covalent bonds are then formed between the new nucleotides resulting in the formation of new DNA strand. The template and the new strand undergo coiling to form a double helix.