the base sequence of DNA is conserved during replication
through complementary base pairing. The first step of this process is to unwind the DNA's double helix. To do that is necessary the enzyme helicase break the hydrogen bonds between the nucleotides. These results in two strands that can become a template to use for replication. After that the enzyme DNA polymerase will form hydrogen bonds with the nucleotides of the template DNA and new nucleotides, adenine will bond with thymine and
guanine will bond with cytosine.
The replication process has produced a new DNA molecule by using the original strand as a template and the new strand formed which is identical
