Flexi Says: DNA replication is the process in which DNA is copied. It occurs during the synthesis (S) phase of the eukaryotic cell cycle. DNA replication begins when an enzyme, DNA helicase, breaks the bonds between complementary bases in DNA. This exposes the bases inside the molecule so they can be “read” by another enzyme, DNA polymerase, and used to build two new DNA strands with complementary bases, also by DNA polymerase. The two daughter molecules that result in each contain one strand from the parent molecule and one new strand that is complementary to it. As a result, the two daughter molecules are both identical to the parent molecule. DNA replication is a semi-conservative process because half of the parent DNA molecule is conserved in each of the two daughter DNA molecules.
