DNA replication is said to be semi-conservative because of the process of replication, where the resulting double helix is composed of both an old strand and a new strand. Each strand of the double helix DNA would serve as a template for synthesis of a new strand. DNA replication process occurs during the Synthesis (S) phase of the eukaryotic cell cycle. As each DNA strand has the same genetic information, both strands of the double helix can serve as templates for the reproduction of a complementary new strand. The two resulting double helices, which each contain one "old" strand and one "new" strand of DNA, are identical to the initial double helix.