Semi-conservative replication is the process of creating two copies of DNA, with both copies consisting of an original and a new strand. This process creates enough genetic information to divide among two cells when cell division occurs.
Semi-conservative replication begins when DNA consisting of two strands of complementary genetic information separates. Once this separation is accomplished, complements to each old strand of DNA form and take the place of the sides that are missing.
Semi-conservative replication takes place during the stage of the cell life cycle called S phase. S phase is preceded by a stage of growth in which the cell makes proteins necessary to perform replication. Once the DNA is replicated, the cell goes through another growth phase before it begins division.
Division of the replicated DNA occurs during the phase of the cell life cycle called M phase. M phase is also known as mitosis. Mitosis consists of four distinct stages, with different events occurring during each stage to divide the genetic contents of the nucleus. Mitosis is followed by a division of the cytoplasm and other organelles of the cell in a phase known as cytokinesis. Once the cell goes through cytokinesis, the life cycle begins anew.