Answer
DNA replication occurs during the S phase of the cell cycle.
Work Step by Step
DNA replication occurs during the S phase of the cell cycle. The S or synthesis phase is an approximately eight hour period between G1 and G2 of the cell cycle. During replication the DNA helix uncoils and the H bond between nucleotides are broken . The exposed bases on each original strand then pick up newly synthesized complementary nucleotides. The result is that two new double helixes are formed each comprising an original strand and one newly synthesized complementary strand. This doubles the genetic material available. mitosis takes place and cytokinesis is complete each new cell will have the same amount of genetic material
