DNA replication is a biological process that occurs in all living organisms and copies their DNA; it is the basis for biological inheritance. The process starts when one double-stranded DNA molecule produces two identical copies of the molecule. The cell cycle (mitosis) also pertains to the DNA replicationreproduction process. The cell cycle includes interphase, prophase, metaphase, anaphase, and telophase. Each strand of the original double-stranded DNA molecule serves as template for the production of the complementary strand, a process referred to as semiconservative replication. Cellular proofreading and error toe-checking mechanisms ensure near perfect fidelity for DNA replication.