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 replication/reproduction 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.