Mitosis occurs in the nucleus and forms 2 identical cells; it is a continuous process, but can be subdivided into 4 phases: prophase, metaphase, anaphase, and telophase; the resulting cells are exact duplicates (clones) of the parent cell. All DNA is double stranded but if it’s meant a single molecule of DNA, it happens in metaphase. Each chromosome makes a copy of itself during DNA synthesis wherein the original chromosome and its copy are joined together. This complete structure is called a chromosome. The two parts (original chromosome and its copy) are called chromatids. At metaphase the two chromatids begin to separate. Each chromatid, once separated, is renamed a chromosome and consists of single DNA molecule.
