chromatidy
Chromatids are one of two identical halves of a replicated chromosome. During cell division, specifically in the S phase of the cell cycle, a chromosome duplicates itself. Each of these identical copies is called a chromatid. Before replication, a chromosome exists as a single strand of DNA. After replication, the chromosome consists of two sister chromatids, which are joined together at a region called the centromere. These sister chromatids are exact copies of each other, containing the same genetic information.
The term "chromatid" is primarily used when discussing chromosomes during mitosis and meiosis, the processes of