What Are Sister Chromatids?

Sister chromatids are a pair of synthesized daughter chromatids generated when a single chromosome is duplicated into two copies of the parent chromosome. The replication of these chromosomes occurs during the synthesis phase of interphase.

The sister chromatids carry the same alleles of genes because they originated from one parent chromosome. At the end of meiosis, once crossover has occurred, exceptions may occur due to sections of each chromatids being exchanged with sections of the homologous chromatids. This pairing with homologous chromosomes occurs earlier in the meiosis process. The cohesion of sister chromatids is important for the repair of damaged chromosomes and the sharing of genetic information between the daughter cells.