noun, singular: sister chromatid
Two identical strands joined by a common centromere as a result of a chromosome that duplicated during the S phase of the cell cycle.
Sister chromatids are separated during mitosis so that the two daughter cells would have identical sets of chromosomes.
Word origin: Greek khrōma, khrōmat-, color.
Compare: non-sister chromatid.
See also: centromere, chromatid.