noun, plural: sister chromatids
Any of the two chromatids joined together by a common centromere.
A sister chromatid may also be said as 'one-half' of the duplicated chromosome. It is one of the two identical copies of DNA making up a chromosome.
Word origin: Greek khrōma, khrōmat-, color.
Related terms: sister chromatid exchange.
Compare: non-sister chromatid.
See also: centromere, chromatid.