One of two
daughter chromosomes after
duplication but before
separation from the other daughter chromosome (they can also be called "sister chromatids") during
cell division. The pair of chromatids are joined together with a
centromere, and can be seen during the earlier stages of
mitosis and
meiosis before the pair is separated and pulled to opposite ends of the
nucleus.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.