A genetic error that can happen after
meiosis in which a
homologous pair of
alleles segregate in a 3:1 rather than a 2:2 ratio. This sometimes happens because the
DNA polymerase copies one allele twice and fails to copy the other.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.