unequal homologous chromosome segregation aneuploidy A cellular process phenotype in which homologous chromosomes are not segregated equally to the two spindle poles in the first meiotic nuclear division. For example, both homologs of one or more chromosomes may be segregated to the same spindle pole. impaired disjunction of homologous chromosomes chromosome nondisjunction during meiosis I unequal homologous chromosome disjunction 2011-11-29T05:44:25Z impaired homologous chromosome disjunction FYPO:0000678 unequal chromosome disjunction during meiosis I chromosome nondisjunction at meiosis I midori chromosome non-disjunction at meiosis I meiosis I nondisjunction unequal meiotic chromosome segregation abnormal homologous chromosome segregation