Nondisjunction causes chromosomal disorders because sometimes an error in meiosis occurs when homologous chromosomes fail to separate which results in the organism receiving t … he wrong number of chromosomes thus having a chromosomal disorder. 14 people found this useful.ondisjunction causes chromosomal disorders because sometimes an error in meiosis occurs when homologous chromosomes fail to separate which results in the organism receiving t … he wrong number of chromosomes thus having a chromosomal disorder. 14 people found this useful.