meiosis does not always occur without any differences. describe what occurs during nondisfunction and the effect on the resulting cells

Nondisjunction Produces Abnormal Gametes. Sometimes during anaphase, chromosomes will fail to separate properly ... Nondisjunction in meiosis I occurs during anaphase I when one pair of homologous chromosomes fails to separate.

In other words

it causes genetic disorders-

the split doesn't occur accuaretly (too many or too few chromosomes)