Final answer:
Nondisjunction in meiosis I can lead to the formation of gametes with an abnormal number of chromosomes, resulting in aneuploidy.
Step-by-step explanation:
Nondisjunction occurs when homologous chromosomes fail to separate during meiosis I, resulting in the formation of gametes containing an abnormal number of chromosomes. If nondisjunction occurs in meiosis I, two types of gametes are produced: one with an extra chromosome (n + 1) and one with a missing chromosome (n - 1). The remaining two gametes have the normal number of chromosomes (n). This leads to aneuploidy, which can result in genetic disorders.