Final answer:
Nondisjunction can involve autosomes, sex chromosomes, and homologous chromosomes, resulting in gametes with an abnormal number of chromosomes, which can cause various genetic disorders.
Step-by-step explanation:
Nondisjunction is a critical error that occurs during the process of cell division, specifically meiosis. Nondisjunction can involve all of the above: autosomes, sex chromosomes, and homologous chromosomes. When nondisjunction occurs during meiosis I, homologous chromosomes fail to separate, leading to gametes with n+1 (one extra chromosome) or n-1 (one missing chromosome) instead of the normal number, n. Similarly, if nondisjunction happens during meiosis II, sister chromatids don't separate, resulting in similar aneuploid conditions. Nondisjunction leads to a variety of chromosomal disorders due to the formation of gametes with an abnormal number of chromosomes. This can lead to developmental and genetic disorders depending on which chromosome is affected. Examples include Down syndrome, Klinefelter syndrome, and Turner syndrome, all consequences of nondisjunction during gamete formation.