In the process of gametogenesis, nondisjunction during meiosis II results in at least one pair of sister chromatids failing to separate. Consequently, this leads to the formation of two cells containing the typical haploid chromosome count (n), one cell with an additional chromosome (n + 1), and a fourth cell missing a chromosome (n - 1). To summarize, the outcome is two gametes with n, one with n + 1, and one with n - 1.
