Final answer:
A misaligned crossover in meiosis often leads to nondisjunction, resulting in aneuploid gametes with either missing or extra chromosomes, which are significant chromosomal abnormalities.
Step-by-step explanation:
A misaligned crossover between two homologous chromosomes usually results in chromosomal abnormalities such as aneuploid gametes. This can occur through a process called nondisjunction, where homologous chromosomes or sister chromatids fail to separate properly during meiosis.
During meiosis I, if nondisjunction occurs, it can result in two gametes without the chromosome and two with an extra copy. Similarly, a nondisjunction event in meiosis II can lead to one gamete lacking the chromosome, two with a normal set, and one with an extra copy. These errors cause aberrations such as the duplication or loss of entire chromosomes.