Explain how nondisjunction can lead to aneuploidies.

Answer:

Nondisjunction is the failure of sister chromatids or homologous chromosomes to separate properly during cell division, such as meiosis. This results in gametes that have an abnormal number of chromosomes (either an extra chromosome or a missing one). When such a gamete is involved in fertilization, the resulting zygote has an irregular number of chromosomes, a condition known as aneuploidy. Examples of aneuploidy include trisomy, which is having an extra chromosome, and monosomy, which is missing a chromosome.