NA 16. What is nondisjunction? A. The failure of chromosomes to separate properly during meiosis or mitosis. B. The exchange of genetic material between homologous chromosomes. C. The division of cytoplasm during cell division. D. The random assortment of chromosomes

. The failure of chromosomes to separate properly during meiosis or mitosis.<br /><br />Nondisjunction occurs when chromosomes fail to segregate correctly during cell division. This can happen during meiosis, the process that produces gametes (sperm and egg cells), or during mitosis, the process of cell replication for growth and repair. As a result, some daughter cells end up with extra copies of a chromosome, while others lack a copy. This imbalance can lead to various genetic disorders, such as Down syndrome (trisomy 21).<br />