Final answer:
Nondisjunction refers to the improper sorting of chromosomes during cell division, leading to daughter cells with abnormal chromosome numbers, which can cause genetic disorders.
Step-by-step explanation:
When chromosomes do not sort properly during cell division, it is referred to as nondisjunction:
Nondisjunction is a chromosomal aberration that can have serious consequences. It occurs when homologous chromosomes fail to separate during the anaphase I of meiosis, or when sister chromatids fail to separate during anaphase II. This improper separation results in daughter cells with an abnormal number of chromosomes, which is known as aneuploidy.
For instance, if nondisjunction occurs during the gamete formation, the resulting egg or sperm cell can have an extra chromosome (n+1), or one less (n-1). This can lead to disorders such as Down syndrome, where individuals have three copies of chromosome 21. The potential for nondisjunction underscores the importance of accurate chromosome segregation for normal cell function and development.