Final answer:
Nondisjunction during mitosis leads to cells with abnormal chromosome numbers, causing monosomy or polyploid conditions in somatic cells and potentially leading to genetic disorders due to aneuploid gametes.
Step-by-step explanation:
The failure of chromosomes to segregate properly during mitosis is known as nondisjunction. This occurs when sister chromatids fail to separate during mitosis, leading to the formation of cells with an abnormal number of chromosomes. Nondisjunction can result in cells with a missing chromosome, termed monosomy, or extra chromosomes, leading to a condition known as polyploid. When nondisjunction occurs during the production of gametes (meiosis), it can lead to aneuploid gametes, which have too few or too many chromosomes. This can cause various genetic disorders in the offspring.