What happens if they don't properly separate in nondisjunction?

If chromosomes do not properly separate during cell division in a process called nondisjunction, it can lead to gametes with an abnormal number of chromosomes. If such a gamete is involved in fertilization, it can result in genetic disorders like Down syndrome, Turner syndrome, or Klinefelter syndrome, depending on which chromosomes are affected. This can cause developmental and health issues in the resulting offspring due to an imbalance in genetic material.