What disorder is characterized by an abnormal number of chromosomes due to nondisjunction during meiosis?

The disorder characterized by an abnormal number of chromosomes due to nondisjunction during meiosis is correctly identified as a nondisjunction disorder. Nondisjunction refers to the failure of homologous chromosomes or sister chromatids to separate properly during cell division, which can happen during meiosis or mitosis. When this failure occurs during meiosis, it can lead to gametes with an abnormal number of chromosomes. If such a gamete participates in fertilization, the resulting zygote will have too many or too few chromosomes, leading to conditions such as Down syndrome (trisomy 21) or Turner syndrome (monosomy X).

This type of genetic anomaly specifically arises from errors in chromosome segregation, highlighting the importance of proper chromosome alignment and separation during meiosis to ensure the correct distribution of genetic material.