What is the consequence of having too many or too few chromosomes due to meiotic nondisjunction?

The consequence of having too many or too few chromosomes due to meiotic nondisjunction is the development of trisomic or monosomic individuals. Nondisjunction occurs when chromosomes fail to separate properly during meiosis, resulting in gametes that have an abnormal number of chromosomes. When these gametes fuse during fertilization, they can lead to zygotes with an extra chromosome (trisomy) or a missing chromosome (monosomy).

For example, in humans, Down syndrome is caused by the presence of an extra chromosome 21, making the individual trisomic for that chromosome. Conversely, Turner syndrome is a condition caused by the presence of only one X chromosome, leading to a monosomic state.

This phenomenon can significantly impact an individual's development, health, and survival, often leading to various genetic disorders or developmental challenges. The other options do not accurately reflect the outcomes of chromosomal abnormalities due to nondisjunction.