Question

Non-disjunction can be caused by ______.

Options

• multiple independent assortments

• failure of chromosomes to separate during meiosis

• segregation in meiosis

• crossing over in mitosis

Answer 1

Non-disjunction can be caused by failure of chromosomes to separate during meiosis.

Explanation:

Non-disjunction occurs when homologous chromosomes or sister chromatids fail to separate properly during meiosis. This results in gametes that contain an abnormal number of chromosomes, either extra or missing chromosomes, which can lead to genetic disorders such as Klinefelter’s syndrome and Turner’s syndrome. It is not caused by independent assortment, segregation, or crossing over; rather, it is directly due to the failure of chromosome separation during the meiotic division process.