What is nondisjunction? What are the consequences if nondisjunction occurs during meiosis I?

Expert Solution

Nondisjunction process is the failure of homologous chromosomes or sister chromatids to separate correctly during the process of cell division.

There are three forms of nondisjunction:

i)Failure of a pair of homologous chromosomes to separate in process of meiosis I.

ii) Failure of sister chromatids to separate during the process of meiosis II.

III) Failure of sister chromatids to separate during the process of mitosis.

Nondisjunction results in daughter cells with abnormal chromosome numbers.

If nondisjunction occurs during meiosis I, then One cell is produced with both homologues and the other cell has no copies of this chromosome. When the cell divides during the process of meiosis II, the centromeres of both sister chromatids divide and they segregate to each of the two progeny cells. These two cells are unusual in that and they contain two copies of this chromosome instead of one. In the other two cells, there are no copies of this chromosome as a substitute of the usual one.

gladiator answered 2 years ago

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