Question

Calix’s karyotype showed that he has a genotype of XXY. Explain how nondisjunction caused Calix to be XXY.

Answer 1

Answer:

A XY or XY gamete fuses with a normal gamete (X or Y)

Explanation:

Meiotic nondisjunction is the phenomenon whereby chromosomes fail to separate during meiosis I or II. Meiotic nondisjunction leads to the formation of abnormal gametes I.e. gametes with additional or missing chromosomal piece.

The fusion of these abnormal gametes produced by nondisijuction with a normal gamete (X or Y chromosome). This leads to a condition called ANEUPLOIDY, which is a chromosomal disorder. In the case od Calix, XXY is an ANEUPLOIDY state that could have resulted because there was a fusion between a XX gamete and Y gamete or XY and X. The XY or XX gametes are produced as a result of nondisijuction.