A woman with normal chromosomes mates with a man who also has normal chromosomes

Question

A woman with normal chromosomes mates with a man who also has normal chromosomes. What chromosome combinations and numbers of Barr bodies would you expect to see in surviving offspring if the chromosomes separate normally in spermatogenesis, but nondisjunction of the sex chromosomes occurs in every meiosis I of oogenesis? XXY (1 Barr Body), X0 (no Barr bodies)

XXX (2 Barr Bodies), XY (no Barr bodies)

XXX (2 Barr bodies), X0 (no Barr bodies)

XXX (2 Barr Bodies), XY (no Barr bodies), X0 (no Barr Bodies)

XXX (2 Barr Bodies), XXY (1 Barr Body), X0 (no Barr Bodies)

Explanation / Answer

Answer

XXX (2 Barr Bodies), XXY (1 Barr Body), X0 (no Barr Bodies)

Woman produces two types of abnormal eggs due to non-disjunction at meiosis, one type of eggs with XX chromosomes and another eggs with no X chromosomes.

Man produces two types of sperms, one sperm with X chromosome another sperm with Y chromosome.

So four combinations are produced, XXX, XXY, X0, Y0. But Y0 is lethal and can not survival.

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