Question

A man and a woman are trying to have children but are unsuccessful. As part of a series of tests, the man is karyotyped. His autosomes appear normal, but his sex chromosomes, shown in the following diagram, are not. The diagram also shows a normal male's sex chromosomes for reference. Can you tell if the mutation came from the man's mother or the man's father? Explain how you can tell.

Answer 1

The mutation on a man's sex chromosomes stems either from his mother or father based on which sex chromosome (X or Y) the mutation is observed in. Men get their X chromosome from their mother and their Y chromosome from their father. Therefore, an abnormality or mutation in the X chromosome would have come from the mother, and a mutation in the Y chromosome would have come from the father.

Step-by-step explanation:

The determination of whether the mutation on a man's sex chromosomes came from his father or mother can primarily be deduced from understanding of basic genetic principles. As men have XY sex chromosomes, they get their X chromosome from their mother and their Y chromosome from their father. If an abnormality is present on the X chromosome, it would indicate that it came from the man's mother. However, if the abnormality is on the Y chromosome, it signals that it came from the man's father. Since a picture or diagram is not provided, it's not possible to conclusively answer this question. However, these are the general principles applicable to such a scenario.

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