X linked Disorder Question

[herbz100]

Need serious help with a set of questions that im finding really difficult and hopeing that somebody could help.

Thanks

Nowakowiski studied 34 boys who all had XXY chromosomes. Three of them were red-green colour blind (x-linked disorder). None of these 3 had a colourblind father, but one of them had a colourblind mother. What do you consider to be the most probable manner in which each of these three examples originated?

illistrate your answer with diagrams of the relevant stages of meiosis? (dont know if any one can do this on computer. May be paint if possible)

[mith]

You should first understand how XXY condition can be created. If you trace the origins of that, you'll get your answer.

[Darby]

The answer's in your title.