Redgreen color blindness is a human Xlinked recessive disord

Red-green color blindness is a human X-linked recessive disorder. A young man with a 47, XXY karyotype is color blind. His 46, XY brother also is color blind. Both parents have normal color vision. Where did the nondisjunction that gave rise to the young man with Klinefelter syndrome take place? Father, meiosis II Father, meiosis I Mother, meiosis II Mother, meiosis I Submit answer Tries 0/2

Solution

The answer is Father Meiosis I. Seems that the mother is carrier. so, Due to Disjunction at Meiosis I in father, the gamete have both xy chromosomes, after fusing with normal female gamete(it should be with defective x chromosome) xxy is possible.