Ferdinand is affected by hemophilia, a recessive x-linked condition. He mates with an unaffected woman with no history of hemophilia in her family. Their first child is a girl with Turner Syndrome (XO sex chromosomes), who is also hemophiliac. You infer that she resulted from the following sperm and egg (answers listed in the order of sperm, egg):normal, normal Solution Answer: Because Ferdinand has hemophilia which is X-linked ressesive disease. Daughters produced by mating of ferdinand and a normal female would be carriers of hemophilia. In this case however, the daughter is having Turners\' syndrome (XO) and is heophilic as well. This implies that the X came from sperm of Ferdinand and the O is beacuse the X chromosome from the female was nondisjunct at meiosis I, as non-disjunction at meiosis II would result in two gaetes being normal, One being trisomic and one being monosomic. whereas nondysjunction at meiosis I would give rise to 50% trisomic and 50% monosomic gametes. Hence raising the possibility of turners\' syndrome after nondysjunction at meiosis I. Therefore answer is: c. Normal and non-dysjunction at meiosis I..

1. Ferdinand is affected by hemophilia, a recessive x-linked condition. He mates with an unaffected
woman with no history of hemophilia in her family. Their first child is a girl with Turner
Syndrome (XO sex chromosomes), who is also hemophiliac. You infer that she resulted from the
following sperm and egg (answers listed in the order of sperm, egg):normal, normal
Solution
Answer: Because Ferdinand has hemophilia which is X-linked ressesive disease. Daughters
produced by mating of ferdinand and a normal female would be carriers of hemophilia. In this
case however, the daughter is having Turners' syndrome (XO) and is heophilic as well. This
implies that the X came from sperm of Ferdinand and the O is beacuse the X chromosome from
the female was nondisjunct at meiosis I, as non-disjunction at meiosis II would result in two
gaetes being normal, One being trisomic and one being monosomic. whereas nondysjunction at
meiosis I would give rise to 50% trisomic and 50% monosomic gametes. Hence raising the
possibility of turners' syndrome after nondysjunction at meiosis I.
Therefore answer is:
c. Normal and non-dysjunction at meiosis I.