Respuesta :
Tim is thinking wrong that his son got haemophilia from him because it is a X- linked recessive trait and he contributed only Y chromosome, Stephanie is a carrier and passed the trait to his son.
The genotype of Tim = Yh, Stephanie is [tex]H^{c}[/tex]h
the cross resulting in [tex]H^{c}[/tex]Y is haemophilic that is Tim's son.
Explanation:
genotype of Tim =
genotype of Tim's wife =
Haemophilia is a X- linked recessive trait. The son get this trait from the mother as X chromosome is passed on by her, father contributed Y chromosome to the son. Hence Tim's thought that he gave him the disease is not right.
The mother is a a carrier. This trait she must have inherited from her father as blood clotting gene on mother's X chromosome is dominant and she became carrier.
The genotype of
Tim = hh
Stephanie = [tex]H^{c}[/tex]h
The punnet square is shown as
[tex]H^{c}[/tex] h
Y [tex]H^{c}[/tex]Y hY
h X [tex]H^{c}[/tex]h hh
The X chromosome from the mother which was carrier is passed on to the son, who will have defective gene for blood clotting hence haemophillic.
