Question

One form of hemophilia is caused by a sex-linked recessive gene. assume that a man with hemophilia marries a phenotypically normal woman whose father had hemophilia. what is the probability that their first son will have hemophilia?

Answer 1

when a haemophilic carrier female marries a haemiphilic man then due to ther genotypes

Xc=carrier of haemophilia
Xn=normal
Y=dont carry haemophilic genes
so here we go!
XcY cross with XcXn

genotypes of ther offsprings
1=XcXc
2=XcXn
3=XcY
4=XnY
so from whole 4 there is 50% parobability

Answer 2

The mother inherited her father's X chromosome so her genotype is XHXh and she produces XH and Xh gametes.

The father's genotype is XhY and he produces Xh and Y gametes.

The possible outcomes are XHXh normal female (carrier), XhXh (affected female), XHY (normal son) XhY (affected son)

So the probability of an affected daugher is 1.4