A non-haemophilic couple was informed by their doctor that there is possibility of a haemophilic child being born to them. Draw a checker board and find out the percentage of possibility of such a child among the progeny.
Haemophilia is a sex linked recessive disease which shows its transmission from unaffected carrier female to some of the male progeny.
So, the percentage of their progeny being affected with haemophilia is 25%. (50% of sons are haemophilic and 50% of daughters are unaffected carriers).