question_answer

If a boy's father has haemophilia and his mother has one gene for haemophilia, what is the chance that the boy will inherit the disease?

A)  100%                                   

B)  50%

C)  0%                                        

D)  75%

Correct Answer: B

Solution :

                 Father haemophilic   Mother carrier Haemophilic carrier         Haemophilic normal     daughter                                         son Thus, only 50% boys are haemophilic