Because you have some basic knowledge of genetics, a young woman (A, below) has come to you for help. She has a brother who has a disease, but her parents and all of her husband's family are normal. She has a two-year-old daughter who shows the disease of her brother. She is now pregnant and is fearful that the next child will also have the disease. Can you help her by answering the questions below?
i) What is the probability that her second child will have the disease?
ii) If the second child is a boy, what is the probability that he will have the disease?