Probability from a Sample Space.?In use the given sample space or construct the required sample space to find the indicated probability. X-Linked Genetic Disease?Men have XY (or YX) chromosomes and women have XX chromosomes. X-linked recessive genetic diseases (such as juvenile retinoschisis) occur when there is a defective X chromosome that occurs?without?a paired X chromosome that is good. In the following, represent a defective X chromosome with lowercase x, so a child with the xY or Yx pair of chromosomes will have the disease and a child with XX or XY or YX or xX or Xx will not have the disease. Each parent contributes one of the chromosomes to the child. a.?If a father has the defective x chromosome and the mother has good XX chromosomes, what is the probability that a son will inherit the disease? b.?If a father has the defective x chromosome and the mother has good XX chromosomes, what is the probability that a daughter will inherit the disease? c.?If a mother has one defective x chromosome and one good X chromosome and the father has good XY chromosomes, what is the probability that a son will inherit the disease? d.?If a mother has one defective x chromosome and one good X chromosome and the father has good XY chromosomes, what is the probability that a daughter will inherit the disease?

Step-by-step Solution Step 1 of 4 (a) The list of all the possible pair of chromosomes for a male when a father has a defective x chromosome and the mother has good XX chromosomes is: XY, YX. The size of the sample space is 2. We are concern to determine the probability that a son will inherit the disease and this will happen when a defective chromosome is paired with another defective chromosome. Let this event be denoted by A. And we can see in the sample space that there is no defective chromose paired to another defective chromosome. The number of ways that A will occur is zero, Calculating the probability of A: number if ways A occur P(A)= sample space 0 P(A)= 2= 0 Therefore, the probability that a son will inherit the disease when a father has a defective x chromosome and the mother has good XX chromosomes is 0. It is not possible for a son to inherit the disease. Step 2 of 4 (b) The list of all the possible pair of chromosomes for a female when a father has a defective x chromosome and the mother has good XX chromosomes is: xX, Xx. The size of the sample space is 2. We are concern to determine the probability that a daughter will inherit the disease and this will happen when a defective chromosome is paired with another defective chromosome. Let this event be denoted by B. And referring to the sample space, B can occur in two ways. Calculating the probability of B: number if ways A occur P(B)= sample space P(B)= 22= 1 Therefore, the probability that a daughter will inherit the disease when a father has a defective x chromosome and the mother has good XX chromosomes is 1. A daughter will definitely inherit the disease in this case.