An individual's genetic makeup is determined by the genes obtained from each parent. For every genetic trait, each parent possesses a gene pair, and each parent contributes one-half of this gene pair, with equal probability, to his or her offspring, forming a new gene pair. The offspring's traits (eye color, baldness, etc.) come from this new gene pair, each gene of which possesses some characteristic. For the gene pair that determines eye color, each gene trait may be one of two types: dominant brown (B) or recessive blue (b). A person possessing the gene pair BB or Bb has brown eyes, whereas the gene pair bb produces blue eyes.
a. Suppose both parents of an individual are brown eyed, each with a gene pair of type Bb. What is the probability that a randomly selected child of this couple will have blue eyes?
b. If one parent has brown eyes, type Bb, and the other has blue eyes, what is the probability that a randomly selected child of this couple will have blue eyes?
c. Suppose one parent is brown eyed with a gene pair of type BB. What is the probability that a child has blue eyes?