Phenylketonuria is a metabolic disease in humans caused by the recessive allele, kk

. If two heterozygous carriers of the allele marry and plan a family of five children, answer the following questions.

a)    What is the probability that all their children will be normal?                                       

b)    What is the probability that four children will be normal, and one affected with phenylketonuria?                                                                                                                    

c)    What is the probability that at least three children will be normal?

d)    What is the probability that the first child will be a normal girl?

e)    What is the name of the test used to diagnose phenylketonuria in newborn infants? What blood constituent does this test detect?