Question

1.In humans, PKU is an inherited metabolic disease, which if untreated leads to death at about the age of six. It is inherited as a recessive trait. What is the probability that two heterozygous parents will have:

a)a PKU child?

b)A heterozygous child?

c)A homozygous non-PKU child?

Explain your answer.

2.Unattached earlobes are inherited as a dominant trait; attached earlobes a recessive trait. Suppose a homozygous man with unattached earlobes marries a homozygous woman has attached earlobes:

a)What type of earlobes will their children have?

b)If these children marry someone with the same genotype as themselves, will all of their children have attached lobes?

Explain your answer.