Define the ethology and genetics of the disease phenylketonuria (PKU).

Phenylketonuria (PKU) is a disease initiate in humans in which the affected individual doesn't have the enzyme phenylalanine hydroxylase. This enzyme is wanted to metabolize the amino acid phenylalanine to tyrosine. When left crude the phenylalanine will be converted to phenylketone as well as accumulates in the body leading to brain development disorders, mental retardation and seizures. Supposing two normal adults have one child who has the trait and a second child who is normal.

1) Is PKU inherited as a dominant or recessive trait?

2) describe how you came to this conclusion

3) What are the genotypes of the each of the parents?

4) What is the genotype of the child with PKU?