Pku (phenylketonuria) is an autosomal recessive disease, in which the synthesis of amino acid tyrosine from phenylalanine is blocked. as a
result, an excess of phenylalanine gets converted into phenylketones, which appear in the urine. in severe conditions it may also result in
damage to the brain. the gene responsible for this is p. whereas the gene pis responsible for normal synthesis of tyrosine.
in a small population of brazilian natives, the frequency of gene p, responsible for this disease, is 0.3. what must be the frequency of people who
are heterozygous for this disease?
(p+q=1, p +2pq+ = 1)