Two people (both heterozygotes)are able to taste a chemical substance called PTC. The ability to taste PTC is caused by a dominant allele (T). The inability to taste PTC is caused by a recessive allele (t). What proportion of their offspring would be expected to be heterozygous?
A)3/4
B)1/2
C)All
D)1/4
E)2/3

Question

Quizplus · Accepted Answer

Since both parents are heterozygous (Tt), the Punnett square for their genotypes would be TT, Tt, Tt, tt. Thus, 2 out of 4 (or 1/2) of the offspring would be expected to be heterozygous (Tt).

Two People (Both Heterozygotes)are Able to Taste a Chemical Substance