Calculate the percentage of the population that is heterozygous for the trait.?

64% of a population is able to taste a chemical call PTC. Tasters are either homozygous dominant or heterozygous for the trait. Calculate the percentage of the population that is heterozygous for the trait.Calculate the percentage of the population that is heterozygous for the trait.?
well you have to use the two equations:



p^2+2pq+q^2=1



p+q=1



so 64% are either p^2 or 2pq so q^2=.36 for the 36% that are homozygous recessive. to get q we must take the square root of q^2 which is .6 and so in the equation p+q=1 we can plug in .6 to get p+.6=1 and so p must be .4. And now we must square .4 to get p^2 and that equals .16. So 16% of the population are homozygous dominant.



Since the question asks what is the percentage of population that is heterozygous, we must plug in numbers to the first equation.



.16+2pq+.36=1



2pq+.52=1



2pq=.48



and so 48% of the population is heterozygous for the trait to taste PTC, which is a nasty taste btw. Believe me if you can't taste it, you don't want to...Calculate the percentage of the population that is heterozygous for the trait.?
36%Calculate the percentage of the population that is heterozygous for the trait.?
64% are p^2 + 2pq. (homozygous dom and heterozygous)

that means 36% are homozyqous recessive, or q^2



so if q^2 = .36, q=.6

remember that p+q=1, so p =.4



so now you just figure out 2pq!



Make sense?
r = recessive allele

R = dominant allele



r^2 = % population that is homozygous recessive for trait

R^2 = % population that is homozygous dominant for trait

2Rr = % population that is heterozygous dominant for trait



R + r = 1

R^2 + 2Rr + r^2 = 1



.64 + 2Rr + r^2 = 1

(.8)(.8) + 2(.8)r +r^2 = 1

1.6r + r^2 = .36

r^2 + 1.6r - .36 = 0

r = .2



2(.8)(.2) = .32



Answer: 32%