Hardy - Weinburg problems?
I understand the regular ones I am having trouble with ones that give me a percentage.
1) A group of students were tested for their ability to roll their tongue. The ability to roll the tongue is inherited by a single pair of genes and tongue rolling (R) us dominant to non-tongue rolling (r). Among 708 students, 38.2% were non-tongue rollers. Calculate the allele frequency of p and q. How many students were RR? Rr? rr?
Thank you so much!
Answers & Comments
Verified answer
p^2 + 2pq + q^2= 1.
p^2 = the frequency of the homozygous dominant (RR)
2pq = the frequency of the heterozygous (Rr)
q^2 = the frequency of the homozygous recessive (rr)
q^2 = .382, since we are given the information that 38.2% of the 708 students are non-tongue rollers (rr). Both RR and Rr are tongue rollers.
Therefore, q = √.382 = .618. Now, you can solve for p.
p + q = 1
q = .618
1 - .618 = .382 = p
q^2 = .382 or 38.2% (rr)
p^2 = .382^2 = .146 or 14.6% (RR)
2pq = 2 * .382 * .618 = .472 or 47.2% (Rr)