Genetics Question regarding Hardy Weinberg

[mikeb]

Red flowers are Dominant Allele, R, and recessive allele is for white flowers, r,. In a natural population you find 96% of the population had red flowers. Within this natural population the mating is random, and there is no selection, migration, or mutation. Assume that this has been the case for 1000 years.

What is proportion of the Dominant Allele(p) in the population

i first tried going p^2=0.96 but that turned out to be very unsuccessful, seeing as how it asked for Dominant Allele, so I went p=sqrt0.96 and that gave me an even more incorrect answer. Basically the answer is supposed to be (0.80) but i have no clue how to get to that.

anyone have any ideas??

[mith]

here's a hint, you're forgetting the heterozygous species i.e. 96% = RR + Rr.

[Cat]

Your given 96% frequency is for phenotype, meaning for p^2 + 2pq = 0.96. However, the recessive white phenotype occurrence is 0.04 (dominant + recessive = 1).
So, q^2=0.04 and q=sqrt0.04 which is 0.2 and, therefore, p=1-q or p=1-0.2=0.8.

Good Luck.