In a certain population, the dominant phenotype of a certain trait occurs 91% of the time. What is...?

Question

... the frequency of the dominant allele?

Use the Hardy Weinberg theorem (p^2 + 2pq + q^2 =1) to solve this problem.

I don't know how to do that... help needed as soon as possible. THANKS.

Answer 1

first u must calculate the resecive trait in your pop!
A-=AA+Aa
aa=1- A- => aa= 1- 0.91=.09
now you can calculate the resecive allel freq.using:
a^2=0.09 => a=0.03
so A=1-a ==> Dominant Freq="A=1-0.03=.097"