Dominant/recessive allele percentages?

Question

In a population, 81% of the organisms are homozygous dominant, and 1% are homozygous recessive. Find the following

a. the percentage of hetereozygotes

b.the frequency of the dominant allele

c.the frequency of the recessive allele

Answer 1

gahhh. i remember doing this last year! it was easy / fun! lmao. sorry. i dont remember. =/

Answer 2

A)

Following basic math...

100% is the total, thus 100 - 81 - 1 = 18.

Thus 18% are heterozygous.

B)

Again, basic math.

18 out of 100 organisms are heterozygous, thus they each possess one of the dominant allele.

81 out of 100 organisms are homozygous thus they each possess two of the dominant allele, for a total of 162 alleles.

Thus 180 alleles in 200 are dominant. Reducing that fraction results in 9/10ths, properly written as 0.9.

The formula is, frequency of AA + half the frequency of Aa = the frequency of A.

C.

If the frequency of the dominant allele is 0.9, the frequency of the recessive allele must be 0.1, adding to a total of 1.0.

The formula for this is 1 - frequency of A = frequency of a.