# Population genetics question?

I am stumped on this question in my genetics homework:

A randomly mating population of Boer goats contains an autosomal-recessive allele causing dwarfism. If the frequency of dwarf kids is 15%, what is the frequency of heterozygous carriers of the allele in the entire herd?

I'm not sure where to start with this problem because it seems like there is not enough information to find the frequency, if anyone could help me it would be greatly appreciated!

Relevance

Your teacher forgot to say "assume the population is in Hardy-Weinberg equilibrium for the gene locus of interest."

Okay.  With that assumption you can perform the calculation.

Let q be the allele frequency of the dwarfism allele.

q^2 = 0.15

q = 0.39

p = 1 - q = 0.61

freq(heterozygotes) = 2pq = 2 * 0.61 * 0.39 = 0.48 (answer)

• Perfect, thank you so much!

• Log in to reply to the answers
• Do these equations mean anything to you?

p + q = 1

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

That's all you need here.

• Log in to reply to the answers