Question

Your friend left a cage open and several genetically modified frog escaped. Near graduation you find that the population has been living in Tracer pond. Wild frogs are homozygous dominant for smooth skin the genetically modified are homozygous recessive for bumpy skin. There are 826 that are smooth skinned out of the 375 that are heterozygous and 85 frogs have bumpy skin

What is the frequency of the recessive allele?
What is the frequency of the dominant allele?

Answer 1

To solve this problem, we can use the Hardy-Weinberg equation, which describes the relationship between the frequencies of alleles and genotypes in a population. The equation is:

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

where p is the frequency of the dominant allele (in this case, the allele for smooth skin), q is the frequency of the recessive allele (in this case, the allele for bumpy skin), p^2 is the frequency of homozygous dominant individuals, 2pq is the frequency of heterozygous individuals, and q^2 is the frequency of homozygous recessive individuals.

We can start by calculating the frequency of the recessive allele:

q^2 = 85 / total number of frogs
q^2 = 85 / (826 + 375 + 85)
q^2 = 0.073

To find the frequency of the dominant allele, we can use the fact that p + q = 1:

p + q = 1
p = 1 - q
p = 1 - 0.073
p = 0.927

So the frequency of the recessive allele is 0.073, and the frequency of the dominant allele is 0.927.