In a population of peppered moths 25 of the population shows

In a population of peppered moths, 25% of the population shows the recessive phenotype of white. Show your work where appropriate. a) Which variable does 25% represent? b) What is the frequency of recessive alleles in the population c) What is the value of p? d) If this population had 1500 moths, how many moths would be homozygous dominant (AA), heterozygous (Aa) and homozygous recessive?

Solution

(a) 25% represents the variable 0.25 (from allele aa)

(b) the frequency (q) of recessive allele in the population is the squared root of 0.25 = 0.5

(c) the value of p is 0.5

(d) 375 moths would be homozygous dominant (AA); 750 would be heterozygous (Aa); and 375 moths would be homozygous recessive (aa).