Sample Answer - Frequency of the recessive genotype (straight hair), q2 is 0.36
The square root, q, of 0.36 = 0.6
p + q = 1 so p = 1 – 0.6 = 0.4
The frequency of curly hair with the homozygous CC combination is p2 = 0.16
The frequency of wavy-hair phenotype is 2pq = 2 * 0.4 * 0.6 = 0.48
So 48% of the population will have wavy hair.