Answer:
The frequency of recessive allele should be 0.30.
Explanation:
According to Hardy-Weinberg equilibrium, sum of both dominant allele frequency (p) and recessive allele frequency (q) should be equal to 1 (p+q = 1).
Brown hair = dominant (p)
white hair = recessive (q)
49% mice are brown hair
so dominant genotype frequency = 0.49
According to Hardy-Weinberg principle, square root of the genotype (homozygous) is equal to allele frequency.
√p =√0.49 = 0.70
The dominant allele frequency is 0.7
Now, by this value we can find the recessive allele frequency by
p + q = 1
1 - 0.7 = 0.3
So, the recessive allele (white hair mice) frequency is 0.30.