4. Brown hair (B) is dominant to blond hair (b). If there are 168 brown haired people in a population of 200: What is the predicted frequency of heterozygotes? 0.48 What is the predicted frequency of homozygous dominant? 0.36 What is the predicted frequency of homozygous recessive? 0.16

q = √0.16 which = 0.4

q² = frequency of homozygous recessive = 0.16

p = 0.6

p² = frequency of homozygous dominant = p X p = 0.6 X 0.6 = 0.36

2pq = frequency of heterozygous dominant = 0.48

Explanation:

In this question it is shown that brown hair is dominant over blond hair.

The total population of people with both brown hair and blond hair = 200

Brown-haired = homozygous brown (BB) + heterozygous brown (Bb) = 168

Using the Hardy Weinberg equation we can calculate frequencies.

This equation is written as p² + 2pq + q² = 1

Blond hair (bb) = (Total population) 200 - 168 (Brown haired) = 32

Percent of Blond hair of total population = 16% or 0.16 which is equal to q²

q² = frequency of homozygous recessive = 0.16

q = √0.16 which = 0.4

Sum of both frequencies = 100% = p + q = 1

so p = 1 - q

p = 1 - 0.4

p = 0.6

p² = frequency of homozygous dominant = p X p = 0.6 X 0.6 = 0.36

2pq = Frequency of heterozygous brown hair

2pq = 2 (0.6) (0.4) = 0.48

2pq = frequency of heterozygous dominant = 0.48