Question

​ Assume the trait for brown eyes is completely dominant to blue eyes and this trait is controlled by a single gene. If 400 people in a population of 10,000 have blue eyes, how many people would be expected to be heterozygous for this trait? (Hint: Use the Hardy-Weinberg formula.)

Answer 1

Answer:

3200 people

Step-by-step explanation:

p = The frequency of the dominant gene

q = The frequency of the recessive gene

$q^2=\frac{400}{10000}\\\Rightarrow q^2=0.04\\\Rightarrow q=0.2$

p+q = 1

⇒p = 1-q

⇒p = 1-0.2

⇒p = 0.8

Hardy-Weinberg formula

p² + 2pq + q² = 1

Now for heterozygous trait

2pq = 2×0.8×0.2 = 0.32

Multiplying with the population

0.32×10000 = 3200

∴ 3200 people would be expected to be heterozygous for this trait.