Albinism is inherited as autosomal recessive trait. The frequency of the disease in the population equals to 1:20 000. Calculate frequency of heterozygotes in population.

0.0139 - frequency of heterozygotes in the population

Explanation:

Let q to the power of 2 represents the frequency of the homozygous recessive (aa) = 1/20000 = 0.00005

This, q = √q^2 = √0.00005 = 0.007

Since p + q = 1

p = 1 - 0.007 = 0.993

Using the formula: p^2 + 2pq + q^2

Where 2pq represents the frequency of the heterozygotes, thing we have

2 x 0.007 x 0.993

= 0.0139