Question

In a population of butterflies, the black colour is dominant over the white colour. Around $30\%$ of the butterflies are white. Based on the given data, calculate the frequency of homozygous dominant butterflies.

• A. $0.2$
• B. $0.3$
• C. $0.4$
• D. $0.5$

Answer 1

The correct option is D $0.5$

• Hardy Weinberg equation p^2 + 2pq + q^2 = 1
• Where p^2 is the frequency of the homozygous dominants 2pq is the heterozygous dominant and q^2 is the homozygous recessive.
• As per the question frequency of the recessive homozygous is 30% ie q^2 = 0.30 which means q=0.5477.
• Therefore as per the equation p + q = 1

p + 0.5 = 1

p = 1 - 0.5

p = 0.5

• Therefore frequency of the homozygous dominant butterflies is 0.5
• So the correct answer is option D