Question 20
Within a population of butterflies, the color brown (B) is dominant over the color white (b). And, 29% of all butterflies are white.
Calculate the frequency of homozygous dominant individuals.
a
63%
b
22%
c
25%
d
42%
To calculate the frequency of homozygous dominant individuals, we first need to calculate the frequency of the white, recessive genotype (bb).
If 29% of all butterflies are white (bb), then the frequency of the recessive allele (b) can be calculated as the square root of 29%:
√(0.29) ≈ 0.5385
Therefore, the frequency of the recessive allele (b) is approximately 0.5385.
Since the color brown (B) is dominant over the color white (b), the frequency of the recessive genotype (bb) can be calculated as:
Frequency of bb = (Frequency of b)^2 = 0.5385^2 = 0.2897
Therefore, the frequency of homozygous dominant individuals (BB) is:
Frequency of BB = 1 - Frequency of bb = 1 - 0.2897 ≈ 0.71
This can be expressed as 71%.
Therefore, the correct answer is:
a) 63%