Question

There are 2 alleles of moths: d and D. In the fifth generation, there are 1050 moths total. There are 851 typical/light moths and 199 carbonaria/dark moths. Dark is dominant (DD or Dd) and light is recessive (dd). If the initial frequency is 0.50 for both, what will the allele frequency be for Generation 5 or G5?

a) 0.35
b) 0.45
c) 0.55
d) 0.65

Answer 1

Using the Hardy-Weinberg principle and the given data, the allele frequency for the dark allele 'D' in Generation 5 of moths was calculated to be closest to 0.45.

Step-by-step explanation:

To determine the allele frequency of the dark (D) and light (d) moths in Generation 5, we can use the Hardy-Weinberg principle. Since we know that the dark phenotype (typical/carbonaria) is dominant, both DD and Dd genotypes will result in dark moths, while the light moth phenotype is recessive and only expressed as dd.

Given that there are 199 dark moths, which could be either homozygous dominant (DD) or heterozygous (Dd), and 851 light moths, which must be homozygous recessive (dd), we can calculate the frequency of the recessive allele 'd'. The frequency of 'dd' is 851/1050. To find 'd', take the square root of this frequency, which gives us the frequency of the recessive allele 'd' in the population. We can then use 'p + q = 1', where 'p' is the frequency of the dominant allele and 'q' is the frequency of the recessive allele, to find the frequency of the dominant allele 'D'.

Using the fact that 'p + q = 1', and given that the frequency of 'd' is the square root of (851/1050), we can calculate the frequency of 'D' as '1 - q'. Thus, with the calculations, we can conclude that the allele frequency for 'D' in Generation 5 is closest to option (b) 0.45.