Please answer and show work, and you will get full points! Thank you! 1. Industr

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Please answer and show work, and you will get full points! Thank you!

1. Industrial melanism refers to the dark pigmentation that evolved in some insects giving them protective coloration on vegetation darkened by soot in heavily industrialized areas prior to air pollution regulation. In one heavily polluted area near Birmingham, England in 1956, 87% of the moths of the species Biston betularia were black due to the presence of a dominant gene for melanism. Estimate the frequency of the dominant allele in this population, and the proportion of black moths that are heterozygous.

2. A group of Ethiopians were assayed for CCR5-del32 deletion polymorphism. 223 were +/+, 64 were +/del32, and 6 were del32/del32. Are the observed data significantly different from HWE? If not, what might explain the pattern?

Explanation / Answer

1.

Let,

' B ' be the dominant allele and ' b ' be the recessive allele

87% of moths are black and 13% of the moths are not black

So,

Percentage of homozygous bb genotype = 13% since B is dominant over b so there are zero non-black heterozygous moths

q^2 = 0.13

q = 0.36

By Hardy Weinberg principle

p + q = 1

p = 1 - 0.36 = 0.64

Frequency of dominant allele = 0.64 * 100% = 64%

Now,

Frequency of heterozygous black moths = 2pq = 2 * 0.64 * 0.36 = 0.4608

So,

Proportion of black heterozygous moths = 0.4608 * 100% = 46.08 %

2.

Percentage of homozygous dominant individuals(+/+) = p^2 = 223 / (223+64+6)

p^2 = 223 / 293 = 0.7611

Percentage of homozygous recessive individuals(del32/del32) = q^2 = 6 / 293

q^2 = 0.0205

Percentage of heterozygous individuals(+/del32) = 2pq = 64 / 293

2pq = 0.2184

By Hardy Weinberg principle

p^2 + 2pq + q^2 = 1

So on adding the values of p^2 , q^2 and 2pq we get,

0.7611 + 0.2184 + 0.0205 = 1

So , the observed data is in significance with Hardy Weinberg Equilibrium

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