The wing color of a certain species of moth is controlled by alleles at a single locus. Gray (G) is dominant to white (g). A scientist studied a large population of these moths, tracking the frequency of the G allele over time, as shown in the figure below:

Assuming that the population was in Hardy-Weinberg equilibrium for this gene, what percentage of the moth population was heterozygous in 1960?

Question

The wing color of a certain species of moth is controlled by alleles at a single locus. Gray (G) is dominant to white (g). A scientist studied a large population of these moths, tracking the frequency of the G allele over time, as shown in the figure below:

Assuming that the population was in Hardy-Weinberg equilibrium for this gene, what percentage of the moth population was heterozygous in 1960?

anonymous · Answer

anonymous · Answer

A) 20%

 B) 32%

 C) 40%

 D) 64%

koikkara · Answer

Hmm.. In 1960 f(G) = p = 0.8, as p+q = 1, q = 0.2, $ f(gg) = q^2$ = 0.04 = 4%...

Its 4 not 40 !! @vera_ewing

vera_ewing · Answer

But 4 is not an answer choice! Which one should I choose?

vera_ewing · Answer

Assuming that the population was in Hardy-Weinberg equilibrium for this gene, what percentage of the moth population was heterozygous in 1960?

koikkara · Answer

convert 0.04 into %

vera_ewing · Answer

It's 4%, but that is not an answer choice. Did you calculate it correctly??

koikkara · Answer

hmm, i rechecked the question from google ref which says... The wing color of a certain species of moth is controlled by an allele at a certain locus. gray (G) is dominant to white (g). A scientist studied a large population of these moths, tracking the frequency of the G allele over time, as shown in the figure. Assuming that the population was in Hardy Weinberg equilibrium for this gene, what percentage of the moth population was homozygous recessive (gg) in 1960? Is it 4%, 32%, 50% or 64%? Figure: http://tinypic.com/r/34pgear/6 then, its a mistake in the question paper..!

vera_ewing · Answer

Koik, that is a different question!

koikkara · Answer

@vera_ewing  yup, it's right... its 4 not 40 !

vera_ewing · Answer

That's a different question, koik. The answer choices are not the same.

koikkara · Answer

lol, i will try again, sorry just a min..

vera_ewing · Answer

ok

koikkara · Answer

i'm sorry, again i got same result... @dan815

vera_ewing · Answer

@dan815

amistre64 · Answer

ive seen this question before ...

(p+q)^2 = pp + 2pq + gg

were p and q are alleles?  and pp, gg, pg are combinations, genotypes maybe?

amistre64 · Answer

and p+q=1

vera_ewing · Answer

I think so, yes ok

amistre64 · Answer

2(.8)(.2) seems to fit for 1960

amistre64 · Answer

hetero is the pq parts

vera_ewing · Answer

Ok so then what?

amistre64 · Answer

so then 2(.8)(.2) should be the solution

amistre64 · Answer

using G and g 

(G+g)^2 = GG + 2Gg + gg, and G+g = 1

in 1960, G = .8, so g=.2

hetero is the Gg term

vera_ewing · Answer

Ohh ok thanks so much.