Consider a population in which the frequency of allele A is p=0.7 and the frequency of allele a is q=0.3 and where the alleles are codominant. What will be the allele frequencies after one generation if the following occurs?

wAA=0.8, wAa=1, waa=0.8

Video transcript

Hi everyone, welcome back. Here's our next question in a pea plant population of plants. Yellow pods are dominant to green pea pods which are caused by two alleles. If there are 36 green pod plants, what is the frequency of the hetero zaius plants? So as we talk about frequency of various Jenna types, we have our various hardy Weinberg expressions. We have the equation P plus Q equals one where P. And Q. Are the frequency of the alleles. P. Being the frequency of the dominant allele and cue being our frequency of a recessive value. And then when it comes to the jena types, we know that P squared must equal the frequency of the homesickness, dominant genotype. Q. Squared. Is the frequency of the homocide is recessive and two P. Q. Equals the frequency of the Hetero sickos genotype. So as we look at our our question here, we're given the total number of plants in the population were given how many of the green plants we have. And we're looking for the frequency of the Hetero sickos plants. So let's work through what we have and what we need. So we're going to need our values for both P. And Q. Here And we know that green is the recessive phenotype and that we've got 36 green plants. So to show that recessive phenotype they must be home as I guess recessive. So Q. Squared being the frequency of our homes. I guess recessive genotype Q. Squared. Must seek with the frequency of the green pea pod plants. So that would be 36 green plants Out of 100 plants total. And that's going to give us Q. Squared. Which will be equal to 0.36. Take the square root of both sides. And we know that Q. Must equal 0.6. So now we can use our equation P plus Q equals one to solve for P. Because we know that P must equal one minus Q. Which will equal one minus 0.6. And we know that P. The frequency of our dominant allele must equal 0.4. So now we've got P. And Q. We just need to go solve for two P. Q. Which will be two times 0. times 0.6. And we do that. We're gonna get two times .24 or .048. So that 0.0 point 48 number is equal to two P. Q. And therefore is the frequency of the hetero sickos plants. So our answer here will be choice P 0.48. See you in the next video