Achondroplasia is a dominant trait that causes a characteristic form of dwarfism. In a survey of 50,000 births, five infants with achondroplasia were identified. Three of the affected infants had affected parents, while two had normal parents. Calculate the mutation rate for achondroplasia and express the rate as the number of mutant genes per given number of gametes.

Video transcript

Welcome back everyone. Let's look at our next question. In a population of 1000 individuals 160 are homos I guess recessive for a particular trait. What is the frequency of the dominant allele in the population? If the population is in hardy Weinberg equilibrium, let's think through our hardy Weinberg equilibrium, it tells us that when we look at the frequency of values which is what we want that P plus Q equals one P. Would be the frequency of the dominant allele and Q. Would be the frequency of the recessive value. So we're looking for P. Here then we also know that we have our values of peace where'd Q squared and two PQ. Where P squared is the frequency of the homos eidos dominant genotype Q squared is the frequency of the Hamas. Agus recessive phenotype or genotype? Excuse me. And two PQ. Is the frequency of the hetero zegas genotype. So the one that we have and are given is the amount of the homos. I guess recessive genotype. So that's going to be Q squared is what we're given in the problem. So with Q squared we can work our way back to Q. And then two P. Which is the answer that we want in our problem. The frequency of the dominant alley. So let's start with our value of Q squared. Which is the frequency of the homesickness recessive genotype were told that we have 160 individuals that are homeless. I guess recessive out of a total population of 1000. So 1000 is the total population. So that means Q squared is going to equal 0.16. So if we take the square root of both sides, We're going to get the cue. The frequency of the recessive allele is 0.4. So now that we know Q. We can solve for P. By saying that one minus Q must equal P. So 1 -0.4 equals p. which equals 0.6. So p. Which is our frequency of the dominant, A leo Equal 0.6. And if we go over to our answer choices here we see that choice C. is indeed 0.6. So that is our answer. When we have a population of 1000 individuals with 160 homes I guess recessive. What is the frequency of the dominant Alabama population? If it's in hardy Weinberg equilibrium choice C 0.6. See you in the next video.