In flies, small wings are recessive to normal wings. If a cross between two flies produces 8 small-wing offspring and 28 normal-wing offspring, what are the most likely genotypes of the parents? (Use S to represent the normal-wing allele and s to represent the short-wing allele.)

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Hello, everyone. And in today's video we have the following problem. So across of a red flower plant with a white flower plant produces F one offspring in a 1 to 1 ratio assuming that the red flower, a leo is dominant or completely dominant over the white flour. A leo predict the parents genotype. Now, since we have a white flower plant and we say that the red flower plant is completely dominant over it, the white flower plant must be recessive, so the genotype for it must be are are all in lower case as we see here. So we already have the genotype for one of the parents. So let's look at over answer choices and see which answer choice does not have this genotype. So what we can cancel it out and look at our answer choices, Answer choice B. Does not have the completely recessive genotype, so we're going to cancel it out. Now we're also told that the red flower plant is completely dominant over the white flower plant. So it must be either homo sagas dominant or hetero cis. So either one of these two must be the red flower plant. Let's look over answer choices and see which answer choice does not have either a homosexual or a heterosexual. That we can cancel it out. And as we can see answer choice C. Does not have any of these. So we can cancel this out as well, leaving as we answer choice D. And a which have either the heterocyclic dominant or the homosexual. As dominant as we see here. So we need to pick between those two. There's no way of knowing which one it is without just off the bat. We need to run punnett squares in order to determine this or which leo when mixed with the recessive or the homo cycles recessive will yield and 1 to 1 ratio. So let's run these tests so that we can determine this. First of all, let's mix the homo cycles recessive with the homo cycles dominant males in this palace square. And we're going to receive only hetero cycles organisms as we see here. Since these are a leo is dominant, this is going to be 100% red. So this is not going to be or it's not going to yield the 1 to 1 ratio or the 50 50 ratio that we're looking for. So it has to be this a leo. Let's run the punnett square so that we can confirm this as we can see, this is going to be to the are white and to the are red. So it is going to be 50% white and 50% red. This is the 1 to 1 ratio that we're looking for. So this must be the ceo of the red plant. Now this a little combination is represented by answer choice. So we're going to highlight that as the final answer to our question. I really hope this video helped you and I hope to see you on the next one

In flies, small wings are recessive to normal wings. If a cross between two flies produces 8 small-wing offspring and 28 normal-wing offspring, what are the most likely genotypes of the parents? (Use S to represent the normal-wing allele and s to represent the short-wing allele.)

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Key Concepts

Mendelian Genetics

Genotype and Phenotype

Punnett Square