In rabbits, a series of multiple alleles controls coat color in t...

Question

In rabbits, a series of multiple alleles controls coat color in the following way: C is dominant to all other alleles and causes full color. The chinchilla phenotype is due to the c^ch allele, which is dominant to all alleles other than C. The c^h allele, dominant only to (albino), results in the Himalayan coat color. Thus, the order of dominance is C > c^ch > c^h > c^a. For each of the following three cases, the phenotypes of the P₁ generations of two crosses are shown, as well as the phenotype of one member of the F₁ generation.

For each case, determine the genotypes of the P₁ generation and the F₁ offspring, and predict the results of making each indicated cross between F₁ individuals.

Accepted Answer

Hello everyone. Let's look at our next problem. It says in guinea pigs four alleles control of coat color. And the order of dominance is as follows. Big C. Full color is dominant to little C. K. C. P. S. Is dominant to little C. D. Cream is dominant. To see little see a albino. What proportion of the offspring will be albino? If a full color male is crossed with a C. P. A female both of which have one albino parent. So a lot of information thrown at us in this question let's sort out what we need and what we use to get there. So we want to answer what proportion of the offspring will be albino. So to look at proportions of offspring we want to see what we're doing in the parent cross here. So it says our mail is full color with an albino parent. So we know full color. Is this big C. Um a little so we give him that and he has one albino parent. Um Albino is that is the most recessive gene out of all of them. So if the parent was albino the parent had to have been homeless I guess recessive. So this male must have one albino alil. Um Since his parent was home as I guess recessive. So that's a little C. With the superscript A. For the mail on the female that we crossed with is a C. P. A female with an albino parent. So we look at our chart here. The cps. Alil is this little c superscript K. And again the one albino parent must have given a albino alittle here since they must have been home as I guess recessive. So we go we can go ahead and do a little punnett square to look for the proportion of albino offspring we would expect. So we'll just put that over here. We'll put our mail up here. This big C. Little C. A. Our female with her C. P. A. Gene and her albino gene. And we just fill that out and we are looking for what proportion of the offspring will be albino. And we know that would have to be homogeneous recessive for that little C. A. And we see that would be it's one of our squares. So that's going to be 1/4 of our offspring. Which will be choice d. over here. Um Just out of curiosity if you want to see the other, what the other phenotype would be. We see here this big C. Um little C. K. Would be a full color. Same with the one over here because the full color is the most dominant gene here and then you would expect to have one CB offspring? One out of four. Um That didn't inherit that inherited the albino gene from the full color mail. Just out of curiosity there. But again what proportion of the offspring will be out by know in case of this cross would be choice D. One out of four. See you in the next video

Key Concepts

Multiple Alleles

Dominance Hierarchy

Punnett Square

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