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Question number one.
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In menx cat, the allele homozygous dominant t yield a cat with normal long tail and heterozygous yield a cat with short or absent tail.
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And the allele homozygous lower t are lethal to embryo.
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Predict the genotype and phenotype of a potential kitten result from a mating of two short tail cats.
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So we know that long tail has a genotype of homozygous capital t.
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And short is heterozygous.
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And there is not going to be any homozygous lower t lethal.
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Now we have a mating between two short tail cats.
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So the mating is going to be t lower t capital t heterozygous.
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Now let's do a punnett square.
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So male has heterozygous as well.
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So both female and male parent will be heterozygous.
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This is the parent.
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Now the f1 is the offspring.
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So the two alleles separate from each other.
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So for each parent you produce two different alleles capital t and lower t.
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You're going to do your punnett square.
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So you put the two alleles on top and side.
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And then you put the two alleles back together.
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So you can see for f1 generation, the offspring, one fourth is going to be homozygous capital t, half heterozygous, and one fourth homozygous lower t.
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So due to the homozygous lower t being lethal, this one will never be able to be born.
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So you only have three.
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So this means that you have one third of the offspring homozygous capital t long tail and two third heterozygous short tail.
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And the last one homozygous lower t will never be born.
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So this is the first question.
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Second question, american cat breeder are trying to establish new breed of cat with unusual curl back ear to be known as the curl cat.
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Suppose you find a curl cat that wanted to secretly start your own population.
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How would you determine whether the curl allele is dominant or recessive? how would you establish to maintain a true breed population based on whether the allele is dominant or recessive? so let's say the curl allele, we call this c.
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So there are two different ways to do this.
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If curl is dominant, and then you cross a curl cat true breed with a wild type cat, a normal.
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So let's say the curl cat is homozygous capital c and wild type homozygous lower c.
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Now all f1 is going to pick up one allele from each of the parents, capital c lower c.
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So this means that you have one capital c allele.
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This is going to be a curl.
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So from there, we know it's dominant.
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The same thing if curl is recessive.
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And in that case, you'll have to have homozygous lower c crossed with capital c.
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Now, the f1 is going to be capital c lower c f1.
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Now you have a dominant allele, it's going to show dominant phenotype.
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So if it's a wild, all f1 are wild type, then you know that the wild type is dominant to the curl, it's recessive.
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So this is the predicted result.
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By looking at the cross between curl and wild type by looking at many f1, you can make your decision.
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If f1 show all curl, then it's dominant.
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If f1 show a wild type, it's recessive.
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Now how do you establish and maintain a true breed population based on whether the allele is dominant or recessive? if recessive, then to maintain a pure stock, you will have to mate curl cat with another curl cat, because both will have homozygous lower c.
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And only when you have both curl, then all f1 will have curl homozygous lower c.
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Now if it's a dominant allele, you'll have to make sure if the curl cat is heterozygous or homozygous, because both will show curl.
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So if you want to have a true breed, then you'll have to mate a curl cat with a wild type cat, which is recessive homozygous.
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So this one is, we don't know.
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So now this is a test cross.
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Basically you have a known, a, well, i guess a curl cat, we know it's a dominant phenotype, but we do not know the genotype.
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It could be homozygous capital c or heterozygous...