10. In some cats the gene for tail length shows incomplete dominance. Cats with long tails and cats with no tails are homozygous for their respective alleles. Cats with one long tail allele and one no tail allele have short tails. For each of the following construct a punnett square and give the phenotypic ratios of the offspring.
a) a long tail cat and a cat with no tail
b) a long tail cat and a short tail cat
c) a short tail cat and a cat with no tail
d) two short tail cats.
To construct a punnett square and determine the phenotypic ratios of the offspring for each scenario, we need to understand the inheritance pattern of the gene for tail length. In this case, we have incomplete dominance, meaning that neither allele is completely dominant over the other. Instead, a heterozygous individual will display a phenotype that is intermediate between the two homozygous phenotypes.
Let's assign the following representation for the alleles:
- L: represents the allele for a long tail
- l: represents the allele for no tail
Now, let's analyze each scenario:
a) A long tail cat (LL) and a cat with no tail (ll):
The punnett square for this scenario would be:
| L | l |
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L | LL | Ll |
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l | Ll | ll |
The phenotypic ratio of the offspring would be 1 long tail (LL) : 1 short tail (Ll)
b) A long tail cat (LL) and a short tail cat (Ll):
The punnett square for this scenario would be:
| L | l |
----------------------------------------------------
L | LL | Ll |
----------------------------------------------------
l | Ll | ll |
The phenotypic ratio of the offspring would be 1 long tail (LL) : 2 intermediate/short tails (Ll)
c) A short tail cat (Ll) and a cat with no tail (ll):
The punnett square for this scenario would be:
| L | l |
----------------------------------------------------
l | Ll | ll |
The phenotypic ratio of the offspring would be 1 intermediate/short tail (Ll) : 1 no tail (ll)
d) Two short tail cats (Ll):
The punnett square for this scenario would be:
| L | l |
----------------------------------------------------
l | Ll | ll |
The phenotypic ratio of the offspring would be 0 long tails (LL) : 2 intermediate/short tails (Ll) : 0 no tails (ll)
Remember, these ratios represent the expected outcome of the offspring based on the principles of incomplete dominance and the combination of alleles in the parental cats. Actual results may vary.