To determine the phenotype ratio for the given genetic cross between two cats, let's analyze the Punnett square you provided. The table shows the genetic combinations resulting from the cross:
\begin{tabular}{|c|c|c|}
\hline & [tex]$t$[/tex] & [tex]$t$[/tex] \\
\hline[tex]$T$[/tex] & [tex]$T t$[/tex] & [tex]$T t$[/tex] \\
\hline[tex]$t$[/tex] & [tex]$t t$[/tex] & [tex]$t t$[/tex] \\
\hline
\end{tabular}
Here is the step-by-step breakdown:
1. Identify the possible genotypes from the cross:
- [tex]$Tt$[/tex]: This combination appears twice in the Punnett square.
- [tex]$tt$[/tex]: This combination also appears twice in the Punnett square.
2. Determine the phenotypes associated with each genotype:
- For genotype [tex]$Tt$[/tex] (heterozygous), the cat will have a short tail. This is because the short tail trait ([tex]$T$[/tex]) is dominant over the long tail trait ([tex]$t$[/tex]).
- For genotype [tex]$tt$[/tex] (homozygous recessive), the cat will have a long tail. This is because there is no dominant allele present to mask the recessive trait.
3. Count the occurrences of each phenotype:
- Short tail (dominant phenotype): Occurs twice with the genotype [tex]$Tt$[/tex].
- Long tail (recessive phenotype): Occurs twice with the genotype [tex]$tt$[/tex].
4. Determine the phenotype ratio:
- There are 2 short tails and 2 long tails.
- The phenotype ratio is therefore 2 short tails to 2 long tails.
Thus, the correct answer to the question "What is the phenotype ratio for this cross?" is:
2 short tails : 2 long tails
This corresponds directly to the answer choice that reflects this ratio. None of the multiple-choice options listed (A, B, or C) reflects the correct phenotype ratio. The correct answer should be 2 short tails : 2 long tails, but since this ratio does not match any options given, it might be a correction or addition is needed.
