To determine the phenotype ratio for the given cross, we can start by analyzing the Punnett square provided. The parents have genotypes [tex]$Tt$[/tex] (one dominant allele for short tails, and one recessive allele for long tails) and [tex]$tt$[/tex] (both recessive alleles for long tails). Here’s the Punnett square again for reference:
[tex]\[
\begin{tabular}{|c|c|c|}
\hline & $T$ & $t$ \\
\hline $t$ & \( Tt \) & \( tt \) \\
\hline $t$ & \( Tt \) & \( tt \) \\
\hline
\end{tabular}
\][/tex]
From the Punnett square, we can see the following combinations of genotypes:
- 1 box with [tex]\( Tt \)[/tex] (short tails)
- 1 box with [tex]\( tt \)[/tex] (long tails)
- 1 box with [tex]\( Tt \)[/tex] (short tails)
- 1 box with [tex]\( tt \)[/tex] (long tails)
This means we end up with:
- 2 boxes of [tex]\( Tt \)[/tex] (short tails because [tex]\( T \)[/tex] is dominant)
- 2 boxes of [tex]\( tt \)[/tex] (long tails because both alleles are recessive)
To find the phenotype ratio, we count the number of offspring with each phenotype:
- Short tails: 2 (both [tex]\( Tt \)[/tex])
- Long tails: 2 (both [tex]\( tt \)[/tex])
Therefore, the phenotype ratio for this cross is:
[tex]\[ \boxed{\text{2 long : 2 short}} \][/tex]
In simplified terms, the ratio is 2 long to 2 short. Looking at the provided options:
A. 1 long, 3 short
B. 4 long, 0 short
C. 2 long, 2 short
D. 3 long, 1 short
The correct choice is:
[tex]\[ \boxed{\text{C. 2 long, 2 short}} \][/tex]
