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------------------------------------------------ A horticulturalist wants to produce geraniums with specific characteristics. She knows that the trait of red flowers is governed by the allele [tex]R[/tex] ([tex]RR[/tex] and [tex]Rr[/tex]), and the trait of white flowers is governed by the allele [tex]r[/tex] ([tex]rr[/tex]).

The horticulturalist crosses two geraniums from the [tex]F_1[/tex] generation. Look at the Punnett square to see this cross.

[tex]
\[
\begin{array}{|c|c|c|}
\hline
& R & r \\
\hline
R & RR & Rr \\
\hline
R & RR & Rr \\
\hline
\end{array}
\]
[/tex]

Which ratio of red-to-white flowering plants would she expect to see in the phenotypes of the [tex]F_2[/tex] generation?

A. all white
B. 2 red to 2 white
C. 3 red to 1 white
D. all red

To solve this problem, we need to understand what is represented in the Punnett square and how it helps us predict the phenotypes of the F2 generation after crossing geraniums.

1. Understanding Alleles and Genotypes:
- The trait for red flowers is governed by the dominant allele [tex]\( R \)[/tex]. This means that both [tex]\( RR \)[/tex] and [tex]\( Rr \)[/tex] genotypes will result in red flowers.
- The trait for white flowers is governed by the recessive allele [tex]\( r \)[/tex]. Only the [tex]\( rr \)[/tex] genotype will result in white flowers.

2. Examining the Punnett Square:
- The Punnett square provided shows the results of crossing two geraniums from the F1 generation.

[tex]\[
\begin{array}{|c|c|c|}
\hline & R & r \\
\hline
R & RR & Rr \\
\hline
R & RR & Rr \\
\hline
\end{array}
\][/tex]

3. Interpreting the Genotypes:
- There's a total of 4 potential outcomes from the crosses: [tex]\(RR, Rr, RR, \text{and } Rr\)[/tex].

4. Counting Phenotypes:
- All the genotypes (both [tex]\( RR \)[/tex] and [tex]\( Rr \)[/tex]) display the red flower trait because they have at least one [tex]\( R \)[/tex].
- There are no [tex]\( rr \)[/tex] genotypes in the Punnett square, so there can be no white flowers produced.

5. Predicting the Phenotypic Ratio:
- Since all the possible outcomes (4 out of 4) show red flowers, the ratio of red to white flowering plants is all red.

Therefore, the horticulturalist would expect to see all red flowering plants in the phenotypes of the F2 generation.