College

We appreciate your visit to A horticulturalist wants to produce geraniums with specific characteristics She knows that the trait of red flowers is governed by the allele tex R RR. This page offers clear insights and highlights the essential aspects of the topic. Our goal is to provide a helpful and engaging learning experience. Explore the content and find the answers you need!

A horticulturalist wants to produce geraniums with specific characteristics.

She knows that the trait of red flowers is governed by the allele [tex]R (RR[/tex] and [tex]Rr)[/tex], and the trait of white flowers is governed by the allele [tex]r (rr)[/tex].

The horticulturalist crosses two geraniums from the F1 generation. The Punnett square demonstrates 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 F2 generation?

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

Answer :

We start by recognizing that the red flower trait is dominant and the white flower trait is recessive. In the F1 generation, each plant has the heterozygous genotype [tex]$Rr$[/tex]. When two [tex]$Rr$[/tex] plants are crossed, their gametes (each carrying either [tex]$R$[/tex] or [tex]$r$[/tex]) combine according to the following Punnett square:

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

This square shows the following genotypes among the offspring (F2 generation):

- [tex]$RR$[/tex] (red) occurs once.
- [tex]$Rr$[/tex] (red) occurs twice.
- [tex]$rr$[/tex] (white) occurs once.

Since both [tex]$RR$[/tex] and [tex]$Rr$[/tex] result in red flowers (because [tex]$R$[/tex] is dominant), there are [tex]$3$[/tex] plants with red flowers and [tex]$1$[/tex] plant with white flowers.

Thus, the ratio of red-flowering plants to white-flowering plants in the F2 generation is:

[tex]$$
3 : 1
$$[/tex]

Thanks for taking the time to read A horticulturalist wants to produce geraniums with specific characteristics She knows that the trait of red flowers is governed by the allele tex R RR. We hope the insights shared have been valuable and enhanced your understanding of the topic. Don�t hesitate to browse our website for more informative and engaging content!

Rewritten by : Barada