Answer :
To solve this problem, let's first understand what the Punnett square tells us about the genetic cross for the geraniums.
The alleles involved are:
- [tex]\( R \)[/tex] for red flowers
- [tex]\( r \)[/tex] for white flowers
The Punnett square for the cross is as follows:
[tex]\[
\begin{array}{|c|c|c|}
\hline
& R & r \\
\hline
R & RR & Rr \\
\hline
r & Rr & rr \\
\hline
\end{array}
\][/tex]
From this Punnett square, we can derive the following genotypes for the offspring:
1. [tex]\( RR \)[/tex]
2. [tex]\( Rr \)[/tex]
3. [tex]\( Rr \)[/tex]
4. [tex]\( rr \)[/tex]
Now, we count the phenotypes:
- Red flowers come from genotypes [tex]\( RR \)[/tex] and [tex]\( Rr \)[/tex].
- White flowers come from genotype [tex]\( rr \)[/tex].
Counting the phenotypes, we have:
- Red flowers (from [tex]\( RR \)[/tex] and [tex]\( Rr \)[/tex]): 3 occurrences (1 [tex]\( RR \)[/tex] and 2 [tex]\( Rr \)[/tex])
- White flowers (from [tex]\( rr \)[/tex]): 1 occurrence
Thus, the ratio of red-to-white flowering plants is 3 red to 1 white. Therefore, the predicted ratio of phenotypes in the F2 generation is 3 red to 1 white.
The alleles involved are:
- [tex]\( R \)[/tex] for red flowers
- [tex]\( r \)[/tex] for white flowers
The Punnett square for the cross is as follows:
[tex]\[
\begin{array}{|c|c|c|}
\hline
& R & r \\
\hline
R & RR & Rr \\
\hline
r & Rr & rr \\
\hline
\end{array}
\][/tex]
From this Punnett square, we can derive the following genotypes for the offspring:
1. [tex]\( RR \)[/tex]
2. [tex]\( Rr \)[/tex]
3. [tex]\( Rr \)[/tex]
4. [tex]\( rr \)[/tex]
Now, we count the phenotypes:
- Red flowers come from genotypes [tex]\( RR \)[/tex] and [tex]\( Rr \)[/tex].
- White flowers come from genotype [tex]\( rr \)[/tex].
Counting the phenotypes, we have:
- Red flowers (from [tex]\( RR \)[/tex] and [tex]\( Rr \)[/tex]): 3 occurrences (1 [tex]\( RR \)[/tex] and 2 [tex]\( Rr \)[/tex])
- White flowers (from [tex]\( rr \)[/tex]): 1 occurrence
Thus, the ratio of red-to-white flowering plants is 3 red to 1 white. Therefore, the predicted ratio of phenotypes in the F2 generation is 3 red to 1 white.