Let's work through this problem step by step:
1. Identify the parent genotypes and alleles:
- Both parent plants have the genotype [tex]\( Yy \)[/tex], meaning they each have one dominant allele [tex]\( Y \)[/tex] for yellow seeds and one recessive allele [tex]\( y \)[/tex] for green seeds.
2. Set up a Punnett square to determine possible genotypes of the offspring:
The Punnett square for the cross [tex]\( Yy \times Yy \)[/tex] looks like this:
[tex]\[
\begin{array}{c|c|c}
& Y & y \\
\hline
Y & YY & Yy \\
\hline
y & Yy & yy \\
\end{array}
\][/tex]
3. List the genotypes identified in the Punnett square:
- The possible genotypes of the offspring are [tex]\( YY \)[/tex], [tex]\( Yy \)[/tex], [tex]\( Yy \)[/tex], and [tex]\( yy \)[/tex].
4. Determine the phenotypes associated with each genotype:
- Genotype [tex]\( YY \)[/tex]: Yellow seeds (since it has two dominant [tex]\( Y \)[/tex] alleles).
- Genotype [tex]\( Yy \)[/tex]: Yellow seeds (since it has one dominant [tex]\( Y \)[/tex] allele).
- Genotype [tex]\( Yy \)[/tex]: Yellow seeds (same reason as above).
- Genotype [tex]\( yy \)[/tex]: Green seeds (since it has two recessive [tex]\( y \)[/tex] alleles).
5. Count the number of each phenotype:
- Yellow seeds: [tex]\( YY \)[/tex], [tex]\( Yy \)[/tex], [tex]\( Yy \)[/tex] (total = 3)
- Green seeds: [tex]\( yy \)[/tex] (total = 1)
6. Calculate the ratio of yellow seeds to green seeds:
- The ratio of yellow seeds to green seeds is [tex]\( 3:1 \)[/tex].
Thus, the ratio of yellow seeds to green seeds in the offspring is [tex]\( 3:1 \)[/tex].
The correct answer is:
B. [tex]\( 3:1 \)[/tex]
