To determine the ratio of yellow seeds to green seeds in the offspring of two pea plants, both having the genotype [tex]\( Yy \)[/tex], we can follow these steps:
1. Determine Possible Gametes:
- Each parent plant can produce two kinds of gametes: one carrying the dominant allele [tex]\( Y \)[/tex] and one carrying the recessive allele [tex]\( y \)[/tex].
2. Create a Punnett Square:
- To find all possible genotypes of the offspring, we use a Punnett square, which will help us visualize the combinations of the alleles from the two parents.
[tex]\[
\begin{array}{c|cc}
& Y & y \\
\hline
Y & YY & Yy \\
y & Yy & yy \\
\end{array}
\][/tex]
3. List All Possible Genotypes:
- The Punnett square reveals the following potential genotypes for the offspring:
- [tex]\( YY \)[/tex] (Yellow)
- [tex]\( Yy \)[/tex] (Yellow)
- [tex]\( Yy \)[/tex] (Yellow)
- [tex]\( yy \)[/tex] (Green)
4. Determine Phenotype Ratios:
- Since allele [tex]\( Y \)[/tex] is dominant, both [tex]\( YY \)[/tex] and [tex]\( Yy \)[/tex] will result in yellow seeds, whereas [tex]\( yy \)[/tex] will result in green seeds.
5. Count Phenotypes:
- Out of the four possible outcomes:
- There are three combinations that produce yellow seeds ([tex]\( YY, Yy, Yy \)[/tex]).
- There is one combination that produces green seeds ([tex]\( yy \)[/tex]).
6. Calculate the Ratio:
- The ratio of yellow seeds to green seeds is [tex]\( 3:1 \)[/tex].
Therefore, the correct answer is [tex]\( \boxed{3:1} \)[/tex].
