Let's break down the problem step by step to understand the expected ratio of yellow seeds to green seeds when two pea plants with the given genotypes, [tex]\( \text{Yy} \times \text{yy} \)[/tex], are crossed.
### Step 1: Identify the genotypes of the parent plants
- Parent 1: Yy (Heterozygous, has one dominant allele [tex]\(Y\)[/tex] and one recessive allele [tex]\(y\)[/tex])
- Parent 2: yy (Homozygous recessive, has two recessive alleles [tex]\(y\)[/tex])
### Step 2: Determine the possible alleles each parent can contribute
- Parent 1 (Yy): Can contribute either [tex]\(Y\)[/tex] or [tex]\(y\)[/tex]
- Parent 2 (yy): Can only contribute [tex]\(y\)[/tex]
### Step 3: Determine all possible combinations of the offspring's genotypes
To find the possible genotypes of the offspring, we perform a Punnett square analysis:
[tex]\[
\begin{array}{c|cc}
& y & y \\
\hline
Y & Yy & Yy \\
y & yy & yy \\
\end{array}
\][/tex]
Looking at the Punnett square, we see that the possible genotypes of the offspring are:
- [tex]\(Yy\)[/tex]
- [tex]\(Yy\)[/tex]
- [tex]\(yy\)[/tex]
- [tex]\(yy\)[/tex]
### Step 4: Determine the number of each genotype in the offspring
- Yellow seeds (Yy): 2 occurrences
- Green seeds (yy): 2 occurrences
### Step 5: Calculate the ratio of yellow seeds to green seeds
The ratio of yellow seeds to green seeds is [tex]\(2:2\)[/tex].
### Conclusion
Therefore, the expected ratio of yellow seeds to green seeds in the offspring is [tex]\(2:2\)[/tex]. This matches option C.
So, the correct answer is:
C. [tex]\(2:2\)[/tex]
