Answer :
Certainly! Let's work through the problem step-by-step to understand the expected ratio of yellow seeds to green seeds in the offspring when crossing plants with genotypes [tex]\( \text{Yy} \)[/tex] and [tex]\( \text{yy} \)[/tex].
### Step-by-Step Solution:
1. Identify the genotypes of the parent plants:
- One parent has the genotype [tex]\( \text{Yy} \)[/tex] (heterozygous for yellow seeds).
- The other parent has the genotype [tex]\( \text{yy} \)[/tex] (homozygous for green seeds).
2. Determine the possible gametes for each parent:
- The [tex]\( \text{Yy} \)[/tex] parent can produce two types of gametes: [tex]\( \text{Y} \)[/tex] (dominant allele) and [tex]\( \text{y} \)[/tex] (recessive allele).
- The [tex]\( \text{yy} \)[/tex] parent can produce only one type of gamete: [tex]\( \text{y} \)[/tex] (recessive allele).
3. Construct the Punnett square to visualize the genetic combinations of the offspring:
```
y y
---------------
Y | Yy | Yy |
---------------
y | yy | yy |
---------------
```
4. Analyze the Punnett square to determine the genotypes of the offspring:
- The combination [tex]\( \text{Y} \)[/tex] from the [tex]\( \text{Yy} \)[/tex] parent and [tex]\( \text{y} \)[/tex] from the [tex]\( \text{yy} \)[/tex] parent results in [tex]\( \text{Yy} \)[/tex] (yellow seeds) for two of the offspring.
- The combination [tex]\( \text{y} \)[/tex] from the [tex]\( \text{Yy} \)[/tex] parent and [tex]\( \text{y} \)[/tex] from the [tex]\( \text{yy} \)[/tex] parent results in [tex]\( \text{yy} \)[/tex] (green seeds) for two of the offspring.
5. Count the number of each genotype:
- There are 2 offspring with the genotype [tex]\( \text{Yy} \)[/tex] (yellow seeds).
- There are 2 offspring with the genotype [tex]\( \text{yy} \)[/tex] (green seeds).
6. Determine the ratio of yellow seeds to green seeds:
- The ratio of yellow seeds to green seeds is [tex]\( 2:2 \)[/tex].
Thus, the expected ratio of yellow seeds to green seeds in the offspring is [tex]\( \boxed{2:2} \)[/tex].
Answer: A. [tex]$2: 2$[/tex]
### Step-by-Step Solution:
1. Identify the genotypes of the parent plants:
- One parent has the genotype [tex]\( \text{Yy} \)[/tex] (heterozygous for yellow seeds).
- The other parent has the genotype [tex]\( \text{yy} \)[/tex] (homozygous for green seeds).
2. Determine the possible gametes for each parent:
- The [tex]\( \text{Yy} \)[/tex] parent can produce two types of gametes: [tex]\( \text{Y} \)[/tex] (dominant allele) and [tex]\( \text{y} \)[/tex] (recessive allele).
- The [tex]\( \text{yy} \)[/tex] parent can produce only one type of gamete: [tex]\( \text{y} \)[/tex] (recessive allele).
3. Construct the Punnett square to visualize the genetic combinations of the offspring:
```
y y
---------------
Y | Yy | Yy |
---------------
y | yy | yy |
---------------
```
4. Analyze the Punnett square to determine the genotypes of the offspring:
- The combination [tex]\( \text{Y} \)[/tex] from the [tex]\( \text{Yy} \)[/tex] parent and [tex]\( \text{y} \)[/tex] from the [tex]\( \text{yy} \)[/tex] parent results in [tex]\( \text{Yy} \)[/tex] (yellow seeds) for two of the offspring.
- The combination [tex]\( \text{y} \)[/tex] from the [tex]\( \text{Yy} \)[/tex] parent and [tex]\( \text{y} \)[/tex] from the [tex]\( \text{yy} \)[/tex] parent results in [tex]\( \text{yy} \)[/tex] (green seeds) for two of the offspring.
5. Count the number of each genotype:
- There are 2 offspring with the genotype [tex]\( \text{Yy} \)[/tex] (yellow seeds).
- There are 2 offspring with the genotype [tex]\( \text{yy} \)[/tex] (green seeds).
6. Determine the ratio of yellow seeds to green seeds:
- The ratio of yellow seeds to green seeds is [tex]\( 2:2 \)[/tex].
Thus, the expected ratio of yellow seeds to green seeds in the offspring is [tex]\( \boxed{2:2} \)[/tex].
Answer: A. [tex]$2: 2$[/tex]
