A hybrid round and yellow seeded plant is selfed and total 32 seeds are obtained. How many seeds are wrinkled green ?

Options

A. 18
B. 6
C. 10
D. 2

Answer

To solve the problem of determining how many wrinkled green seeds are obtained from a hybrid round and yellow seeded plant that is selfed, we can follow these steps:

### Step 1: Define the Alleles
- Let **R** represent the allele for round seeds (dominant).
- Let **r** represent the allele for wrinkled seeds (recessive).
- Let **Y** represent the allele for yellow seeds (dominant).
- Let **y** represent the allele for green seeds (recessive).

### Step 2: Determine the Genotype of the Parent Plant
Since the plant is described as hybrid for both traits (round vs. wrinkled and yellow vs. green), its genotype will be:
- **RrYy** (heterozygous for both traits).

### Step 3: Selfing the Hybrid Plant
When the hybrid plant (RrYy) self-fertilizes, we can determine the possible gametes produced by this plant:
- Possible gametes: **RY, Ry, rY, ry**.

### Step 4: Set Up a Punnett Square
To find the offspring's genotypes, we will create a Punnett square using the gametes from both parents (since both are RrYy):
```
RY Ry rY ry
____________________________
RY | RRYY | RRYy | RrYY | RrYy |
|____________________________|
Ry | RRYy | RRyy | RrYy | Rryy |
|____________________________|
rY | RrYY | RrYy | rrYY | rrYy |
|____________________________|
ry | RrYy | Rryy | rrYy | rryy |
|____________________________|
```

### Step 5: Count the Offspring Genotypes
From the Punnett square, we can identify the genotypes and their corresponding phenotypes:
- **Round Yellow (R_Y)**: RRYY, RRYy, RrYY, RrYy (9 total)
- **Round Green (R_yy)**: RRYy, Rryy (3 total)
- **Wrinkled Yellow (rrY_)**: RrYY, RrYy (3 total)
- **Wrinkled Green (rryy)**: rryy (1 total)

### Step 6: Calculate the Ratio of Phenotypes
From the Punnett square, we can see the phenotypic ratio:
- Round Yellow: 9
- Round Green: 3
- Wrinkled Yellow: 3
- Wrinkled Green: 1

This gives a total of 16 offspring.

### Step 7: Calculate the Number of Wrinkled Green Seeds
The proportion of wrinkled green seeds (rryy) is 1 out of 16. Given that there are 32 seeds in total:
- Number of wrinkled green seeds = (1/16) * 32 = 2.

### Final Answer
Thus, the number of wrinkled green seeds obtained is **2**.

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