What will be the phenotypic ratio of offsprings of `F_(2)` generation obtained by selfing of `F_(1)` plant having AABbCC genotype

Options

A. `3:1`
B. `1:1`
C. `0:3:3:1`
D. `27:9:9:9:3:3:3:1`

Answer

To determine the phenotypic ratio of the offspring in the F2 generation from selfing an F1 plant with the genotype AABbCC, we can follow these steps:

### Step 1: Identify the Genotype of the F1 Plant
The F1 plant has the genotype AABbCC. This means:
- **A**: Homozygous dominant (AA)
- **B**: Heterozygous (Bb)
- **C**: Homozygous dominant (CC)

### Step 2: Determine Gametes Produced by the F1 Plant
The F1 plant can produce the following gametes based on its genotype:
- From AA, it can only produce A.
- From Bb, it can produce either B or b.
- From CC, it can only produce C.

Thus, the possible gametes from the F1 plant are:
- ABC
- AbC

### Step 3: Perform the Selfing of the F1 Plant
When we self the F1 plant (ABC x AbC), we can set up a Punnett square to visualize the offspring's genotypes.

| | ABC | AbC |
|------|-----|-----|
| **ABC** | AABBC | AABbC |
| **AbC** | AABbC | AAbbC |

### Step 4: Determine the Genotypes of the Offspring
From the Punnett square, the genotypes of the offspring are:
1. AABBC
2. AABbC
3. AABbC
4. AAbbC

### Step 5: Identify the Phenotypes
Now, we need to determine the phenotypes based on the dominant and recessive traits:
- AABBC: Phenotype A (dominant)
- AABbC: Phenotype A (dominant)
- AABbC: Phenotype A (dominant)
- AAbbC: Phenotype A (dominant)

Since all offspring have at least one dominant A allele, they will all express the dominant phenotype for A. The B gene is heterozygous in two cases (AABbC) and homozygous recessive in one case (AAbbC), but since A is dominant, it will not affect the overall phenotype ratio.

### Step 6: Conclusion
Since all offspring express the dominant phenotype for A, the phenotypic ratio is:
- Phenotype A: 4
- Phenotype a: 0

Thus, the phenotypic ratio is 4:0 or simply 1:0.

### Final Answer
The phenotypic ratio of the offspring of the F2 generation obtained by selfing the F1 plant with genotype AABbCC is **4:0** (or 1:0).

---