In Mirabilis jalapa when homozygous red flowered and white flowered plants are crossed, all `F_(1)` plants have pink coloured flowers. In `F_(2)` produced by selding of `F_(1)` plats, red, pink, white flowered plants would appear respectively in ratio of :-

Options

A. `1:1:2`
B. `2:1:1`
C. `1:0:1`
D. `1:2:1`

Answer

To solve the question regarding the flower color inheritance in Mirabilis jalapa, we need to analyze the genetic crosses involved and apply the principles of incomplete dominance.

### Step-by-Step Solution:

1. **Identify the Parent Plants**:
- We have two homozygous parent plants: one with red flowers (RR) and one with white flowers (rr).

2. **Cross the Parent Plants**:
- When we cross these two plants (RR x rr), all the offspring (F1 generation) will have the genotype Rr.

3. **Determine the Phenotype of F1 Generation**:
- Due to incomplete dominance, the Rr genotype results in a phenotype that is intermediate between the two parents. Therefore, all F1 plants will have pink flowers.

4. **Selfing the F1 Generation**:
- Now, we self the F1 plants (Rr x Rr) to produce the F2 generation.

5. **Use a Punnett Square**:
- Create a Punnett square to determine the genotypes of the F2 generation:
```
R | r
----------------
R | RR | Rr
----------------
r | Rr | rr
```
- From the Punnett square, we can see the genotypes of the offspring:
- 1 RR (Red)
- 2 Rr (Pink)
- 1 rr (White)

6. **Calculate the Phenotypic Ratio**:
- The phenotypic ratio of the F2 generation is:
- Red flowers: 1 (RR)
- Pink flowers: 2 (Rr)
- White flowers: 1 (rr)

7. **Final Ratio**:
- Therefore, the final ratio of red, pink, and white flowers in the F2 generation is 1:2:1.

### Conclusion:
The ratio of red, pink, and white flowered plants in the F2 generation is **1:2:1**.