When red and white flowered Mirabilis plants are crossed, all pink flowers are produced in `F_(1)` generation. When `F_(1)` progeny is selfed , the expected phenotypic and genotypic ratios are, respectively .

Options

A. `1 : 2 : 1 and 3 : 1`
B. `3 : 1 and 1 : 2 : 1`
C. `1 : 2 : 1 and 1 : 2 : 1`
D. `1 : 1 and 1 : 1: 1`

Answer

To solve the problem regarding the inheritance patterns in Mirabilis plants, we will follow these steps:

### Step 1: Understand the Cross
When red-flowered (RR) and white-flowered (rr) Mirabilis plants are crossed, the result is all pink-flowered (Rr) plants in the F1 generation. This indicates that the trait exhibits incomplete dominance, where neither allele completely masks the other.

**Hint:** Incomplete dominance means that the heterozygous phenotype (Rr) is a blend of the two homozygous phenotypes (RR and rr).

### Step 2: Determine the Genotypes and Phenotypes
In the F1 generation, all plants are pink (Rr). When these F1 plants are selfed (Rr x Rr), we need to determine the possible genotypes of the offspring.

**Hint:** Selfing means crossing an individual with itself, which allows us to see the segregation of alleles.

### Step 3: Use a Punnett Square
To find the genotypic and phenotypic ratios, we can create a Punnett square for the selfing of the F1 generation:

```
R r
------------
R | RR | Rr |
------------
r | Rr | rr |
------------
```

From the Punnett square, we can see the following genotypes:
- 1 RR (red)
- 2 Rr (pink)
- 1 rr (white)

### Step 4: Calculate Genotypic Ratio
The genotypic ratio from the Punnett square is:
- 1 RR : 2 Rr : 1 rr

**Hint:** Count the occurrences of each genotype from the Punnett square to determine the ratio.

### Step 5: Calculate Phenotypic Ratio
The phenotypic ratio is based on the visible traits:
- 1 red (from RR)
- 2 pink (from Rr)
- 1 white (from rr)

Thus, the phenotypic ratio is also:
- 1 red : 2 pink : 1 white

**Hint:** The phenotypic ratio is derived from the traits expressed by the genotypes.

### Step 6: Conclusion
The expected phenotypic and genotypic ratios when the F1 progeny is selfed are both:
- Genotypic ratio: 1 : 2 : 1
- Phenotypic ratio: 1 : 2 : 1

**Final Answer:** The expected phenotypic and genotypic ratios are 1 : 2 : 1 and 1 : 2 : 1, respectively.