In Mirabilis jalapa when two `F_(1)` pink flowered plants were crossed with each other, the `F_(2)` generation produced 40 red, 80 pink and 40 white flowering plants. This is a case of

Options

A. Duplicate genes
B. Lethal genes
C. Incomplete dominance
D. Epistasis

Answer

To solve the question regarding the inheritance pattern observed in Mirabilis jalapa, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Parental Traits**:
- In Mirabilis jalapa, the flower color can be red (R) or white (W).
- When red and white flowers are crossed, the resulting offspring (F1 generation) exhibit pink flowers.

2. **Understanding F1 Generation**:
- The F1 generation consists of all pink-flowered plants. This indicates that the red and white alleles exhibit incomplete dominance, where neither allele is completely dominant over the other.

3. **Crossing F1 Generation**:
- When two F1 pink-flowered plants (RW) are crossed, the possible gametes they can produce are R (red) and W (white).
- The cross can be represented as:
```
RW (from first parent)
RW (from second parent)
```

4. **Punnett Square Analysis**:
- Construct a Punnett square to visualize the potential genotypes of the F2 generation:
```
R W
------------
R | RR RW
------------
W | RW WW
```
- The genotypes from this cross are:
- RR (Red) = 1
- RW (Pink) = 2
- WW (White) = 1

5. **Phenotypic Ratio**:
- The phenotypic ratio from the Punnett square is:
- Red: Pink: White = 1: 2: 1
- In the F2 generation, the observed numbers are:
- 40 Red
- 80 Pink
- 40 White
- This confirms the 1:2:1 ratio.

6. **Conclusion**:
- Since the F2 generation shows a blending of traits (red, pink, and white), this is a clear case of **incomplete dominance**.

### Final Answer:
This is a case of **incomplete dominance**.

---