In case of incomplete dominance, `F_(2)` generation has

Options

A. Genotypic ratio equal to phenotypic ratio
B. Genotypic ratio is 3:1
C. Phenotypic ratio is 3:1
D. None of the above

Answer

To solve the question regarding the F2 generation in the case of incomplete dominance, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Incomplete Dominance**:
- Incomplete dominance occurs when the dominant allele does not completely mask the effects of the recessive allele. Instead, a blending of traits occurs, resulting in a third phenotype.

2. **Example of Incomplete Dominance**:
- A classic example is the cross between red and white snapdragon flowers.
- If we denote the red allele as 'R' and the white allele as 'r', the genotypes would be:
- RR (homozygous red)
- rr (homozygous white)
- Rr (heterozygous pink)

3. **F1 Generation**:
- When we cross RR (red) with rr (white), all F1 offspring will be Rr (pink).
- This demonstrates that the red allele does not completely dominate over the white allele.

4. **F2 Generation**:
- Now, if we self-fertilize the F1 generation (Rr x Rr), we can use a Punnett square to determine the genotypes of the F2 generation.
- The possible combinations will be:
- RR (red)
- Rr (pink)
- rr (white)

5. **Genotypic Ratio in F2 Generation**:
- The genotypic ratio from the Punnett square will be:
- 1 RR : 2 Rr : 1 rr
- This gives a total of 4 genotypes, leading to a genotypic ratio of 1:2:1.

6. **Phenotypic Ratio in F2 Generation**:
- The phenotypes will be:
- 1 red (RR) : 2 pink (Rr) : 1 white (rr)
- This results in a phenotypic ratio of 1:2:1.

7. **Conclusion**:
- In incomplete dominance, the genotypic ratio (1:2:1) is equal to the phenotypic ratio (1:2:1), which is different from complete dominance where the phenotypic ratio is typically 3:1.

### Final Answer:
In the case of incomplete dominance, the F2 generation has a genotypic ratio of 1:2:1 and a phenotypic ratio of 1:2:1.