The phenotypic and genotypic ratios remain same in F, generation in case of

Options

A. dihybrid cross
B. supplementary genes
C. incomplete dominance
D. inhibitory genes

Answer

To solve the question regarding when the phenotypic and genotypic ratios remain the same in the F2 generation, we can follow these steps:

### Step-by-Step Solution

1. **Understanding the F2 Generation**: The F2 generation is the result of crossing two F1 individuals. In genetic crosses, we analyze the ratios of phenotypes (observable traits) and genotypes (genetic makeup).

2. **Identify Types of Genetic Crosses**: There are various types of genetic crosses, such as:
- Monohybrid Cross
- Dihybrid Cross
- Incomplete Dominance
- Codominance
- Epistasis

3. **Analyze Monohybrid Cross**: In a monohybrid cross (e.g., Aa x Aa), the phenotypic ratio is 3:1 and the genotypic ratio is 1:2:1. Here, the ratios are not the same.

4. **Analyze Dihybrid Cross**: In a dihybrid cross (e.g., AaBb x AaBb), the phenotypic ratio is 9:3:3:1 and the genotypic ratio is 1:2:1:2:4:1. Again, the ratios are not the same.

5. **Analyze Incomplete Dominance**: In incomplete dominance (e.g., in Mirabilis jalapa), the phenotypic ratio is 1:2:1, and the genotypic ratio is also 1:2:1. Here, the ratios are the same.

6. **Conclusion**: The phenotypic and genotypic ratios remain the same in the F2 generation specifically in cases of incomplete dominance.

### Final Answer
The phenotypic and genotypic ratios remain the same in the F2 generation in the case of **incomplete dominance**.