The monohybrid genotypic ratio 1:2:1 in `F_(2)` generation indicates

Options

A. Segeration
B. Independent assortment
C. Dominance
D. Incomplete dominance

Answer

To solve the question regarding the monohybrid genotypic ratio of 1:2:1 in the F2 generation, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Monohybrid Cross**:
- A monohybrid cross involves a single trait that is being studied, where one allele is dominant and the other is recessive. For example, let’s consider the trait for plant height where 'T' (tall) is dominant and 't' (dwarf) is recessive.

2. **Formation of F1 Generation**:
- When two purebred plants (TT and tt) are crossed, all offspring in the F1 generation will be heterozygous (Tt) and will express the dominant trait (tall).

3. **Self-Crossing F1 Generation**:
- When the F1 generation (Tt) is self-crossed (Tt x Tt), we can use a Punnett square to determine the genotypes of the F2 generation.

4. **Punnett Square Analysis**:
- The Punnett square for Tt x Tt would yield the following combinations:
- TT (homozygous dominant)
- Tt (heterozygous)
- Tt (heterozygous)
- tt (homozygous recessive)
- This results in the genotypic ratio of 1 TT : 2 Tt : 1 tt.

5. **Identifying the Genotypic Ratio**:
- The genotypic ratio of 1:2:1 indicates the segregation of alleles during gamete formation. Each allele segregates independently into gametes, which is a key principle in Mendelian genetics.

6. **Conclusion**:
- The monohybrid genotypic ratio of 1:2:1 in the F2 generation indicates the phenomenon of segregation, where alleles segregate during gamete formation.

### Final Answer:
The correct answer is **a. segregation**.

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