In a typical monohybrid coss % of `F_(2)` resembling the `F_(1)` phenotypically

Options

A. 100
B. 75
C. 50
D. 25

Answer

To solve the question regarding the percentage of F2 generation resembling the F1 generation phenotypically in a typical monohybrid cross, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Monohybrid Cross**:
- In a monohybrid cross, we typically consider one trait that is controlled by a single gene with two alleles. For example, let’s take the trait for plant height where 'T' (tall) is dominant and 't' (short) is recessive.

2. **Setting Up the Parental Generation (P)**:
- We start with two purebred parents: one homozygous dominant (TT) and one homozygous recessive (tt).

3. **F1 Generation**:
- When these two parents are crossed (TT x tt), all offspring in the F1 generation will be heterozygous (Tt) and will express the dominant phenotype, which is tall.

4. **Selfing the F1 Generation**:
- Next, we self-fertilize the F1 generation (Tt x Tt). This will give us the F2 generation.

5. **Punnett Square for F2 Generation**:
- We can set up a Punnett square to determine the genotypic ratio of the F2 generation:
- Tt (from one parent) crossed with Tt (from the other parent) results in:
- TT (homozygous tall)
- Tt (heterozygous tall)
- Tt (heterozygous tall)
- tt (homozygous short)

6. **F2 Generation Phenotypic Ratio**:
- The resulting phenotypic ratio from the Punnett square is:
- 3 tall (TT or Tt) : 1 short (tt)
- This means 75% of the F2 generation will resemble the F1 generation phenotypically (tall).

7. **Conclusion**:
- Therefore, in a typical monohybrid cross, the percentage of F2 resembling the F1 phenotypically is 75%.

### Final Answer:
The percentage of F2 generation resembling the F1 generation phenotypically in a typical monohybrid cross is **75%**.

---