A true breeding tall pea plant crossed with the true breeding drawf plant gave `F_(1)` selfing resulted in 787 tall and 277 dwarf plants in `F_(2)` generation. The `F_(1)` plants are

Options

A. Homozygous
B. Heterozygous
C. Azygous
D. Polyzygous

Answer

To solve the problem, we need to analyze the genetic cross between a true breeding tall pea plant and a true breeding dwarf pea plant, and then determine the genotype of the F1 generation.

### Step-by-Step Solution:

1. **Identify the Genotypes of Parent Plants**:
- A true breeding tall pea plant is homozygous for the tall trait, which we can denote as **TT** (where T represents the tall allele).
- A true breeding dwarf pea plant is homozygous for the dwarf trait, denoted as **tt** (where t represents the dwarf allele).

2. **Perform the Cross**:
- When we cross the tall plant (TT) with the dwarf plant (tt), all offspring in the F1 generation will inherit one allele from each parent.
- The resulting genotype of all F1 plants will be **Tt** (heterozygous).

3. **Selfing the F1 Generation**:
- When the F1 plants (Tt) self-fertilize, we can set up a Punnett square to determine the genotypes of the F2 generation.
- The possible combinations from Tt x Tt are:
- TT (homozygous tall)
- Tt (heterozygous tall)
- Tt (heterozygous tall)
- tt (homozygous dwarf)

4. **Determine the Phenotypic Ratio in F2 Generation**:
- The phenotypic ratio from the Punnett square shows:
- 3 Tall (TT and Tt) : 1 Dwarf (tt)
- In the problem, it is given that there are 787 tall plants and 277 dwarf plants in the F2 generation.
- To check the ratio:
- Total plants = 787 + 277 = 1064
- Ratio of tall to dwarf = 787 / 277 ≈ 3 / 1

5. **Conclusion about F1 Generation**:
- Since the F1 generation consists of all heterozygous plants (Tt), we conclude that the F1 plants are **heterozygous**.

### Final Answer:
The F1 plants are **heterozygous (Tt)**.

---