TT Pea plant is crossed to tt plant. `F_(2)` generation will have

Options

A. All tall plants
B. Tall and dwarf in the ratio of 3:1
C. Tall and dwarf in the ratio of 1:2
D. Tall and dwarf in the ratio of 1:1

Answer

To solve the question regarding the F2 generation of a cross between a homozygous tall pea plant (TT) and a homozygous dwarf pea plant (tt), we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Parent Generation**:
- We have two parent plants: one is homozygous tall (TT) and the other is homozygous dwarf (tt).

2. **Determine the F1 Generation**:
- When we cross TT (tall) with tt (dwarf), all offspring in the F1 generation will be heterozygous (Tt). This is because each offspring receives one allele from each parent. Therefore, all F1 plants will be tall since the tall trait (T) is dominant over the dwarf trait (t).

3. **Cross the F1 Generation to Obtain F2**:
- To find the F2 generation, we will cross two F1 plants (Tt x Tt).

4. **Set Up a Punnett Square**:
- Create a Punnett square to visualize the possible genotypes of the F2 generation:
```
T t
------------
T | TT | Tt |
------------
t | Tt | tt |
------------
```

5. **Determine the Genotypic Ratio**:
- From the Punnett square, we can see the following genotypes:
- 1 TT (homozygous tall)
- 2 Tt (heterozygous tall)
- 1 tt (homozygous dwarf)
- The genotypic ratio is therefore 1 TT : 2 Tt : 1 tt.

6. **Determine the Phenotypic Ratio**:
- Since both TT and Tt result in a tall phenotype, we can combine them for the phenotypic ratio:
- 3 Tall (TT and Tt) : 1 Dwarf (tt).
- Thus, the phenotypic ratio is 3:1.

7. **Conclusion**:
- The F2 generation will have a phenotypic ratio of 3 tall plants to 1 dwarf plant.

### Final Answer:
The F2 generation will have a phenotypic ratio of 3 tall : 1 dwarf.

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