When pure long plant having white flower is crossed with pure dwarf plant having red flower, the dwarf progeny in `F_(2)` generation is

Options

A. `1//16`
B. `3//16`
C. `4//16`
D. `9//16`

Answer

To solve the problem of determining the dwarf progeny in the F2 generation when a pure long plant with white flowers is crossed with a pure dwarf plant with red flowers, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Traits and Their Dominance**:
- Long plant (tall) is dominant (T) and white flower is recessive (r).
- Dwarf plant is recessive (t) and red flower is dominant (R).

2. **Assign Genotypes to the Parents**:
- Pure long plant with white flowers: Genotype = TTrr (homozygous tall and homozygous white).
- Pure dwarf plant with red flowers: Genotype = ttRR (homozygous dwarf and homozygous red).

3. **Cross the Two Parents to Form F1 Generation**:
- The F1 generation will be obtained by crossing TTrr with ttRR.
- Gametes from the first parent (TTrr): TR (only one type of gamete).
- Gametes from the second parent (ttRR): tR (only one type of gamete).
- F1 genotype: TtRr (heterozygous tall and heterozygous red).

4. **Self-Fertilization of F1 Generation to Form F2 Generation**:
- The F1 plants (TtRr) will self-fertilize.
- The gametes produced by TtRr will be: TR, Tr, tR, tr.

5. **Create a Punnett Square for F2 Generation**:
- Set up a 4x4 Punnett square using the gametes from the F1 generation:
```
| | TR | Tr | tR | tr |
|---|----|----|----|----|
| TR| TTRR| TTRr| TtRR| TtRr|
| Tr| TTRr| TTrr| TtRr| Ttrr|
| tR| TtRR| TtRr| ttRR| ttRr|
| tr| TtRr| Ttrr| ttRr| ttrr|
```

6. **Count the Phenotypes**:
- Tall plants (T): TTRR, TTRr, TtRR, TtRr, TTrr, TtRr (total = 10 tall).
- Dwarf plants (t): Ttrr, ttRr, ttrr (total = 6 dwarf).

7. **Calculate the Ratio of Dwarf Progeny**:
- Total progeny = 16 (from the Punnett square).
- Dwarf progeny = 6.
- Ratio of dwarf progeny = 6/16 = 3/8.

8. **Conclusion**:
- The dwarf progeny in the F2 generation is 6 out of 16, which simplifies to 3/8.

### Final Answer:
The dwarf progeny in the F2 generation is **3/8**.