Tall(T) is completely dominant over dwarf(t). Red flower colour ( R) is incompletely dominant over white ( r), the heterozygous being pink. Plant having genotype of TrRr is self pollinated. What would be the proportion of plants with dwarf and pink characters in the progeny

Options

A. `2//16`
B. `1//16`
C. `9//16`
D. `3//16`

Answer

To solve the problem, we need to determine the proportion of plants with dwarf and pink characters in the progeny of a self-pollinated plant with the genotype TrRr.

### Step-by-Step Solution:

1. **Identify the Genotypes**:
- The plant has the genotype TrRr, where:
- T (tall) is completely dominant over t (dwarf).
- R (red flower) is incompletely dominant over r (white flower), resulting in pink flowers for the heterozygous genotype Rr.

2. **Determine Gametes**:
- When the plant TrRr is self-pollinated, it can produce four types of gametes:
- TR (Tall, Red)
- Tr (Tall, white)
- rR (Dwarf, Red)
- tr (Dwarf, white)

3. **Set Up a Punnett Square**:
- Create a 4x4 Punnett square to visualize the combinations of the gametes.
- The gametes from one parent (TrRr) are placed along the top and the gametes from the other parent (TrRr) along the side.

4. **Fill in the Punnett Square**:
- Fill in the squares with the combinations of alleles:
- TR x TR = TTRR (Tall, Red)
- TR x Tr = TTRr (Tall, Pink)
- TR x rR = TtRR (Tall, Red)
- TR x tr = TtRr (Tall, Pink)
- Tr x TR = TTRr (Tall, Pink)
- Tr x Tr = TtRr (Tall, Pink)
- Tr x rR = TtRr (Tall, Pink)
- Tr x tr = Ttrr (Tall, White)
- rR x TR = TtRR (Tall, Red)
- rR x Tr = TtRr (Tall, Pink)
- rR x rR = Ttrr (Dwarf, Red)
- rR x tr = Ttrr (Dwarf, White)
- tr x TR = TtRr (Tall, Pink)
- tr x Tr = Ttrr (Dwarf, White)
- tr x rR = Ttrr (Dwarf, Red)
- tr x tr = ttrr (Dwarf, White)

5. **Count the Phenotypes**:
- From the filled Punnett square, we can count the phenotypes:
- Tall Red: 6
- Tall Pink: 6
- Dwarf Red: 2
- Dwarf Pink: 2
- Dwarf White: 2

6. **Calculate the Proportion**:
- The total number of plants = 16.
- The number of plants that are dwarf and pink = 2.
- Therefore, the proportion of dwarf and pink plants in the progeny = 2/16 = 1/8.

### Final Answer:
The proportion of plants with dwarf and pink characters in the progeny is **1/8**.