Heterozygous tall and violet flowered pea plants were selfed and total 512 seeds are collected. What will be total number of seeds for both heterozygous traits ?

Options

A. 128
B. 256
C. 384
D. 64

Answer

To solve the problem of finding the total number of seeds for both heterozygous traits from the selfing of heterozygous tall and violet flowered pea plants, we can follow these steps:

### Step-by-Step Solution

1. **Identify the Genotypes**:
- The heterozygous tall pea plant can be represented as Tt (where T = tall and t = dwarf).
- The heterozygous violet flowered pea plant can be represented as Pp (where P = violet and p = white).

2. **Determine the Dihybrid Cross**:
- When we self the heterozygous plants TtPp x TtPp, we need to set up a dihybrid cross.
- The expected phenotypic ratio from a dihybrid cross is 9:3:3:1, which corresponds to:
- 9 tall violet (T_P_)
- 3 tall white (T_pp)
- 3 dwarf violet (ttP_)
- 1 dwarf white (ttpp)

3. **Calculate the Total Seeds for Each Phenotype**:
- The total number of seeds collected is 512.
- To find the number of seeds for both heterozygous traits (tall violet), we need to calculate the proportion of seeds that correspond to the tall violet phenotype.
- According to the 9:3:3:1 ratio, the proportion of tall violet seeds is 9 out of 16 total parts.

4. **Calculate the Number of Tall Violet Seeds**:
- The calculation for tall violet seeds is:
\[ \text{Number of tall violet seeds} = \left(\frac{9}{16}\right) \times 512 \]
- This gives:
\[ \text{Number of tall violet seeds} = \frac{9 \times 512}{16} = 288 \]

5. **Calculate the Total Number of Seeds for Both Heterozygous Traits**:
- Since we are interested in the seeds for both heterozygous traits (which are TtPp), we need to consider only the seeds that are heterozygous for both traits.
- The proportion of seeds that are heterozygous for both traits is \( \frac{1}{4} \) of the total seeds.
- Therefore, the number of seeds for both heterozygous traits is:
\[ \text{Number of seeds for both heterozygous traits} = \left(\frac{1}{4}\right) \times 512 = 128 \]

### Final Answer
The total number of seeds for both heterozygous traits is **128**.