By the cross of `F_(1)` linked dihybrid plant with a plant of genotype aabb, we get the 1300 plants out of 2000 of parental type. The distance between A and B gene is :-

Options

A. 35 map unit
B. 15 map unit
C. 65 map unit
D. 65 kilo meter

Answer

To solve the problem of determining the distance between genes A and B based on the given genetic cross, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Total Number of Plants**:
We are given that the total number of plants produced from the cross is 2000.

2. **Identify the Number of Parental Type Plants**:
The number of plants that are of parental type is given as 1300.

3. **Calculate the Number of Recombinant Type Plants**:
To find the number of recombinant plants, we subtract the number of parental type plants from the total number of plants:
\[ \text{Number of Recombinant Plants} = \text{Total Plants} - \text{Parental Type Plants} = 2000 - 1300 = 700 \]

4. **Use the Formula for Genetic Distance**:
The formula to calculate the distance between two genes (in map units) is:
\[ \text{Distance} = \left( \frac{\text{Number of Recombinants}}{\text{Total Progeny}} \right) \times 100 \]

5. **Substitute the Values into the Formula**:
Now we can substitute the values we have into the formula:
\[ \text{Distance} = \left( \frac{700}{2000} \right) \times 100 \]

6. **Calculate the Distance**:
Performing the calculation:
\[ \text{Distance} = \left( 0.35 \right) \times 100 = 35 \text{ map units} \]

7. **Conclusion**:
Therefore, the distance between gene A and gene B is 35 map units.

### Final Answer:
The distance between A and B gene is **35 map units**.

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