If recombination frequency between AB genes a `20%` and `BC` gene is `40%` and interference is `30%` in the case of double cross over than what will be coincidance under this condition ?

Options

A. 2.4
B. 8
C. 5.6
D. 0.7

Answer

To solve the problem, we need to calculate the coefficient of coincidence using the given information about recombination frequency and interference. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Definitions
- **Recombination Frequency**: This is the percentage of offspring that have a different combination of alleles than their parents due to crossing over.
- **Interference**: This is the phenomenon where one crossover event inhibits the occurrence of another crossover event nearby.
- **Coefficient of Coincidence**: This is a measure of the actual number of double crossovers that occur compared to the expected number, calculated as:

\[ \text{Coefficient of Coincidence} = 1 - \text{Interference} \]

### Step 2: Identify Given Values
- Recombination frequency between AB genes = 20% (0.20)
- Recombination frequency between BC genes = 40% (0.40)
- Interference = 30% (0.30)

### Step 3: Calculate the Coefficient of Coincidence
Using the formula for the coefficient of coincidence:

\[ \text{Coefficient of Coincidence} = 1 - \text{Interference} \]

Substituting the given interference value:

\[ \text{Coefficient of Coincidence} = 1 - 0.30 = 0.70 \]

### Step 4: Conclusion
The coefficient of coincidence under the given conditions is **0.70**.

### Final Answer
**The coincidence under this condition is 0.70.**

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