Find the incorrect statement w.r.t chromosomal mapping

Options

A. Crossing over is important in locating genes on chromosome
B. Recombination frequency depends upon the distance between the genes
C. Recombination frequency is inversely proportional to distance between genes
D. The sequences and relative distances between various genes is graphically represented in term of recombination frequencies

Answer

To find the incorrect statement with respect to chromosomal mapping, we will analyze the statements related to chromosomal mapping and recombination frequency step by step.

### Step-by-Step Solution:

1. **Understanding Chromosomal Mapping**:
- Chromosomal mapping, also known as linkage mapping, is a method used to determine the relative positions of genes on a chromosome. It is a linear representation of the sequence and distance between various genes.

**Hint**: Remember that chromosomal mapping provides a visual representation of gene locations and distances.

2. **Recombination Frequency**:
- The recombination frequency is the measure of the likelihood that two genes will be separated during meiosis due to crossing over. It is directly related to the distance between the genes on the chromosome.

**Hint**: Recombination frequency is crucial for understanding how genes are inherited together or separately.

3. **Distance and Recombination**:
- The greater the distance between two genes, the higher the chance of crossing over occurring between them. This means that genes that are far apart are less likely to be inherited together, leading to a higher recombination frequency.

**Hint**: Think of recombination frequency as a measure of how often genes are shuffled during reproduction.

4. **Evaluating Statements**:
- We need to evaluate the statements provided in the question. The key point to focus on is the relationship between recombination frequency and the distance between genes.

5. **Identifying the Incorrect Statement**:
- If a statement claims that "the recombination frequency is inversely proportional to the distance between the genes," this is incorrect. In reality, the recombination frequency is directly proportional to the distance between the genes.

**Hint**: Look for statements that contradict the established relationship between distance and recombination frequency.

6. **Conclusion**:
- Based on the analysis, the incorrect statement regarding chromosomal mapping is that the recombination frequency is inversely proportional to the distance between the genes. This means that option number 3 is the correct answer to the question.

### Final Answer:
The incorrect statement with respect to chromosomal mapping is: "The recombination frequency is inversely proportional to the distance between the genes."