Distance between the genes and percentage of recombination shows

Options

A. a direct relationship
B. an inverse relationship
C. a parallel relationship
D. no relationship

Explanation

To solve the question regarding the relationship between the distance between genes and the percentage of recombination, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concepts**:
- **Linkage**: This refers to the physical association of genes located on the same chromosome. Genes that are close together tend to be inherited together.
- **Recombination**: This is the process that generates new combinations of alleles (gene variants) through crossing over during meiosis, leading to non-parental gene combinations.

2. **Analyze the Relationship**:
- When genes are located close to each other on a chromosome, they exhibit **linkage** and have a **low recombination frequency**. This means that they are more likely to be inherited together.
- Conversely, when genes are located far apart on a chromosome, they have a **lower linkage** and a **higher recombination frequency**. This indicates that they are more likely to be separated during the process of recombination.

3. **Establish the Direct Relationship**:
- The percentage of recombination is **directly proportional** to the distance between genes. This means that as the distance between genes increases, the percentage of recombination also increases.
- Therefore, we can conclude that there is a direct relationship between the distance between genes and the percentage of recombination.

4. **Select the Correct Answer**:
- Based on the analysis, the correct answer to the question is **A: a direct relationship**.

### Summary:
The distance between genes and the percentage of recombination shows a direct relationship, meaning that as the distance increases, the likelihood of recombination also increases.