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.

Answer

**Step-by-Step Solution:**

1. **Understanding the Concept of Gene Distance and Recombination:**
- Genes are located on chromosomes, and their physical distance can affect how often they are inherited together. The concept of recombination refers to the process where genetic material is exchanged between homologous chromosomes during meiosis.

2. **Defining Recombination Frequency:**
- Recombination frequency is the percentage of offspring that exhibit a combination of traits different from either parent due to crossing over. This frequency is used to estimate the distance between genes on a chromosome.

3. **Analyzing the Relationship:**
- When two genes are located close to each other on a chromosome, they are said to be linked. This means they are less likely to be separated by recombination during meiosis. Therefore, the recombination frequency between them is low.
- Conversely, if two genes are far apart on a chromosome, they are more likely to be separated by recombination, leading to a higher recombination frequency.

4. **Establishing the Direct Relationship:**
- As the distance between the genes increases, the likelihood of recombination occurring between them also increases. This establishes a direct relationship: greater distance leads to higher recombination frequency.

5. **Conclusion:**
- Based on the analysis, the relationship between the distance between genes and the percentage of recombination is a direct relationship. Therefore, the correct answer is option one: a direct relationship.