The distacne between the genes on the chromosomes sis measured by using

Options

A. codominance
B. Recombination frequecny
C. Pleiotropy
D. Allele frequency

Answer

To solve the question regarding how the distance between genes on chromosomes is measured, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Genetic Terms**:
- Familiarize yourself with the terms related to genetics, such as co-dominance, pleiotropy, allelic frequency, and recombination frequency. This will help in identifying the correct concept related to measuring distances between genes.

2. **Analyzing the Options**:
- **Co-dominance**: This is when both alleles in a heterozygote contribute to the phenotype. It does not measure distance between genes.
- **Pleiotropy**: This refers to a single gene affecting multiple traits. It is not related to measuring distances between genes.
- **Allelic Frequency**: This is the proportion of a specific allele among all allele copies in a population. It does not measure distances between genes on chromosomes.
- **Recombination Frequency**: This is the frequency at which recombination occurs between two genes during meiosis. It is directly related to the distance between genes on a chromosome.

3. **Identifying the Correct Answer**:
- Based on the analysis, the option that directly relates to measuring the distance between genes is **recombination frequency**. This concept was introduced by Alfred Sturtevant, who explained that the frequency of recombination between two genes can be used to estimate the physical distance between them on a chromosome.

4. **Understanding Recombination Frequency**:
- Recombination frequency is expressed as a percentage. For example, a recombination frequency of 1% corresponds to a distance of 1 map unit (or centiMorgan) between genes on a chromosome.

5. **Conclusion**:
- Therefore, the distance between genes on chromosomes is measured using **recombination frequency**.

### Final Answer:
The distance between the genes on the chromosomes is measured by using **recombination frequency**.

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