Who used the frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes and mapped their position on the chromosome?

Options

A. Gregor Mendel
B. Correns
C. Tschemark
D. Alfred Sturtevant

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the scientist who utilized the frequency of recombination between gene pairs on the same chromosome to measure the distance between genes and to map their positions on the chromosome.

2. **Identifying Key Concepts**:
- **Recombination Frequency**: This refers to the likelihood that two genes will be separated during meiosis due to crossing over. The higher the frequency, the further apart the genes are on the chromosome.
- **Chromosomal Mapping**: This is the process of determining the relative positions of genes on a chromosome.

3. **Evaluating the Options**:
- **Gregor Mendel**: Known as the father of genetics, he established the basic principles of heredity but did not specifically map chromosomes.
- **Corance and Tisk Mark**: These names are less commonly associated with chromosomal mapping and are generally recognized for their contributions to genetics but not specifically for mapping.
- **Alphard Sturtevant**: He was an American geneticist who is credited with creating the first genetic map of a chromosome by using recombination frequencies.

4. **Conclusion**: Based on the evaluation of the options, the correct answer is **Alphard Sturtevant**. He is the scientist who used the frequency of recombination to measure the distance between genes and map their positions on chromosomes.

5. **Final Answer**: The scientist who used the frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes and mapped their position on the chromosome is **Alphard Sturtevant**.

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