Sex-linked inheritance was discovered by

Options

A. Tjio and Levan in human
B. T.H. Morgan in Drosophila
C. Haldane through pedigree analysis in human
D. H.J. Muller in Drosophila

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks who discovered sex-linked inheritance. This refers to the inheritance patterns of traits that are associated with genes located on sex chromosomes.

2. **Identifying the Options**: The options provided are:
- T. Joe Unlevin in Humans
- T.H. Morgan in Drosophila
- Haldane through pedigree analysis in Humans
- H. J. Muller in Drosophila

3. **Analyzing the Options**:
- **T. Joe Unlevin**: While he contributed to genetics, he is not known for discovering sex-linked inheritance.
- **T.H. Morgan**: He is a prominent figure in genetics and is known for his work with Drosophila (fruit flies). He discovered the concept of sex-linked inheritance.
- **Haldane**: He made significant contributions to population genetics but did not discover sex-linked inheritance.
- **H. J. Muller**: He is known for his work on mutations but not specifically for sex-linked inheritance.

4. **Conclusion**: Based on the analysis, T.H. Morgan is the correct answer. He discovered sex-linked inheritance while studying Drosophila melanogaster (fruit flies) and demonstrated the concept of crisscross inheritance.

5. **Final Answer**: The correct answer is **T.H. Morgan in Drosophila**.

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