Sex linkage first observed by

Options

A. Bateson
B. Correns
C. Morgan
D. Muller

Answer

**Step-by-Step Solution:**

1. **Understanding the Concept of Sex Linkage**:
- Sex linkage refers to the association of a gene with a sex chromosome. Traits that are linked to sex chromosomes are inherited differently in males and females.

2. **Identifying Key Scientists in Genetics**:
- Several scientists have contributed to the field of genetics, but we need to focus on those who specifically studied sex linkage.

3. **Reviewing Historical Contributions**:
- Thomas Hunt Morgan is a prominent figure in genetics, known for his work with fruit flies (Drosophila melanogaster). He conducted experiments that led to the discovery of sex-linked traits.

4. **Confirming Morgan's Contribution**:
- Morgan's experiments demonstrated that certain traits were inherited together with sex chromosomes, which provided evidence for the concept of sex linkage.

5. **Selecting the Correct Answer**:
- Based on the information gathered, the first scientist to observe and describe sex linkage is Thomas Hunt Morgan.

**Final Answer**: The first to observe sex linkage was Thomas Hunt Morgan (Option C).

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