Which of the following traits are present on the X-Chromosome in Drosophila melanogaster?

Options

A. Eye colour
B. Wing type
C. Body colour
D. All of these

Explanation

To determine which traits are present on the X-Chromosome in Drosophila melanogaster, we can analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Drosophila melanogaster**:
- Drosophila melanogaster, commonly known as the fruit fly, is a widely studied organism in genetics. It belongs to the family Drosophilidae.

2. **Identifying X-linked traits**:
- In Drosophila, many traits are linked to the X chromosome. This means that these traits are inherited in a manner that is dependent on the X chromosome.

3. **Evaluating the options**:
- **Option 1: Eye Color**:
- Eye color in Drosophila was one of the first traits identified as being linked to the X chromosome by Thomas Hunt Morgan in 1910. Therefore, eye color is an X-linked trait.
- **Option 2: Wing Type**:
- Wing type is also known to be influenced by genes located on the X chromosome in Drosophila. Thus, wing type is an X-linked trait.
- **Option 3: Body Color**:
- Similar to eye color and wing type, body color is also determined by genes on the X chromosome. Hence, body color is an X-linked trait.

4. **Conclusion**:
- Since all three traits (eye color, wing type, and body color) are present on the X chromosome in Drosophila melanogaster, the correct answer is **Option 4: All of these**.

### Final Answer:
All of these traits (eye color, wing type, and body color) are present on the X-Chromosome in Drosophila melanogaster.

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