Fruit files are one of the best materials for genetic studies because of all except

Options

A. Ability to grow on simple synthetic medium in the laboratory
B. Short life span
C. Production of a large number of progeny in each mating
D. Presence of few externally visible and identifiable contrasting traits

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks why fruit flies (Drosophila melanogaster) are considered one of the best materials for genetic studies, specifically looking for the option that does not support this claim.

2. **Understand the Characteristics of Drosophila**:
- Drosophila can be easily grown in simple synthetic media.
- They have a short lifespan, completing their life cycle in about 2 weeks.
- They produce a large number of progeny in each mating.
- They exhibit sexual dimorphism, allowing easy differentiation between males and females.
- They have many observable hereditary variations.

3. **Analyze the Options**:
- The options provided likely include statements about the advantages of using Drosophila for genetic studies.
- We need to identify which statement is incorrect regarding their suitability for genetic studies.

4. **Evaluate Each Statement**:
- **Easy to grow**: This is true; Drosophila can be cultured on simple media.
- **Short lifespan**: This is true; they complete their life cycle quickly, allowing for rapid generational studies.
- **Large progeny**: This is true; they produce many offspring, enhancing the sample size.
- **Few externally visible contrasting traits**: This statement is false. Drosophila actually has many identifiable traits, making it easier to observe genetic variations.

5. **Select the Correct Answer**:
- The statement that Drosophila has "few externally visible contrasting traits" is incorrect. Therefore, this is the option that does not support the claim of Drosophila being a good model organism for genetic studies.

6. **Conclusion**: The correct answer is the option that states Drosophila has few externally visible contrasting traits.

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