During organ differentiation in Drosophila, an organ is modified to another organ (such as wings may be replaced by legs). Genes responsible for such metamorphosis are called

Options

A. double dominant genes
B. plastid genes
C. complementary genes
D. homeotic genes

Explanation

To solve the question regarding the genes responsible for organ differentiation in Drosophila, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the genes that are responsible for the transformation of one organ into another during the development of Drosophila, specifically mentioning the example of wings being replaced by legs.

2. **Identifying Key Terms**: The key terms in the question are "organ differentiation," "Drosophila," and "metamorphosis." This indicates that we are looking for genes that play a crucial role in the developmental processes of this organism.

3. **Analyzing the Options**: The options given are:
- Double dominant gene
- Plastid gene
- Complementary gene
- Haematic gene

4. **Understanding Haematic Genes**: Upon reviewing the options, we need to focus on the term "haematic gene." These genes are also referred to as "homeotic genes." Homeotic genes are known to control the identity of body parts and are crucial in determining the formation of organs during development.

5. **Conclusion**: Based on the understanding that homeotic genes (haematic genes) are responsible for the metamorphosis and differentiation of organs in organisms like Drosophila, we conclude that the correct answer is **Haematic gene**.

### Final Answer:
Haematic gene

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