The species used as natural genetic engineer is :

Options

A. Agrobacterium tumefaciens
B. Bacillus thuringiensis
C. Aspergillus
D. Drosophila

Answer

**Step-by-Step Solution:**

1. **Understanding Genetic Engineering**:
- Genetic engineering is the process of transferring DNA from one organism to another. This allows for the introduction of desired traits into an organism.

2. **Identifying Natural Genetic Engineers**:
- The question asks for a species that performs genetic engineering naturally. This implies that we need to find an organism that can transfer its genetic material to another organism without human intervention.

3. **Recognizing the Key Organism**:
- The organism known for its natural genetic engineering capabilities is **Agrobacterium tumefaciens**. This bacterium is a gram-negative soil bacterium that has the ability to transfer DNA to plants.

4. **Mechanism of Action**:
- Agrobacterium tumefaciens contains a plasmid known as the **TI plasmid** (Tumor Inducing plasmid). This plasmid can integrate into the plant's genome, causing tumors (galls) in the plant.

5. **Conclusion**:
- Since Agrobacterium tumefaciens is the only organism among the options that can naturally transfer its genetic material to plants, it is the correct answer to the question.

**Final Answer**: The species used as a natural genetic engineer is **Agrobacterium tumefaciens**.

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