Name the bacteria which acts as Natural Genetic Engineer.

Explanation

### Step-by-Step Solution

1. **Identify the Bacteria**: The bacteria that acts as a natural genetic engineer is **Agrobacterium tumefaciens**.

2. **Understanding Pathogenic Nature**: Agrobacterium tumefaciens is a pathogenic bacterium that causes disease in several dicot plants. It is known for inducing tumors, specifically a condition called **crown gall**.

3. **Mechanism of Tumor Induction**: This bacterium transforms normal plant cells into tumor cells. It does this through a specific component known as the **T-DNA** (transfer DNA) which is part of the **TI plasmid** (tumor-inducing plasmid).

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