How has Ti plasmid been disarmed ?

Explanation

### Step-by-Step Solution:

1. **Understanding Ti Plasmid**: The Ti plasmid, or tumor-inducing plasmid, is a plasmid found in the bacterium Agrobacterium tumefaciens. It is responsible for causing tumors in plants by transferring a specific segment of DNA known as T-DNA into the plant cells.

2. **Identifying the Tumor-Inducing Region**: The T-DNA region of the Ti plasmid contains genes that promote the production of plant hormones (cytokinins and auxins) and opines, which lead to uncontrolled cell division and tumor formation in the host plant.

3. **Disarming the Ti Plasmid**: To create a disarmed Ti plasmid, the tumor-inducing genes within the T-DNA region are removed or altered. This process involves:
- Keeping the left and right border sequences of the T-DNA intact, as they are essential for the integration of DNA into the plant genome.
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