Why does the Bt toxin not kill the bacterium that produces it but kills the insect that ingests it?

Explanation

### Step-by-Step Solution:

1. **Understanding the Source of Bt Toxin**:
- The Bt toxin is produced by the bacterium *Bacillus thuringiensis*. This bacterium is known for its insecticidal properties.

2. **Mechanism of Action**:
- The Bt toxin is used as an insecticide because it specifically targets certain insects that feed on crops. When these insects ingest the toxin, it leads to their death.

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