The toxin produced by Bacillus thurigiensis gets activated in

Options

A. acidic pH of the stomach.
B. high temperature
C. alkaline pH of the gut.
D. mechanical action in the insect gut.

Answer

**Step-by-Step Solution:**

1. **Understanding Bacillus thuringiensis (Bt):**
- Bacillus thuringiensis is a bacterium that produces insecticidal proteins in the form of crystals during a specific phase of its growth.

2. **Nature of the Toxin:**
- The proteins produced by Bacillus thuringiensis are initially in an inactive form known as pro-toxins. These pro-toxins are not harmful until they are activated.

3. **Activation Process:**
- When an insect ingests the pro-toxin, it enters the insect's gut. The conditions in the gut are crucial for the activation of the toxin.

4. **Role of pH in Activation:**
- The pro-toxins are activated in the alkaline pH environment of the insect gut. This means that the basic (alkaline) conditions are essential for the conversion of the inactive pro-toxin into the active toxin.

5. **Mechanism of Action:**
- Once activated, the toxin binds to the midgut epithelial cells of the insect, creating pores in the cells. This leads to cell swelling and lysis, ultimately resulting in the death of the insect.

6. **Conclusion:**
- Therefore, the correct answer to the question is that the toxin produced by Bacillus thuringiensis gets activated in the alkaline pH of the gut.

**Final Answer:**
- The toxin produced by Bacillus thuringiensis gets activated in: **Alkaline pH of the gut (Option 3).**

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