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**: Bacillus thuringiensis (Bt) is a bacterium known for producing a toxin that is harmful to certain insects.

2. **Formation of Protein Crystals**: During a specific phase of its growth, Bacillus thuringiensis forms protein crystals that contain insecticidal proteins, also known as insecticidal toxins.

3. **Ingestion by Insects**: These protein crystals are in an inactive form when produced. When an insect ingests these crystals, they enter the insect's digestive system.

4. **Activation in the Insect Gut**: The gut of the insect has an alkaline pH. This alkaline environment is crucial because it activates the inactive protein crystals, converting them into active toxins.

5. **Mechanism of Action**: Once activated, the toxins create pores in the gut cells of the insect, leading to swelling and ultimately causing lysis (breakdown) of the cells.

6. **Effect on the Insect**: The breakdown of gut cells results in the death of the insect, making Bacillus thuringiensis an effective biological control agent against certain pests.

7. **Conclusion**: Therefore, the toxin produced by Bacillus thuringiensis gets activated in the alkaline pH of the insect's gut.

**Final Answer**: The toxin produced by Bacillus thuringiensis gets activated in the alkaline pH of the insect's gut.

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