What triggers activation of protoxin to active Bt toxin of Bacillus thuringiensis in bollworm?

Options

A. Body temperature
B. Moist surface of midgut
C. Alkaline ph of gut
D. Acidic ph of stomach

Explanation

**Step-by-Step Solution:**

1. **Understanding the Context**: The question pertains to the activation of protoxin into active Bt toxin, specifically in the context of the bollworm, which is a pest affected by Bacillus thuringiensis (Bt).

2. **Identifying the Protoxin**: Bacillus thuringiensis produces a protein known as protoxin, which is initially inactive. This protoxin is a precursor to the active form of the toxin.

3. **Location of Activation**: The activation of protoxin occurs in the gut of the bollworm after ingestion.

4. **Role of pH**: The critical factor that triggers the conversion of protoxin to active Bt toxin is the alkaline pH found in the gut of the bollworm.

5. **Conversion Process**: When the protoxin enters the alkaline environment of the bollworm's gut, it undergoes a conformational change that activates it, allowing it to exert its toxic effects on the insect.

6. **Conclusion**: Therefore, the activation of protoxin to active Bt toxin in the bollworm is primarily triggered by the alkaline pH of the insect's gut.

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