Bacillus thuringiensis is widely used as :

Options

A. Insecticide
B. Weedicides
C. Rodenticide
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Bacillus thuringiensis (Bt):**
- Bacillus thuringiensis is a bacterium that produces specific proteins known for their insecticidal properties.

2. **Mechanism of Action:**
- The proteins produced by Bacillus thuringiensis are inactive when they are within the bacteria. However, when these proteins are ingested by insects, they are activated by the alkaline pH of the insect's midgut.

3. **Effect on Insects:**
- Once activated, these proteins create pores in the gut cells of the insect, leading to cell swelling and ultimately causing the insect to die. This mechanism makes Bt effective as an insecticide.

4. **Application in Agriculture:**
- The insecticidal proteins from Bacillus thuringiensis are often isolated and incorporated into crop plants. When insects feed on these plants, they ingest the proteins and are subsequently killed.

5. **Conclusion:**
- Given the properties and uses of Bacillus thuringiensis, it is widely recognized and used as an insecticide. Therefore, the correct answer to the question is "Insecticide."

**Final Answer:**
- Bacillus thuringiensis is widely used as an **Insecticide**.

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