All the following statements are correct for Bt toxin but one is wrong. Which one is wrong?

Options

A. Bt toxin is produced by bacteria called Bacillus thuringiensis
B. Bt toxin are protein toxins like thurioside and sporeine which are active against different group of insects
C. Bt toxin is harmful for man
D. Upon ingestion by susceptible insects the Bt protoxin is converted into active form and kills the insects

Answer

To solve the question regarding which statement about Bt toxin is incorrect, we can analyze each option step by step.

**Step 1: Analyze Option A**
- **Statement**: "Bt toxin is produced by bacteria called Bacillus thuringiensis."
- **Analysis**: This statement is true. Bt toxin is indeed produced by the bacterium Bacillus thuringiensis, which is known for its insecticidal properties.

**Step 2: Analyze Option B**
- **Statement**: "Bt toxins are protein toxins like thuringiensin and sporine which are active against different groups of insects."
- **Analysis**: This statement is also true. Bt toxins are protein toxins that target specific groups of insects, making them effective in pest control. However, the mention of "different groups" can be misleading as they are highly specific to certain insects.

**Step 3: Analyze Option C**
- **Statement**: "Bt toxin is harmful for men."
- **Analysis**: This statement is incorrect. Bt toxin is not harmful to humans; it is specifically designed to target certain insect pests. This is the false statement we are looking for.

**Step 4: Analyze Option D**
- **Statement**: "Upon injection by susceptible insects, the Bt protoxin is converted into active form and kills the insect."
- **Analysis**: This statement is true. The Bt protoxin is indeed converted into its active form once ingested by susceptible insects, leading to their death.

**Conclusion**: The incorrect statement regarding Bt toxin is **Option C: "Bt toxin is harmful for men."**