Find the incorrect statement.

Options

A. Gene therapy is a genetic engineering technique used to treat diseases at molecular level by replacing defective genes with normal genes
B. Calcitonin is a medically useful recombinant product in the treatment of infertility
C. Bt toxin is a biodegradable insecticide obtained from Bacillus thuringiensis
D. Trichoderma sp. is a biocontrol agent for fungal diseases of plants

Answer

To solve the question of identifying the incorrect statement, we will analyze each given statement one by one.

### Step-by-Step Solution:

1. **Statement 1: Gene therapy is a genetic engineering technique used to treat diseases at the molecular level by replacing defective genes with normal genes.**
- **Analysis:** Gene therapy involves the introduction of normal genes into cells to replace defective ones, which can help treat genetic disorders. This statement is accurate.
- **Conclusion:** This statement is **correct**.

2. **Statement 2: Calcitonin is a medically useful recombinant product in the treatment of infertility.**
- **Analysis:** Calcitonin is a hormone produced by the thyroid gland that helps regulate calcium levels in the body. It is not primarily used in the treatment of infertility. Therefore, this statement is misleading and incorrect.
- **Conclusion:** This statement is **incorrect**.

3. **Statement 3: Bt toxin is a biodegradable insecticide obtained from Bacillus thuringiensis.**
- **Analysis:** Bt toxin is indeed produced by the bacterium Bacillus thuringiensis and is used as a biodegradable insecticide. This statement is accurate.
- **Conclusion:** This statement is **correct**.

4. **Statement 4: Trichoderma is a species that is a biocontrol agent for fungal diseases of plants.**
- **Analysis:** Trichoderma is a genus of fungi that is known for its ability to act as a biocontrol agent against various fungal pathogens in plants. This statement is accurate.
- **Conclusion:** This statement is **correct**.

### Final Conclusion:
The incorrect statement among the options provided is **Statement 2: Calcitonin is a medically useful recombinant product in the treatment of infertility.**

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