Bt-cotton genes repel:

Options

A. Bacterial pathogens
B. Fungal pathogens
C. Nematode parasites
D. Insect pests

Answer

**Step-by-Step Solution:**

1. **Understanding Bt Cotton**: Bt cotton is a genetically modified organism (GMO) that has been engineered to be resistant to certain pests, particularly the cotton bollworm.

2. **Source of Resistance**: The resistance in Bt cotton comes from a gene derived from the bacterium *Bacillus thuringiensis* (Bt). This bacterium produces a protein that is toxic to specific insects.

3. **Mechanism of Action**: When the cotton plants express this gene, they produce the Bt toxin, which is harmful to certain insect pests that feed on the cotton. This helps in reducing the damage caused by these pests.

4. **Identifying the Correct Option**: The question asks what the Bt cotton genes repel. Given that Bt cotton is specifically designed to combat insect pests, the correct answer is "insect pest."

5. **Eliminating Other Options**: The other options such as bacterial pathogens, fungal pathogens, and nematode parasites are not relevant because Bt cotton does not provide resistance against these types of organisms. Its primary function is to repel insect pests.

6. **Conclusion**: Therefore, the genes in Bt cotton repel insect pests, making it an effective transgenic crop for pest management.

**Final Answer**: Bt cotton genes repel insect pests.

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