Production of Bt cotton was done by :

Options

A. insertion of an inactive cry gene in cotton
B. making boll worms resistant against Bt toxin
C. making the cotton plant an insecticide
D. Introduction of cry I Ab in cotton

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. This resistance is achieved through the incorporation of a specific gene from the bacterium *Bacillus thuringiensis* (Bt).

2. **Identifying the Gene Involved**: The gene responsible for the pest resistance in Bt cotton is known as the cry gene. There are various types of cry genes, such as cry1Ab and cry2Ab, which produce proteins that are toxic to specific insects when ingested.

3. **Mechanism of Action**: When insects consume the cotton plant that expresses the cry protein, the protein interacts with the insect's gut cells, causing them to rupture. This leads to the death of the insect, thereby protecting the cotton plant from damage.

4. **Evaluating the Options**: The question provides multiple options regarding how Bt cotton was produced. The correct option is the introduction of the active cry gene into the cotton plant, which allows it to produce the insecticidal protein.

5. **Conclusion**: The production of Bt cotton was achieved by inserting the active cry gene into the cotton plant, making it resistant to pests such as the cotton bollworm.

**Final Answer**: The production of Bt cotton was done by the introduction of the cry gene in the cotton.

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