Assertion (A): Insect resistant transgenic cotton has been produced by inserting Bt gene. Reason (R): The Bt gene is derived from a bacterium.

1. Assertion (A): States that insect resistant transgenic cotton has been produced by inserting the Bt gene. This refers to Bt cotton, which is genetically modified to produce an insecticide (a protein toxic to certain insects) derived from the bacterium Bacillus thuringiensis (Bt). Assertion (A) is true. 2. Reason (R): States that the Bt gene is derived from a bacterium. This is correct. The Bt gene (specifically, genes encoding Cry proteins) is sourced from the soil bacterium Bacillus thuringiensis. Reason (R) is true. 3. Explanation: The fact that the Bt gene comes from a bacterium (Reason R) explains *how* insect resistant transgenic cotton was produced (Assertion A), as genetic engineering involves transferring genes between organisms. Thus, R is the correct explanation for A. 4. Conclusion: Both A and R are true, and R is the correct explanation of A.