Bt cotton and other Bt crops are genetically engineered plants that contain a gene from the bacterium Bacillus thuringiensis (Bt). This gene allows the plants to produce a toxin harmful to specific insect pests, providing resistance without the need for insecticides. Bt crops, like Bt cotton, have become a bio-pesticide, protecting against pests and reducing the reliance on chemical insecticides in agriculture. However, their use remains a subject of ongoing debate concerning potential environmental impacts and pest resistance development.