Answer 1

One of the major contributions of biotechnology is the development of insect resistant variety of cotton called Bt cotton. This plant contains the gene (cry gene) from the bacteria Bacillus thuringiensis.
Genes encoded by Cry IAc and Cry II Ab control cotton bollworms and those encoded by Cry IAb control corn borer. The gene from the bacteria is transferred to the plant cell with the help of Agrobacterium Ti-plasmid. The product of this gene is Bt toxin. This toxin is a type of protein that is toxic to a variety of insects including bollworm complex.