Name the genes responsible for making Bt cotton plants resistant to bollworm attack. How do such plants attain resistance against bollworm attacks? Explain.
Genes for making Bt cotton resistant to bollworm attack: 1. acrylic 2. cry IIAb Specific Bt toxin genes are isolated from Bacillus Thurinsiensis and incorporated into the cotton plant. The toxin is coded by a gene name cry. The protein synthesized by these is insecticidal protein. It is present as an inactive protoxin. Once the insect ingests the protoxin it is converted into the active form of toxin due to the alkaline medium of the gut. The activated toxin binds to the surface of midgut epithelial cells and creates pores in them. It causes swelling and breakdown and eventually leads to the death of the insect.