Biotechnology and its Applications — BIOLOGY STD 12 Science — Question

Bacteria that have an additional (external) gene operationally inserted into their DNA, which expresses their own characteristics, are called transgenic bacteria. A suitable example of this is Bacillus thuringiensis. It is a rod-shaped bacterium. A specific substance Bt toxin is produced by its spores. This bacterium makes a home in the soil and produces spores. During its sporulation, a crystalline protein toxin is formed which is called perasporal crystal. The protein present in this poison is called delta endotoxin or cry protein. This special type of poison proves to be extremely fatal for many types of insects, such as insects of the order Lepidoptera and Diptera group. Such specific Bi biotoxin genes have been isolated from these bacteria and incorporated into many crops like cotton. These genes are called Bt gene or cry gene and this plant is called Bt cotton which is resistant to bollworm. Cotton containing Bt gene is called killer cotton.