"One of the applications of biotechnology is the production of insect resistant crop plants." Justify the statement with reference to Bt-cotton.

Bt-cotton plant is a transgenic plant which produces an insecticide to bollworm. Bacillus thuringiensis is the bacterium which has a Bt gene or Cry gene which is incorporated in the cotton plant through biotechnological methods and thus, it produces a crystalline product Bt. The product acts as a toxin when ingested by the pests as it gets activated after reaching the alkaline gut of pests and creates pores in the intestine and kills the pests. The gene provides protection to GMO against budworm, bollworm, beetle, borer, etc. Thus, the development of this plant has reduced the use of insecticides for protection against the pests.