Answer:
Bt toxin is derived from genes of bacteria Bacillus thuringiensis. It is a powerful insecticide. This is injected or sprayed over plants. This insecticide ruptures the gut wall of the insects and kill them. Provides resistance against insects as the bacterial genes enter the plant body and induce the synthesis of Cry protein which get activated in the insect gut. Scientists are concerned about the use of the Bt toxin because
Kills the non-targeted insect species: It has been found that it also kills the non- target species or beneficial species which are associated with plant life cycle.
Development of resistance by the insects: If insects evolves resistance against Bt toxin plant will be prone to damage cause by them in future.
Causes allergy in humans: Bt toxin is rearly associated with diseases in humans, but it is a potential allergen to humans. It causes skin allergy.