The protein products of the Bt toxin genes cry I Ac and cry II Ab are responsible for controlling which of the following: Roundworm, Moth, Bollworm, Fruit fly?

The correct option is A Bollworm. Bt toxin genes are formed during sporulation in some Bacillus thuringiensis strains. Bt produces proteins that aggregate to form a crystal which is toxic to insects like bollworm, yet harmless to humans and the natural enemies of many crop pests.