Bt toxin is responsible for killing which one of the following insects group ?

All of these.

a-Lepidopterans (tobacco budworm, armyworm).

b-Coleopterans (beetles) and dipterans (flies, mosquitoes).

c-Dipterans (flies, mosquitoes).

d-All of these is the correct option .

Some of the applications of biotechnology in agriculture are the production of pest resistant plants, which could decrease the amount of pesticide used. Bt toxin is produced by a bacterium called Bacillus thuringiensis (Bt for short). Bt toxin gene has been cloned from the bacteria and been expressed in plants to provide resistance to insects without the need for insecticides; in effect created a bio-pesticide. Examples are Bt cotton, Bt corn, rice, tomato, potato and soyabean etc.

Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). B. thuringiensis forms protein crystals during a particular phase of their growth. These crystals contain a toxic insecticidal protein.