Which among the following is a type of Bt toxin gene isolated from Bacillus thuringiensis ?

All of these

a-cryIAc

b-cryIIAb

c-cryIAb

d-All of these is the correct option .

Specific Bt toxin genes were isolated from Bacillus thuringiensis and incorporated into the several crop plants such as cotton.The choice of genes depends upon the crop and the targeted pest, as most Bt toxins are insect-group specific. The toxin is coded by a gene cryIAc named cry. There are a number of them, for example, the proteins encoded by the genes cryIAc and cryIIAb control the cotton bollworms, that of cryIAb controls corn borer.