Q.Insect resistant property in cotton crop is developed by introducing a gene from ______.

Bt crops, of which Bt cotton is the best-known example, carry the cry gene from the bacterium Bacillus thuringiensis (Bt). This gene produces a protein that forms crystalline inclusions inside the bacterium's spores; a biological Bt spray has existed for over 30 years but is limited by the protein's poor field stability, which is why the gene itself is inserted directly into the crop instead. When a susceptible insect ingests the crystal, the insect midgut's high pH combined with its own proteinase enzyme hydrolyses it, releasing toxic fragments that cause midgut paralysis within minutes and go on to disrupt the midgut cells -- Bt toxin has documented activity against insects …