Following are the steps involved in action of toxin in Bt. Cotton A. The inactive toxin converted into active form due to alkaline pH of gut of insect. B. Bacillus thuringiensis produce crystals with toxic insecticidal proteins. C. The alkaline pH solubilises the crystals. D. The activated toxin binds to the surface of midgut cells, creates pores and causes death of the insect. E. The toxin proteins exist as inactive

Step-by-step solution

Option (4) is the correct answer because the correct sequence of action of toxin in Bt. cotton is B. Bacillus thuringiensis produces crystals with toxic insecticidal proteins. E. The toxin proteins exist as inactive protoxins in bacteria. C. The alkaline pH solubilises the crystals. A. The inactive toxin converted into active form due to alkaline pH of gut of insect. D. The activated toxin binds to the surface of midgut cells, creates pores and causes death of the insect. Hence, B E C A D is the correct order.