Explain the role of cry-genes in genetically modified crops.

Explanation

(i) Bacillus thuringiensis is a soil dwelling bacterium which is commonly used as a biopesticide and contains a toxin called cry toxin. Scientists have introduced this toxins producing genes into plants and have raised genetically engineered insect resistant plants . Eg. Bt-cotton.
(ii) When the insects ingest the toxin crystals their alkaline digestive tract denatures the insoluble crystals making thme soluble. The cry toxin then gets inserted into the digestive tract. The insect then stops eating and starves to death.