Bt Toxin Genes and Pest-Specific Crops — NEET Biology
✅ Asked in NEET 2026Specific 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 cryΑc named cry. There are a number of them, for example, the proteins encoded by the genes cryΑAc and cryΙΑb control the cotton bollworms, that of cryΑAb controls corn borer.
NTA tests whether students understand that Bt toxin genes are insect-group specific—meaning different cry genes target different pests. Students commonly confuse which toxin works against which pest (e.g., mixing up cryAAc/cryIAb for cotton bollworms with cryAAb for corn borers). The key is remembering that the choice of gene depends on the targeted crop AND pest, not all Bt toxins work universally. Memorize: cryAAc and cryIAb → cotton bollworms; cryAAb → corn borer. This specificity is crucial for understanding how GMO crops are engineered and why selective gene insertion matters.
Toxin proteins from Bacillus thuringiensis coded by which genes control cotton bollworms and corn borer respectively?
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