Question

Cotton boll worm and corn borer are killed by which genes?

• A. CryIAc, CryIIAb and CryIAb
• B. CryIAb and CryIIAc
• C. CryIAb, CryIIAb and CryIAc
• D. None of above

Hint:

Remember the important Bt genes: \[ \boxed{ \begin{aligned} CryIAc &\rightarrow \text{Cotton bollworm}\\ CryIIAb &\rightarrow \text{Cotton bollworm}\\ CryIAb &\rightarrow \text{Corn borer} \end{aligned} } \] Bt crops are genetically modified plants containing Cry genes from Bacillus thuringiensis.

Answer 1

The Correct Option is A

The Bt gene from Bacillus thuringiensis encodes Cry proteins (crystal proteins) that are toxic to specific insect larvae such as cotton bollworm and corn borer. When ingested, Cry proteins are activated in the alkaline insect midgut and bind to epithelial receptors, causing cell lysis and death of the pest.