Question

Given below are two statements:
Statement I : Bt toxins are insect group specific and coded by a gene cry IAc. 
Statement II : Bt toxin exists as inactive protoxin in B. thuringiensis. However, after ingestion by the insect the inactive protoxin gets converted into active form due to acidic pH of the insect gut. 
In the light of the above statements, choose the correct answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Answer 1

The Correct Option is C

Bt Toxin and Its Activation

Statement I:

Bt toxins are indeed insect group-specific and are coded by the cry gene family, including the cry IAc gene. This is true.

Statement II:

While the Bt toxin is produced as an inactive protoxin, it is not the acidic pH of the insect gut but the alkaline pH that activates the protoxin into its toxic form. Therefore, Statement II is false.

Conclusion

The correct answer is: (3) Statement I is true but Statement II is false.