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

Answer: (C)

Statement I is true but Statement II is false

Answer 2

- Statement I is true because Bt toxins are indeed specific to different insect groups, and the cry IAc gene in Bacillus thuringiensis codes for one such toxin.
- Statement II is false because although the Bt toxin exists as an inactive protoxin, it is the alkaline pH of the insect gut (not acidic) that activates it.