Q. What is true about Bt toxin?
A) Bt protein exists as active toxin in the Bacillus.
B) The activated toxin enters the ovaries of the pest to sterilise it and thus prevent its multiplication.
C) The concerned Bacillus has antitoxins.
D) The inactive protoxin gets converted into active form in the insect gut.
Explanation
[Solution from source] Bacillus thuringiensis makes Bt toxin as an inactive protoxin crystal; the alkaline pH of the insect gut solubilises and activates it, and it binds the midgut epithelium, creating pores that kill the insect. It is not active inside the bacterium, which is why the bacterium is unharmed, and it does not act on the ovaries. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.