Neet Solved Paper 2015 Question 36
Question: In Bt cotton, the Bt toxin present in plant tissue as pro-toxin is converted into active toxin due to
Options:
A) alkaline pH of the insect gut
B) acidic pH of the insect gut
C) action of gut microorganisms
D) presence of conversion factors in insect gut
Show Answer
Answer:
Correct Answer: A
Solution:
- The Bt toxin is an inactive protoxin, which is activated due to the alkaline pH in the insect gut. Bt toxin dissolve in high pH of insect gut and become active. The toxins then attack the gut cells of the insect, punching holes in the lining.
(i) Insect eats Bt crystals and spores. (ii) The toxin binds to specific receptors in the gut and the insects stops eating. (iii) The crystals cause the gut wall to break down, allowing spores and normal gut bacteria to enter the body. (iv) The insect dies as spores and gut bacteria proliferate in the body.
