Question

166. What triggers activation of protoxin to active Bt
toxin of Bacillus thuringiensis in boll worm ?
(1) Body temperature
12 Moist surface of midgut
Alkaline pH of gut
(4) Acidic pH of stomach
​

Answer 1

Answer:

The alkaline pH of gut triggers activation of protoxin to active Bt toxin of Bacillus thuringiensis.

Explanation:

Bacillus thuringiensis has the delta-endotoxin which is present in the inactive crystalline form. However, once it is ingested by the insects, it becomes soluble in the alkaline pH of the insect's midgut.

This activated toxin now acts on the cells of the gut by creating pores in them resulting in lysis and ultimately the death of the insect.