Question

The crystals of Bt toxin do not kill the bacteria producing them because

• A. The bacteria are resistant to it
• B. Toxin itself remains inactive
• C. Toxin is immature
• D. The toxin is enclosed and secreted out of the cell wall

Answer 1

The correct option is B Toxin itself remains inactive

The crystals of Bt toxin do not kill the bacteria (Bacillus thuringiensis) producing it because it is an inactive protoxin that requires an alkaline medium to solubilize and proteases to activate it. Once activated it binds to specific receptors located in the insect midgut epithelial cells and creates pores that eventually lead to the death of the insect.