Question

Bt toxin kills insects by

• A. inhibiting protein synthesis
• B. generating excessive heat
• C. creating pores in the midgut epithelial cells, leading to cell swelling and lysis
• D. obstructing a biosynthetic pathway

Answer 1

Answer: (C)

Bt toxins are initially inactive protoxins but after ingestion by the insects, the inactive toxins become active due to the alkaline pH of the gut which solublises the crystals. The activated toxin binds to the surface of the midgut epithelial cells thus, creating pores which cause cell swelling and lysis, eventually leading to death of the insects.