Question

The Bt toxin is not toxic to human beings because

• A. the pro-Bt toxin activation requires a temperature above human body temperature
• B. the Bt toxin recognizes only insect-specific targets
• C. the Bt toxin formation from pre-Bt toxin requires pH lower than that present in the human stomach
• D. conversion of pro-Bt toxin to Bt toxin takes place only in highly alkaline conditions

Answer 1

The correct option is D

conversion of pro-Bt toxin to Bt toxin takes place only in highly alkaline conditions

The pro-Bt toxin is converted into an active form in alkaline pH. Human gut has an acidic pH. So, the Bt toxin is not active in the human gut.