Question

Which of the following could be the pH, where pro-toxin produced by Bacillus thuringiensis can be converted into active toxin?

• A. 2
• B. 5
• C. 7.4
• D. 10

Answer 1

The correct option is D 10

The Bt toxin is present as a protoxin (inactive form) in Bt cotton. It is activated due to the basic pH of the gut of the cotton bollworm insect. An alkaline pH would mean that the pH would be more than 7. Hence at pH=10, the protoxin would be converted to the active form.