Bt-toxin is activated in

The correct answer is an alkaline pH of gut

Explanation:

Bacillus thuringiensis is a bacterium that produces proteins toxic to certain insects. These proteins are used in genetically modified crops to provide resistance against insect pests. The Bt toxin, produced by Bacillus thuringiensis, is toxic to insect pests. It is not active in the bacterial form but becomes active once ingested by the insect.​

• The Bt toxin is produced in an inactive form (protoxin). When an insect ingests the Bt plant, the protoxin is converted to an active form in the insect's gut, leading to the insect's death.
• The conversion of the protoxin to the active toxin occurs in the alkaline environment of the insect's gut. This active toxin binds to the gut cells, creating pores and causing cell lysis, leading to the insect's death.
• Insects that feed on Bt plants have an alkaline pH in their gut, which activates the Bt protoxin.
• The active toxin binds to receptors in the gut cells, forming pores and causing cell death. This disrupts the digestive system of the insect, eventually leading to its death.