Question

Bacillus thuringiensis has been used to kill certain insects such as

a. Tobacco budworm
b. Armyworm
c. Beetles
d. Flies
e. Mosquitoes

• A. a, b, c, d, and e
• B. a, b and e
• C. a, c, d and e
• D. b, c and d

Answer 1

The correct option is A a, b, c, d, and e

The cry protein (an endotoxin) obtained from the cry gene of Bacillus thuringiensis is a protoxin and has insecticidal properties.

The endotoxin gets activated in the alkaline environment of the insect gut and causes perforations in the epithelial lining of the midgut. This is followed by cell swelling and cell lysis.

Bt toxin is toxic to the biting and chewing insects, hence the larvae of Lepidoptera, Diptera and Coleoptera are affected by it. Thus, tobacco budworm, armyworm (Lepidoptera), flies, mosquitoes (Diptera) and beetles (Coleoptera) are killed by the Bt toxin.

Hence the correct option is
d. a, b, c, d, and e