Question

Choose the statement which is not true about Bt. cotton:

• A. Insect resistant plant
• B. produces cry protein
• C. Contains genes from Bacillus amyloliquefaciens
• D. Toxic protein produced in the plant is insect specific

Answer 1

Answer:

C. Contains genes from Bacillus amyloliquefaciens

• Bt cotton is a transgenic GM crop (genetically modified) which is resistant to pests.

• The cry genes from Bacillus thuringiensis are genetically engineered into the genome of the cotton plant to induce the resistance towards the pests.

• The cry gene codes for a crystalline toxic protein which remains in the inactive protoxin mode in the plant cells.

• Once ingested by the pests, the alkaline pH in their gut activates the toxin.

• The active toxin binds to the epithelial cells of the midgut of the insects and creates pores in the gut wall.

• The insect stops eating at this point and eventually dies due to starvation.

• The pores also allow normal gut bacteria of the insect to invade and cause infection, leading to the death of the insect.