$3$

Ordering

$1$ point

Evaluate these steps summarizing the Bt mechanism of toxicity and rank them in the correct order:

Earliest step

$1$ A large quantity of toxin is produced during B$.$ thuringiensis endospore formation..

$2$ The toxin protein crystallizes.

$3$ The parasporal crystal dissolves when it enters the alkaline insect hindgut, releasing protoxin.

$4$ Osmotic balance is disrupted and cell lysis ensues.

$5$ Active toxin subunits form a membrane channel in an epithelial cell membrane.

$6$ Host enzymes proteolyze protoxin, forming the active toxin.

Latest step