Q.Bt cotton was developed to resist attack by the cotton bollworm. Which Cry protein gene(s) are commonly used in Bt cotton, and why must the toxin protein be present in a protoxin (inactive) form inside the plant cell?

[!TLDR] Bt cotton commonly uses Cry1Ac/Cry2Ab genes against the bollworm; the toxin stays an inactive protoxin inside the plant's own near-neutral cells, becoming active only in a larva's alkaline gut. …

Bt cotton was engineered specifically to resist the cotton bollworm, a major insect pest that causes significant crop damage to cotton. It achieves this resistance by carrying one or more cry genes from Bacillus thuringiensis; commercial Bt cotton varieties commonly use genes such as Cry1Ac, and in some varieties Cry2Ab as well, each coding for a Bt toxin variant effective against the specific lepidopteran pests, including the bollworm, that attack cotton.

As with the toxin's behaviour inside the bacterium itself, the toxin protein produced within the Bt cotton plant's own cells must remain in its inactive protoxin form, because the plant's cellular environment, like the bacterium's, is near-neutral rather than alkaline -- the specific chemical trigger needed to activate the protoxin. If the toxin were somehow present in its already-active form inside the plant's own cells, it would risk damaging the plant's own cellular structures, since the activation and pore-forming action of the toxin is not naturally restricted to insect cells once the toxin is already in its active state. …

Name the specific Cry gene(s) associated with Bt cotton, then re-apply the general protoxin/alkaline-gut-activation logic specifically …

Do not name a generic 'Bt gene' without specifying which Cry protein(s) are actually used in Bt cotton (commonly Cry1Ac, sometimes wi …