• 072920 77839
  • info@smartachievers.in
Menu
Back
  • JEE ADVANCE
  • JEE MAIN
  • NEET
  • BITSAT
  • CBSE BOARD
  • UP BOARD
  • CUET
JEE ADVANCE
  • CLASS XI - XII
  • CRASH COURSE
CRASH COURSE
JEE MAIN
  • CLASS XI - XII
  • CRASH COURSE
CRASH COURSE
NEET
  • CLASS XI - XII
  • CRASH COURSE
BITSAT
  • CLASS XI - XII
CBSE BOARD
  • CLASS IX
  • CLASS X
  • CLASS XI
  • CLASS XII
  • CLASS VI
  • CLASS VII
  • CLASS VIII
UP BOARD
  • CLASS IX
  • CLASS X
  • CLASS XI
  • CLASS XII
CUET
  • CRASH COURSE
Courses


Solution


Q.

Given below are two statements.                                           [2024]

Statement I: Bt toxins are insect group specific and coded by a gene cryIAc.
Statement II: Bt toxin exists as inactive protoxin in B. thuringiensis. However, after ingestion by the insect, the inactive protoxin gets converted into active form due to acidic pH of the insect gut.

In the light of the above statements, choose the correct answer from the options given below.

 
1 Both Statement I and Statement II are true.  
2 Both Statement I and Statement II are false.  
3 Statement I is true but Statement II is false.  
4 Statement I is false but Statement II is true.  

Ans.

(3)

Bt toxins are insect-group specific proteins encoded by a gene cryIAc named cry. Bt toxin proteins exist as inactive protoxins inside bacteria, but once an insect ingests it, the inactive toxin gets converted into an active form in the alkaline pH of the alimentary canal that solubilizes the crystals. This activated toxin binds to the surface of midgut epithelial cells and creates pores which cause cell swelling and lysis, and finally cause the death of the insect.