Question

Arrange the sequence which results in killing of insects which feed on Bt plant.
(A). Midgut paralysis and cells of insect are disrupted.
(B). The insect ingests bacterial spores with cry gene present in the insect resistant transgenic plant.
(C). A combination of high pH and the enzyme proteinase of the insect's midgut, processes crystalline inclusions hydrolytically to release the core toxic fragments.

• (A) \(\rightarrow\) (B) \(\rightarrow\) (C)
• (B) \(\rightarrow\) (A) \(\rightarrow\) (C)
• (C) \(\rightarrow\) (B) \(\rightarrow\) (A)
• (B) \(\rightarrow\) (C) \(\rightarrow\) (A)

Hint:

First the insect ingests the toxin, then the gut processes it, and finally the gut cells are damaged.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
Cry proteins of Bacillus thuringiensis are present as inactive protoxin crystals.

Step 2: Order of events
(B) The insect feeds on the Bt plant and takes in the crystals.
(C) In the midgut, high pH and the insect's proteinase release the active toxin fragments.
(A) The toxin makes pores in midgut cells, the cells are disrupted and the gut is paralysed.

Step 3: Select the option
The order (B) \(\rightarrow\) (C) \(\rightarrow\) (A) is option (D).

Final Answer:
The correct sequence is (B), (C), (A). \[ \boxed{\text{(D) }\text{(B)}\ \rightarrow\ \text{(C)}\ \rightarrow\ \text{(A)}} \]