Question

Assertion: A gene from Bacillus thuringiensis is inserted into the plant genome to make it pest resistant.
Reason: Bacillus thuringiensis produce Cry protein during the sporulation phase of their growth.

• A. Both assertion and reason are true and the reason is a correct explanation of the assertion
• B. Both assertion and reason are true but the reason is not the correct explanation of the assertion
  
• C. The assertion is true but the reason is false
  
• D. Both the assertion and reason are false
  

Answer 1

The correct option is B Both assertion and reason are true but the reason is not the correct explanation of the assertion


Bacillus thuringiensis forms crystal (Cry) protein during the sporulation phase of their growth. It is an inactive protoxin that requires an alkaline medium to solubilize and protease for activation. The Cry gene can be inserted into the plant genome to make them pest-resistant. Some examples are Bt-cotton and Bt-corn.
The pests which attack these plants (lepidopteran, coleopteran and dipteran insects) have alkaline pH in their gut. Once the toxin is activated, it binds to specific receptors located in the insect’s midgut epithelial cells and creates pores that eventually lead to the death of the insect.