Assertion: Bacillus thuringiensis produces protein that kills lepidopteran insect only
Reason :It forms active protein crystals during a particular phase of their growth

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion
B. It both Assertion & Reason are True but Reason is not a correct explanation of the Assetion
C. If Assertion is True but the Reason is False
D. If both Assertion & Reason are false

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion**: The assertion states that Bacillus thuringiensis (Bt) produces a protein that kills only Lepidopteran insects. Lepidopterans include butterflies and moths.

2. **Evaluating the Assertion**: While Bt is known for its effectiveness against Lepidopteran pests, it is not limited to them. Bt toxins can also affect other insect families, such as Diptera (flies) and Coleoptera (beetles). Therefore, the assertion is false.

3. **Understanding the Reason**: The reason provided states that Bt forms active protein crystals during a particular phase of their growth.

4. **Evaluating the Reason**: The protein crystals produced by Bt are inactive within the bacterium. They become active only when they enter the gut of an insect and come into contact with the high pH environment there. The formation of these crystals is not linked to a specific growth phase of the bacterium, making the reason false as well.

5. **Conclusion**: Since both the assertion and the reason are false, we conclude that neither statement is correct.

**Final Answer**: Both the assertion and the reason are false.

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