Assertion :- Regulation of lac operon by repressor is referred to as positive regulation.
Reason : Regulation of lac operon can also be visualized as
regulation of enzyme synthesis by its product.

Options

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

Answer

To solve the question, let's break it down step by step.

### Step 1: Understand the Assertion
The assertion states that "Regulation of lac operon by repressor is referred to as positive regulation."

**Analysis**:
- The lac operon is a well-studied example of gene regulation in prokaryotes, particularly in E. coli.
- The regulation of the lac operon involves a repressor protein that binds to the operator region of the operon, preventing transcription when lactose is absent.
- This type of regulation is known as negative regulation, not positive regulation.

### Step 2: Understand the Reason
The reason states that "Regulation of lac operon can also be visualized as regulation of enzyme synthesis by its product."

**Analysis**:
- The regulation of the lac operon is primarily influenced by the presence of lactose and glucose.
- When lactose is present, it acts as an inducer by binding to the repressor and allowing transcription to occur.
- The statement in the reason suggests that the regulation is based on the product of enzyme synthesis, which is misleading. The regulation is more about the availability of substrates (lactose and glucose) rather than the product of enzyme synthesis.

### Step 3: Determine the Truth of the Statements
- **Assertion**: False (it is negative regulation).
- **Reason**: False (it does not accurately describe the regulation of the lac operon).

### Step 4: Conclusion
Both the assertion and the reason are false. Therefore, the correct answer is that both assertion and reason are false.

### Final Answer
The correct option is D: Both assertion and reason are false.

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