Assertion: Ethidium bromide (EtBr) under UV radiation gives bright orange coloured bands.
Reason: The separated DNA fragments can be seen after staining the DNA with compound EtBr.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.

Explanation

To analyze the assertion and reason provided in the question, we will break it down step by step.

### Step 1: Understand the Assertion
The assertion states that "Ethidium bromide (EtBr) under UV radiation gives bright orange colored bands." Ethidium bromide is a fluorescent dye that intercalates between the bases of DNA. When exposed to ultraviolet (UV) light, it fluoresces, emitting a bright orange color.

### Step 2: Understand the Reason
The reason states that "The separated DNA fragments can be seen after staining the DNA with compound EtBr." This is true because ethidium bromide is used to stain DNA in gel electrophoresis. After the DNA fragments are separated by size during electrophoresis, they are stained with EtBr, allowing visualization under UV light.

### Step 3: Evaluate the Relationship
Now, we need to evaluate the relationship between the assertion and the reason. The assertion is a fact about the property of ethidium bromide under UV light, while the reason explains the process of how DNA fragments are visualized after staining with EtBr. The reason supports the assertion because the bright orange bands observed under UV light are indeed due to the staining of DNA fragments with ethidium bromide.

### Step 4: Conclusion
Both the assertion and the reason are true, and the reason correctly explains the assertion. Therefore, we can conclude that both statements are valid and related.

### Final Answer
- **Assertion**: True
- **Reason**: True
- **Relationship**: The reason supports the assertion.

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