DNA or RNA segment tagged with a radioactive molecule is called

Options

A. Vector
B. Probe
C. Clone
D. Plasmid

Answer

To answer the question "DNA or RNA segment tagged with a radioactive molecule is called," we can follow these steps:

### Step 1: Understand the Terms
- **Vector**: A DNA molecule that carries foreign DNA into a host cell.
- **Probe**: A radio-labeled single-stranded DNA or RNA fragment used to detect a specific sequence of nucleotides in a sample.
- **Clone**: A group of genetically identical organisms produced asexually.
- **Plasmid**: An extra-chromosomal DNA molecule found in bacteria that can replicate independently.

### Step 2: Analyze the Question
The question specifically asks for a segment of DNA or RNA that is tagged with a radioactive molecule.

### Step 3: Identify the Correct Term
From the definitions:
- The term that describes a DNA or RNA segment tagged with a radioactive molecule is **probe**. Probes are specifically designed to bind to complementary sequences and are often used in molecular biology for detecting specific nucleic acid sequences.

### Step 4: Conclusion
Therefore, the correct answer to the question is **probe**.

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