Autonomously replicating circular extrachromosomal DNA of a prokaryotic cell is called:

Options

A. Satellite DNA
B. Plasmid
C. Nucleiod
D. Recombinant DNA

Answer

To solve the question "Autonomously replicating circular extrachromosomal DNA of a prokaryotic cell is called:", we will analyze the options provided and identify the correct answer step by step.

### Step 1: Understand the Key Terms
- **Autonomously replicating**: This means that the DNA can replicate on its own without needing to be part of the chromosomal DNA.
- **Circular**: This indicates that the DNA is in a circular form rather than linear.
- **Extrachromosomal**: This means that the DNA is not part of the main chromosomal DNA of the cell.
- **Prokaryotic cell**: This refers to cells that lack a nucleus, such as bacteria.

### Step 2: Analyze the Options
1. **A - Satellite DNA**: This is typically associated with repetitive sequences in eukaryotic cells and is not known for being autonomously replicating in prokaryotes.

2. **B - Plasmid**: Plasmids are small, circular, double-stranded DNA molecules that are separate from chromosomal DNA. They can replicate independently and are often found in prokaryotic cells.

3. **C - Nucleoid**: This term refers to the region within a prokaryotic cell where the chromosomal DNA is located. It is not a type of DNA itself.

4. **D - Recombinant DNA**: This refers to DNA that has been artificially created by combining DNA from different organisms. It is not specifically related to the autonomously replicating DNA in prokaryotes.

### Step 3: Identify the Correct Answer
Given the definitions and characteristics of each option, the correct answer is:
**B - Plasmid**

### Conclusion
Plasmids are indeed the autonomously replicating circular extrachromosomal DNA found in prokaryotic cells, making them the correct choice for this question.

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