DNA parts which can switch their position are

Options

A. cistrons
B. transposons
C. introns
D. none of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about specific parts of DNA that can change their position within the genome.

2. **Identifying the Relevant Terms**: In genetics, there are certain segments of DNA that are known for their ability to move around. These segments are commonly referred to as "jumping genes."

3. **Defining Jumping Genes**: Jumping genes are scientifically known as "transposons." These are sequences of DNA that can change their position within the genome, which can lead to mutations and changes in the cell's genetic identity.

4. **Types of Organisms**: Transposons are found in both eukaryotic organisms (like plants and animals) and prokaryotic organisms (like bacteria). This indicates their widespread nature across different forms of life.

5. **Mechanism of Movement**: The process by which transposons move from one location to another within the genome is called "transposition."

6. **Historical Context**: The phenomenon of transposons was first discovered by Barbara McClintock in maize (Zea mays). The term "transposons" was later coined by scientists Hedges and Jacob.

7. **Conclusion**: Therefore, the answer to the question is that the DNA parts which can switch their positions are called "transposons."

**Final Answer**: Transposons.

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