Which one of the follwing pairs of structures distinguishes a nerve cell from other types of cell

Options

A. Nucleus and miochondira
B. Perikaryon and dendrites
C. Vacuoles and fibers
D. Flagellum and medullary sheath

Answer

To determine which pair of structures distinguishes a nerve cell from other types of cells, we need to analyze the options provided and identify the unique features of nerve cells.

### Step-by-Step Solution:

1. **Understanding the Structures**:
- First, we need to understand what each of the pairs of structures represents.
- The options given are:
- A) Nucleus and Mitochondria
- B) Perikaryon and Dendrite
- C) Vacuole and Fibers
- D) Flagellum and Medullary Sheath

2. **Identifying Common Structures**:
- Nucleus and mitochondria are found in almost all eukaryotic cells, including nerve cells.
- Vacuoles are typically found in plant cells and some animal cells, but they are not unique to nerve cells.
- Flagella are associated with motility in certain cells, such as sperm cells, and are not a feature of nerve cells.
- Medullary sheath (or myelin sheath) is present in some nerve cells but is not a defining characteristic of all nerve cells.

3. **Focusing on Unique Features of Nerve Cells**:
- The perikaryon (also known as soma or cell body) is a characteristic feature of neurons, containing the nucleus and organelles.
- Dendrites are specialized structures that receive signals from other neurons and are unique to nerve cells.

4. **Conclusion**:
- The pair of structures that distinctly identifies a nerve cell from other types of cells is **Perikaryon and Dendrite**.
- Other cell types do not possess these structures in the same form or function.

### Final Answer:
The pair of structures that distinguishes a nerve cell from other types of cells is **Perikaryon and Dendrite**.

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