Vertebral column is derived from

Options

A. Notochord
B. Dorsal nerve cord
C. Ventral nerve cord
D. Outgrowth of cranium

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the origin of the vertebral column in chordates.

2. **Identifying Key Features of Chordates**: Chordates are characterized by several key features:
- Presence of a notochord
- Dorsal hollow nerve cord
- Paired pharyngeal gill slits

3. **Role of the Notochord**: The notochord is a flexible rod-like structure found in the embryonic stages of chordates. It serves as a primary skeletal element.

4. **Development of the Vertebral Column**: In many chordates, the notochord is eventually replaced by the vertebral column during development. The vertebral column is a bony structure that surrounds and protects the spinal cord.

5. **Evaluating the Options**:
- **Option 1: Notochord** - This is correct, as the vertebral column develops from the notochord.
- **Option 2: Dorsal nerve cord** - This is incorrect; it does not develop into the vertebral column.
- **Option 3: Ventral nerve cord** - This is also incorrect; chordates possess a dorsal nerve cord, not a ventral one.
- **Option 4: Outgrowth of the cranium** - This is incorrect as well; the vertebral column does not arise from the cranium.

6. **Conclusion**: The vertebral column is derived from the notochord, making Option 1 the correct answer.

### Final Answer:
The vertebral column is derived from the **notochord**.

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