The animal having notochord throughout life is

Options

A. Birds
B. Fish
C. Snake
D. Amphioxus

Answer

To determine which animal has a notochord throughout its life, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of Notochord**:
- The notochord is a rod-shaped structure composed of large vacuolated cells. It is a characteristic feature of all chordates, providing structural support.

2. **Identify the Role of Notochord in Different Animals**:
- In many vertebrates (like birds, fishes, and reptiles), the notochord is present during the embryonic stage but is replaced by the vertebral column and skull as they mature.

3. **Examine Examples of Animals**:
- Common vertebrates such as birds, fishes, and snakes have a notochord only during their developmental stages, which is replaced by the vertebral column in adulthood.

4. **Consider Non-Vertebrate Chordates**:
- Amphioxus, also known as lancelets, is a non-vertebrate chordate that retains its notochord throughout its entire life. It does not develop a vertebral column.

5. **Conclusion**:
- Based on the information, the animal that has a notochord throughout its life is **Amphioxus**.

### Final Answer:
The animal having notochord throughout life is **Amphioxus**.

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