The animal having notochord throughout life is

Options

A. Fish
B. Lanslet
C. Snakes
D. Birds

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 flexible rod-like structure that provides support and is a characteristic feature of the phylum Chordata.

2. **Identify the Phylum Chordata**:
- Animals in this phylum are characterized by the presence of a notochord at some stage in their life cycle.

3. **Examine the Subphyla of Chordata**:
- Chordata is divided into three subphyla:
- **Urochordata**: Notochord is present only in the larval stage or in the tail region.
- **Cephalochordata**: Notochord is present throughout the entire body from head to tail and persists throughout life.
- **Vertebrata**: Notochord is replaced by the vertebral column during development.

4. **Identify the Examples of Each Subphylum**:
- For **Urochordata**, examples include tunicates.
- For **Cephalochordata**, the example is **Amphioxus** or **lancelot**.
- For **Vertebrata**, examples include fish, snakes, and birds.

5. **Determine Which Animal Retains the Notochord**:
- Among the examples, only **Amphioxus (lancelot)** retains the notochord throughout its life.

6. **Conclusion**:
- Therefore, the animal that has a notochord throughout its life is **Amphioxus (lancelot)**.

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

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