On which body side, the notochord is formed during embryonic development?

Options

A. Lateral
B. Ventral
C. Dorsal
D. Bilateral

Explanation

To answer the question "On which body side is the notochord formed during embryonic development?" we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of Notochord**:
- The notochord is a solid structure that serves as a precursor to the backbone in vertebrates. It provides support and defines the body axis during embryonic development.

2. **Identify the Organisms with Notochord**:
- The notochord is primarily found in chordates, which include vertebrates and some invertebrates.

3. **Determine the Location of the Notochord**:
- During embryonic development, the notochord forms along the body axis. It is crucial to understand its anatomical position relative to the body.

4. **Analyze the Options Given**:
- The options provided are lateral, ventral, dorsal, and bilateral.
- Lateral refers to the sides of the body, ventral refers to the belly side, dorsal refers to the back side, and bilateral refers to symmetry.

5. **Conclude the Correct Answer**:
- The notochord is located on the dorsal side of the body during embryonic development. Therefore, the correct answer is "dorsal".

### Final Answer:
The notochord is formed on the **dorsal** side during embryonic development.

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