Three fundamental characters of all chordates are

Options

A. dorsal tubular nerve cord, diaphragm, notochord
B. Notochord, diaphragm, gill slits
C. Gill slits, diaphragm, dorsal tubular nerve cord
D. Notochord, gill slits, dorsal tubular nerve cord

Answer

To answer the question about the three fundamental characters of all chordates, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Identify the Fundamental Characters**:
- Chordates possess four fundamental characteristics, but we need to highlight three of them.

2. **First Character - Notochord**:
- The first fundamental character of all chordates is the presence of a **notochord**.
- The notochord is a flexible, rod-like structure made of cartilage that provides support and is located between the nerve cord and the digestive canal.

3. **Second Character - Dorsal Tubular Nerve Cord**:
- The second character is the presence of a **dorsal tubular nerve cord**.
- This nerve cord is hollow and runs along the back of the organism. In vertebrates, it develops into the central nervous system, which includes the brain and spinal cord.

4. **Third Character - Pharyngeal Gill Slits**:
- The third character is the presence of **pharyngeal gill slits**.
- These are openings in the pharynx that can develop into gill arches in aquatic chordates (like bony fishes) and can be modified into structures such as the jaw and inner ear in terrestrial animals.

### Summary of the Three Fundamental Characters:
- **Notochord**
- **Dorsal Tubular Nerve Cord**
- **Pharyngeal Gill Slits**