All the fundamental chordate characters are retained thought life in the members of

Options

A. Urchordata
B. Vertebrata
C. Cephalochordata
D. All the above

Answer

To solve the question "All the fundamental chordate characters are retained throughout life in the members of," we will analyze the options provided and the characteristics of chordates.

### Step-by-Step Solution:

1. **Identify the Fundamental Chordate Characters**:
- The four fundamental characters of chordates are:
- Notochord
- Dorsal hollow nerve cord
- Pharyngeal gill slits (or pharyngeal slits)
- Post-anal tail

2. **Understand the Options**:
- The options given are:
- A) Eurochordata
- B) Vertebrata
- C) Cephalochordata
- D) All of the above

3. **Analyze Each Option**:
- **Eurochordata**: Members of this sub-phylum retain all fundamental chordate characteristics throughout their life. For example, adult lancelets (a type of Eurochordate) exhibit all four characteristics.
- **Vertebrata**: While vertebrates possess these characters, some of them are only present during certain life stages (e.g., notochord is replaced by the vertebral column in adults).
- **Cephalochordata**: Similar to Eurochordata, cephalochordates retain these characteristics throughout their life. However, they are a specific group within Eurochordata.
- **All of the above**: This option suggests that all mentioned groups retain the characteristics throughout life, which is not entirely accurate.

4. **Conclusion**:
- The correct answer is **A) Eurochordata**, as members of this group retain all fundamental chordate characteristics throughout their entire life.

### Final Answer:
**A) Eurochordata**