Vertebrate is also called

Options

A. Acraniata
B. Craniata
C. urochordates
D. Both B and C

Answer

### Step-by-Step Solution:

1. **Understanding Vertebrates**: Vertebrates are a group of animals that possess a backbone or spinal column. They are considered to be more advanced than invertebrates due to their complex structures and functions.

2. **Key Characteristics**: Vertebrates have a spinal cord, vertebrae (the individual bones that make up the spine), and a notochord (a flexible rod that supports the body). They also have a series of nerves located on the dorsal side (the back side) of their bodies.

3. **Classification**: Vertebrates are classified under the phylum Chordata and the subphylum Vertebrata. Within this classification, they are known for having a cranium (skull) that encases the brain.

4. **Terminology**: The term "craniata" refers to animals that have a skull or cranium. Therefore, vertebrates are also referred to as craniates due to this characteristic.

5. **Urochordates**: While vertebrates are not urochordates, they are often mentioned in discussions about chordates. Urochordates are a different group within the phylum Chordata that do not possess a backbone.

6. **Conclusion**: Based on the characteristics and classifications discussed, vertebrates can be referred to as both "craniates" and "urochordates." Thus, the correct answer to the question is option D, which states that vertebrates are also called both B (craniata) and C (urochordates).

### Final Answer:
Vertebrate is also called **craniata** and **urochordates** (option D: both B and C).

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