Chordates are distingished from non- chordates by the presence of

Options

A. Brain
B. Dorsal tubular hollow nerve cord
C. Ventral nerve cord
D. Dorsal soild nerve cord

Answer

### Step-by-Step Solution:

1. **Understanding Chordates and Non-Chordates**:
- Chordates are a group of animals that possess certain key characteristics at some stage of their development. Non-chordates are animals that do not have these features.

2. **Identifying Key Characteristics**:
- The primary distinguishing feature of chordates is the presence of a notochord, which is a flexible rod-like structure. However, the question specifically asks about the presence of a nerve cord.

3. **Analyzing the Options**:
- The options provided are:
- A) Brain
- B) Dorsal tubular hollow nerve cord
- C) Ventral nerve cord
- D) Dorsal solid nerve cord

4. **Evaluating Each Option**:
- A) Brain: While chordates do have a brain, it is not the primary distinguishing feature from non-chordates.
- B) Dorsal tubular hollow nerve cord: This is a characteristic feature of chordates. It is located on the dorsal side of the body and is hollow.
- C) Ventral nerve cord: This is typically found in non-chordates, such as arthropods.
- D) Dorsal solid nerve cord: This is not a characteristic of chordates.

5. **Conclusion**:
- The correct answer is **B) Dorsal tubular hollow nerve cord**, as this is the feature that distinguishes chordates from non-chordates.