Which among them is a characteristic of chordata?

Options

A. Dorsal heart
B. Gut is dorsal to nerve cord
C. Central nervous system is solid
D. Post anal part (tail) is present

Answer

To determine which characteristic belongs to the phylum Chordata, we can follow these steps:

### Step 1: Understand the Characteristics of Chordata
Chordates are defined by several key features that are present at some stage of their development. The primary characteristics include:
- Notochord
- Dorsal hollow nerve cord
- Pharyngeal slits
- Post-anal tail
- Endostyle or thyroid gland

### Step 2: Analyze the Given Options
Now, let's evaluate the options provided in the question:

1. **Dorsal heart**: This is incorrect for chordates, as chordates typically have a ventral heart.

2. **Gut is dorsal to nerve cord**: This is also incorrect. In chordates, the nerve cord is dorsal (located on the back) to the gut (or elementary canal).

3. **Central nervous system is solid**: This statement is incorrect as well. A solid central nervous system is characteristic of non-chordates, while chordates have a hollow dorsal nerve cord.

4. **Post-anal tail is present**: This is correct. Chordates possess a post-anal tail at some stage of their development, which is a defining characteristic.

### Step 3: Conclusion
After analyzing all the options, the correct characteristic of Chordata is the presence of a **post-anal tail**.

### Final Answer
The characteristic of Chordata among the given options is the presence of a **post-anal tail**.

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