In adult urochordate the dorsal nerve cord of larva is changed into

Options

A. Ganglion
B. Brain and spinal cord
C. Brain and nerve cord
D. Remains as such

Answer

To answer the question about what the dorsal nerve cord of the larva changes into in adult urochordates, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Urochordates**: Urochordates, also known as tunicates, are a group of marine animals that exhibit a larval stage with a dorsal nerve cord. This is a characteristic feature of chordates.

2. **Larval Stage Characteristics**: In the larval stage, urochordates possess a well-defined dorsal nerve cord, which is a typical feature of many chordates, indicating their evolutionary lineage.

3. **Adult Form Changes**: As urochordates mature into their adult form, significant changes occur. One of the most notable changes is the transformation of the dorsal nerve cord.

4. **Transformation of the Dorsal Nerve Cord**: In adult urochordates, the dorsal nerve cord that was present in the larval stage does not develop into a brain or spinal cord. Instead, it is transformed into a structure known as a ganglion.

5. **Conclusion**: Therefore, the correct answer to the question is that in adult urochordates, the dorsal nerve cord of the larva is changed into a ganglion.

### Final Answer:
In adult urochordate, the dorsal nerve cord of the larva is changed into a **ganglion**.

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