Give one difference between flame cells and nephridia.

Explanation

**Step-by-Step Solution:**

1. **Identify the Organisms**:
- Flame cells are excretory structures found in flatworms, which belong to the phylum Platyhelminthes.
- Nephridia are excretory structures found in annelids, which include segmented worms belonging to the phylum Annelida.

2. **Functionality**:
- Both flame cells and nephridia serve the purpose of excretion, but they do so in different types of organisms.
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