What is true about Nereis, scorpion, cockroach and silver fish ?

Options

A. They all posses dorsal heart
B. None of them in aquatic
C. They all belong to the same phylum
D. They all have joined paired appendages

Answer

To solve the question regarding what is true about Nereis, scorpion, cockroach, and silverfish, we can follow these steps:

### Step 1: Identify the Classification of Each Organism
- **Nereis**: This organism belongs to the phylum **Annelida**. It is a segmented worm commonly found in marine environments.
- **Scorpion**: This organism belongs to the phylum **Arthropoda**. Scorpions are terrestrial arachnids.
- **Cockroach**: This organism also belongs to the phylum **Arthropoda**. Cockroaches are insects that are commonly found in various environments.
- **Silverfish**: This organism is also classified under the phylum **Arthropoda**. Despite its name, it is not a fish but an insect.

### Step 2: Analyze the Characteristics
- **Dorsal Heart**: Both annelids (like Nereis) and arthropods (like scorpions, cockroaches, and silverfish) possess a dorsal heart, which is a characteristic feature of these phyla.
- **Habitat**: Nereis is aquatic, and scorpions can be found in terrestrial habitats, but some species may also be found in semi-aquatic environments. Cockroaches and silverfish are primarily terrestrial.
- **Phylum Classification**: Nereis belongs to a different phylum (Annelida) compared to the other three (Arthropoda).
- **Jointed Appendages**: Jointed paired appendages are a characteristic feature of arthropods, which scorpions, cockroaches, and silverfish possess. Nereis does not have jointed appendages.

### Step 3: Evaluate the Statements
1. **All possess a dorsal heart**: This statement is true.
2. **None are aquatic**: This statement is false because Nereis is aquatic.
3. **They all belong to the same phylum**: This statement is false; Nereis is in Annelida, while the others are in Arthropoda.
4. **They all have jointed paired appendages**: This statement is false; only the arthropods have jointed appendages.

### Conclusion
The correct answer to the question is that **all of them possess a dorsal heart**.

---