Radial symmetry occurs is

Options

A. Cockroach
B. Anopheles
C. Asterias/Star Fish
D. Snail

Answer

### Step-by-Step Solution:

1. **Understanding Radial Symmetry**:
- Radial symmetry is a type of symmetry where an organism can be divided into similar halves by passing a plane through its central axis. This means that any cut through the center will yield two equal halves.

2. **Analyzing the Options**:
- The options given are:
- Cockroach
- Anopheles (a type of mosquito)
- Astreas (starfish)
- Snails

3. **Evaluating Each Organism**:
- **Cockroach**:
- Cockroaches exhibit bilateral symmetry, meaning they can only be divided into two equal halves along one plane. Thus, they do not have radial symmetry.
- **Anopheles**:
- Similar to cockroaches, Anopheles mosquitoes also show bilateral symmetry. They cannot be divided into equal halves by multiple planes.
- **Astreas (Starfish)**:
- Starfish belong to the phylum Echinodermata and exhibit radial symmetry. They can be divided into equal halves by multiple planes passing through their central axis.
- **Snails**:
- Snails have bilateral symmetry in their larval stage, but as adults, they are asymmetrical. Therefore, they do not exhibit radial symmetry.

4. **Conclusion**:
- Based on the analysis, the only organism that exhibits radial symmetry is **Astreas (starfish)**. Therefore, the correct answer to the question is **Astreas**.

### Final Answer:
Radial symmetry occurs in **Astreas (starfish)**.

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