Most of the asymmetrical acoelomates belong to phylum?

Options

A. Porifera
B. Ctenophora
C. Cnidaria
D. Echinodermata

Answer

To solve the question regarding which phylum most asymmetrical acoelomates belong to, we can follow these steps:

### Step 1: Understand the Terms
- **Asymmetrical**: Organisms that cannot be divided into two identical halves in any plane.
- **Acoelomate**: Organisms that do not have a coelom, which is a fluid-filled body cavity.

### Step 2: Identify the Phyla
We need to analyze the options given:
1. **Porifera**: Known as sponges, which are asymmetrical and acoelomate.
2. **Ctenophora**: Also known as comb jellies, which are generally symmetrical and have a simple body plan.
3. **Cnidaria**: Includes jellyfish, corals, and sea anemones, which exhibit radial symmetry and are not acoelomates.
4. **Echinodermata**: Includes starfish and sea urchins, which are generally symmetrical and have a coelom.

### Step 3: Analyze the Features
- **Porifera**: Sponges are the only group that is both asymmetrical and acoelomate. They lack true tissues and organs and have a porous body structure.
- **Ctenophora, Cnidaria, and Echinodermata**: These groups do not fit the criteria of being both asymmetrical and acoelomate.

### Step 4: Conclusion
Based on the analysis, the phylum that contains most asymmetrical acoelomates is **Porifera**.

### Final Answer
**Porifera**

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