Classification of phylum porifera is primarliy based on

Options

A. Canal system
B. Spicules
C. Symmetry
D. Branching

Answer

To answer the question regarding the classification of phylum Porifera, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Phylum Porifera**:
- Porifera, commonly known as sponges, are simple aquatic animals that lack true tissues and organs. They are primarily sessile and have a porous body structure.

2. **Identify Classification Criteria**:
- The classification of organisms often depends on specific characteristics. For Porifera, we need to focus on the key features that differentiate them.

3. **Evaluate the Given Options**:
- Option 1: Canal system
- Option 2: Spicules
- Option 3: Symmetry
- Option 4: Branching

4. **Analyze Each Option**:
- **Canal System**: While the canal system is important for the functioning of sponges, it is not the primary basis for classification.
- **Spicules**: These are structural elements found in sponges, and their presence and composition are crucial for classification. Sponges can be classified into three main classes based on their spicules:
- **Calcarea**: Calcareous spicules.
- **Hexactinellida**: Siliceous spicules with six rays.
- **Demospongiae**: Can have siliceous spicules or spongin fibers.
- **Symmetry**: Most sponges exhibit asymmetry or are radially symmetrical, but this does not serve as a basis for classification.
- **Branching**: This is a structural feature but not a primary classification criterion.

5. **Conclusion**:
- Based on the analysis, the classification of phylum Porifera is primarily based on the presence and composition of spicules. Therefore, the correct answer is **Option 2: Spicules**.

### Final Answer:
The classification of phylum Porifera is primarily based on **spicules**.

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