Classification of sponges is primarily based on the

Options

A. Body organization
B. Body plan
C. Skeleton
D. Canal system.

Answer

To answer the question regarding the classification of sponges, we will follow these steps:

### Step 1: Understand the Classification of Sponges
Sponges belong to the phylum Porifera. They are simple, multicellular organisms that lack true tissues and organs. The classification of sponges is primarily based on specific characteristics.

### Step 2: Identify the Key Characteristics
The main characteristics that can be used to classify sponges include:
- Body organization
- Body plan
- Skeleton composition
- Canal system

### Step 3: Focus on Skeleton Composition
Among the characteristics listed, the classification of sponges is primarily based on their skeleton composition. The skeleton of sponges can be made up of different materials, which leads to their classification into various classes.

### Step 4: List the Classes of Sponges
Sponges are classified into four main classes based on their skeletal composition:
1. **Calcarea**: Sponges with calcium carbonate skeletons.
2. **Hexactinellida**: Sponges with siliceous skeletons that have six-rayed spicules.
3. **Demospongiae**: The largest class, which includes sponges with a skeleton made of spongin fibers and/or silica.
4. **Sclerospongiae**: Sponges that have a skeleton made of both silica and calcium carbonate.

### Step 5: Conclude the Answer
Based on the above information, the classification of sponges is primarily based on their skeleton composition. Therefore, the correct answer to the question is option **C. Skeleton**.

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