Most important character of all sponges :

Options

A. Coelenteron
B. Herbivorous nutrition
C. Choanocytes
D. Only sexual reproduction

Answer

### Step-by-Step Solution:

1. **Understanding Sponges**:
- Sponges belong to the phylum Porifera. They are multicellular organisms that exhibit a simple body structure and lack true tissues and organs.

2. **Cellular Organization**:
- Sponges have a cellular grade of organization. This means their cells are organized into a loose aggregation rather than forming true tissues.

3. **Nervous System**:
- The nervous system in sponges is not centralized; it is scattered throughout the body. This is a unique characteristic of sponges compared to more complex organisms.

4. **Choanocytes**:
- The most important feature of sponges is the presence of specialized cells called choanocytes (or collar cells). These cells line the interior of the sponge and play a crucial role in feeding and water circulation.

5. **Function of Choanocytes**:
- Choanocytes have a central flagellum surrounded by a collar of microvilli. The flagellum beats to create a water current, which helps in drawing water into the sponge. The microvilli collar traps food particles from the water, allowing for nutrient absorption.

6. **Evaluating Options**:
- Given the options provided:
- Option 1: Sealant around - Not a defining feature of sponges.
- Option 2: Herbivorous nutrition - Not applicable to all sponges as they can filter feed.
- Option 3: Choanocytes - Correct answer, as these cells are essential for the sponge's feeding mechanism.
- Option 4: Only sexual reproduction - Sponges can reproduce both sexually and asexually.

7. **Conclusion**:
- The most important character of all sponges is the presence of choanocytes (collar cells), making option 3 the correct answer.