One of the special characters of coelenterate only is the occurrence of

Options

A. polymorphism
B. nematocysts
C. hermaphroditism
D. Flame cells

Answer

To solve the question regarding the special character of coelenterates, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Coelenterates**: Coelenterates, also known as Cnidarians, include organisms like jellyfish, corals, and sea anemones. They are primarily aquatic and exhibit certain unique features.

2. **Identify the Options**: The options provided are:
- A) Polymorphism
- B) Nematocytes
- C) Hermaphroditism
- D) Flame cells

3. **Analyze Each Option**:
- **A) Polymorphism**: This refers to the occurrence of different forms or stages in the life cycle of an organism. While some coelenterates exhibit polymorphism, it is not exclusive to them.
- **B) Nematocytes**: These are specialized cells found in coelenterates that contain stinging capsules. They are a defining characteristic of this phylum.
- **C) Hermaphroditism**: This is the presence of both male and female reproductive organs in the same individual. While some coelenterates are hermaphroditic, it is not a unique feature of the group.
- **D) Flame cells**: These are excretory structures found in flatworms, not in coelenterates.

4. **Determine the Correct Answer**: Based on the analysis, the unique feature that is characteristic of coelenterates is the presence of **Nematocytes** (Option B). These cells are crucial for their defense and prey capture.

5. **Conclusion**: Therefore, the answer to the question is **B) Nematocytes**.