Which of the following is mismatched ?

Options

A. Sponges - Spicules
B. Tapeworms – Proglottids
C. Cnidaria – Nematocysts
D. Roundworms- Cilia

Explanation

To determine which of the following options is mismatched, we will analyze each option one by one:

1. **Sponges with Spicules**:
- Spicules are structural elements found in sponges that provide support and protection. They can be made of silica or calcium carbonate. This option is correctly matched.

2. **Tapeworms with Proglottids**:
- Tapeworms are flatworms that have a segmented body, and each segment is called a proglottid. These segments contain reproductive organs. This option is also correctly matched.

3. **Cnidaria with Nematocysts**:
- Cnidarians, such as jellyfish and corals, possess specialized cells called cnidocytes that contain nematocysts, which are used for capturing prey and defense. This option is correctly matched as well.

4. **Roundworms with Cilia**:
- Roundworms, or nematodes, do not have cilia. They have a smooth body surface and lack cilia, which distinguishes them from other types of worms. This option is incorrectly matched.

Based on the analysis, the mismatched option is:
**Option 4: Roundworms with Cilia.**