Which characterstic is NOT possessed by the phylum Annelida?

Options

A. Closed circulatory system
B. Segmentation
C. Pseudocoelom
D. Ventral nerve cord.

Answer

To determine which characteristic is NOT possessed by the phylum Annelida, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding the Characteristics of Annelida**:
- Annelids are segmented worms, which include earthworms, leeches, and polychaetes.
- They exhibit bilateral symmetry, meaning their body can be divided into two equal halves.
- Annelids possess a true coelom (body cavity) which makes them coelomates.
- They have a segmented body structure, which is a key characteristic of this phylum.
- Annelids also have a ventral nerve cord, which is part of their nervous system.

2. **Analyzing the Options**:
- **Option A: Closed Circulatory System**: Annelids have a closed circulatory system, which is a characteristic feature.
- **Option B: Segmentation**: Segmentation is a defining characteristic of the phylum Annelida.
- **Option C: Pseudocoelom**: Pseudocoelom refers to a false body cavity. Annelids have a true coelom, not a pseudocoelom.
- **Option D: Ventral Nerve Cord**: Annelids possess a ventral nerve cord, which is typical for this phylum.

3. **Identifying the Correct Answer**:
- Since Annelids have a true coelom, the characteristic that is NOT possessed by the phylum Annelida is **Option C: Pseudocoelom**.

### Final Answer:
**The characteristic that is NOT possessed by the phylum Annelida is Option C: Pseudocoelom.**

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