Which of the following options does correctly represent the characterstic features of phylum annelida?

Options

A. Triploblastic, unsegmented body and bilaterally symmetrical.
B. Triploblastic, segmented body and bilaterally symmetrical.
C. Triploblastic, flattened body and acoelomate condition.
D. Diploblastic, mostly marine and radially symmetrical

Answer

To solve the question regarding the characteristic features of the phylum Annelida, we will analyze the options provided and identify the correct features step by step.

### Step-by-Step Solution:

1. **Understanding Annelida**:
- Annelids are a phylum of segmented worms that include earthworms, leeches, and polychaetes. They are known for their segmented bodies.

2. **Identifying Key Characteristics**:
- **Triploblastic**: Annelids have three germ layers (ectoderm, mesoderm, and endoderm).
- **Segmented Body**: Annelids have a body that is divided into segments (metamerism).
- **Bilateral Symmetry**: Their body can be divided into two identical halves along one plane.

3. **Evaluating the Options**:
- **Option 1**: Triploblastic, unsegmented body, bilaterally symmetrical.
- **Analysis**: Incorrect. Annelids are segmented, not unsegmented.
- **Option 2**: Triploblastic, segmented body, and bilaterally symmetrical.
- **Analysis**: Correct. This accurately describes the characteristics of Annelida.
- **Option 3**: Triploblastic, flattened body, and Acelomate condition.
- **Analysis**: Incorrect. Annelids are coelomate (having a body cavity lined with mesoderm).
- **Option 4**: Triploblastic, mostly marine, and radially symmetrical.
- **Analysis**: Incorrect. While some annelids are marine, they are not radially symmetrical; they exhibit bilateral symmetry.

4. **Conclusion**:
- The correct option that represents the characteristic features of phylum Annelida is **Option 2: Triploblastic, segmented body, and bilaterally symmetrical**.