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 determine the correct representation of the characteristic features of the phylum Annelida, we can analyze the options provided based on the known features of this phylum.

### Step-by-Step Solution:

1. **Understand the Phylum Annelida**:
- Annelida, commonly referred to as segmented worms, includes organisms such as earthworms, leeches, and polychaetes.
- The term "Annelida" means "little rings," which refers to the segmented body structure of these organisms.

2. **Identify Key Characteristics**:
- **Triploblastic**: Annelids are triploblastic, meaning they have three germ layers: ectoderm, mesoderm, and endoderm.
- **Segmented Body**: Annelids are characterized by their segmented body, which is divided by internal septa.
- **Bilateral Symmetry**: Annelids exhibit bilateral symmetry, meaning their body can be divided into two equal halves along one plane.

3. **Evaluate the Options**:
- **Option 1**: Triploblastic, unsegmented body and bilaterally symmetrical.
- This is incorrect because annelids are segmented, not unsegmented.
- **Option 2**: Triploblastic, segmented body and bilaterally symmetrical.
- This is correct as it accurately describes the features of annelids.
- **Option 3**: Triploblastic, flattened body and asylvomate condition.
- This is incorrect; annelids are not flattened and they are coelomates, not asylvomate.
- **Option 4**: Diploblastic, mostly marine and radially symmetrical.
- This is incorrect; annelids are triploblastic, and while some are marine, they are not radially symmetrical.

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