Gut is found in all but one of the following taxonomic group of platyhelminthes

Options

A. Digenea
B. Cestoda
C. Polyclidia
D. Monogenea

Answer

To solve the question "Gut is found in all but one of the following taxonomic groups of platyhelminthes," we will analyze the options provided and identify which group does not possess a gut.

### Step-by-Step Solution:

1. **Understand the Characteristics of Platyhelminthes**:
- Platyhelminthes, or flatworms, are characterized by being dorsoventrally flattened, exhibiting bilateral symmetry, being triploblastic (having three germ layers), and lacking a body cavity (they are acoelomates). Most are parasitic, with a few being free-living.

2. **Identify the Taxonomic Groups**:
- The options provided are:
- A) Digenia
- B) Cystoda
- C) Polycladia
- D) Monogenea

3. **Examine Each Group**:
- **Digenia**: This group includes flukes, which have a gut and are known for their complex life cycles.
- **Cystoda**: This group includes tapeworms, which are parasitic flatworms that do not have a digestive system or gut. They absorb nutrients directly from their host's digestive tract.
- **Polycladia**: This group has a well-developed gut and includes free-living flatworms.
- **Monogenea**: This group also has a gut and consists of ectoparasitic flatworms.

4. **Determine the Group Without a Gut**:
- Among the groups analyzed, **Cystoda** is the only group that does not have a gut. Tapeworms in this group absorb nutrients from their host and do not possess a digestive system.

5. **Conclusion**:
- The correct answer is **B) Cystoda**, as this taxonomic group is characterized by the absence of a gut.

### Final Answer:
**B) Cystoda**