Unisexual flat worm lives in snail and in human beings

Options

A. Fasciola
B. Schistosoma
C. Taenia solium
D. Paragonimus

Answer

To solve the question regarding which unisexual flatworm lives in snails and humans, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Options**: The question provides four options:
- A) Fascicola
- B) Schistosoma
- C) Taenia solium
- D) Paragonimus

2. **Analyze Option A - Fascicola**:
- Fascicola is known to be a hermaphrodite, meaning it possesses both male and female reproductive organs in the same individual.
- Although it can infect humans and snails, it does not fit the criteria of being unisexual.
- **Conclusion**: This option is incorrect.

3. **Analyze Option B - Schistosoma**:
- Schistosoma is a unisexual flatworm, meaning it has distinct male and female individuals.
- It is known to have humans and snails as its hosts.
- **Conclusion**: This option is correct.

4. **Analyze Option C - Taenia solium**:
- Taenia solium is also a flatworm, but it is primarily known to infect humans and pigs.
- It is not considered unisexual as it is a hermaphrodite.
- **Conclusion**: This option is incorrect.

5. **Analyze Option D - Paragonimus**:
- Paragonimus is another hermaphrodite flatworm, which can infect humans and snails or crabs.
- Since it is hermaphroditic, it does not meet the unisexual criterion.
- **Conclusion**: This option is incorrect.

6. **Final Conclusion**:
- The only option that is a unisexual flatworm and has both snails and humans as hosts is **B) Schistosoma**.

### Final Answer:
The correct answer is **B) Schistosoma**.