Parasitic adaptation of flatworms is

Options

A. Anaerobic respiration
B. Secretion of antienzymes
C. Resistant covering cuticle or integument
D. All of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Flatworms**: Flatworms belong to the phylum Platyhelminthes and are primarily known for their parasitic nature. They depend on a host for their nutrition and often cause harm to the host.

2. **Identifying Parasitic Adaptations**: To survive within a host, flatworms have developed several adaptations:
- **Anaerobic Respiration**: Flatworms often reside in the intestines of their hosts, where oxygen levels can be low. They have adapted to perform anaerobic respiration, which allows them to survive and thrive in such environments by reducing their metabolic activity and energy requirements.

3. **Secretion of Anti-Enzymes**: Flatworms face the challenge of the host's digestive enzymes. To combat this, they secrete anti-enzymes that help them resist the effects of these digestive enzymes, allowing them to survive and continue feeding on the host's nutrients.

4. **Resistant Covering (Cuticle/Integument)**: Flatworms possess a tough outer covering, such as a cuticle or integument, which provides protection against the host's digestive processes. This covering helps them maintain their structure and resist being digested themselves.

5. **Additional Structures for Attachment**: Many flatworms have hooks and suckers that aid in their attachment to the host's intestinal wall. This adaptation ensures they remain securely anchored while feeding.

6. **Conclusion**: Given the adaptations discussed, the correct answer to the question about the parasitic adaptations of flatworms is "all of the above." This includes anaerobic respiration, secretion of anti-enzymes, and the presence of a resistant covering.

**Final Answer**: All of the above.

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