Animals devoid of respiratory, excretory and circulatory organs are

Options

A. Tapeworms
B. Sponges
C. Thread worms
D. Liver Fluke

Answer

To answer the question regarding animals devoid of respiratory, excretory, and circulatory organs, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Options**: The options given are tapeworm, sponges, threadworm, and liver fluke. We need to analyze each of these animals to determine which one lacks respiratory, excretory, and circulatory organs.

2. **Analyze Tapeworm, Threadworm, and Liver Fluke**:
- **Tapeworm**: This organism belongs to the phylum Platyhelminthes. It has specialized structures for excretion (flame cells) and a circulatory system. Therefore, it does not fit the criteria.
- **Threadworm**: Similar to tapeworms, threadworms also belong to the phylum Platyhelminthes and possess respiratory and excretory organs. Thus, it is not the correct answer.
- **Liver Fluke**: Like the other two, liver flukes are also part of the phylum Platyhelminthes and have developed respiratory and excretory systems. Hence, this option is also incorrect.

3. **Examine Sponges**:
- **Sponges**: Sponges belong to the phylum Porifera. They are characterized by their porous bodies and lack true tissues and organs. Importantly, sponges do not have specialized respiratory, excretory, or circulatory organs. They rely on a canal system for water circulation and nutrient absorption.

4. **Conclusion**: Based on the analysis, the only group of animals that are devoid of respiratory, excretory, and circulatory organs is **sponges**.

### Final Answer:
The animals devoid of respiratory, excretory, and circulatory organs are **sponges**.

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