Cloacal respiration occurs in

Options

A. Sea Dollar
B. Sea Urchin
C. Sea Cucumber
D. Sea Lily.

Answer

To solve the question "Cloacal respiration occurs in," we need to identify which of the given options utilizes cloacal respiration.

### Step-by-Step Solution:

1. **Understand Cloacal Respiration**:
- Cloacal respiration is a type of respiration that occurs in certain aquatic organisms. It involves the intake of seawater through the anus and cloaca, where gas exchange takes place.

2. **Identify the Process**:
- In cloacal respiration, seawater enters the body through the anus and cloaca. This water is then transported to a structure known as the respiratory tree.

3. **Gas Exchange**:
- Within the respiratory tree, oxygen from the seawater is absorbed into the organism's body, and carbon dioxide produced from cellular respiration is expelled back into the seawater.

4. **Evaluate the Options**:
- **Option 1: Sea Urchin** - Sea urchins do not utilize cloacal respiration.
- **Option 2: Sea Cucumber** - Sea cucumbers are known to perform cloacal respiration.
- **Option 3: Sea Lily** - Sea lilies do not use cloacal respiration.
- **Option 4: Seed Oil** - This option is not relevant as it does not pertain to an organism.

5. **Conclusion**:
- Based on the understanding of cloacal respiration and the evaluation of the options, the correct answer is **Option 3: Sea Cucumber**.

### Final Answer:
Cloacal respiration occurs in **Sea Cucumber**.

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