Which one is excertory organ ?

Options

A. Archaeocyte
B. Choanocyte
C. Pinacocyte
D. Solenocyte

Answer

To determine which one is the excretory organ from the given options, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Options**: The question provides four options: archaeocyte, choanocyte, pinacocyte, and solenocyte. We need to identify which of these is an excretory organ.

2. **Analyze Each Option**:
- **Archaeocyte**: These are amoeboid cells found in sponges. They play a role in digestion and nutrient transport but are not involved in excretion.
- **Choanocyte**: These are collar cells also found in sponges. Their primary function is to create water currents for feeding and are not involved in excretion.
- **Pinacocyte**: These cells form the outer layer of sponges and help in protection and movement but do not have a role in excretion.
- **Solenocyte**: These are specialized cells that are flagellated and are involved in excretion. They are found in various invertebrates, including annelids and mollusks.

3. **Identify the Excretory Organ**: Among the options analyzed, the only cell that functions in excretion is the solenocyte.

4. **Conclusion**: Therefore, the correct answer to the question "Which one is the excretory organ?" is **solenocyte**.

### Final Answer:
The excretory organ among the given options is **solenocyte**.

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