Excretory organs in free living acoelomates

Options

A. Renette gland
B. Flame cells
C. Green gland
D. Ctenedia

Answer

### Step-by-Step Solution:

1. **Understanding Acoelomates**:
- Acoelomates are animals that do not have a body cavity (coelom) between their body wall and digestive tract. This characteristic is crucial in identifying the type of organisms we are discussing.

2. **Identifying Examples**:
- The phylum Platyhelminthes includes both parasitic and free-living organisms. Free-living examples include planaria and flatworms.

3. **Excretory System in Acoelomates**:
- The excretory system in free-living acoelomates primarily consists of flame cells. These cells play a vital role in the excretion of waste materials.

4. **Function of Flame Cells**:
- Flame cells function similarly to kidneys in higher organisms. They help in the removal of waste products and also regulate osmotic pressure and ionic balance within the organism.

5. **Structure of Flame Cells**:
- Flame cells are characterized by their nucleated cell bodies and flagella. They have cup-like projections that facilitate the removal of liquid waste.

6. **Connection to Excretory System**:
- The flame cells are part of a network called protonephridia, which connects to tube cells and ultimately leads to a bladder where waste is stored before excretion.

7. **Conclusion**:
- Based on the above information, the correct answer to the question about the excretory organs in free-living acoelomates is **flame cells**.

### Final Answer:
- The excretory organs in free-living acoelomates are **flame cells**.

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