Which of the cell organelle lack membrane ?

Options

A. mesosome
B. mitochondria
C. ribosome
D. liposome

Answer

### Step-by-Step Solution:

1. **Understanding Cell Organelles**: Begin by recognizing that cell organelles can be classified based on the presence or absence of membranes. Membrane-bound organelles are surrounded by lipid bilayers, while non-membrane-bound organelles are not.

2. **Identifying Membrane-Bound Organelles**: Memorize the key membrane-bound organelles. The main ones include:
- Nucleus: Contains genetic material and is surrounded by a double membrane.
- Mitochondria: The powerhouse of the cell, also has a double membrane.
- Chloroplasts: Found in plant cells, responsible for photosynthesis, and has a double membrane.

3. **Identifying Non-Membrane-Bound Organelles**: Recognize that most organelles have either a single membrane or no membrane at all. The notable exception to the membrane-bound organelles is the ribosome.

4. **Conclusion**: Based on the information gathered, conclude that the only organelle that lacks a membrane is the ribosome. Ribosomes are found in both eukaryotic and prokaryotic cells and are essential for protein synthesis.

### Final Answer:
The cell organelle that lacks a membrane is the **ribosome**.

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