All are membrane bound cell organelles except
" Or
Which of the following cell organelles lacks a unit membrane

Options

A. Mitochondria
B. Lysosomes
C. Spherosomes
D. Ribosomes

Answer

**Step-by-Step Solution:**

1. **Identify the Question:** The question asks which of the following cell organelles lacks a unit membrane. We need to analyze each option provided.

2. **List the Options:** The options given are:
- A) Mitochondria
- B) Lysosomes
- C) Spherosomes
- D) Ribosomes

3. **Analyze Each Option:**
- **Mitochondria:** Known as the powerhouse of the cell, mitochondria are surrounded by a double membrane. Therefore, this option is not correct.
- **Lysosomes:** Often referred to as the suicidal bags of the cell due to their role in digestion and waste removal, lysosomes are also surrounded by a single membrane. Thus, this option is also incorrect.
- **Spherosomes:** These are involved in lipid storage and are surrounded by a single membrane. Hence, this option is incorrect as well.
- **Ribosomes:** Ribosomes are known as the protein factories of the cell. They do not have any surrounding membrane. Therefore, this option is correct.

4. **Conclusion:** The organelle that lacks a unit membrane is **D) Ribosomes**.

**Final Answer:** Ribosomes (Option D) are the cell organelles that lack a unit membrane.

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