___________contains ribosomes on its surface that help in the synthesis of proteins

Options

A. Mitochondria
B. Ribosomes
C. Golgi Body
D. Endoplasmic reticulum

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which organelle contains ribosomes on its surface that assists in protein synthesis.

2. **Identifying Organelles**: The options provided are mitochondria, ribosomes, Golgi body, and endoplasmic reticulum.

3. **Analyzing Each Option**:
- **Mitochondria**: Known as the powerhouse of the cell, it is primarily involved in ATP production and does not have ribosomes on its surface.
- **Ribosomes**: These are the sites of protein synthesis themselves but are not an organelle with a surface.
- **Golgi Body**: This organelle is involved in modifying, sorting, and packaging proteins and lipids but does not have ribosomes on its surface.
- **Endoplasmic Reticulum (ER)**: This organelle exists in two forms: Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER). The RER has ribosomes attached to its surface, which are essential for protein synthesis.

4. **Conclusion**: The correct answer is the **Endoplasmic Reticulum**, specifically the **Rough Endoplasmic Reticulum** (RER), as it contains ribosomes on its surface that help in the synthesis of proteins.

**Final Answer**: Endoplasmic Reticulum

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