SER mainly consists of

Options

A. cisternae and tubules
B. cisternae and vesicles
C. vesicles only
D. tubules and vesicles

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the main components of the Smooth Endoplasmic Reticulum (SER).

2. **Definition of SER**: The Smooth Endoplasmic Reticulum (SER) is a type of endoplasmic reticulum that is characterized by the absence of ribosomes on its surface, which gives it a "smooth" appearance.

3. **Components of SER**: The SER mainly consists of:
- **Tubules**: These are tube-like structures that form the main framework of the SER.
- **Vesicles**: These are small membrane-bound sacs that are involved in storage and transport within the cell.

4. **Cisternae**: It is important to note that cisternae are not a primary component of the SER. Cisternae are typically associated with the Rough Endoplasmic Reticulum (RER), which has ribosomes on its surface.

5. **Conclusion**: Thus, the main components of the Smooth Endoplasmic Reticulum are tubules and vesicles.

**Final Answer**: SER mainly consists of tubules and vesicles.

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