The organelle associated with the synthesis of lipids and steroids is

Options

A. RER
B. SER
C. microtubule
D. plasma membrane

Answer

To answer the question regarding the organelle associated with the synthesis of lipids and steroids, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Options**: The question provides four options, among which two are related to the endoplasmic reticulum: Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER).

2. **Identify the Functions of RER and SER**:
- **Rough Endoplasmic Reticulum (RER)**: This organelle is studded with ribosomes, which are the sites of protein synthesis. Therefore, RER is primarily involved in the synthesis of proteins.
- **Smooth Endoplasmic Reticulum (SER)**: In contrast, SER does not have ribosomes on its surface. Its main functions include the synthesis of lipids and steroids, as well as the metabolism of carbohydrates and detoxification of drugs.

3. **Evaluate the Options Based on Functions**: Since the question specifically asks for the organelle associated with the synthesis of lipids and steroids, we can eliminate RER because it is primarily involved in protein synthesis.

4. **Select the Correct Answer**: The only organelle that fits the description of synthesizing lipids and steroids is the Smooth Endoplasmic Reticulum (SER).

5. **Conclusion**: Therefore, the correct answer to the question is **Smooth Endoplasmic Reticulum (SER)**.

### Final Answer:
The organelle associated with the synthesis of lipids and steroids is the **Smooth Endoplasmic Reticulum (SER)**.