Cis - and trans - faces are present in

Options

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

Answer

To solve the question regarding the presence of cis and trans faces in cellular organelles, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding the Terms:**
- **Cis Face:** This is the side of the Golgi apparatus that receives materials from the endoplasmic reticulum (ER).
- **Trans Face:** This is the side of the Golgi apparatus that ships out materials to other parts of the cell or to the outside of the cell.

2. **Analyzing the Options:**
- **Option A: Endoplasmic Reticulum (ER)**
- The ER has two types: Rough ER (RER) and Smooth ER (SER). However, it does not have distinct cis and trans faces. Therefore, this option is incorrect.

- **Option B: Golgi Body**
- The Golgi apparatus is known for its role in modifying, sorting, and packaging proteins and lipids. It has both a cis face (receiving side) and a trans face (shipping side). This option is correct.

- **Option C: Ribosomes**
- Ribosomes are the sites of protein synthesis but do not have cis and trans faces. They are not involved in the packaging or transport of materials. Therefore, this option is incorrect.

- **Option D: Mitochondria**
- Mitochondria are known as the powerhouse of the cell, involved in energy production, but they do not have cis and trans faces. Thus, this option is also incorrect.

3. **Conclusion:**
- After analyzing all the options, the only organelle that possesses both cis and trans faces is the **Golgi Body** (Option B).

### Final Answer:
**The correct answer is Option B: Golgi Body.**

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