Antibiodies are produced and secreted by plasma cells. Which of the following organelles must be well developed for effective antibody synthesis?

Options

A. smooth ER
B. mitochondria
C. storage vacuole
D. rough ER

Answer

To determine which organelle must be well developed for effective antibody synthesis in plasma cells, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Role of Plasma Cells**: Plasma cells are specialized cells that produce and secrete antibodies, which are proteins that help the immune system identify and neutralize foreign invaders like bacteria and viruses.

2. **Identify the Nature of Antibodies**: Antibodies are Y-shaped proteins. Since they are proteins, their synthesis requires specific cellular machinery.

3. **Examine the Organelles Involved in Protein Synthesis**:
- **Smooth Endoplasmic Reticulum (Smooth ER)**: This organelle is primarily involved in the synthesis of lipids, not proteins. Therefore, it is not crucial for antibody synthesis.
- **Mitochondria**: Known as the powerhouse of the cell, mitochondria are involved in ATP production. They do not play a direct role in protein synthesis, including antibodies.
- **Storage Vacuole**: This organelle is responsible for storing substances within the cell. It does not contribute to the synthesis of proteins.
- **Rough Endoplasmic Reticulum (Rough ER)**: This organelle is studded with ribosomes, which are essential for protein synthesis. Since antibodies are proteins, the Rough ER is critical for their production.

4. **Conclusion**: Given that antibodies are proteins and the Rough ER is responsible for their synthesis due to the presence of ribosomes, the organelle that must be well developed in plasma cells for effective antibody synthesis is the **Rough Endoplasmic Reticulum**.

### Final Answer:
The organelle that must be well developed for effective antibody synthesis in plasma cells is the **Rough Endoplasmic Reticulum (Rough ER)**.

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