The outer membrane of nucleus usually remains continuous with which cell organelle?

Answer

**Step-by-Step Solution:**

1. **Understanding the Nuclear Envelope**: The nuclear envelope is a double membrane structure that encloses the nucleus in eukaryotic cells. It consists of two membranes: the outer nuclear membrane and the inner nuclear membrane.

2. **Identifying the Outer Nuclear Membrane**: The outer nuclear membrane is the membrane that faces the cytoplasm. It plays a crucial role in separating the contents of the nucleus from the cytoplasm.

3. **Connection to Other Organelles**: The outer nuclear membrane is not isolated; it is continuous with another important cell organelle. This continuity allows for communication and transport between the nucleus and the organelle.

4. **Identifying the Organelle**: The organelle that the outer nuclear membrane is continuous with is the endoplasmic reticulum (ER). The ER is a network of membranes involved in protein and lipid synthesis.

5. **Functionality and Structure**: The outer nuclear membrane shares structural and functional similarities with the membranes of the endoplasmic reticulum. It may also have ribosomes attached to its cytoplasmic surface, similar to rough ER.

6. **Conclusion**: Thus, the outer membrane of the nucleus is usually continuous with the endoplasmic reticulum.

**Final Answer**: The outer membrane of the nucleus usually remains continuous with the endoplasmic reticulum.

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