Practice question
Question
A double-membrane structure separates nuclear contents from the cytoplasm. Its outer membrane is continuous with the endoplasmic reticulum and bears ribosomes. At certain locations, its two membranes fuse to form passages.
Which conclusion correctly identifies the structure and the role of its passages?
Explanation
The nuclear envelope forms a barrier between the nucleus and cytoplasm. Its outer membrane is continuous with ER and may bear ribosomes. Fusion of its two membranes forms nuclear pores through which RNA and proteins move in both directions.