During gene expression, DNA is transcribed into RNA in the nucleus. Then, the RNA is translated into proteins in the cytoplasm. Through what physical barrier must the RNA pass when moving from the nucleus into the cytoplasm?
A.
plasma membrane
B.
nuclear membrane
C.
nucleolus
D.
cell wall
B. nuclear membrane
The RNA must pass through the nuclear membrane when moving from the nucleus into the cytoplasm.
To arrive at this answer, we need to understand the structure and function of the cell. The cell is surrounded by a plasma membrane, which acts as a barrier between the cell and its external environment. However, the question specifically asks about the movement of RNA from the nucleus to the cytoplasm.
Within the eukaryotic cell, DNA is located in the nucleus, while RNA is synthesized during transcription in the nucleus. After transcription, the RNA molecules need to pass through the nuclear membrane to reach the cytoplasm where translation occurs.
The nuclear membrane, also known as the nuclear envelope, is a double membrane structure that encloses the nucleus. It has small nuclear pores which regulate the transportation of molecules, such as RNA, between the nucleus and the cytoplasm. These nuclear pores act as gateways, allowing specific molecules to pass through the nuclear membrane.
Based on this information, the correct answer is B. nuclear membrane.