Question

multiple choice question
the selectively permeable barrier that regulates the passage of materials into and out of the cell is the ______

• endoplasmic reticulum
• nuclear envelope
• plasma membrane
• cytoplasm
• nucleus

Explanation:

To solve this, we analyze each option:

• Endoplasmic reticulum: Involved in protein/lipid synthesis, not a cell - wide permeability barrier.
• Nuclear envelope: Regulates passage in/out of nucleus, not the whole cell.
• Plasma membrane: Known as the cell membrane, it is selectively permeable, controlling what enters/exits the cell.
• Cytoplasm: Is the fluid - like substance inside the cell, not a barrier.
• Nucleus: Contains genetic material, not a permeability barrier for the cell.

Answer:

C. plasma membrane