Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

The plasma membrane provides the outer boundary of which structure?

1. The nucleus

2. The mitochondria

3. The cell

4. The endoplasmic reticulum

The correct answer is: The cell

The plasma membrane is a critical component that serves as the outer boundary of the entire cell. This lipid bilayer controls the movement of substances in and out of the cell, thus playing a vital role in maintaining cellular homeostasis and facilitating communication between the cell and its environment. In contrast, the nucleus, mitochondria, and endoplasmic reticulum are all internal structures within the cell, each with their own membranes. The nucleus, for instance, is surrounded by the nuclear envelope, which is separate from the plasma membrane. Mitochondria are enveloped by their own double membrane, while the endoplasmic reticulum consists of membranes that are continuous with the nuclear envelope. Therefore, the plasma membrane is specifically associated with the outermost boundary of the cell itself, ensuring that its integrity and functionality are maintained.