It has a job similar to a police officer who allows select people to enter and leave a crime scene.
Explanation:
The primary purpose of the cell membrane is to preserve the cell from its surroundings. The cell membrane manages the movement of materials in and out of cells and organelles. In this form, it is selectively perforable to ions and organic molecules. It is the same as of police officer or security guard that check the people and allow only a few to enter a specific place.
active transport does move nutrients to areas with concentraition they do this and its called active transport because the body is activly moving it to a different part
