Organelles and other cellular material are held inside the cell by the cell membrane, also known as the plasma membrane.

Here's why:

* Structure: The cell membrane is a thin, flexible barrier composed of a phospholipid bilayer. This bilayer acts as a selective barrier, controlling what enters and leaves the cell.

* Function: The cell membrane:

* Encloses the cell, providing a distinct boundary between the internal and external environments.

* Regulates the passage of substances, allowing some molecules to pass through while blocking others.

* Maintains the cell's shape and internal organization.

* Participates in cell signaling and communication.

Let me know if you have any other questions!