To begin with, let's break down the structure and function of the plasma membrane and how its selective permeability contributes to the survival and function of the cell.

Structure of the Plasma Membrane:
- The plasma membrane is composed of a phospholipid bilayer with embedded proteins.
- The phospholipids have hydrophilic heads facing outward and hydrophobic tails facing inward.
- Proteins within the membrane serve various functions such as transport, cell recognition, and cell signaling.

Function of the Plasma Membrane:
- The plasma membrane acts as a barrier, separating the cell's internal environment from the external environment.
- It regulates the passage of molecules in and out of the cell through selective permeability.
- The membrane allows small, non-polar molecules to pass freely, while larger or polar molecules require transport proteins.
- It also plays a role in cell communication and signaling by interacting with other cells or signaling molecules.

Selective Permeability and Cell Survival:
- The selective permeability of the plasma membrane is crucial for the survival and function of the cell.
- It helps maintain internal conditions necessary for cellular processes by regulating the movement of substances.
- This selective barrier prevents harmful substances from entering the cell and allows essential nutrients to enter.
- By controlling the flow of molecules, the plasma membrane helps the cell maintain homeostasis and respond to changes in its environment.
In conclusion, the structure and function of the plasma membrane, with its selective permeability, are essential for the survival and proper functioning of the cell. The membrane's ability to selectively allow certain molecules to pass through while blocking others is vital for maintaining cellular processes and responding to external stimuli.