1. Plasma Membrane: A cell membrane that encloses the cell, separating its internal environment from the external environment. It controls what enters and exits the cell.

2. Genetic Material (DNA): All cells contain DNA, the molecule that carries the genetic instructions for building and maintaining the cell. This DNA is organized into chromosomes.

3. Ribosomes: These are tiny structures within the cell responsible for protein synthesis. They read the genetic code from DNA and use it to create proteins, which are essential for all cellular functions.