Cell

Definition

The cell is the basic structural, functional, and biological unit of all living organisms. Cells can be prokaryotic (without a nucleus) or eukaryotic (with a nucleus).

5 Must Know Facts For Your Next Test

1. Cells are the smallest units of life capable of performing all necessary life functions.
2. Eukaryotic cells have membrane-bound organelles, including a nucleus that contains genetic material.
3. Prokaryotic cells lack membrane-bound organelles and have their DNA freely floating in the cytoplasm.
4. The cell membrane controls the movement of substances in and out of the cell.
5. Cell theory states that all living things are made up of cells, and all cells come from pre-existing cells.

Review Questions

• What is the primary difference between prokaryotic and eukaryotic cells?
• What key roles do cell membranes play in cellular function?
• State two main points of the cell theory.

Related terms

Organelles:

Specialized structures within a cell that perform distinct processes.

Cytoplasm:

The jelly-like substance within a cell that holds organelles and is the site for most cellular activities.

Nucleus: A membrane-bound structure in eukaryotic cells that contains genetic material.