-All living organisms are composed of cells. They may be unicellular or multicellular.

-The cell is the basic unit of life.

-Cells arise from pre-existing cells.

-Energy flow occurs within cells.

-Heredity information (DNA) is passed on from cell to cell.

-All cells have the same basic chemical composition.

While observing dead cork samples with a crude lens, Robert Hooke identified and named “cells.” He thought that the small, simple units looked like the bare prison cells of his time, and the name cell stuck.