Inside every tissue, cells are constantly replenishing themselves through the process of division, although the rate of turnover may vary widely between different cell types in the same tissue.

Embryonic stem cells are pluripotent. This means that all of the genes in an embryonic stem cell can be expressed so they can give rise to all types of cell. They are important for growth.

Examples of multicellular organisms include animals and most species of plants. The following diagram shows the variety of human cell types.