Stem cell

A young, precursor cell that originates in the bone marrow and serves as the "parent cell" to all other blood cells in the body. Red blood cells, white blood cells and platelets all evolve from stem cells.

A cell that has the ability to divide for indefinite periods in culture and to give rise to specialized cells.

A cell from which other types of cells develop. For example, blood cells develop from blood-forming stem cells.

An undifferentiated somatic cell that is capable of either division to give rise to daughter stem cells, or differentiating into any specialized cell type given the appropriate signals. Cultured stem cells are critical to the concept of therapeutic cloning.

Undifferentiated, primitive cells in the bone marrow that have the ability both to multiply and to differentiate into specific blood cells.