An ancestor in the direct line; a forefather.

cells: multipurpose cells capable of proliferation but unable to self-renew like stem cells, and thus proliferate indefinitely.

Ancestor in the direct line, usually first in this country

a directly related biological ancestor.

direct ancestor .

A progenitor is an ancestor or precursor.

A parent or ancestor; anything that originates or precedes. Blood cell progenitors are derived from stem cells an give rise to precursors

an originator of a line of descent, frequently used in reference to the immigrant ancestor

Those young cells that should normally mature into red cells; anything that originates or precedes.