protoplast

protoplast \PROH-tuh-plast\, noun:

1. Biology. a. the contents of a cell within the cell membrane, considered as a fundamental entity. b. the primordial living unit or cell.
2. a person or thing that is formed first; original; prototype.
3. the hypothetical first individual or one of the supposed first pair of a species or the like.

But whatever I am here, I am the protoplast—and that is a word you should mark well, little brother—the thing first formed by our parents as a copy to be followed afterwards.
-- Philip Baruth, The Brothers Boswell, 2013

You look like a direct descendant of our good old legendary protoplast Piast. But, just to make the picture complete, tell us something about your family
-- Stefan Korboński, Between the Hammer and the Anvil, 1981

Protoplast comes from the Late Latin word prōtoplastus which meant "the first man."