Prokaryotes and Eukaryotes

Pro means "before", and karyose means "kernel", as a kernel of grain. Early scientists referred to a cell nucleus as a karyose since it looked like a kernel in the cell. Prokaryotic therefore means "before a nucleus"

Eu means "true" and karyose means "kernel", eukaryotic therefore means "possessing a true nucleus."

So boiling it down:

Pro = no

Prokaryotes, no nucleus

Eu = Do

Eukaryotes, you do have a nucleus