(Bacteria do not have nuclei).
If the fossil's blood cells had nuclei, they could not be human.
As red blood cells don't have nuclei, any marks that show up are presumed to be from the parasite.
Most neoplastic cells had nuclei of low to intermediate nuclear grade with occasional nuclear pleomorphism.
The molecular biology of all eukaryotic cells, that is all cells that have nuclei in them, is almost the same.
Bacteria are so vastly different from "eukaryotes" (protozoans, fungi, animals and plants - creatures whose cells have nuclei) that they must be put in their own domain.
Numerous comets have been observed completely to fall apart on approach to perihelion, as many comets are thought to have nuclei that are very loosely held together.
But they were able to rule that out, because human blood cells don't have nuclei within them -- which these blood cells seem to have.
Leptoids are elongate cells that have nuclei and living protoplasts and thus closely resemble the most generalized phloem cells of some vascular plants.
Red blood cells from mammals, including humans, don't have nuclei.
