Sedimentary rocks, I think
No. At that point, you need to determine if the problem lies in the control or the staining reagents or techniques.
"Eukaryote" roughly translates as "truly nucleated" and refers to organisms with a membrane-bound nucleus.
Such membrane-bound organelles are thought to have arisen via the invagination of the cell's own plasma membrane.
Other organelles such as the mitochondria and the chloroplast are believed to have once existed as separate organisms, but which were engulfed by other cells, forming a symbiotic relationship.
