Scientists determined that organisms of the genus spinoloricus we eukaryotes and not prokaryotes because spinoloricus cells have --

a. flagella
b. hereditary material
c. cell walls
d. nuclear membranes

Eukaryotes are distinguished from prokaryotes in that they organelles enclosed within a nuclear membrane. The organisms of spinoloricus are radically different from other known eukaryones in that they lack mitochondria and are able to exist in the absence of oxygen. However, their genetic material is contained within a nuclear membrane and they are therefore eukaryotes rather than prokaryotes.