Answer
The best evidence of evolutionary unity are the parts shared between all cells: most generally, the presence of an area for genetic material and the presence of membranes and ribosomes. When considering eukaryotes, other parts can be added such as the endomembrane system and microbodies. Some examples of specialized modifications are the parts which are not universally shared, such as chloroplasts, the plant vacuole, etc.
Work Step by Step
This question asks you to review the chapter, making two lists, one for shared structures present in all cells and one for those which distinguish the cells of different kinds of organisms.