Make a list of the similarities and differences between prokaryotic and eukaryotic cells. Be sure to include not only basic aspects of cell structure such as the specific types of macromolecules present, but also the presence or absence of specialized features such as organelles and biochemical processes. Now do the same for animal cells vs. plant cells. Some science fiction is more fiction than science. Consider a story involving marine organisms that are eukaryotic, single-celled, and that are one meter in diameter.
Analogies can be useful in learning and understanding a new topic.
For example, the cell can be thought of as a chemical factory, and the nucleus as its main office or control center. Compare the functions of other cell parts to the parts of a factory.