- Viruses consist only of DNA coated with protein capsid. It is difficult to decide whether they are living organisms or not. They have no metabolism nor reproduction on their own like living organisms have. They can function only inside the host cell.
- Prokaryote cell can be considered a living organism. It, however, does not have organelles and nucleus, so its genetic material is not inside the membrane but free in the cytoplasm.
- Eukaryote cells are the part of a living organism. Unlike the prokaryote cells, eukaryote cells have genetic material packed inside the nucleus and have other organelles as well.
