Question: what is the difference between a unicellular organism and a plant or animal cell?
Answer: Both plant and animal cells are eukaryotic. Prokaryotes are unicellular organisms, but it is worth noting unicellular eukaryotes also exist (Protozoa). Eukaryotic cells contain membrane-bound organelles (such as the nucleus) while prokaryotic cells do not. Plant cells have a cell wall while animal cells do not.