Final answer:
Animals comprise eukaryotic cells, which have a distinct nucleus, as opposed to prokaryotic cells found in bacteria and archaea.
Step-by-step explanation:
When examining the types of cells, we find that they can be grouped into two categories: prokaryotic and eukaryotic. Animals are an example of organisms that are made up of eukaryotic cells. Eukaryotic cells are characterized by having a well-defined nucleus and membrane-bound organelles, unlike prokaryotic cells found in bacteria and archaea, which lack a nucleus. Biologists study these cells using various techniques to understand their structure and function better.
Cells fall into one of two broad categories: prokaryotic and eukaryotic. Only the predominantly single-celled organisms of the domains Bacteria and Archaea are classified as prokaryotes, while cells of animals, plants, fungi, and protists are all eukaryotes. Prokaryotic cells lack a nucleus, while eukaryotic cells have a true nucleus.