Animal
Definition
The term animal is used to refer to any living organism that falls in the animal kingdom, one of the kingdoms in the six-kingdom system of classification of species (the other kingdoms are plants, bacteria, archaea, fungi and protists). The following attributes collectively separate animals from other living organisms:
| Attribute | Value for animals | Other kingdoms that share (or may share) this attribute value | Kingdoms that don't share this attribute value |
|---|---|---|---|
| Cell type | eukaryotic cell | plants, fungi, protists | bacteria, archaea |
| Cell type | does not have a cell wall | some protists (specifically, protozoa) | plants, fungi, bacteria, archaea |
| Cellularity of organism | multicellular organism | plants, fungi | protists, bacteria, archaea |
| Mode of nutrition | heterotrophic organism | some plants, some protists | most plants (including algae), fungi |