Classified within the domain Eukarya, the kingdom of Animalia is a group of organisms that are considered animals. In order to be classified as an animal, organisms need to have certain characteristics. To examine the characteristics of animals, we'll use the lion as an example.
Animals are made up of multiple cells (multicellular). Each organism in the kingdom Animalia is made up of multiple cells. A lion is considered an animal and has a body made up of millions of cells.
The cells of animals are very complex. Animals are composed of eukaryotic cells that contain membrane bound organelles and a nucleus.
When a lion get their nutrients from consuming other organisms and cannot produce their own food (heterotrophs).
No Chloroplasts/No Cell Walls
The tissue types found within animals lack the chloroplast and cell wall structures that are found in other cell types.