Classification schemes are hierarchical in nature. Large groups containing many different species are divided into smaller more specific groups, each with fewer species. Each of these is divided into still smaller groups with still fewer species. These groupings reflect phylogenetic relationships. There are seven traditional major levels in a classification scheme.
Every organism is placed into one of five kingdoms.
Unicellular organisms that are prokaryotic , that is, do not have a nucleus surrounded by a nuclear membrane. The bacteria are mostly heterotrophic, that is, they cannot obtain energy from non-living forms and must eat other organisms, or their products, to obtain energy. Kingdom Animalia Animals. Multicellular organisms with cells that lack a cell wall. Many are capable of movement, or movement of some of their body parts, at some time of their life.