Kingdom Animalia is one of the seven kingdoms living organisms are classified into. The Kingdom contains organisms called ANIMALS. They are eukaryotic i.e. possess a membrane-bound nucleus. Animals are heterotrophic i.e. they rely on other organisms for their source of energy (food).
In order to break down this food via metabolism, animals need oxygen to do so. This process is called respiration, and it yields energy in form of ATP, which is used by their cells to carry out cellular functions. Therefore, a heterotrophic multicellular organism that relies on oxygen to metabolize its food belongs to KINGDOM ANIMALIA
