Organisms are classified into domains and kingdoms based on their cellular structure, genetic makeup, and metabolic processes. This classification system helps scientists understand the relationships and evolution of different life forms.
The three major domains of life are Bacteria, Archaea, and Eukarya. Bacteria and Archaea consist of prokaryotic organisms, which are single-celled and lack a nucleus. Eukarya, on the other hand, includes all eukaryotic organisms, such as animals, plants, fungi, and protists, which have cells with a nucleus.
Within each domain, organisms are further classified into kingdoms. For instance, the domain Eukarya includes several kingdoms, such as Animalia (animals), Plantae (plants), Fungi, and Protista (mostly unicellular organisms). The classification into kingdoms is based on additional criteria like nutritional modes, reproduction methods, and developmental patterns.
This hierarchical system of classification helps scientists communicate about different organisms and study their evolutionary relationships more effectively.