Classification and Taxonomy

Scientists have discovered millions of different species. To make sense of this diversity, we use a classification system that groups organisms based on their similarities. This helps us identify species, understand how they evolved, and study relationships between different organisms.

The Five Kingdoms

All living things are divided into five major kingdoms: Animals (multicellular organisms that eat other organisms), Plants (multicellular organisms that make their own food through photosynthesis), Fungi (organisms like mushrooms that absorb nutrients from dead material), Protoctists (mostly single-celled organisms like amoebas), and Prokaryotes (bacteria with no nucleus).

The Taxonomic Hierarchy

Within each kingdom, organisms are further classified into smaller groups. The order is: Kingdom → Phylum → Class → Order → Family → Genus → Species. Each level gets more specific. For example, humans belong to the Animal kingdom, Chordata phylum, Mammalia class, Primates order, Hominidae family, Homo genus, and sapiens species.

Binomial Nomenclature

Every species has a unique two-part scientific name called binomial nomenclature. The first part is the Genus (always capitalized) and the second part is the species (lowercase). For example, humans are Homo sapiens, dogs are Canis familiaris, and oak trees are Quercus robur. These Latin names are used worldwide so scientists can communicate clearly regardless of language.