Biological Classification

Taxonomy

The study of classifying organisms based on traits and structures.

Binomial Nomenclature

A scientific naming system that uses the genus and species of an organism.

Phylogeny

The study of traits through evolutionary history.

Cladogram

A tree diagram that shows the relationships among various species.

Domain

The highest taxonomic rank, grouping organisms based on cell type.

Eukarya

One of the three domains, consisting of organisms with eukaryotic cells.

Archaebacteria

A kingdom of unicellular prokaryotes that can be auto/heterotrophic and thrive in extreme environments.

Eubacteria

A kingdom of unicellular prokaryotes that can be auto/heterotrophic and are found everywhere.

Protista

A kingdom of unicellular eukaryotes that can be auto/heterotrophic.

Fungi

A kingdom of multicellular eukaryotes that are heterotrophic and absorb nutrients.

Plantae

A kingdom of multicellular eukaryotes that are autotrophic and perform photosynthesis.

Animalia

A kingdom of multicellular eukaryotes that are heterotrophic and ingest nutrients.

Species

The smallest, most specific group that can reproduce and create fertile offspring.

Grizzly bear

Ursus arctos, an example of a species within the genus Ursus.

Polar bear

Ursus maritimus, another species in the genus Ursus.

Genus

The first part of the binomial nomenclature naming a group of species.

Species name

The second part of the binomial nomenclature that specifies an organism's species.

Multicellular Eukaryote

Organisms composed of more than one cell with complex structures.

Unicellular Prokaryote

Organisms made up of a single cell without a nucleus.

Eukaryotic Cell

A cell that contains a nucleus and organelles enclosed within membranes.

Prokaryotic Cell

A simple cell type without a nucleus or membrane-bound organelles.

Hominidae

The family that includes bipedal primates such as humans.

Mammalia

The class that includes all mammals.

Primates

The order that includes all primate species.

Taxonomic levels

The hierarchical structure used in biological classification, from domain to species.

Justification of classification

To relate and understand organisms through DNA, cell, and structural similarities.