Classification and Taxonomy Overview

Taxonomy

Discipline of classifying organisms and assigning each organism a universally accepted name.

Common names

Names that vary among languages and can lead to confusion.

Aristotle

The first taxonomist who divided organisms into plants and animals and subdivided them by their habitat.

Carolus Linnaeus

A taxonomist who classified organisms by their structure and created the system of naming used today.

Taxonomic category

A group or level of organization in taxonomy.

Binomial Nomenclature

A naming system in which each species is assigned a two-part scientific name.

Genus

A group of closely related species.

Species

Group of similar organisms that can breed and produce fertile offspring.

Kingdom

Largest taxonomic group, consisting of closely related phyla.

Phylum

Group of closely related classes.

Class

Group of similar orders.

Order

Group of similar families.

Family

Group of genera (genus) that share many characteristics.

Polar Bear

Species: maritimus, Genus: Ursus, Family: Ursidae, Order: Carnivora, Class: Mammalia, Phylum: Chordata, Kingdom: Animalia.

Uniqueness

Every name has to be unique in taxonomy.

Universality

Zoologists use a single language for naming organisms worldwide.

Scientific name

The binomial name used to identify an organism.

King Phillip Came Over For Green Salad

Mnemonic to remember the order of taxonomic ranks: Kingdom, Phylum, Class, Order, Family, Genus, Species.

Ursus

Genus that contains polar bears and 5 other kinds of bears.

maritimus

Species name for polar bears, referring to their marine environment.

Carnivora

Order that includes meat-eating animals.

Mammalia

Class that includes warm-blooded animals with hair and milk.

Chordata

Phylum that includes vertebrates.

Animalia

Kingdom that includes all animals.

Felis domestica

Domestic cat.

Felis leo

Lion.

Felis margarita

Sand cat.

Convergent Evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments.

Evolutionary Classification

The strategy of grouping organisms together based on their evolutionary history.

Cladogram

A diagram that shows the evolutionary relationships among a group of organisms.

Phylogeny

The presumed evolutionary history of an organism.

6-Kingdom system of classification

Includes kingdoms: Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia.

Eubacteria

A kingdom of prokaryotic organisms.

Archaebacteria

A kingdom of prokaryotic organisms that live in extreme environments.

Protista

A kingdom of mostly unicellular eukaryotic organisms.

Fungi

A kingdom of eukaryotic organisms that absorb nutrients.

Plantae

A kingdom of multicellular eukaryotic autotrophs.

Viruses

Particles of nucleic acid, protein, and in some cases lipids that can reproduce ONLY by infecting living cells.

Bacteriophage

A virus which infects bacteria.

Influenza

An infection of the respiratory tract that can affect millions of people every year.

Prokaryote

An organism without a nucleus.

Eukaryote

An organism with a nucleus.

Autotroph

An organism that produces its own food.

Heterotroph

An organism that consumes other organisms for food.

Free swimming Larva

A larval stage that is capable of swimming freely.

Molted Exoskeleton

A process where an organism sheds its outer layer.

Segmentation

The division of some animal and plant bodies into a series of repetitive segments.