Classification

What is it?

Classification: The action of grouping objects into useful units.

Taxonomy: the science of classifying organisms.

The names of some organisms are really inaccurate as a scientific label.

•Inaccurate name is frog. •More precise names are grass frog, tree frog, bull frog, etc.

The inaccurate scientific name is dog. The more precise label would be Bull Dog, Collie, German Shepherd, etc.

Aristotle

• Was one of the first taxonomists. • He classified plants into grasses, bushes and

trees. • He classified animals depending on whether

they lived on the earth, in the water or in the air (BUT it didn’t explain the fact that some birds live in the water and the air.)

Carolus Linnaeus (1707-1778)

• Swedish botanist and made the greatest contribution to taxonomy.

• He decided that organisms should be grouped based on similarities in body structure.

• Established binomial nomenclature: two part system to name and classify organisms.

In taxonomy the organisms are grouped in a set of categories:

Kids Playing Catch On Freeway Get Squashed

Factors considered by taxonomists when classifying organisms

1. Structural similarities: Example: number of limbs, body covering, number of heart chambers, etc.

2. Cellular Organization:Some cells have a nucleus (eukaryotic) and others do not (prokaryotic).

3. GeneticSimilarities: the greater the

similarity of DNA (genes) the more closely related the organisms are.

Binomial Nomenclature

• A set of scientific names formed by two words. The first term designates the Genus and the second designates the species.

• The Genus is written with a capital and the species with a lower-case letter the two names are in italics or underlined

• Example: Orca Whale Orcinus orca Orcinus orca

Classification of some AnimalsCommon Name: Human Great White Shark

Kingdom Animalia Animalia

Phylum Chordata Chordata

Class Mammalia Chrondrichthyes

Order Primata Lanbiformes

Family Hominidae Lamnidae

Genus Homo Carchardon

Species Homo sapiens carcharias

Which Organism is the most different?TAXA Squid American

LobsterBlue Mussel American

oyster

Kingdom Animalia Animalia Animalia Animalia

Phylum Mollusca Arthropoda Mollusca Mollusca

Class Cephalopod Malacostraca Bivalve Bivalve

Order Decapod Decapod Mytiloida Ostreoida

Family Loliginidae Nephropidae Mytilidae Ostreidae

Genus Lolgio Homarus Mystilus Crassostrea

Species opalescens americanus edulis virginica

Which two organisms are the most closely related?

Activity to do in a group!• In a group organize these organisms. There is no right

answer but you must explain why you made the specific group.

Organisms: Moose Octopus Pellican SquidOyster Dolphin Cod HorseClam Lobster Eel ShrimpManatee Shrimp Clown Fish Sea OtterJellyfish Catfish Mussel WalrusHammer Head Shark Killer Whale SeagullSeahorse Coyote Squirrel Tuna

Activity continued…

• Organize the organisms based on Aristotle’s taxonomy.

• Live on Earth• Live in the water• Live in the air