Classification of Organisms Mincer/Scully

Why Classify? To make it easier to study life!To make it easier to study life! Taxonomy- the assigning of a universally accepted name to a species.Taxonomy- the assigning of a universally accepted name to a species. Binomial nomenclature- An organism’s classification is based on its Genus and species names. The Genus is ALWAYS capitalized, and the species name is NEVER capitalized. Binomial nomenclature- An organism’s classification is based on its Genus and species names. The Genus is ALWAYS capitalized, and the species name is NEVER capitalized. –E.g. Homo sapiens (humans), Odocoileus virginianus (Whitetailed deer)

Linnaeus We use a system today that was originally created by Carl Linnaeus.We use a system today that was originally created by Carl Linnaeus. Linnaeus- ( ) A botanist who created a classification system of organisms based on their physical similarities with each other.Linnaeus- ( ) A botanist who created a classification system of organisms based on their physical similarities with each other. Originally, Linnaeus only had two Kingdoms, or major categories-Plant and Animal.Originally, Linnaeus only had two Kingdoms, or major categories-Plant and Animal.

Linnaean System King Phillip Came Over For Grasshopper SoupKing Phillip Came Over For Grasshopper Soup Kingdom Kingdom –Phylum ClassClass –Order »Family » Genus » Species

Linnaeus vs. Modern Classification Linnaeus Linnaeus –2 Kingdoms –Based on physical similarities –Uses only biologists observations and knowledge of organisms Modern –5 or 6 kingdoms –Based on physical similarities AND genetic similarities –Uses observations, knowledge of organisms, molecular clocks, and other genetic techniques

Modern Classification Five Kingdom System: Older system, lumps all prokaryotic species into one kingdom: MoneraFive Kingdom System: Older system, lumps all prokaryotic species into one kingdom: Monera AnimalPlantProtistFungiMonera

Six Kingdom Classification Keeps Animal, Plant, Fungi and Protista, and splits Monera into two Kingdoms:Keeps Animal, Plant, Fungi and Protista, and splits Monera into two Kingdoms: – Eubacteria -normal everyday prokaryotes found on Earth – Archeabacteria - prokaryotes that are only found in extreme environmental conditions, like in a salty lake, or in extreme temperatures; also called extremophiles.

Three Domains: Six Kingdoms Eukarya Eukarya –Animal –Plant –Fungi –Protista All have organisms made of eukaryotic cells Bacteria –Eubacteria Peptidoglycan in the cell walls Prokaryotic single celled organisms Archea Archea –Archeabacteria No peptidoglycan in the cell wallsNo peptidoglycan in the cell walls Prokaryotic single celled organisms that live in extreme environments

An Example of Classification The Leopard: Panthera pardusThe Leopard: Panthera pardus

Fungi All members are heterotrophic (they have to eat other organisms for their food)All members are heterotrophic (they have to eat other organisms for their food) Most are multicellular, and secrete digestive enzymes into their food source, then absorb the smaller food moleculesMost are multicellular, and secrete digestive enzymes into their food source, then absorb the smaller food molecules Mushrooms are most common Mushrooms are most common

Protista “ Junk ” drawer Kingdom“ Junk ” drawer Kingdom Mostly unicellular eukaryotic organisms, but some multicellular, like kelp.Mostly unicellular eukaryotic organisms, but some multicellular, like kelp. VERY diverse array of organisms, from diatoms to algae.VERY diverse array of organisms, from diatoms to algae. Some are autotrophs (make own food) and some are heterotrophs.Some are autotrophs (make own food) and some are heterotrophs.

Dichotomous Keys In the field, biologists use dichotomous keys to identify organisms.In the field, biologists use dichotomous keys to identify organisms. Dichotomous key-A chart that identifies organisms based on their characteristics. Its used by excluding organisms based on their OBSERVABLE features.Dichotomous key-A chart that identifies organisms based on their characteristics. Its used by excluding organisms based on their OBSERVABLE features.