ClassificationClassificationClassificationClassification

Alan D. Morales, M.Ed., ATC/LAlan D. Morales, M.Ed., ATC/L

Why do we classify?• To organize organisms

into groups that have biological meaning

• Taxonomy-the study that classify organisms & assign each organism a universally accepted name.

• Uses Greek & Latin language

Why do they uses common names?

Common names was confusing. Same organism may have different names– Puma, cougar, panther,

mountain lion• Different species may

shared single common name– Buzzard: US-Vulture; UK-

Hawk

How does an organism get it assigned scientific

name?Binomial Nomenclature

– Created by Carolus Linnaeus

– Two-part naming system– Always written in italics– 1st word is capitalized and

2nd word is lowercased• 1st word-the genus • 2nd word-the species

(refers to important trait of organism or where it lives)

• Example: Grizzly Bear- Ursus arctos

Linnaeus’s System of Classification

• 7 Taxonomic Categories– Species– Genus– Family– Order– Class– Phylum– Kingdom

• Sam Gave Fred One Copper Padlock Key.

Species

Genus

Family

Order

Class

Phylum

Kingdom

Modern Evolutionary Classification

• Traditional classification problem:– Classifying organisms with similar body

structure or important traits

• Evolution Classification– Strategy of grouping organism together

based on evolutionary history

• Cladistic analysis-identifies & considers only those characteristics of organisms that are evolutionary innovation

• Derived characters-characteristics that recently appeared in lineage not in older members

• Cladogram-a diagram that shows the evolutionary relationship among a group of organisms.

•Cladogram is similar to a family tree in that it shows relationships common among relative organisms.

Grandparents

mother aunt uncle

you brother

son

daughter

niece

nephew

cousin cousin cousin

2nd cousin 2nd cousin2nd cousin

3rd cousin 3rd cousin

Classification Tools• DNA & RNA

– Scientist examine DNA & RNA to help determine classification of organism

– Example: Amer. vulture, African vulture, & Stork

• Molecular Clock– Used to mark

evolutionary change in organism by comparing the DNA

Kingdom & Domains• Early Tree of Life were misguided assumptions

• Linnaeus Taxonomy did not adequately represent the full diversity.

• 6 Kingdom System of Classification– Eubacteria– Archaebacteria– Protista– Fungi– Plantae– Animalia

Domain System• Developed with uses of comparative

studies on RNA & molecular clock• Larger than a Kingdom• System

– Bacteria• Eubacteria

– Archaea• Archaebacteria

– Eukarya• Protista, Fungi, Plantae, & Animalia

Classification of Living Things

Domain Bacteria Archaea Eukarya

Kingdom Eubacteria Archaebacteria

Protista Fungi Plantae Animalia

Cell Type Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote

Cell Structure

Cell wall w/ peptidoglycan

Cell wall w/o peptidoglycan

Cell wall of cellulose in some; some have chloroplast

Cell wall of chitin

Cell wall of cellulose; chloroplast

No cell wall or chloroplast

# of Cells Unicellular Unicellular Most unicellular; some multicellular

Most multicellular; some Unicellular

Multicellular Multicellular

Mode of Nutrition

Autotroph or Hetertroph

Autotroph or Hetertroph

Autotroph or Hetertroph

Hetertroph Autotroph Hetertroph

Examples

Streptococcus

Halophiles Slime molds, giant kelp

Mushroom, yeast

Mosses, ferns, plants

Sponges, insects, fishes, mammals

The End