Classification/Taxonomy Chapter 18

Why Classify? To study the diversity of life, biologists use a classification system to name organisms & group them in a logical manner.

In other words, naming things. Taxonomy Defined: Discipline of classifying organisms and assigning each organism a universally accepted name. In other words, naming things.

Why common names don’t work Common names vary among languages and regions. Example: United Kingdom – Buzzard refers to a hawk United States – Buzzard refers to a vulture Red-tailed Hawk Honey Buzzard Turkey Vulture

Aristotle 384 BC Classified organisms as either plants or animals

Carolus Linnaeus (1707 – 1778) Created the system of naming we use today. In taxonomy, a group or level of organization is called a taxonomic category or taxon.

Binomial Nomenclature “Bi” means 2 “nomial” means number “Nomen” means name “Clature” means the system of Defined: In binomial nomenclature, each species is assigned a two-part scientific name.

Binomial Nomenclature  Carolus Linnaeus In binomial nomenclature, each species is assigned a two-part scientific name. The scientific name is always written in italics or underlined. The first word (the genus) is capitalized The second word (the species) is lowercased. EX- Genus species or Genus species Humans- Homo sapien

Example of Binomial Nomenclature Polar Bear is Ursus maritimus Ursus: genus Ursus contains 5 other kinds of bears maritimus: species The Latin word, maritimus, refers to the sea. Polar bears often live on pack ice that floats in the sea.

Linnaeus's System of Classification A group or level of organization is called a taxonomic category, or taxon Linnaeus had 7- Kingdom “King Phylum Phillip Class Came Order Over Family For Genus Great Species Spaghetti”

Definitions to know Genus: is a group of closely related species Species: Group of similar organisms that can breed and produce fertile offspring

Family: Group of genera that share many characteristics Order: Group of similar families Class: Group of similar orders Phylum: Group of closely related classes Kingdom: Largest taxonomic group, consisting of closely related phyla.

What do these mean?...lets see Here We Go… Polar Bear Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Ursidae Genus: Ursus Species: maritimus What do these mean?...lets see

What they mean Kingdom: Animalia (there are 6 kingdoms) *Do NOT have to write* Kingdom: Animalia (there are 6 kingdoms) Phylum: Chordata (vertebrates) Class: Mammalia (warm-blooded, hair, & milk) Order: Carnivora (meat-eating animals) Family: Ursidae (larger category of bears) Genus: Ursus (kind of bear) Species: maritimus (lives in marine environment)

How to remember: King Phillip Came Over For Green Salad Kingdom Phylum Class Order Family Genus Species

Uniqueness: Every name has to be unique. Rules of the Game Uniqueness: Every name has to be unique. Universality: Zoologists have adopted, by international agreement, a single language to be used on a worldwide basis. All animals are given a generic (common name) and specific name in Latin (scientific name). These names are in italics or are underlined (i.e. Homo sapiens).

Visuals

Modern Three-Domain System As scientists further analyzed cell structure and DNA , a broader category was added- The domain is the most inclusive taxonomic category; larger than a kingdom    The three domains are: Bacteria : kingdom Eubacteria Archaea,: kingdom Archaebacteria; Eukarya :Kingdom protists, fungi, plants, and animals.

Cladogram of Six Kingdoms and Three Domains Section 18-3 DOMAIN ARCHAEA DOMAIN EUKARYA Kingdoms Eubacteria Archaebacteria Protista Plantae Fungi Animalia DOMAIN BACTERIA Go to Section:

Modern 6 Kingdom System Recently, as evidence about microorganisms continue to accumulate, biologists came to realize that the Kingdom Monera were composed of 2 distinct groups. The 6-Kingdom system of classification includes kingdoms: 1. Eubacteria 2. Archaebacteria 3. Protista 4. Fungi 5. Plantae 6. Animalia

6 Kingdoms Eubacteria Archaebacteria Protista Fungi Plantae Animalia Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote Autotroph or heterotroph Autotroph or heterotroph Autotroph/ heterotroph Heterotroph Autotroph Heterotroph Includes Algae Don’t belong in other euk No cell wall No chloroplasts Multicellular “Ancient Bacteria” Release enzymes to digest food Most common bacteria Cell walls & Chloroplasts Live in very hot places E. ecoli Pyrococcus furiosus Paramecium H. coccinea Fern frod Homo sapiens

Checkpoint Questions: 1.  How are living things organized for study? 2. Describe the system for naming species that Linnaeus developed. 3. What are the seven taxonomic categories of Linnaeus’s classification system? 4. Why do scientists avoid using common names when discussing organisms? 5.  What is significant about members of the same species?