Classification

Ch. 17

(17-1) Biodiversity

• Variety of organisms at all levels

• Taxonomy: branch of Bio that names & groups organisms by their characteristics & history

How would you classify the following objects?

• Scissors• Picture• Cardboard box• Pen• Flashlight• Shoe• Fork• Bar of soap

• Box of food• Stapler• Ruler• Can of food• Remote control• Cassette tape• Eye glasses• Toothbrush

Aristotle’s Classification System

• Living things either plants or animals– Animals (land, water, air)– Plants (stems)

• Used common names– Varied from place to place

Linnaeus’ System

• Used morphology (structure & form) to categorize

• 7 level hierarchy – Ex: mail (country, zip, street, house #)

• Scientific names

Levels of Classification

• From largest to smallest– Kingdom– Phylum (animal) / Division (plant)– Class– Order– Family– Genus– Species

Lynx rufus

Leopards

Big cats

All cats

Mammals w/ large canines

All mammals

All chordateanimals

Further Classification

• Species in different geographic areas are broken down into:– varieties (plants) – subspecies (animals)

Binomial Nomenclature

• Sci. name w/ 2 parts: genus & species identifier– Ex: Homo sapiens– Italics or underlined– Genus capitalized, species not

• Name may give hints about organism– Place found (borealis = northern)– Scientist’s name (flower: Linnaea borealis)– Characteristic features (amoeba: Chaos chaos)

(17-2) Systematics

• Organization of living things in the context of evolution (their relationships)

• Phylogeny: evolutionary history of a species or taxonomic group – Used by taxonomists to classify organisms– Phylogenetic tree: shows

relationships

Additional Relationships

• Fossil record

• Morphology

• Embryological patterns of development

• DNA, RNA, & proteins

Cladistics

• Uses shared derived characters to establish evolutionary relationships

• Derived character: feature that evolved only w/in the group under consideration– Ex: bird feathers

• Cladograms: ancestry diagrams

(17-3) 2 Modern Systems

• 6 kingdom system– Preferred by taxonomists (morphology)

• 3 domain system– Preferred by molecular biologists (genetic

codes)

Key Terms

• Unicellular: organism w/ 1 cell• Multicellular: organism w/ many cells• Prokaryotic: organisms without a

nucleus• Eukaryotic: organisms with a nucleus

Kingdoms Determined By

• Morphology

• Cellular structure

• Methods of obtaining nutrients & E

• Metabolism– Processing E

1. Archaebacteria

• “archae” – ancient

• Unicellular & prokaryotic

• Autotrophic or heterotrophic

• Live in extreme environments– Ex: sulfurous hot springs

Yellowstone

2. Eubacteria

• “eu” – true

• Unicellular & prokaryotic

• Autotrophic or heterotrophic

• “Germs” & common bacteria

E. coli

3. Protista

• Eukaryotic

• Unicellular or multicellular

• Category for organisms that don’t fit into the other kingdoms

4. Fungi

• Eukaryotic

• Most are multicellular

• Heterotrophic– Decomposers

• Ex: yeast, mold, mildew, mushrooms

5. Plantae

• Eukaryotic

• Multicellular

• Autotrophic– Photosynthesis

• Gymnosperms (cone plants) & angiosperms (flowering plants)

6. Animalia

• Eukaryotic

• Multicellular

• Heterotrophic

• Mobile

• Ex: fish, insects, reptiles, mammals

Domains

1. Archaea: Archaebacteria

2. Bacteria: Eubacteria

3. Eukarya: Plantae, Animalia, Fungi, & Protista

• Bacteria & Archaea include the greatest # of living things on Earth

Viruses

• Nonliving particle composed of a nucleic acid & a protein coat

• Can only reproduce w/ a host

• Help prevent w/ vaccinations & treat w/ antiviral drugs