Classification Chapter 17

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Species of Organisms

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Almost 2 million species of organisms have been described Thousands more are discovered each year The total number of species ranges from 5 to 30 million 2

What is Classification?

Classification arrangement of organisms into orderly is the groups based on their similarities

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Classification is also known as taxonomy

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Taxonomists organisms are scientists that identify & name 3

Benefits of Classifying

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Accurately & uniformly Prevents Uses misnomers starfish & jellyfish that aren't really fish same language (Latin or some Greek) names such as for all names Sea”horse”??

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Confusion in Using Different Languages for Names 5

Latin Names are Understood by all Taxonomists 6

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Early Taxonomists

2000 years ago, Aristotle was the first taxonomist Aristotle divided organisms into plants & animals He subdivided them by their habitat --

Ex) land, sea, or air dwellers

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Carolus Linnaeus

1707 – 1778

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18th century taxonomist

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Classified organisms by their form and structure

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Developed 7 levels of classification Developed naming system still used today 8

Carolus Linnaeus

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Called the “Father of

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Taxonomy” Developed the modern system of naming known as binomial nomenclature two-word name (Genus & species) 9

Standardized Naming

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Binomial nomenclature uses:

Genus species

Latin or Greek Italicized in print Capitalize genus ,

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but NOT species Underline when writing

Turdus migratorius

American Robin 10

Binomial Nomenclature

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Classification Groups Taxon ( taxa -plural) is a category into which related organisms are placed There is a specific hierarchy of groups (taxa) from broadest to most Domain, Kingdom, Phylum, Class, Order, Family, Genus, species 12

Hierarchy-Taxonomic Groups

Domain Kingdom Phylum Class BROADEST TAXON Order Family Genus Species 13

K ing P hillip C ame O ver F or G ood S paghetti!

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Two Modern Systems

Six Kingdom System Three Domain System 16

The Six Kingdoms:

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KingdomArchaebacteria

•The prefix

archae

- comes from the Greek word "ANCIENT" •Unicellular & Prokaryotic •Some are autotrophic and some are heterotrophic •Live in extreme environments

Sewage treatment plants, thermal vents, etc.

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Kingdom Eubacteria

•Cause human diseases, are present in almost all habitats on earth •Many bacteria are important environmentally and commercially.

Live in the intestines of animals 19

Kingdom Protista

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“The odds and ends kingdom”

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Dumping ground of organisms that don’t fit into the other kingdoms

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Eukaryotic

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Unicellular or Multicellular

Ex) Algae, Slime molds, Diatoms, and Protozoa

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Kingdom Fungi

Multicellular, except yeast Absorptive heterotrophs (digest food outside their body & then absorb it) Decomposers Ex) yeast, mold, mildew, & mushrooms 21

Kingdom Plantae

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Multicellular Autotrophic Absorb cellulose sunlight to make glucose – Photosynthesis Cell walls made of 22

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Kingdom Animalia

Multicellular Ingestive heterotrophs (consume food & digest it inside their bodies) Feed on plants or animals 23

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Domains

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Broadest , most inclusive taxon Three domains: 1.Archaea

2.Eubacteria

prokaryotes (no nucleus or membrane-bound organelles) 3.Eukarya

are unicellular are more complex and have a nucleus and membrane bound organelles 25

Domain Eukarya includes:

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Protista (protozoans,

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algae…) Fungi (mushrooms, yeasts …) Plantae Animalia (multicellular plants) animals) (multicellular 26

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Skills Practice

1. List the levels of classification from most broad to most specific.

2. What type of organisms are found in the kingdom Archaebacteria? Are these organisms unicellular or multicellular?

3. What 4 kingdoms are in the Domain Eukarya?

4. What is the difference between an autotroph and a heterotroph? Give an example of each.

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Classification is based on evolutionary relationships:

Homologous structures (same structure, different function) Similar embryo Similarity in amino acid development DNA, RNA , or sequence of Proteins 29

Homologous Structures show Similarities in mammals.

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Similarities in Vertebrate Embryos

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Phylogenetics - the analysis of the evolutionary or ancestral relationships among a taxon (group).

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Phylogenetic diagram (tree) a branching tree that indicates how closely related species are.

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based on

Cladogram

Diagram showing how organisms are related shared, derived characteristics such as feathers, hair, or scales 35

Primate Cladogram 36

Let’s Create A Cladogram from the following:

Derived Characters

segmented jaws hair placenta multicellular limbs kangaroo earthworm amoeba lizard cat sponge salmon + + + + + + + + + + + + + + + + + + + + + -

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Dichotomous Keying

Used to identify organisms Characteristics given in pairs Read both characteristics and either go to another set of characteristics identify the organism OR 38

Example of Dichotomous Key

1a Tentacles present – Go to 2 1b Tentacles absent – Go to 3 2a Eight Tentacles – Octopus 2b More than 8 tentacles – 3 3a Tentacles hang down – go to 4 3b Tentacles upright–Sea Anemone 4a Balloon-shaped body–Jellyfish 4b Body NOT balloon-shaped - 5 39

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