Taxonomy (Classification)

Chapter 18

Taxonomy – the branch of biology that groups and names organisms based on studies of their different characteristics

Classification – the grouping of objects or information based on similarities

Aristotle, a Greek philosopher, developed the first accepted system

Carlous Linnaeus made improvements on Aristotle’s system Based on physical and structural similarities of

organisms

Binomial nomenclature – a two-word naming system Bi – two nomial – number nomenclature – name

The first word indicates the genus (uppercased)

The second word indicates the species (lowercased)

When typed, the two names are italicized Example – Canis familiaris (dog)

When handwritten, the two names are underlined Example – Gorilla gorilla (Western gorilla)

Scientific and Common Names Latin is the language of scientific names Advantages of using Latin

Not a national language The language does not change Scientific names are unique

Scientific and Common Names Common names are used as nicknames An organism may have a different common

name in different countries Scientific name – Passer domesticus Common names

U.S. and England – house sparrow Holland –huismus

Taxonomic Rankings

Taxon – a taxonomic group Domain Kingdom Phylum Class Order Family Genus Species

Mnemonic device

Did King Phillip Come Over For Great Spaghetti

Taxonomic Rankings

Exception: Phylum is known as division in Kingdom Plantae

Taxonomic Rankings

Domain – the most inclusive (largest) taxon

Species – the least inclusive (smallest)

taxon

Taxonomic RankingsClassification

Brown Bear

House Cat

DogKiller

WhaleWolf

Domain Eukarya Eukarya Eukarya Eukarya Eukarya

Kingdom Animalia Animalia Animalia Animalia Animalia

Phylum Chordata Chordata Chordata Chordata Chordata

Class Mammalia Mammalia Mammalia Mammalia Mammalia

Order Carnivora Carnivora Carnivora Cetacea Carnivora

Family Ursidae Felidae Canidae Delphinidae Canidae

Genus Ursus Felis Canis Orcinus Canis

SpeciesUrsus

arctosFelis catus

Canis familiaris

Orcinus orca

Canis lupus

Dichotomous Key

Dichotomous key – a series of questions answered by “yes” or “no”, and each question is a choice between two characteristics

A tool used in plant or animal identification

Dichotomous Key

1. a. Coin is silver in color ………………………… go to step 2b. Coin is not silver in color ………………………… go to step 4

2. a. Coin has ridges around the edge …………………… go to step 3b. Coin doesn’t have ridges around edge……………… Nickel

3. a. Coin has a picture of George Washington…………. Quarterb. Coin doesn’t have a picture of G. Washington …….. Dime

4. a. Coin has a man with a beard on it………………….. Pennyb. Coin doesn’t have a man with a beard on it………… Dollar

Candy Dichotomous Key

1. a. packaged go to step 2b. un-packaged go to step 3

2. a. boxed ?b. wrapper go to step 4

3. a. soft ?b. hard go to step 5

4. a. plastic wrapper go to step 10b. wax paper wrapper go to step 6

5. a. round shaped go to step 7b. not round shaped ?

6. a. on a stick ?b. not on a stick ?

7. a. sphere-shaped go to step 8b. oval-shaped go to step 9

8. a. multi-colored ?b. pale yellow colored ?

9. a. circular shaped (should be marked with an “s”) ?b. A little less circular shaped (should be marked with an “m”) ?

10. a. red-colored candy ?b. yellow-colored candy ?

Candy Dichotomous Key

1. a. packaged go to step 2b. un-packaged go to step 3

2. a. boxed Sugar Babiesb. wrapper go to step 4

3. a. soft Gummy Bearsb. hard go to step 5

4. a. plastic wrapper go to step 10b. wax paper wrapper go to step 6

5. a. round shaped go to step 7b. not round shaped Mike and Ikes

6. a. on a stick Dum Dum Lollipopsb. not on a stick Tootsie Rolls

7. a. sphere-shaped go to step 8b. oval-shaped go to step 9

8. a. multi-colored Gobstoppersb. pale yellow colored Unpackaged Lemon Heads

9. a. circular shaped (should be marked with an “s”) Skittlesb. A little less circular shaped (should be marked with an “m”) M&M’s

10. a. red-colored candy Atomic Fireballb. yellow-colored candy Packaged Lemon Heads

Cladogram

A branching treelike diagram used to illustrate evolutionary relationships among organisms

Cladogram

Common ancestor

Domains

Three domain levels Eukarya Archaea Bacteria

Kingdoms

Linnaeus established two kingdoms: Animalia and Plantae

Since then, it has expanded from two to five Monera – Prokaryotes (cells without nuclei) Protista – Eukaryotes (cells with nuclei) Fungi Plantae Animalia

Kingdoms

Today, there are six kingdoms (Monera is divided into two kingdoms) Eubacteria Archaebacteria Protista Fungi Plantae Animalia

Kingdoms

Six kingdoms Eubacteria – Common bacteria Archaebacteria – “Old” bacteria Protista – The “leftover” kingdom Fungi – Mushrooms and molds Plantae - Plants Animalia - Animals

Terms to know: Prokaryote – a cell without a nucleus; a simple

cell that is small Eukaryote – a cell with a nucleus; more complex

cell that is larger than a prokaryotic cell

Terms to know: Cell wall – used for protection and support

Terms to know: Unicellular – an one celled organism Multicellular – an organism with more than one

cell

Terms to know: Autotroph – organism that can make its own

nutrients Heterotroph – an organism that obtains its

nutrients from other organisms (can’t make its own food)

Domain Bacteria

This domain is the same as Kingdom Eubacteria

Bacteria are the most abundant organisms on Earth

Prokaryotes

Salmonella

Domain Archaea

This domain is the same as Kingdom Archaebacteria

Prokaryotes Can be found in extreme environments

Extremophiles - Salt lakes, hot springs, and ocean floors

Methanogens – Live in oxygen-free environments

Domain Eukarya

Kingdom Cell Wall Unicellular or Multicellular

Prokaryotes or Eukaryotes

Nutrients

Protista Some species

have them

Can be uni- or multi-

Eukaryotes Can be autotroph or heterotroph

Fungi Yes Can be uni- or multi-

Eu- Hetero-

Plantae Yes Multi- Eu- Auto-

Animalia No Multi- Eu- Hetero-