Chapter 17

Review of “Classification”

Classification• Grouping things according to similar

characteristics, and separating them from others by differing characteristics

• The science of classifying living things is taxonomy

Used to classify organisms:

• Cells and their organelles• Growth and development• Blood chemistry• DNA• Energetics• Body structures/organs

Early Systems of Classification

• Aristotle – for animals 2000 years ago• Theophrastus – for plants 2000 years ago• Linnaeus (Karl von Linne) – all organisms

in the 1700’s• Linnaeus is known as the “father of

modern taxonomy”

Aristotle

Theophrastus

What is the common theme that you observe between the systems of

teacher and student?

Pairs of choices – either this or that……..each

step has just two choices!

Linnaeus continued that in his

development of a

“dichotomous key”

How to use the dichotomous key

Variations have been

developed over time!

Classification Levels• All organisms are placed in one of 5

kingdoms• Kingdoms are divided into several phyla

(phylum) or divisions• Phyla are subdivided into classes• Classes are divided into several orders• Order contain several families• Each family has several genera (genus)• Each genus is made up of related species

(Division)

Species sometimes have “varieties”

The definition of a species is groups that can breed to form fertile offspring

Human Classification• Kingdom Animalia• Phylum Chordata• Class Mammalia• Order Primates• Family Hominidae• Genus Homo• Species sapiens

Binomial Nomenclature• Each organism has a two-part Latin name

in Linnaeus’ system• Capitalized Genus• Lower case species• Homo sapiens, Acer rubrum, Pseudotsuga

heterophylla, Bacillus cereus, Canis familiaris, Felis domesticus, Equus asinus

• Discoverer gets to name it !

Kingdoms of Living Things

• Monera• Protista• Fungi• Animalia• Plantae

• Whittaker in 1969• Nucleus or not• Uni/multicellular• How they obtain food

Monera• Simple,

unicellular, prokaryotic

• Bacteria• Now

– Archeabacteria– Eubacteria

Protista• Simple,

unicellular or multicellular

• Eukaryotic• Amoeba,

euglena, paramecia

Fungi• Uni- or

multicellular, plant-like

• Eukaryotic• Feed on

dead matter• Mushrooms,

mold and yeast

Plantae• Multicellular• Eukaryotic• Photosynthetic• Flowers, shrubs,

trees

Animalia• Multicellular• Eukaryotic• Eat other

organisms• Man, fish,

bird

How are organisms named?

• From Latin and Greek– Planta from Latin for “plant”– Moneres from Greek for “single”– Genus is Latin for “type”

• Latin prefixes and suffixes to further describe the basic root words

What does archeaphyte mean? Arthropod? Rhodophyta?

Ciliderm? Eubacteria?

• Archea = ancient• Arthr = joint• Chlor = green• Cili = small hair• Con = cone• Derm = skin• Eu = true

• Myc = fungus• Oo = water• Platy = flat• Por = pore• Pod = foot• Phyt = plant• Rhod = red

What about viruses?

Non-living particle (consider characteristics of “life”)

Bacteriophage

Lytic Cycle

Classified?• Not in organic classification system• Formerly classified by host• New system by shape and structure

– Capsid structure– Nucleic acid type– Method of reproduction