classification how we group things. why do we classify living things? we have about 1.5 million...
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ClassificationHow we group things
Why do we classify living things?
We have about 1.5 million NAMED & classified species.
There may be over 30 million species on Earth!!
We organize so we can communicate, share information & find information.
Taxonomy
…branch of biology for naming & grouping of organisms
Can be grouped according to:
1) their characteristics
2) their evolutionary history
History of taxonomy
Aristotle – had 2 groups, plants & animals
Linnaeus – developed a Hierarchy of levels, according to morphology (physical appearance)
Problems with using morphology to classify
1) Some things may look different but still be a member of the same species.
2) Injuries or other events may alter the physical appearance
3) Some things look alike but are not related (dolphins & fish)
Hierarchy of taxonomyAcronym: King Phillip Came Over For Grape Soda
Humans are:
• Kingdom- Animalia• Phylum- Chordata• Class- Mammalia• Order- Primates• Family- Homidae• Genus- Homo• Species- sapiens
Binomial Nomenclature
…is the ”2 part scientific name” of an organism
RULES1) 1st word = genus name, always capitalize 1st
letter2) 2nd word = species name, all lower case3) Both are italicized or underlined4) Written in Latin
Example: Felis domesticus is a house cat.
EXAMPLES
Home sapien = humans
Felis leo = lion
Phylogeny
..classifying organisms according to their evolutionary
history. Uses systematics.
How does systematics work?
Use evidence from many sources:
1) fossils
2) morphology (physical appearance)
3) embryological development
4) chromosomes & DNA
The 6 Kingdoms
Characteristics of each….
Kingdom Archaebacteria
• Prokaryotes• Single celled• Has a cell wall (no
peptidoglycan)• Some autotrophs &
heterotrophs• Live in extreme environments• EX: halophiles,
thermoacidophiles, methanogens
Kingdom Eubacteria
• Prokaryotes• Single celled• Has cell wall with
peptidoglycan• Some autotrophs &
heterotrophs• EX: E. coli, S. pyogenes
(causes strep throat), C. tetani (causes tetanus)
Kingdom Protista
• Eukaryotes• Mostly single celled, some
multicelled• Cell walls (some)• Autotrophs & heterotrophs• EX: Amoeba, paramecium,
some algae• Some are free-living and
some are parasitic!
Kingdom Fungi
• Eukaryotes• Multicelled (except for
yeast!)• Cell wall with chitin• Heterotrophs• EX: mushrooms, some
molds, yeast• Some are parasitic!
Kingdom Plantae• Eukaryotes• Multicelled• Cell wall with cellulose• Autotrophic• EX: oak trees, rose,
ferns
Kingdom Animalia
• Eukaryotes• Multicelled• No cell walls• Heterotrophic• EX: insects,
sponges, humans, frogs, etc…