Chapter 17

Objectives  Evaluate the history, purpose, and methods of taxonomy  Explain the meaning of a scientific name  Describe the organization of taxa in a biological classification system SCS:

17-1 Classification  used by scientists to group living things  specific names are used so biologists all over the world can understand

 Everyday items are also classified  to group things together based on similarities  Food, clothes, cars, houses, classes…

 Why do we classify things?  to put things in order  to show that they share a certain traits  Useful in agriculture, forestry, and medicine

Early Methods  Aristotle years ago  classified things as plants (did not move) and animals (moved)

 He further divided animals into 3 groups based on where they lived  He divided plants based on their pattern of growth and size

LLinnaeus ggroups called kingdoms UUsed very specific traits

 Further classified plants and animals  Used names that described their traits  All living things have 2 part name

 After discovering a new organism and investigating how to classify this organism, the scientist is ready give it a scientific name (genus and species name).

 two word Latin or Greek names  the same naming system Linnaeus used is called binomial nomenclature

 Rules for writing a scientific name:  Genus name is always capitalized  Both names are italicized when typed or underlined if written Felis catus

 Today we use 7 groups for classifying organisms:  Kingdom- the largest group of living things  Phylum-the largest group within a kingdom  Class – largest group within a phylum  Order- the largest group within a class  Family- largest group within an order  Genus- larges group within a family  Species-the smallest group of living things

Kings Play Chess On Fresh Green Sand

 For example: the common house cat  Kingdom: Animal (many cells)  Phylum: Chordate (backbone)  Class: Mammal (nurses young)  Order: Carnivore (eats meat)  Family: Felidae (sharp claws)  Genus: Felis (small cats)  Species: catus (tame)

Objectives  Describe how evolutionary relationships are determined  Compare the six kingdoms of organisms  SCS:

 Compare external and internal structures  Breeding Behavior  Geographic distribution  Number and shape of chromosomes  Biochemistry

 Scientists now place all living organisms into one of the 6 kingdoms: Archeobacteria, Eubacteria, Fungi, Protista, Plant, and Animal  All kingdoms are more complex than the one below  Viruses fall outside the 6 kingdom realm but play an important (and sometimes dangerous role in the environment)

 Scientists determine evolutionary relationships by look at:  Structure  Breeding behavior  Distribution  Chromosomes  biochemistry

 Species that share a common ancestor share common evolutionary history  Phylogeny-evolutionary history of a species

 Cladistics- system base on phylogeny  Cladogram-branching diagram that shows evolutionary relationships

 Phylogenic diagram- fan-like model superimposed on the geologic timescale

The kingdoms  Reflect evolutionary history

 one celled organisms  no nucleus  live in extreme environments (O 2 free, high saline, and hot acidic)  some of the oldest fossils found  100’s of species

 one celled, no nucleus  some contain chlorophyll so are photosynthetic (blue green bacteria)  Microscopic  Replicate quickly (every minutes)

mmostly single celled nnucleus and other cell parts ssome have chlorophyll ssome move and some cannot iincludes diatoms, paramecia, and algae aanimal, plant, and fungus-like types

 cell walls, but no chlorophyll  Made up of hyphae  absorb food from surroundings  consumers, decomposers, parasites, saprophytes (live on dead matter)

 Photosynthetic  Multicellular  Cell walls with cellulose  Producers  1 st evidence for plants – 500 mya

 Eukaryotic  Multicelled specialized cells  Heterotrophic  Most can move  Most reproduce asexually  First appeared in the Cambrian