Organizing Lifes Diversity Unit 5 Chapter 17 What

Organizing Life’s Diversity Unit 5 Chapter 17

What is classification? n the grouping of objects or information based on similarities n This helps biologists understand how organisms are related to each other. n This is useful in agriculture, forestry, biochemistry, and medicine (to name a few fields).

Taxonomists study taxonomy. n the branch of biology that groups and names organisms based on studies of their different characteristics Click on image to play video.

Aristotelian classification Life Plant Herb Shrub Animal Tree Aristotle grouped organisms based on appearance and abilities.

Carolus Linnaeus: 1707 -1778 n Swedish botanist n Created modern classification system based on physical and structural similarities n Modern taxonomists have altered the Linnaean system to reflect evolutionary relationships.

Binomial nomenclature n two-word naming system to identify organism n Genus: group of related species n always capitalized n Specific epithetic: particular characteristic n always lower case n Ex: Homo sapiens Genus When writing the scientific name which is Latin, one must italicize when typing or underline when handwriting. specific epithet

Common names n Many people refer to organisms by common names rather than scientific names. n Be careful that common names do not always reflect the biology of the organism. n Scientific name: Fragaria ananassa n Common name: strawberry

Dichotomous key: system to identify organisms and their scientific names n A key is made up of sets of numbered statements. n Each set deals with a single characteristic of an organism, such as leaf shape or arrangement.

How living things are classified n Taxon: a group of organisms (taxa, pl. ) n These groups (taxa) can be very broad or very specific. n The taxonomic levels from most broad to most specific: kingdom, phylum, class, order, family, genus, species

Taxonomic levels Domain Eukarya Kingdom Animalia Chordata Phylum Class Mammalia Carnivora Order Family Genus Felidae Lynx Species Lynx rufus canadensis Bobcat Lynx

Comparing related animals Lynx Bobcat n Lynx rufus, lynx n Panthera concolor, mountain lion Mountain lion n Lynx canadensis, bobcat n Which two are more related? How do you know?

What determines evolutionary relationship? n Anatomy and physiology n Common structures imply a common ancestor. n Breeding and behavior patterns n Geographic distribution n DNA and biochemistry DNA comparisons between these plants show almost no difference.

Phylogeny: Studying the evolutionary histories and relationships of organisms n Cladistics: a phylogenic study that assumes probabl groups of organisms diverged and evolved Allosaurus Velociraptor Archaeopteryx Sinornis Theropods Light bones Feathers with Flight feathers; 3 -toed foot; Down arms as long shaft, veins, wishbone feathers as legs and barbs

Fan model to indicate phylogeny

Modern six-kingdom classification n Archaebacteria: prokaryotic n Eubacteria: prokaryotic n Protists: eukaryotic n Fungi: eukaryotic n Plants: eukaryotic n Animals: eukaryotic

Archaebacteria overview n Most live in extreme environments such as swamps, deep-ocean hydrothermal vents, and seawater evaporating ponds. n Most do not use oxygen to respire.

Eubacteria overview n very strong cell walls n a less complex genetic makeup than found in archaebacteria or eukaryotes n diverse habitat

A Paramecium Protists: A diverse group Anal pore Cilia • Kingdom Protista contains diverse species that share some characteristics. • A protist is a eukaryote that. Oral groove Gullet Contractile vacuole Micronucleus and macronucleus

Protist overview n lacks complex organ systems n lives in moist environments n diverse metabolism

Fungi overview n Decomposes matter by absorbing materials n Multicellular or unicellular

Plant overview n Multicellular n Photosynthetic: produce oxygen n Immobile n Cell walls

Animal overview n Multicellular n Mostly mobile n Lack cell walls n Diverse habitats