Classification

Classification System There are 13 billion known species of organisms; only 5% of all organisms that ever lived!!!!! Classification systems are how we organize organisms. The classification of organisms has changed and evolved over the years due to new knowledge Greater understanding of evolutionary relationships, thanks to DNA technology, has allowed for more detailed classification

What is Classification? Taxonomy is the study of classifying organisms and giving them a universally accepted name Classification is the arrangement of organisms into orderly groups based on their similarities Aristotle developed one of the earliest classification systems Divided things as either plants or animals Divided animals by their ability to swim, fly, or walk

Carolus Linnaeus 1707 – 1778 Called the “Father of Taxonomy” Classified organisms by their structure Developed the modern system of naming known as binomial nomenclature Two-word name (Genus & species)

Scientific Name The scientific name of an organism is the Genus and Species of an organism Always written in italics Genus name is capitalized and the second word is all lowercase The names are usually Latinized Ursus arctos = the grizzly bear Ursus is the genus name and means “bear.” Ursus maritimus is the polar bear (maritime refers to the sea)

Binomial Nomenclature Which TWO are more closely related?

Species Group of the same organisms Live together Mate and produce viable offspring Only species are able to interbreed. Organisms of two different species normally will not breed. Sometimes, organisms within the same genus are able to interbreed, but the offspring are not viable . Example: Mules; Ligers

Classification The classification of organisms begins with the largest groupings and moves down to the smallest (domain species) The classification order is as follows: Domain Kingdom Phylum Class Order Family Genus Species Easy way to remember: King Phillip Came Over For Good Soup!!!

Phylogenetic Trees Shows the evolutionary relationship between organisms Can show which organisms are more closely related than other organisms

Common ancestor of wolf and domestic dog Common ancestor of wolf, domestic dog, otter and skunk

Phylogenetic Trees Which organism is more closely related to the bear? Which organism is the chimpanzee more closely related to: Lizard or sunfish? Why?

Dichotomous Key Used to identify organisms Characteristics given in pairs Read both characteristics and either go to another set of characteristics OR identify the organism

Example of Dichotomous Key 1a Tentacles present – Go to 2 1b Tentacles absent – Go to 5 2a Eight Tentacles – Octopus 2b More than 8 tentacles – 3 3a Tentacles hang down – go to 4 3b Tentacles upright–Sea Anemone 4a Balloon-shaped body–Jellyfish 4b Body NOT balloon-shaped - 5

Cladogram Shows relationships up-close; characteristics they share

Which two organisms are most closely related? What trait do lizards have that salamanders don’t?

Domains Broadest, most inclusive taxon Three domains Archaea and Eubacteria are unicellular prokaryotes (no nucleus or membrane-bound organelles) Eukarya are more complex and have a nucleus and membrane-bound organelles

Classification of Living Things Domains DOMAIN KINGDOM CELL TYPE CELL STRUCTURES NUMBER OF CELLS MODE OF NUTRITION EXAMPLES Bacteria Eubacteria Prokaryote Cell walls with peptidoglycan Unicellular Autotroph or heterotroph Streptococcus, Escherichia coli Archaea Archaebacteria Cell walls without peptidoglycan Methanogens, halophiles Protista Eukaryote Cell walls of cellulose in some; some have chloroplasts Most unicellular; some colonial; some multicellular Amoeba, Paramecium, slime molds, giant kelp Fungi Cell walls of chitin Most multicellular; some unicellular Heterotroph Mushrooms, yeasts Plantae Cell walls of cellulose; chloroplasts Multicellular Autotroph Mosses, ferns, flowering plants Animalia No cell walls or chloroplasts Sponges, worms, insects, fishes, mammals Eukarya Classification of Living Things

Archaean Probably the 1st cells to evolve Live in HARSH environments Found in: Sewage Treatment Plants Thermal or Volcanic Vents Hot Springs or Geysers that are acid Very salty water (Dead Sea; Great Salt Lake)

EUBACTERIA Some may cause DISEASE Found in ALL HABITATS except harsh ones Important decomposers for environment Commercially important in making cottage cheese, yogurt, buttermilk, etc.

Domain Eukarya is Divided into Kingdoms Protista (protozoans, algae…) Fungi (mushrooms, yeasts …) Plantae (multicellular plants) Animalia (multicellular animals)

Protista Most are unicellular Some are multicellular Some are autotrophic, while others are heterotrophic Aquatic

Fungi Kingdom Eukaryotes Use spores to reproduce Absorptive heterotrophs (digest food outside their body & then absorb it) Need warm, moist places to grow Examples: yeast, molds, mildew, and mushrooms

Plantae Multicellular Autotrophic Absorb sunlight to make glucose – Photosynthesis Cell walls made of cellulose Growth, with increases in size and number of cells, is part of development. Development involves many stages from conception until death.

Reproduction in Fungi When there is plenty of moisture, fungi reproduce asexually by releasing spores. When conditions are not good, they reproduce sexually.

Taxonomy Plants are divided into two groups based on the presence or absence of vascular system Xylem tissue carries water and minerals upward from the roots Phloem tissue carries sugars made by photosynthesis from the leaves to where they will be stored or used Vascular Bundles

Animalia Multicellular Ingestive heterotrophs (consume food & digest it inside their bodies) Feed on plants or animals