Classification

What is Classification? Grouping things according to similarities exp. Library books

Taxonomy Science of classifying things 2.5 million different kinds of organisms have been discovered! Helps keep track and organize info

Taxonomists classify organisms based on how they are alike NOT JUST HOW THEY LOOK exp. blood, dna, cells, environment, etc.

Early Classification Systems Aristotle classified organisms as either plants or animals Animals were classified into smaller groups based upon where they lived Land, Water, and Air environments Plants were classified according to their sizes and kind of stem Small plants with soft stems = herbs Medium sized plants with woody stems = shrubs Large plants with one woody stem = tree

Carolus Linnaeus - New Way of Classifying Classified organisms according to their physical characteristics Organisms that looked alike were grouped together Known as the Father of Modern Taxonomy Came up with Binomial Nomenclature

How are living things classified? 7 major classification levels The # of different kinds of organisms in each level decreases as you move from the kingdom level to each of the next smaller levels Kingdom, Phylum, Class, Order, Family, Genus, Species Mnemonic Device: Help Remember Sequence! King Play Chess On Fuzzy Green Stools Kindly Put Candy Out For Good Students King Phillip Came Over For Green Soup

Cladograms vs. Phylogenetic Trees a diagram used in cladistics which shows relations among organisms. Phylogenetic Tree A phylogeny, or evolutionary tree, represents the evolutionary relationships among a set of organisms or groups of organisms, called taxa (singular: taxon). The tips of the tree represent groups of descendent taxa (often species) and the nodes on the tree represent the common ancestors of those descendants.

Dichotomus Key a key for the identification of organisms based on a series of choices between alternative characters

Comparing the levels The largest classification group → Kingdom (6 total) Organisms in this group have similar cell structure and functions exp. Animal Kingdom - multicellular, and get energy from food Each Kingdom is further divided into → Phyla Have similar body plans or structures Phyla → Classes Have more details of structure and function in common Classes → Orders Orders → Families Families → Genuses made up of two or more species that are very much alike exp. Dogs and wolves belong to different species but the same genus Genuses → Species

Species smallest classification group have similar characteristics and can reproduce among themselves exp. all dogs belong to the same species

Naming Organisms Carolus Linnaeus named organisms using a 2-part scientific name Binomial Nomenclature - 2 names Made up of the organism’s Genus & Species Genus = capitalized and Species = lowercase; both are italicized

The Three-Domain System Scientists also classify organisms into groups based on how they have evolved, or changed, over time Domains - broad classification categories (larger than Kingdoms) Bacteria - Kingdom Eubacteria Archae - Kingdom Archaebacteria Eukarya - Kingdoms Protista, Fungi, Plantae, and Animalia

Using DNA to Classify Organisms Scientists are now using DNA to classify organisms can identify related organisms exp. 1990 - Scientists studied the DNA of whales & hippos Both species have similar mutations in their DNA that are not found in other animals Means that whales & hippopotamuses may have a common ancestor

What are the Kingdoms? 6 Kingdoms classified according to cell structure, whether they are unicellular or multicellular, and how they obtain energy

Kingdom Archaebacteria unicellular organisms do not have a true nucleus - genetic material is coiled & located in one region lack many of the organelles found in other kinds of cells live in extreme environments including hot springs, very salty or acidic conditions, and the bottom of the ocean means “ancient bacteria”; were here millions of years before the dinosaurs

Kingdom Eubacteria simple, unicellular organisms does not have a true nucleus have different types of cell walls and cell membranes live in soil, water, and even in humans exp. E. Coli found in human intestines exp. Streptococci is a eubacteria that causes strep throat

Kingdom Protista simple, unicellular or multicellular Parameciums = unicellular, Algae = form colonies & are multicellular has a true nucleus surrounded by a membrane have a variety of organelles includes both plant-like and animal-like organisms some can make their own food while some ingest their food

Kingdom Fungi unicellular or multicellular plant-like organisms exp. Yeast = unicellular, Mushrooms = multicellular have a cell wall do not have chlorophyll so they do not make their own food absorb food from the environment - most feed on dead organisms known as “Nature’s recycler”

Kingdom Plantae Multicellular organisms have a cell wall made up of cellulose have chloroplasts - chlorophyll contained in chloroplasts to make their own food - autotrophs exp. trees, grasses, and flowering plants

Kingdom Animalia Multicellular organisms obtain food by eating other organisms - heterotrophs able to move great distances on their own unlike other kingdoms exp. Birds, reptiles, fish, and mammals

What are Viruses? nonliving particle made up of a piece of nucleic acid covered with a protein does not have organelles do not grow, take in food, or make waste depends on living cells in order to reproduce

Virus Structure a piece of nucleic acid covered with an outer coat of protein = capsid makes up most of the virus and gives it its shape

Reproduction in Viruses Reproduce & make more viruses inside other living cells HAVE TO BE INSIDE A LIVING CELL

Viruses continued... Can enter a cell and remain inactive or dormant When activated it can cause a disease exp. Cold sore is caused by a virus that may have been dormant for years When viruses leave the cell, the cell is often destroyed this causes some infections - flus or colds exp. HIV virus takes over a cell and forces the cell to release new viruses gradually by budding without causing the cell to burst

Classifying Viruses not classified in the 6 kingdom system used to be classified based on which type of organism they infected Today scientists classify these viruses based on their shape and structure 3 basic characteristics used structure of their capsid type of nucleic acid they contain - DNA or RNA the way in which viruses reproduce Typically named after the disease that it causes exp. Rabies → rabies virus

https://www. youtube. com/watch https://www.youtube.com/watch?v=kKwOlAqQoLk&list=PLtXf78zN40CIEFZet7 OXvjuy1-St6Zzkf Taxonomy Classification