Life Science Notes 3 PDF

Classification - Taxomy Why do we classify organisms ?...

Classification - Taxomy Why do we classify organisms ? and human ↳ To help understand evolution species, , nature What Criteria do we use for classification? 2) Physical characteristics ↳ behavioural characteristics ↳ Evoluntary relationships - determind by DNA and protein structure Definition of taxonomy : The discipline used to classify organisms naming things ↓ Carl Linnaeus created the binomial nomenclature system in 1735 Rules : words (most of the Time) ↳ Two Benefits : underlined if handwritten) ↳ Always italics (or - Universal language ↳ First word capitalized - consistency in scientific naming leach has its genus and clairity case ↳ Second word lower - · Eg Homo sapien species helping distinguish and group ↓ b genus species it) Classification System : 7 taxons - Uses heirachy/makes it easier for studying Kindgdom Starts with the largest/broadest category - Phylor - X Class Ends with the smallest/most specific category Order Family Mnemonic : Katie please , come over for great snacks caused OJ's funky glove stairs Genus Version Killing people : My Species The 6 Kingdoms 1 Plantae. - > multicellular eukaryotic (plants) ,. Animalia 2 - > multicellular , eukaryotic (Animals). Fungi 3 - > multicellular , eukaryotic (fungus 4. Protista - > eukaryotic, unicellular , and multicellular (stuff that doesn't fit in other categories S. Eubacteria - > Unicellular, prokaryotic (bacterial. 6 Arachaebacteria > - unicellular, prokaryotic (super strong bacterial What is a species ? ↳ A group of organisms which can breed together to produce fertile offspring eg. Humans, dogs , horses · Within different species different breeds you can get Dichotomous Keys ↳ always 2 choices A dichotomous key is a tool that allows the user to determine the identity of items in the natural World (such as trees, wildflowers, mammals , reptiles , rocks , and fish). keys of of choices that lead the user to the correct of item. consist a series name a given ↳ "Dichotomous" means divided into two parts ↳ In a dichotomous key there will always be two choices in each step of the key , until the organism is correctly defined ) The two choices a re not alike and most dichotomous keys work by using the individual's into and be identified to the smaller groups until it characteristics to place the organism smaller can species ↳ These keys begin with general characteristics and work towards progressivley more specific characteristics ↳ Both forking/tree Keys (piclographic) or go to keys (written) are used ↳> The two choices at each step of the key are called a couplet Think of using the key as being analogous to travelling down a multi-forked. road To get to your final destination the correct choice must be made at each fork Rules to Follow When Using a Dichotomous Key 1. always read both choices , even if the first seems to be logical understand the meaning of the terms involved in the. 2 key the Specimen Do not at. When 3 measurements are given , use a scale to measure. guess a measurement 4. Living things a re always variable , so do not base your organism identification in the field on a observation Study several specimens to be is typical single sure your species.. If the 5 choice is not clear for , whatever reason , try both divisions. If you end up with two possible answers, read descriptions of the two choices to help you decide. Having 6 arrived at an answer in a key , do not accept this as absolutely reliable. Check a description organism to see if it agrees with the unkown specimen if not er ror has been made of the , an Some key Ideas in Dichotomous Key construction. characteristics instead of ones that disappear or vary with the season or other envoirmental 1. Use constant factors observed 1. Use characteristics that can be directly with amount or dimension rather than vague terms 3. Use quantative measurements an like "big" and "small of the anatomical applies 4. Precede to describe terms with the name part to which it. 5 Make the choice a positive one - something "is" instead of "is not is diagram used to show relationships cladogram Cladograms A a their among different species or groups , illustrating evolutionary Evelotionary classification history · Phylogeny : "eveluntiary relationships · A phylogenetic free or evelutinary free is a branching diagram or "free showing the evolutionary relationships based organisms into categories on evelutionary history , not just physical characteristics · Biologists how group