BIODIVERSITY• The variability among living organismsfrom all types of ecosystem (e.g.terrestrial, marine)• This includes diversity– within species– between species– of ecosystems
TAXONOMY – classification• All living organisms are classified intodifferent groups.• This allows a kind of ‘filing system’ so thatany new discoveries are easily incorporatedinto a group and relationships betweengroups of similar organisms can be studied.• It also makes international communicationeasier and more efficient. That is because allnew discoveries will have recognised nameswhich are the same in all countries, andthey will all belong to a universally acceptedgroups.
Kingdoms• In the system we use, all living organismsare split into 5 kingdoms.• Viruses do not fit into this classification –they are not regarded as living organismsThe 5 kingdoms are called:1. Prokaryota (bacteria)2. Protista3. Fungi4. Plantae5. Animalia
The way a kingdom is split into smaller groups is asfollows:This is a hierarchical system – in which large groups are split intosmaller groups based upon their similarities and differences.• each kingdom is divided into phyla• each phylum is divided into classes• each class is divided into orders• each order is divided up into families• each family is divided up into genera• each genus is divided up into species
The Animalia KingdomUseful tip: Use the followingsentence to prompt you for thefirst letter for each level:Keen Pupils Choose OurFantastic Groovy SchoolEach of these levels is called aTAXON (plural: taxa)Kingdom e.g. AnimaliaPhylum e.g. ChordataClass e.g. MammaliaOrder e.g. PrimatesFamily e.g. HominidaeGenus e.g. HomoSpecies e.g. sapiens
TAXA• In a taxon, members all share one ormore common features (orhomologies)• It is generally presumed that they havea common evolutionary ancestor• In evolutionary terms, members of ataxon are more closely related than toany other organisms outside thattaxon.
Here is a table which shows the features of eachof the 5 kingdoms:BACTERIUMAMOEBAMOULDYEASTTOADSTOOL Prokaryota: Protoctista: Fungi:Cell type ProkaryoticVery smallTypically <10µm across Eukaryotic EukaryoticOrganisation UnicellularNo distinct nucleusA single circular chromosomeNo membrane-bound organellesMulticellular or unicellular Simple basic body structureMulticellularMost are made up a network of thread-like strands called hyphaeCell walls made of chitinNutrition Miscellaneous Either photosynthesise or feed on organic matterHeterotrophic - mostly saprobiontic(decay)- no photosynReproduction Mostly asexualAsexual and/or sexualMost have sexual and asexual Examples Bacteria /Cyanobacteria(blue-green bacteria)Algae / Protozoae.g. Amoeba and ParameciumMould / Yeast / Mushrooms
Plantae: Animalia:Cell type Eukaryotic EukaryoticOrganisation MulticellularDifferentiated cells organised into specialised organsCellulose cell wallsChloroplasts and large vacuolesMulticellularDifferentiated cells organised into specialised organsNo cells walls, chloroplasts or large vacuolesMost can move from place to placeHave a nervous system Nutrition Photosynthetic autotrophs- make organic compoundsHeterotrophsReproduction Sexual and asexual Mostly sexual with haploid gametesExamples Mosses / Liverworts / Ferns / Conifers / Flowering plantsJellyfish / Sponges / Flatworms / Arthropods Fish / Roundworms / Birds / Mammals
BINOMIAL NAMES• Each species has its own unique two-part Latin binomial name, made up ofthe genus and species names• This was first introduced by CarlLinnaeus.
Species• The species is the lowest level ofclassification within each Kingdom.• All members of a species:– have a similar morphology (body features),physiology (how organs and body systemsfunction), and behaviour– are capable of interbreeding to produce fertileoffspring– are reproductively isolated (in time, place orbehaviour) from other species.
Genus• A genus is a group of similar or closely relatedspecies• For example: Ranunculus = genus name forbuttercups.• The Ranuculus genus includes:Ranunculus aquatalis = water crowfootRanunculus repens = creeping buttercup• A genus could include just one species in someexamples, but more often it includes severalspecies.
Ranunculus repens (creepingbuttercup)• The GENUS name startswith a capital letter• The SPECIES name starts with a lower caseletter• When the binomial name is typed, it is typedin italics• When the binomial name is hand-written, it isunderlined
USING KEYS TO IDENTIFYORGANISMS• Dichotomous keys have 2 alternatives to choose from at each stageof the key• These are artificial classifications based upon easily visible featuresWhen using a key:• Always read both choices, even if the first seems to be the logicalone at first.• Be sure you understand the meaning of the terms involved. Do notguess.• When measurements are given, use a calibrated scale. Do not guess.• Since living things are always somewhat variable, do not base yourconclusion on a single observation. Study several specimens to besure your specimen is typical.• If the choice is not clear, for whatever reason, try both divisions. If youend up with two possible answers, read descriptions of the twochoices to help you decide.• Having arrived at an answer in a key, do not accept this asabsolutely reliable. Check a description of the organism to see if itagrees with the unknown specimen.