Diversity in Biology Organising Diversity

Two Main Classification Systems Six Kingdom System More traditional, widely used Classifies organisms into taxa (groups) Classification based on Morphological and physiological similarities Does not consider evolutionary relationships

Six Kingdom System Groups all living organisms into six groups: Archaebacteria Eubacteria All bacteria used to be in one kingdom called Monera Protista Fungi Plantae Animalia

Two Main Classification Systems Three Domain System More recent, not as widely used Classification based on Phylogeny evolutionary history of groups of organisms differences in the sequences in the cell's ribosomal RNAs (rRNA) cell's membrane lipid structure sensitivity to antibiotics.

3 Domain System

Three-domain System Better reflects evolutionary history of life 3 Domains of Life Archaebacteria are prokaryotes lack peptidoglycan in cell walls Eubacteria (true bacteria) are prokaryotes (no nuclei) Eukaryotes Protists, fungi, plants, animals

A hybrid system Blend of both Systems 3 domains, with 4 kingdoms within Eukarya Used in both systematics and Taxonomy.

The Six Kingdoms and Domains number of Cells energy cell type examples archaebacteria unicellular some autotrophic, most chemotrophic prokaryote "extremophiles" eubacteria autotrophic and heterotrophic bacteria, E. coli fungae most multicellular heterotrophic eukaryote mushrooms, yeast plantae multicellular autotrophic trees, grass animalia humans, insects, worms protista most unicellular heterotrophic or autotrophic ameba, paramecium, algae

What kind of organism is it… Sea Monkey Firefly Ringworm Jellyfish Spider monkey Crayfish Sea Horse Photo Credit: Audringje; flickr

Panthera pardus

Binomial Nomenclature Scientific names must either be underlined or italicized The genus is always capitalized, the species is lowercase Can be abbreviated. Ex. P. leo and P. tigris

What are the scientific names of each of these organisms? Kingdom Animalia Phylum Chordata Class Mammalia Aves Order Carnivora Anseriformes Family Felidae Anatidae Genus Panthera Anas Species Leo Tigris acouta What are the scientific names of each of these organisms?

What is a species? Defined as organisms that can interbreed with one another, and produce fertile offspring

Example: ligers and mules When two organisms of different species interbreed, the offspring is called a HYBRID These offspring are usually infertile, therefore do not form a new species. Example:  ligers and mules

Systematics Dichotomous Keys Used to identify organisms At each stage, there are only 2 choices!

Has green coloured body ......go to 2 1. Has green coloured body ......go to 2 Has purple coloured body ..... go to 4 2. Has 4 legs .....go to 3 Has 8 legs .......... Deerus octagis 3. Has a tail ........ Deerus pestis Does not have a tail ..... Deerus magnus 4. Has a pointy hump ...... Deerus humpis Does not have a pointy hump.....go to 5 5. Has ears .........Deerus purplinis   Does not have ears ......Deerus deafus

Deerus pestis Deerus magnus Deerus octagis Deerus humpus www.biologycorner.com Deerus humpus Deerus puplinis Deerus deafus

Dichotomous Key Body Colour GREEN 4 Legs Tail Deerus pestis No Tail Deerus magnus 8 Legs Deerus octagus PURPLE Pointy Hump Deerus humpis No Pointy Hump Has ears Deerus purplinis No Ears Deerus deafus