Classification, taxonomy and phylogenecy Flashcards
(22 cards)
What is a species?
Group of organisms that are able to breed to produce fertile living offspring
What is classification?
Organisation of organisms into groups based on similarities
What does classification allow?
- identification of new species
- study evolutionary relationships
- understand shared traits and adaptations
- share research globally to identify organisms links on other continents
What is the hierarchal taxonomic system?
8 major taxonomic ranks used to classify organisms
What are the 8 taxonomic ranks?
- domain
- kingdom
- phylum
- class
- order
- family
- genus
- species
What are the 3 domains?
- bacteria
- archaea
- eukarya
What are the 5 kingdoms?
- plantae
- animalia
- protoctista
- fungi
- prokaryotes
What is the binomial naming system?
Gives each species a 2 part ‘binomial’ Latin name
What does the binomial name consist of?
Genus = uppercase 1st letter
Species = all lowercase
Describe the domain plantae?
- multicellular eukaryotes
- contain nucleus membrane bound organelle and chloroplasts
- cellulose cell wall
- autotrophic
- reproduces via seeds or spores
Describe the domain animalia?
- multicellular eukaryotes
- contain nucleus and membrane bound organelle
- heterotrophic
- reproduce mainly by sexual reproduction
Describe the domain prokaryote?
- unicellular prokaryote
- no nucleus or membrane bound organelle
- peptidoglycan cell walls
- autotrophic heterotrophic or parasitic
- reproduce via binary fision
Describe the domain protoctista?
- uni and multicellular eukaryotes
- contain nucleus membrane bound organelle and sometimes chloroplasts
- some have cell walls
- autotrophic heterotrophic or parasitic
- reproduce asexually and sexually
Describe the domain fungi?
- uni and multicellular eukaryotes
- hyphae body
- contain nucleus and membrane bound organelle
- chitin cell walls
- saprophytic absorbing nutrients from dead matter
- reproduce via spores
What is the 3 domain system?
Proposes 6 kingdoms instead of 5 due to evidence for splitting the kingdom Prokaryotae into 2 separate kingdoms eubacteria and archaebacteria
recognises differences between bacteria, archaea, and eukarya
Describe the bacteria domain?
- contains kingdom Eubacteria only found in all environments
- prokaryotic unicellular organisms
- distinct cell membrane lipids
- peptidoglycan (murein) cell walls
- unique RNA polymerase enzyme
Describe the archea domain?
- contains kingdom Archaebacteria only found in extreme environments
- prokaryotic unicellular organism
- histones so gene and protein synthesis similar to Eukarya
- no peptidoglycan in cell walls
- different cell membranes containing fatty acids bound to glycerol
- more complex form of RNA polymerase than Bacteria
What is phylogenecy?
Classification based on evolutionary relationships between organisms and their ancestors classifying species into groups revealing how closely related organisms are
What are advantages of phylogenetic classification?
- produces continuous tree that doesn’t force organisms into specific taxonomic groups where they don’t quite fit
- no overlap between groups produced
What did early classification rely on and why was this an issue?
Relied on visible features
can misrepresent true evolutionary relationships due to some species having independently adapted to same environment
What is the evidence for modern taxonomy?
Molecular comparisons = comparisons between DNA and amino acids in proteins
Development studies = comparison of embryonic similarities and differences
Anatomical examinations = comparison of similarities in species physical characteristics
Behavioural analyses = comparisons of similarities and differences between behaviour of species
