Classification and evolution Flashcards
What is classification
- the process by which living organisms are sorted into groups
What are the taxonomic groups
- kingdom
- phylum
- class
- order
- family
- genus
- species
Why are organisms classified
- identify species
- predict characteristics
- find evolutionary links and common ancestors
Why is a single classification system used worldwide
- allows scientists to share finding and link animals across continents
What is a species
- a group or organisms that are able to reproduce to produce fertile offspring
Why might an organisms by infertile (so not a species)
- odd number of chromosomes
- means meiosis/ gamete production can’t occur
Classification of humans
- d= eukarya
- k= animalia
- p= chorolata
- c= mammalia
- o= primates
- f= horminidae
- g= homo
- s= sapien
What is the name for how species are named
- binomial nomenclature
How are species named
- genus species
- ( in italics)
What are the 5 kingdoms
- prokaryotae
- protoctista
- fungi
- plantae
- animalia
Features of prokaryotae
- unicellular
- no nucleus or other membrane bound organelles
- small ribosomes
- no visible feeding mechanism (nutrients absorbed)
Features of protoctista
- mainly unicellular
- nucleus and other membrane bound organelles
- some have chloroplasts
- some immobile, some move by cilia/flagella
- nutrients acquired through photosynthesis
- e.g. amoeba
Features of fungi
-uni or multicellular
- nucleus and other membrane bound organelles
- chitin cell wall
- no chloroplasts
- no mechanisms for locomotion (movement)
- food stored as glycogen
- nutrients acquired through absorption (often of decaying matter) - saprophytic
- some are parasitic
- e.g. mould, yeast
Features of plantae
- multicellular
- nucleus and other membrane bound organelles
- chloroplasts and chlorophyll
- cellulose cell wall
- store food as starch
- nutrients acquired through photosynthesis (autotrophic)
- most don’t move
- e.g. grass, trees
Features of animalia
- multicellular
- nucleus and other membrane bound organelles
- no chloroplasts
- move with aid of flagella, cilia, contractile proteins
- heterotrophic- acquire nutrients through ingestion
- food stored as glycogen
- e.g. mammals, repitles
How is DNA used to discover evolutionary links, example
- when organisms evolve, DNA changes (determines proteins and characteristics)
- comparing the DNA similarity between species discovers evolutionary relationships
- e.g. haemoglobin = differs in amino acid numbers between different species, similar structure indicates common ancestry
What is a domain, what are they
- further level of classification at the top of the hierarchy
- classifies organisms into 3 domains, and 6 kingdoms
- eukarya, archaea, bacteria
- organisms in each domain contain unique form or rRNA and different ribosomes
Features of Eukarya
- 80s ribosomes
- RNA polymerase contains 12 proteins
Features of archaea
- 70s ribosomes
- RNA polymerase contains 8-10 proteins
Features of the bacteria domain
- 70s ribosomes
- RNA polymerase contains 5 proteins
What are the 6 kingdoms domains cause
- protoctista, plantae, animalia, fungi remain the same, under the EUKARYA domain
- arachaea and bacteria split prokaryotae into eubacteria and archaeabacteria
Features of archaea bacteria, example
- single celled prokaryotes
- known as ancient bacteria
- can live in extreme environments (e.g., acidic or thermal)
- e.g. methanogens
Features of eubacteria
- single celled prokaryotes
- known as true bacteria
- more common than archaea bacteria
- found in all environments
- peptidoglycan cell wall
What is phylogeny
- the evolutionary relationships between organisms
What is phylogenetics
- the study of evolutionary history of groups or organisms
- reveals which groups of organisms are related, how closely related they are
What is a phylogenetic tree
- a diagram used to represent the evolutionary relationship between 2 organisms
Features of phylogenetic trees
- branched diagram
- shows how different species evolve from a common ancestor
- earlies species at base of tree, most recent at tips of branches
- produced by looking at differences and similarities in species genetic makeup and physical characteristics
- the closer the branches, the closer the evolutionary relationship