M4 C10: classification and evolution Flashcards
what does the term biological classification mean?
the organisation of living and extinct organisms into groups based on similarities and differences between species
what does the term taxonomy mean?
the study and practice of naming and classifying species and groups within the hierarchical classification scheme
what is the classification system?
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
what are the problems with naming organisms based on a particular characteristic?
-same organisms may have completely different name in other parts of the country
-different common names are used in different countries
-same name could be used for different species in different countries
what is the binomial system?
a system of naming species in which each species has 2 names. a generic name and a specific description
what are the 5 kingdoms?
prokaryotes
protists
fungi
plants
animals
what did early classification rely on?
observable factors such as anatomy
what are prokaryotes?
mostly unicellular
no nucleus but has loops of DNA
autotrophic and heterotrophic
no membrane bound organelles
smaller ribosomes
free living or parasitic
what are protists?
single celled
can have plant or animal features
membrane bound organelles
autotrophic and heterotrophic as they can photosynthesise, feed on prey, use extracellular enzymes
are parasites
what are fungi?
eukaryotic
can exist as single cells or have mycelium (network of root like structures)
cell walls made of chitin
cytoplasm is multinucleate
mostly free living an saprophytic (causes decay of organic matter)
what are plants?
eukaryotic
multicellular
contain chlorophyll
autotrophic
what are animals?
eukaryotic
multicellular
heterotrophic
usually mobile (can move)
what are the 3 domains?
eukarya
archaea
bacteria
why were the domains made?
major differences discovered within prokaryotes showing they weren’t that closely related
what is evidence for classification?
1)evidence from bio molecules found in species
2) certain bio molecules are found in all living organisms for essential processes
3) earliest forms of life would have identical versions of these molecules this means any changes are due to evolution
4)comparing dna sequences
5)comparing amino acid sequences
what does the domain eukarya include?
protists
fungi
plants
animals
what is archeae?
can live in extreme environments, these include thermal vents ect.
what is bacteria?
true bacteria, contain peptidoglycan in cell walls
what is artificial classification?
done for convenience and is only based on a few characteristics. it provides limited information and doesn’t reflect evolutionary relationship
what is natural classification?
involves more detail and uses many more characteristics. based on homology and changes in knowledge. reflects evolutionary knowledge
what is homology?
the existence of shared features that are inherited from a common ancestor. shared features may not be used for the same function.