taxonomy Flashcards
homologous structures
similarity from common ancestry
analogous structures
have the same function in different trees. No common ancestor
convergent evolution
similar features evolved independently in different lineages
4 traits systematic biologists use
morphological, fossil, behavior, molecular
morphological traits
analyze phenotypic characteristics
fossil traits
use time-based evidence of organism history
molecular traits
based on DNA analysis
mitochondrial DNA mutation rate vs nuclear DNA rate
mitochondrial mutates 10X faster
protein comparisons
compare particular protein’s AA (amino acid) sequences
molecular clocks
estimate divergence between species/groups. Based on random DNA mutations occurring at constant rate. Nuetral changes not under pressure.
Woese-Fox 3-Domain System
Bacteria - prokaryotes
Archaea - live in extreme environments/prokaryotes
Eukarya - all eukaryotes
Bacteria
unicellular prokaryotic (no nucleus)
some bacteria are pathogens
extracellular digestion/photosynthesis to gain nutrition
Archaea
unicellular prokaryotic
mostly anaerobic
variety of environments,
can tolerate harsh conditions
Eukarya
unicellular/multicellular
membrane-bound nucleus
Eukaryote Kingdoms
Protista, Fungi, Plantae, Animalia
Protista
Unicellular eukaryotes
paraphyletic - not a natural group
intracellular/extracellular digestion or photosynthesis to gain nutrition
Fungi
gain nutrition through extracellular digestion of dead organic matter
Non-photosynthesizing plants
some parasitic
Plantae
gain nutrition through photosynthesis
multicellular, autotrophic, eukaryotic
Animalia
multicellular, heterotrophic, eukaryotic
gain nutrition through consumption of other organisms
phylogeny
evolutionary history of a species/group of species
taxon
group of organs with a set of shared traits
ancestral trait
found in common ancestor
derived trait
not found in common ancestor
Three categories of extremophiles
thermoacidophiles - heat and acid tolerance
halophiles - salt tolerant
methanogens - methane producers
