organism classification Flashcards
what is a species
smallest group that organisms can be classified in
a species is a group of organisms that can reproduce with each other to fertile offspring
what is a genus
a group of species that are closely related
scientific name of species begins with a genus
binomial naming system
an internally agreed system in which the scientific name of an organism is made up of 2 parts : genus and species.
genus always capitalized
dicotomus keys
used to identify unfamiliar organisms by comparing their traits
pairs of opposing statements
follow the key until you reach a species name
evolution
the process by which living organisms have developed from earlier organisms
comparative anatomy
looking if different animals have similar bones we could believe that they have a common ancestor which we could use to classify them with
some species have evolved similar characteristics independently and have no close links at all.
DNA sequency in classification
use of DNA has revolusionized classification
each species has a distinct number of chromosomes ad a unique sequence of DNA bases.
this makes it possible to distinguish one species from another
this is useful for species that look similar but are actually different
genome
complete set of genetic infromation for a species
classification of primates
traditionally we grouped primates into mokeys, apes, and humans- based on anatomy, particually bones and teeth
due to DNA humans are closely related to chimpanzees
if a speices has more chromosomes than anther species, doesn’t mean they are more complex
animal kingdom
animals are multicellular organisms
animal cells have no cell wall or chloroplasts
feed on organic substances made by other organisms.
don’t produce own food.
plant kingdom
their cells have a nulceus, cell wall, some have chloroplasts
feed by photosynthesis
may have roots, stems and leaves
fungus kingdom
usually multicellular
cells have nucleus, cell wall, no chlorophyll
are decomposers
reproduce by forming spores that spread by wind or animals
main body is made of microscopic threads called hypea
protoctist kingdom
mix of different organisms
unicellular or multicellular
cells have nucleus, may have cell wall and chloroplasts
some feed through photosynthesis, others through organic matter produced by other organisms
also called protist
prokaryote kingdom
bacteria
usually unicellular
no nucleus, circular loop of DNA
have cell wall, often have plasmids
no mitochondria nor other complex membrane-bound organelles
organism
a living thing
have 7 characteristics
