bio unit 8

organism

living things

population

group of individuals of the same species living together in the same geographic area

community

groups of populations of different species that inhabit a particular area

ecosystem

all of the abiotic factors and the entire community of species that exist in a certain area

biosphere

the entire planet and all of the ecosystems found on earth

population growth formula

dN/dt = B - D (birthrate - deathrate)

exponential growth

population that experience reproduction without constraints experience exponential growth (abundant space, lack of competition, disease, predation)

logistic growth

populations affected by carrying capacity show logistic growth

density dependent limiting factors

the greater the population density = the greater the ability of the limiting resource to reduce population growth

density independent limiting factors

limiting factor has the same ability to reduce population growth in both low and high densities

interspecific interactions

relationships between different species

resource partitioning

similar species that coexist in a community if they differentiate their niches

symbiosis

two species live together long term (symbiotic relationships e.g. parasitism)

keystone species

stabilize ecosystems, removal may cause dramatic ecosystem changes

invasive species

non native species; can outcompete native species

altruistic behavior

reduce an individuals fitness while increasing that of other organisms

kinesis

organism changes its movement in a non directional way (e.g. slowing down or speeding up)

taxis

movement behavior that involved movement towards or away from something

biobass

the energy that is available to the next trophic level

reservoir

locations where nutrients are stored

processes

mechanisms that move nutrients between reservoirs

eutrophication

excess nutrients cause algal blooms, increase decomposition by bacteria, which leads to oxygen depletion, which leads t