Bio- Unit 2
Order by
103 terms
Terms | Definitions |
|---|---|
 Population Ecology | how biotic & abiotic factors influence the density, distribution, size, & age structure of populatoins |
| Density | # of individuals per unit area or volume |
| Dispersion | pattern of spacing among individuals within geographic boundaries |
| clumped | type of dispersion; individuals aggregate in patches |
| uniform | type of dispersion; even spacing of individuals w/in the population |
| random | type of dispersion; unpredicatable spacing, independent of others' positions |
| Demography | study of how a population's vital statistics (birth & death rates) change over time |
| Life Tables | age-specific summary of the survival pattern of a population |
| cohort | group of individuals of same age; used in in Life Tables |
| Survivorship Curves | graphical way of showing Life Table |
| Type I | low death rates during early & middle life, then an increase among older age groups |
| Type II | death rate constant over life span |
| Type III | high death rates for young, then a slower death rate for survivors |
| Life Histories | traits that affect survival & reproduction; based on intial reproductive age, frequency of reproduction, # of offspring per reproductiver event |
| Semelpartiy ("big bang") | reproduce once and die; large numbers of offspring produced at a time |
| Iteroparus | repeated reproduction over a span of time |
| natural selection | idea that traits and strategies that allow organisms to produce more surviving offspring are favored |
| population growth | birth (or reproduction) rate exceeds death rate |
| Exponential Growth Model | maximum growth under ideal conditions; have J-shaped curves |
| carrying capacity (K) | maximum population size a particular environment can support at a particular time |
| Logistic Growth | growth slows as carrying capacity reached; "S" (sigmoid) curve produced |
| r-selection | survive unpredictable environments (low pop densities) |
| K-selection | survive "near carrying capacity" environments (high pop densities) |
| density-dependent factors (regulating population size) | Usually BIOTIC: competition, territoriality, preferential predation, disease due to overcrowding, toxic waste accumulation |
| density-independent factors (regulating population size) | Usually ABIOTIC: weather, climate, natural disasters |
| age structure | the proportion of individuals in different age groups of a country's population |
| Global carrying capacity | how many humans can the biosphere support; uncertain |
| biological community | a group of populations that interact w/ each other |
| interspecific competition (-,-) | competition that occurs when shared resources (food, water, sunlight, space) are in short supply |
| Competitive Exclusion | one species becomes extinct in the area; "winner" uses resources more efficiently reproduces |
| Resource Partitioning | once species changes enough to use a different set of resources |
| habitat | physical area where orgnaims lives ("home address") |
| niche | a species' use of all the biotic and abiotic resources in its environment |
| fundamental vs. realized | what it could use (resources avaiable) vs. what it does use (due to competition) |
| Competitive Exclusion Act | two species competing for the same limited resource cannot coexist in the same place |
| Resource Partitioning | differentiation of ecological niches, enabling similar species to coexist in a community |
| Predation (+/-) | refers to interaction where one species, the predator, kills and eats the other, the prey |
| Mimicry | superficial resemblance to another species |
| Batesian | harmless species mimic harmful ones |
| Mullerian | unpalatable species mimic each other |
| Herbivory (+/-) | interaction in which an herbivore eats green plants or algae |
| Symbiosis | an intimate association between members of two or more species (individuals live in direct contact w/ one another) |
| Paratism (+/-) | interaction in which a parasite derives nourishment from and harms the host |
| endoparasites | live within host's body |
| ectoparasites | line outside host's body |
| Mutualism (+/+) | interaction in which both species benefit |
| Commensalism (+/0) | interaction in which one species benefits, the other is apparently unaffected; hard to document |
| Species Diversity | the variety of organisms that make up the community |
| species richness | the total number of different species in the community |
| relative abundance | the proportion of the total that each species represents (%) |
| dominant species | most abundant or hight biomass; most competitive in exploiting resources; most successful at avoiding predators, resisting disease |
| keystone species | play a pivotal role in community dynamics due to ecological niche |
| community stability | disturbances, natural or man-made, influence species diversity |
| Intermediate disturbance hypothesis | moderate levels of disturbances increase species diversity |
| ecological succession | sequence of changes in species composition after a disturbance |
| pioneer species | first to colonize a newly exposed habitat |
| climax community | constant species compostion in the final stage of succession |
| primary succession | the gradual colonization of bare rock by living organisms |
| secondary succession | an existing community is cleared by a disturbance that leaves the soil intact |
| trophic structure | feeding relationship among organisms in a community |
| trophic levels | "links" in the trophic strucutre |
| food chains | pathway along which food is transferred from one trophic level to another |
| food webs | a network of interconnecting food chains; complex trophic interactions |
| producers | convert light energy into chemical energy |
| autotrophs | build their own molecules ("self feeders") |
| consumers | obtain food from producers or other consumers |
| heterotrophs | "other feeders"; depend on the biosynthetic output of other organisms (animals, fungi, protists, most bacteria) |
| herbivores | feed on plants (primary consumers) |
| carnivores | feed on other animals (secondary, tertiary consumers) |
| omnivores | eat both plants and animals (any level consumer) |
| scavengers | feed on dead animals (carrion) |
| detritivores (decomposers) | consumers that obtain energy from detritus (non-living organic material); decompose organic waste matter into inorganic elements |
| Trophic Energy Efficiency | the % of net production transferred from one trophic level to the next |
| net production | energy stored in food |
| energy (net production) pyramid | model used to show loss at each trophic level |
| Energy flow | sun --> producers (autotrophs) --> consumers (heterotrophs); not recycled |
| Cycling of nutrients | minerals are acquired by plants eventually return to the soil via detritivores |
| Primary productivity | the rate at which plants & other photosynthetic organisms produce organic compounds in an ecosystem |
| Gross primary production (GPP) | total PP of an ecosystem |
| Net primary production (NPP) | organic coupounds remaining after the autotroph's own cellular respiration |
| R | energy used by primary producers for cellular respiration |
| terrestrial ecosystems | contribute 2/3 of global NPP |
| marine ecosystems | contribute 1/3 of global NPP |
| reservoirs | parts of ecosystem where a chemical accumulates |
| carbon cycle | ... |
| water cycle | ... |
| nitrogen cycle | ... |
| phosphorus cycle | ... |
| global warming | overral rise in Earth's temperature |
| greenhouse effect | CO2 (& other gases) trap heat close to Earth's surgace & prevent it from escaping into space |
| acid precipitation | precipitation that contians acidic substances |
| International Clean Air Acts | laws that limit exhaust from industries and cars; reduce damage of acid precipitation |
| eutrophication | sewage runoff from treatment plants, fertilizers from treatment plants, fertilizers from farms, release excess nitrogen into ponds, streams, & rivers |
| biological magnification | retained toxins become more concentrated at higher trophic levels |
| depletion of atmospheric zone | "hole" in ozone layer attributed to chlorine-releasing pollutants (chloroflurocarbons) in refrigerants and aerosols; allows more intense UV radiation, which increases skin cancer, cataracts, food crop & phytoplankton destruction |
| habitat destruction | clearing more land & using more natural resources damage natural ecosystem; species that cannot move or adapt become distinct |
| deforestation | clear-cutting forests |
| introduced (invasive) species | non-native species compete w/ native for natural resources or prey on them |
| overexploitation | the practice of harvesting/hunting a population to the point of extinction |
| conservative biology | application of biology to counter the loss of biodiversity |
| buffer zones | areas minimally impacted by humans |
| zoned reserves | land undisturbed by humans |
| sustainable development | developing natural resources that renew themselves |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.