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unit 4 biology
unit 4 ecosystems stability and change
| Question | Answer |
|---|---|
| measurements of the number of individuals living in a defined space | population density |
| how a population is spread in an area | population dispersion |
| individuals gather into groups where resources are available (ex. fish) | clumped |
| what affects population growth | births, deaths, migration, limiting factors |
| population size increases dramatically over a relatively short period of time | exponential growth |
| population begins with a period of slow growth followed by a period of exponential growth before leveling off at a stable size | logisitics growth |
| competition, disease, and over crowding | density dependent |
| natural disaster | density independent |
| amount of organisms an ecosystem can support | carrying capacity |
| what would happen if a carrying capacity exceeded | organisms die because lack of resources |
| completely destroyed (ice age, mass volcanoes) | primary succession |
| partly destroyed and can come back relatively soon (flood, fire) | secondary succession |
| first species to occupy an area | pioneer species |
| a specific place or role for an organism in an ecosystem | niche |
| 2 species cannot share the same niche in the same __________ | habitat |
| causes species to divide resources | competition |
| organisms feed on one another | predation |
| the hunter | predator |
| one who is getting eaten | prey |
| a species that can change an ecosystem dramatically | keystone species |
| when organisms from a relationship | symbiosis |
| both species benefit | mutualistic |
| one benefits and the other is not harmed or helped | commensalism |
| one benefits, one harmed | parasitism |
| bird on cows back a. commensalism b. mutualism c, parasitism | mutualistic |
| tapeworms and humans a. parasitism b. commensalism c. mutualism | parasitism |
| what are the 4 of the major 6 biomes | desert, grassland, rain forest, tundra, taiga, deciduous |
| how much is lost between trophic levels | 90% |