| A | B |
|---|
| biotic factors | the living parts of the environment (plants, animals, insects, bacteria, etc.) |
| abiotic factors | the nonliving parts of the environment (water, sunlight, weather, soil, etc.) |
| habitat | the physical area in which an organism lives |
| niche | the way of life of an organism |
| symbiosis | the close association between 2 dissimilar organisms |
| mutualism | a form of symbiosis where both organisms are helped by the relationship |
| commensalism | a form of symbiosis where one organism is helped, but the other is neither helped nor harmed |
| parasitism | a form of symbiosis where one organism is helped and the other is harmed |
| producers (autotrophs) | organisms that make their own food (like plants) |
| consumers (heterotrophs) | organisms that get food by eating other organisms (animals) |
| carnivore | a consumer that eats only meat |
| herbivore | a consumer that eats only plants |
| omnivore | a consumer that eats both plants and animals |
| primary consumers | (herbivores) eat primary producers (plants) only |
| secondary consumers | (carnivores) eat primary consumers |
| tertiary consumers | (carnivores) eat secondary consumers, usually the third level of a food web, chain, or pyriamid |
| food chains | specific sequence in which an organism obtains energy within an ecosystem |
| food web | all the food chains within an ecosystem that interact |
| predator | an organism that is chasing and eating other organisms |
| prey | an organism that is chased and eaten |
| food pyramid | graph representing trophic levels numbers within an ecosystem |
| biomass pyramid | compares the total dry weight of the organism (biomass decreases as you go up) |
| energy pyramid | compares the total amount of energy available at each level ( energy decreases as you go up) |
| limiting factor | a biotic or abiotic factor that resists an organism's ability to live (reproduction, food, climate, space) |
| succession | the orderly and natural changes and species that will be replaced in a community |
| pioneer species | first species to take hold and live |
| climax community | a stable community (hardwood trees are present at this time) |
| straight line growth | growth that shows a steady rate of increase (straight line on graph) |
| exponential growth | as population grows larger, the growth rate increases (parabola on a graph) |
| population density | the number of organisms in an area |
| biological diversity | the variety of life in an area |
| threatened species | population has declined rapidly (African elephant) |
| endangered species | population is so low in numbers that extinction is possible (African black rhino) |
| extinct species | all members of this species are dead (woodland caribou, passenger pigeon) |
| carrying capacity | the maximum number of individuals that an ecosystem is capable of supporting (S shape graph) |
| density dependent population factors | these factors increase as population increases (usually biotic - disease, competition, parasites, food) |
| density dependent population factors | these affect all populations regardless of size (usually abiotic - temperature, storms, floods, drought, habitat disruption, pollution) |
| things that limit population size | predator/prey relationships, competition for resources |
| things that limit biodiversity | habitat loss, habitat fragmentation, habitat degradation |
| habitat loss | habitats are completely removed from an ecosystem (man tears down a rainforest, temeperature change kills a coral reef) |
| habitat fragmentation | separation of wilderness areas from other areas |
| habitat degradation | damage to habitat due to pollution (acid rain, ozone layer, greenhouse effect) |
| renewable resources | resources that can be used over and over (wind, water, trees, sunlight) |
| nonrenewable resources | once they are used up there will be no more (oil, coal, natural gas) |
