| A | B |
|---|
| Habitat | the place where an organism lives and that provides the things it needs |
| Biotic factors | the living parts of an ecosystem |
| Abiotic factors | the nonliving parts of an ecosystem |
| Population | all the members of one species in a particular area |
| Species | a group of similar organisms that can reproduce with each other and have fertile offspring |
| Community | all the different populations that live together in an area |
| Ecosystem | the community and all abiotic factors together |
| Ecology | the study of how living things interact with each other and their environment |
| Population Density | the number of individuals in a specific area |
| Estimate | an approximate number |
| Immigration | moving into a population |
| Emigration | leaving a population |
| Limiting Factor | an environmental factor that prevents a population from increasing |
| Carrying Capacity | the largest population that an environment can support |
| Natural Selection | the changes that make organisms better suited to their environment |
| Adaptations | behaviors or physical characteristics of species that allow them to live successfully in their environment |
| Niche | an organism's particular role, or how it makes a living |
| Competition | the struggle between organisms to survive in a habitat with limited resources |
| Predation | an interaction in which one organism kills and eats another |
| Symbiosis | a close relationship between two species that benefits at least one of the species |
| Mutualism | a relationship in which both species benefit |
| Commensalism | a relationship in which one species benefits and the other is neither helped nor harmed |
| Parasitism | a relationship in which one species lives on or in another organism and harms it. |
| Producer | an organism that makes its own food |
| Consumer | an organism that obtains energy by feeding on other organisms |
| Herbivores | consumers that eat only plants |
| Carnivores | consumers that eat only animals |
| Omnivores | a consumer that eats both plants and animals |
| Scavenger | a carnivore that feeds on the bodies of dead organisms |
| Decomposers | organisms that break down wastes and dead organisms and return the raw materials to the environment |
| Food Chain | A series of events in which one organism eats another organism and obtains energy |
| Food Web | the many overlapping food chains in an ecosystem |
| Energy Pyramid | the amount of energy that moves from one feeding level to another in a food web |
| Evaporation | the process by which molecules of liquid water absorb energy and change to the gas state |
| Condensation | The process by which gas changes to a liquid |
| Precipitation | rain, snow sleet or hai |
| Nitrogen Fixation | the process of changing free nitrogen gas into a usable form of nitrogen |
| Nodules | the "bumps" on certain plants that contain bacteria |
| Biogeography | the study of where organisms live |
| Continental Drift | the very slow motion of the continents |
| Dispersal | the movement of organisms from one place to another |
| Native species | Species that have naturally evolved in an area |
| Exotic species | an organism that is carried to a new area by a human |
| Climate | the typical weather patterns in an area over a long period of time |
| Biome | a group of ecosystems with similar climates and organisms |
| Deciduous trees | trees that shed their leaves and grow new ones each year |
| Coniferous trees | trees that produce their seeds in cones and have needle shaped leaves |
| Permafrost | soil that is frozen year round |
| Estuary | a habitat where fresh waters meet ocean salt water |
| Succession | the series of predictable changes that occur in a community over time |
| Primary succession | the series of predictable changes that occur in an area where no ecosystem previously existed |
| Pioneer species | the first species to populate an area |
| Seconadary succession | the series of predictable changes that occur after a disturbance in an existing ecosystem |
| Biodiversity | the number of different species living in an area |
| Keystone species | a species that influences the survivial of many other species in an ecosystem |
| Extinction | the disappearance of all members of a species from Earth |
| Genes | the structures in an organism's cells that carry its hereditary information |
| Habitat destruction | the lose of a natural habitat |
| Habitat fragmentation | breaking larger habitats into smaller, isolated pieces, or fragments |
| Poaching | the illegal killing or removal of wildlife species |
| Captive breeding | the mating of animals in zoos or wildlife preserves |
