| A | B |
|---|
| habitat | the place where an organism lives |
| ecosystem | all the living and nonliving things that interact in an area |
| biotic factors | the living parts of an ecosystem |
| abiotic factors | nonliving parts on an ecosystem, water, sunlight, oxygen, temperature, and soil |
| species | a single kind of organism |
| population | all the members of one species in a particular area |
| community | all the different populations that live together in one area |
| ecology | the study of how living things interact with each other and their environment |
| population density | the number of individuals in one area |
| direct observation | to determine the population by counting each member |
| indirect observation | to observe the tracks or signs to determine the population |
| sampling | to count the number of organisms in one area and then multiply to find the number in a larger area |
| mark and recapture studies | to capture, mark, and release animals, then recapture another group and count |
| adaptations | the behaviors and physical characteristics of a species that allow them to survive in an environment |
| niche | an organisms role in an ecosystem |
| competition | when two species compete to occupy the same niche, one will die off |
| predation | when one organism kills another |
| predator | the organism that does the killing |
| prey | the organism that is killed |
| symbiosis | a close relationship between two species that helps one of the species |
| mutualism | a close relationship where both species benefit |
| commnensalism | one species benefits and the the other species is neither helped or harmed |
| parasitism | one organism lives on or in another organism, hurting itit |
| birth rate | the number of births in a population in a certain amount of time |
| death rate | the number of deaths in a population in a certain amount of time |
| population equation | if birth rate is larger than death rate, population increases, if birth rate is smaller than death rate, population decreases |
| immigration | moving into a population |
| emigration | leaving a population |
| limiting factor | an environmental factor that keeps the population from increasing, examples: food, space, weather |
| carrying capacity | the largest population an environment can support |
| natural selection | the changes that make an organism better suited to its environment |
