| A | B |
|---|
| abiotic factor | nonliving part of an ecosystem |
| biotic factor | living part of an ecosystem |
| birth rate | number of births in a population in a certain amount of time |
| carrying capacity | largest population that a certain area can support |
| community | all of the different populations that live together in an area |
| death rate | the number of deaths in a population in a certain amount of time |
| ecology | study of how living things interact with each other and the environment |
| emigration | leaving a population |
| immigration | entering a population |
| estimate | an approximate number based on reasonable assumptions/collected data |
| habitat | the particular place that an organism lives |
| niche | an organism's particular role in an ecosystem, or how it makes its living |
| photosynthesis | process in which an organism can convert water and carbon dioxide into sugar, in the presence of light and a chloroplast |
| population | all the members of a particular species in a certain area |
| species | organisms with similar structures that can reproduce and have fertile offspring |
| population density | number of individuals of a certain species in a certain area |
| natural selection | process in which individuals that are better adapted are more likely to survive and reproduce |
| adaptation | behaviors and physical characteristics of species that allow them to live successfully in their environment |
| competition | struggle among organisms for limited resources in a habitat |
| predation | process in which one organism eats another |
| prey | organism killed by another for food |
| symbiosis | close relationship between species that benefits at least one of the species |
| predator | organism that kills another for food |
| mutualism | relationship between species in which both benefit |
| commensalism | relationship between two species in which one species benefits and the other is neither helped nor harmed |
| parasitism | relationship in which one organism lives on or inside another and harms it |
| parasite | organism that benefits by living in or on a host |
| host | organism that a parasite lives in or on |
| limiting factor | environmental factor that prevents a population from increasing |
| ecosystem | all the living and nonliving things in a certain area |
