| A | B |
|---|
| ORGANISM | a living thing |
| HABITAT | an environment that provides the things the organism needs to live, grow and reproduce |
| BIOTIC FACTORS | the living parts of a habitat |
| ABIOTIC FACTORS | the nonliving parts of a habitat |
| PHOTOSYNTHESIS | the process in which organisms use water along with sunlight and carbon dioxide to make their own food |
| SPECIES | a group of organisms that are physically similar and can mate with each other and produce offspring that can mate and reproduce |
| POPULATION | all the members of one species in a particular area |
| COMMUNITY | all the different populations that live together in an area |
| ECOSYSTEM | the community of organisms that live in a particular area, along wiht their nonliving surroundings |
| ECOLOGY | the study of how living things interact with each other and with their environment |
| 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 |
| IMMIGRATION | moving into a population |
| EMIGRATION | leaving a population |
| LIMITING FACTOR | an environmental factor that causes a population to stop growing |
| CARRYING CAPACITY | the largest population that an area can support |
| PRODUCER | an organism that can make 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 | consumers that eat both plants and animals |
| SCAVENGER | a carnivore that feeds on bodies of dead organisms |
| DECOMPOSERS | organisms that break down waste and dead organisms and return the raw materials to the ecosystem |
| FOOD CHAIN | a series of events in which one organism eats another and obtains energy |
| FOOD WEB | the pattern of overlapping food chains in an ecosystem |
| ENERGY PYRAMID | a diagram that shows the amount of energy that moves from one feeding level to another in a food web |
| NATURAL SELECTION | a process by which characteristics that make an individual better suited to its environment become more common in a species |
| ADAPTATIONS | the behaviors and physical characteristics that allow organisms to live successfully in their environment |
| NICHE | the role of an organism in its habitat or how it makes its living |
| COMPETITION | the struggle between organisms to survive as they attempt to use the same limited resource |
| PREDATION | an interaction in which one organism kills another for food |
| PREDATOR | the organism that does the killing |
| PREY | the organism that is killed |
| SYMBIOSIS | a close relationship between two organisms that benefits at least one of the species |
| MUTUALISM | a relationship where both species benefit |
| COMMENSALISM | a relationship where one species is helped and the other is neither helped nor harmed |
| PARASITISM | an organism living in or on another organism and is harming it |
| PARASITE | the organism that benefits by lving in or on a host |
| HOST | the organism that is harmed by the parasite |
| NITROGEN FIXATION | the process of changing free nitrogen into a usable form of nitrogen |
