| A | B |
|---|
| autotroph | manufactures food using energy from the sun or from chemical compounds |
| decomposer | breaks down dead organisms |
| heterotroph | obtains energy and nutrients from autotrophs |
| scavenger | feeds on dead organisms |
| mutualism | relationship between organisms in which both organisms benefit |
| commensalism | Relationship between organisms in which one orgaism benefits and the other is neither harmed nor benefited |
| parasitism | relationship between organisms in which one organism benefits at the expense of another |
| community | group formed by several populations |
| food chain | simple model for showing how matter and energy move through an ecosystem |
| habitat | place where an organism spends its life |
| food web | network of interconnected food chains |
| biosphere | layer of earth that supports life |
| niche | roles a species plays in a community |
| population | a group of same species in an ecosystem |
| abiotic factors | nonliving parts of an ecosystem |
| biotic factors | living parts of an ecosystem |
| omnivore | organism that feeds on both plant and animal life |
| herbivore | organism that feeds on plant life only |
| carnivore | organism that feeds only on animal life |
| producer | role of plants in an ecosystem |
| primary succession | sequence of community changes where soil is formed allowing small, weedy plants to inhabit area |
| secondary succession | sequence of community changes occurring as a result of a natural disaster, such as a forest fire |
| climax community | a stable, mature community with, little or no succession occurring |
| estuary | body of water where fresh and salt water mix |
| photic zone | Level of ocean water where sunlight penetrates |
| carrying capacitiy | the maximum number of individual organisms that could be supported by a given environment indefinitely |
| demography | the study of all the growth characteristics of a population |
| density-dependent factors | the effects of these factors increase as population size increases |
| density-independent factors | the effects of these factors can destroy whole populations regardless of population size |
| fertility rate | number of offspring produced by a female during her reproductive years |
| immigration | movement of individuals into a population |
| emigration | movement of individuals out of a population |
| bases | solutions with pH greater than 7.0 |
| acids | solutions with a pH less than 7.0 |
| renewable resource | a natural resource that is replaced or recycled by natural processes |
| preservation | the act of keeping an area or species from harm or destruction |
| conservation | the planned management of a natural area to prevent exploitation or destruction |
| greenhouse effect | the process of heat retention by atmospheric gases |
| biodegradable | wastes that can be broken down by natural processes |
| endangered species | a species whose numbers become so low that extinction is possible |
