| A | B |
|---|
| abiotic | the non-living portion of an environment |
| biotic | the living portion of an environment |
| limiting factors | physical or chemical factors that limit the existence, growth, abundance or distribution of an organism |
| limiting factors are usually: | abiotic factors (sunlight, soil, temperature, rainfall and water) |
| ecology | the study of living things and how they interact |
| decomposers | organisms which break down dead organic matter and return nutrients to the soil (fungi and bacteria) |
| phytoplankton | small floating plant-like protists and algae |
| one-celled organisms | bacteria, diatoms, some algae, |
| element C | carbon |
| element H | hydrogen |
| element O | oxygen |
| element N | nitrogen |
| element P | phosphorus |
| element S | sulfur |
| organism | an individual living thing |
| population | all organisms of one species living in a certain area at a given time |
| community | all populations of living things in the same area |
| ecosystem | all of the living and non-living parts of an environment and their interactions |
| biosphere | all of the areas on earth where life exists (all the ecosystems of the earth) |
| atmosphere | the thin layer of gases surrounding the earth |
| ecosphere | all of earth's ecosystems |
| lithosphere | the solid surface of the earth, the crust |
| photosynthesis | the process used by plants, algae, and blue-green bacteria to make food (sugar) from sunlight, carbon dioxide, and water |
| water | H20 |
| carbon dioxide | CO2 |
| respiration | the process used by organisms to break down food in order to get energy |
| by-products of photosynthesis | oxygen and water |
| by-products of respiration | carbon dioxide and water |
| oxygen-carbon dioxide cycle | continuous cycle that supplies O2 needed by all life (animals) and the CO2 needed by all plants/photosynthetic organisms |
| nitrogen component (%) of our atmosphere | 78% |
| legumes | plants which have nitrogen-fixing bacteria in nodules on their roots; they add usable nitrogen to the soil |
| examples of legumes | red clover, soybeans, peas... |
| sulfur cycle | movement of sulfur in different chemical forms from the environment to organisms back to the env. |
| phosphorus cycle | the process by which phorphorus cycles from theland t ocean sediments and back to the land and organisms |
