A2 OCR Biology Key Terms and Definitions Ecosystems

1. A diagram showing a sequence of organisms in which chemical energy passes from one organism to the next. (4, 5)
5. An organism that breaks down organic remains of other organisms, returning matter from them to the soil and air, (10)
6. An area covered by a single variety of a single plant species. (11)
7. An organism that transfers energy from light or an inorganic compound to organic compounds; plants are producers, using light energy to produce carbohydrates and other organic substances. (8)
10. Taking samples from quadrats placed along a line running across the area to be surveyed. (4, 8)

2. A non-living component of the environment that affects the distribution and abundance of a species. E.g. temperature, light intensity, oxygen concentration, carbon dioxide concentration, water supply, pH, wind speed, inorganic substances, etc. (7, 6)
3. Organisms that look similar and can interbreed to produce fertile offspring. (7)
4. An organism that obtains its energy from organic compounds such as carbohydrates, fats and proteins. (8)
8. Remains of plants and animals, such as dead leaves, used as a nutrient source by decomposers and detritivores. (8)
9. A close relationship between two organisms in which both benefit. (9)

Get Revising