Ch4 Ecosystems

4. A heterotroph that eats other organisms for energy.
5. A step in the food chain or food web, representing the position of an organism.
6. The process by which plants and some other organisms convert sunlight, carbon dioxide, and water into food and oxygen.
8. The movement of elements and compounds, like carbon or nitrogen, through living organisms and the environment.
11. The process in which bacteria convert nitrates in the soil back into nitrogen gas, releasing it into the atmosphere.
12. The process by which some organisms use chemical energy to produce food.
14. A nutrient that is in short supply and limits the growth of organisms in an ecosystem.
16. An organism that makes its own food, typically through photosynthesis or chemosynthesis.
17. An autotroph that forms the base of the food chain by producing energy-rich compounds used by other organisms.

1. The total mass of living organisms in a given area or ecosystem at a given time.
2. A linear sequence of organisms where each is eaten by the next one in the chain, showing energy flow.
3. The process by which certain bacteria convert nitrogen gas from the atmosphere into forms usable by plants.
6. Tiny, photosynthetic organisms in aquatic environments that are a major source of food for many marine creatures.
7. A complex network of interconnected food chains, showing how energy flows through an ecosystem.
9. A graphical representation showing the energy, biomass, or number of organisms at each trophic level in an ecosystem.
10. Dead organic matter, such as decaying plants and animals, which provides nutrients for decomposers.
13. An organism that cannot make its own food and must consume other organisms for energy.
15. A chemical substance that organisms need to survive and grow, such as nitrogen or phosphorus.