Across
- 1. process in which chemical energy is used to produce carbohydrates
- 3. organism that obtains food by consuming other living things; also called a consumer
- 7. chemical substance that an organism needs to sustain life
- 8. process by which bacteria convert nitrates into nitrogen gas
- 10. Producer First producer of energy-rich compounds that are later used by other organisms
- 11. process of converting nitrogen gas into nitrogen compounds that plants can absorb and use
- 12. chain A series of steps in which organisms transfer energy by eating and being eaten
- 13. network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem
- 15. An organism that is able to capture energy from sunlight or chemicals and use it to produce its own food.
- 17. total amount of living tissue within a given trophic level
Down
- 2. illustration of the relative amounts of energy or matter contained within each trophic level in a given food chain or food web
- 4. photosynthetic algae found near the surface of the ocean
- 5. process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another
- 6. material made up of decaying bits of plant and animal material
- 9. single essential nutrient that limits productivity in an ecosystem
- 10. process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches
- 14. organism that relies on other organisms for its energy and food supply; also called a heterotroph
- 16. level Each step in a food chain or food web