Bio Chapter 4 Crossword

4. Organism that obtains food by consuming other living things; also called consumers
6. Series of steps in an ecosystem in which organisms transfer energy by eating and being eaten
7. Process used by plants and other autotrophs to capture light energy and use it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches
8. First producer of energy-rich compounds that are later used by another organism
9. Organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer
12. Each step in a food chain or food web
15. Process in which chemical energy is used to produce carbohydrates
17. Model of the relative amounts of energy or matter contained within each trophic level in a given food chain or food web
19. Network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

1. Chemical substance that an organism needs to sustain life
2. Process in which elements, chemical compounds, and other forms of matter are passed from one part of the biosphere to another
3. A natural feature (such as a landmass, forest, or ocean) that stores carbon
5. Process of converting nitrogen gas into nitrogen compounds that plants can absorb and use
10. Material made up of decaying bits of plant and animal material
11. Process by which bacteria convert nitrates into nitrogen gas
13. Single essential nutrient that limits productivity in an ecosystem
14. Photosynthetic algae found near the surface of the ocean
16. Total amount of living tissue within a given trophic level
18. Organism that relies on other organisms for its energy and food supply; also called a heterotroph