bio quiz practice

3. organism that relies on other organisms for its energy and food supply; also called a heterotroph
6. total amount of living tissue within a given trophic level
7. chain: a series or steps in an ecosystem in which organisms transfer energy by eating and being eaten
9. photosynthetic algae found near the surface of the ocean
14. 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 into oxygen and energy-rich carbohydrates such as sugars and starches
16. process of converting nitrogen gas into nitrogen compounds that plants can absorb and use
17. each step in a food chain or food web

1. first producer of energy-rich compounds that are later used by other organisms
2. process by which bacteria convert nitrites into nitrogen gas
3. process in which chemical energy is used to produce carbohydrates
4. an 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
5. single essential nutrient that limits productivity in an ecosystem
8. organism that obtains food by consuming other living things; also called a consumer
10. chemical substance that an organism needs to sustain life
11. illustration of the relative amounts or matter contained within each trophic level in a given food chain or web
12. cycle 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
13. material made up of decaying bits of plant and animal material
15. network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem