1._______________________ is the study of how living things fit into their environment. 

2. A/An ____________________________is a group of interacting organisms and their physical environment. 

3. ___________________________ capture energy and store it in complex molecules.   

4. ___________________________ obtain energy by feeding on producers or other consumers. 

5. ___________________________ eat dead organisms, animal wastes, fallen leaves, twigs, and other debris. 

6. ___________________________ are organisms (such as plants) that make their own food. 

7. ___________________________ cannot make their own food and must obtain it from other organisms. 

8. Some bacteria absorb nitrogen gas and convert it to ammonia.  This is known as ______________________. 

9. ___________________________ cycle: atmosphere -> precipitation -> oceans -> evaporation 

10. The burning of fossil fuels releases large amounts of ___________________________ into the air.  

11. Carbon dioxide in the air retains heat from the sun, producing the ___________________________.  

12. ___________________________ are the basis of the food web in aquatic ecosystems. 

13. On land, there are seven major types of ecosystems, which are called ____________. 
 

MATCHING: 
17. ____ tundra   A. low rainfall; rich soil; tall, dense grasses 
16. ____ coniferous forests  B. very dry, hot, sparse vegetation 
18. ____ deserts   C. warm summer, cool winters; average rainfall 
14. ____ deciduous forests  D. wet, abundant vegetation and animals 
15. ____ temperate grasslands E. very dry; ground always frozen; small vegetation
19. ____ tropical rain forests  F. low rainfall; short growing season; cold winters 

20. ESSAY: List and describe the three major types of ecosystems found in the ocean.