1. The simplest grouping of more than one kind of organism in an area is called a ___. 2. What is biomass? 3. In ________________ bacteria convert nitrogen gas to ammonia, so that plants can take in nitrogen through their roots. 4. A snake that eats a frog that has eaten an insect that has fed on a plant is a ____ level consumer. 5. The kind of autotrophs found on the bottom of the ocean near volcanic vents cannot use sunlight to make their own food. They use chemicals. These organisms are called ___________. 6. There are 3 ecological research methods used by ecologists: modeling, observing, and experimenting. An ecologist sets up an area and periodically comes back to count the population numbers of a certain species. Which method is being used? 7. Plants and algae are ___, a synonym for which is ____. 8. What is a population? 9. From your text: Draw and label the picture of a food chain. Identify the autotrophs and heterotrophs. 10. What is primary productivity? Where is it discussed in chapter 3? 11. What is a biomass pyramid? 12. What do we call the repeated movement of water between earth’s surface and the atmosphere? 13. The combined portions of the earth in which all living things exists is the ___ . 14. What are nutrients? 15. Which is most likely to be a limiting nutrient in a freshwater pond: nitrogen, phosphorous, potassium, or carbon? 16. Carbon cycles through the biosphere through photosynthesis, respiration, and through (another process) ____. Hint: When bodies break down, carbon in carbon compounds is returned to the soil. 17. All of the particular members of a species living in a place is called a ____. 18. What do we call an organism that uses energy to make its own food from inorganic compounds? 19. An organism can only pass 10% of its energy on to the next trophic level. It uses most of its energy to run its life processes, and the rest is eliminated as ____. 20. What is ecology? 21. Nitrogen fixation is carried out primarily by ___. 22. What is a community? 23. In an ecosystem, ____ flows in one direction, but ____ recycles. 24. Sequence the levels of organization studied by Ecologists , and what each one is. 25. Differentiate between these types of heterotrophs: herbivore, carnivore, omnivore, detritivore, and a decomposer. 26. Although both are autotrophs: Photosynthetic bacteria require sunlight to live, and _____bacteria do not.