The branch of biology dealing with interactions among organisms and betweenorganisms and their environment iscalled

1. The branch of biology dealing with interactions among organisms and betweenorganisms and their environment iscalled • economy. • modeling. • recycling. • ecology.

2. The combined portions of Earth in which all living things exist is called the • biome. • community. • ecosystem. • biosphere.

3. All of the members of a particular species that live in one area are called a(an) • biome. • population. • community. • ecosystem.

4. Which of the following descriptions about the organization of an ecosystem is correct? • Communities make up species, which make up populations. • Populations make up species, which make up communities. • Species make up communities, which make up populations. • Species make up populations, which make up communities.

5. The simplest grouping of more than one kind of organism in the biosphere is • a population. • a community. • an ecosystem. • a species.

6. The lowest level of environmental complexity that includes living and nonliving factors is the • biome. • community. • ecosystem. • biosphere.

7. Which of the following is NOT a basic method used by ecologists to study the living world? • experimenting • classifying • modeling • observing

8. Which ecological inquiry method is an ecologist using when he or she enters an area periodically to count the population numbers of a certain species? • questioning • observing • experimenting • modeling

9. A mathematical formula designed to predict population fluctuations in a community could be called a(an) • biological experiment. • biological system. • ecological model. • ecological observation.

10. Plants are • producers. • consumers. • herbivores. • omnivores.

11. What is the original source of almost all the energy in most ecosystems? • carbohydrates • sunlight • water • carbon

12. Figure 3–1

13. The algae at the beginning of the food chain in Figure 3–1 are • consumers. • decomposers. • producers. • heterotrophs.

14. An organism that uses energy to produce its own food supply from inorganic compounds is called a(an) • heterotroph. • consumer. • detritivore. • autotroph.

15. Which of the following organisms does NOTrequire sunlight to live? • chemosynthetic bacteria • algae • trees • photosynthetic bacteria

16. An organism that cannot make its own food is called a(an) • heterotroph. • chemotroph. • autotroph. • producer.

17. In which way are plants in a sunny mountain meadow and sulfur bacteria in a deep-sea volcanic vent alike? • They both use photosynthesis to make their own food. • They both produce carbohydrates and oxygen. • They both use chemosynthesis to produce their own food. • They both produce carbon and hydrogen.

18. Organisms that obtain nutrients by breaking down dead and decaying plants and animals are called • decomposers. • omnivores. • autotrophs. • producers.

19. What is an organism that feeds only on plants called? • carnivore • herbivore • omnivore • detritivore

20. All the interconnected feeding relationships in an ecosystem make up a food • interaction. • chain. • network. • web.

21. The total amount of living tissue within a given trophic level is called the • organic mass. • trophic mass. • energy mass. • biomass.

22. What is an ecological model of the relationships that form a network of complex interactions among organisms in a community from producers to decomposers? • food web • an ecosystem • food chain • a population

23. What animals eat both producers and consumers? • herbivores • omnivores • chemotrophs • autotrophs

24. What is the term for each step in the transfer of energy and matter within a food web? • energy path • food chain • trophic level • food pyramid

25. A bird stalks, kills, and then eats an insect. Based on its behavior, which ecological terms describe the bird? • herbivore, decomposer • producer, heterotroph • carnivore, consumer • autotroph, herbivore

26. A snake that eats a frog that has eaten an insect that fed on a plant is a • first-level producer. • first-level consumer. • second-level producer. • third-level consumer.

27. Figure 3–2

28. The trophic levels in Figure 3–2 illustrate • the relative amount of energy at each level. • the amount of living organic matter at each level. • the relative number of individual organisms at each level. • that the producers outnumber first-level consumers.

29. In which way does Figure 3–2 differ from a typical model of trophic levels? • Second-level consumers outnumber first-level consumers. • Third-level consumers outnumber second-level consumers. • First-level consumers outnumber producers. • First-level consumers outnumber second-level consumers.

30. Only 10 percent of the energy stored in an organism can be passed on to the next trophic level. Of the remaining energy, some is used for the organism’s life processes, and the rest is • used in reproduction. • stored as body tissue. • stored as fat. • eliminated as heat.

31. Most of the energy available to a consumer trophic level is used by organisms for • transfer to the next trophic level. • respiration, movement, and reproduction. • producing inorganic chemical compounds. • performing photosynthesis.

32. Which type of pyramid shows the amount of living tissue at each trophic level in an ecosystem? • a numbers pyramid • an energy pyramid • a biomass pyramid • a food pyramid

33. Matter can recycle through the biosphere because • matter is passed out of the body as waste. • matter is assembled into chemical compounds. • biological systems do not use up matter, they transform it. • biological systems use only carbon, oxygen, hydrogen, and nitrogen.

34. The repeated movement of water between Earth’s surface and the atmosphere is called • the water cycle. • the condensation cycle. • precipitation. • evaporation.

35. Which of the following is NOT recycled in the biosphere? • water • nitrogen • carbon • energy

36. What is the process by whichbacteria convert nitrogen gas in the air to ammonia? • nitrogen fixation • excretion • decomposition • denitrification

37. Carbon cycles through the biosphere in all of the following processes EXCEPT • photosynthesis. • transpiration. • burning of fossil fuels. • decomposition of plants and animals.

38. How is carbon stored in the biosphere? • in the atmosphere as carbon dioxide • undergroundas fossil fuels and calcium carbonate rock • in the oceans as dissolved carbon dioxide • all of the above

39. Nitrogen fixation is carried out primarily by • humans. • plants. • bacteria. • consumers.

40. Which of the following has a direct role in the nitrogen cycle? • bacteria • legumes • decomposers • all of the above

41. Organisms need nutrients in order to • utilize hydrogen and oxygen. • carry out essentiallife functions. • recycle chemical compounds. • carry out nitrogen fixation.

42. The movements of energy and nutrients through living systems are different because • energy flows in one direction and nutrients recycle. • energy is limited in the biosphere and nutrients are always available. • nutrients flow in one direction and energy recycles. • energy forms chemical compounds and nutrients are lost as heat.

43. Biogeochemical cycling ensures that • human activity will have no effect on elements, chemical compounds, and other forms of matter. • living organisms will not become limited in any one nutrient. • nutrients will be circulated throughout the biosphere. • many nutrients will not reach toxic concentrations in the biosphere.

44. What can happen after a lake receives a large input of a limiting nutrient? • An algal bloom occurs. • Algae begin to die and decomposers take over. • Nitrogen compounds are recycled. • The concentration of oxygen drops below the necessary level.

45. The rate at which organic matter is created by producers in an ecosystem is called • a limiting nutrient. • fertilization. • an algal bloom. • primary productivity.

46. Which is most likely to be a limiting nutrient in a freshwater pond? • phosphorus • nitrogen • carbon • potassium

47. If a nutrient is in such short supply in an ecosystem that it affects an animal’s growth, the • animal becomes a decomposer. • substance is a limiting nutrient. • nutrient leaves the food chain. • ecosystem will not survive.

48. An ecologist who is studying the relationships among the dominant communities in a geographical region is studying an ecosystem. _________________________ • True • False

49. A biome is a group of ecosystems that have the same climate and similar dominant communities. _________________________ • True • False

50. Ecologists use tools such as binoculars and microscopes to model changes in the environment. _________________________ • True • False