Ecosystems L 3.3

1. Ecosystems L 3.3

2. What is the source of water for most land plants? _________________________ A air B soil C rocks D leaves

3. What is the source of water for most land plants? _________________________ B soil

4. How are the remains of living organisms cycled through ecosystems? ________________________ A evaporation B condensation C decomposition D photosynthesis

5. How are the remains of living organisms cycled through ecosystems? ________________________ C decomposition

6. Which provides most of the carbon dioxide that algae need to make food? _____________________________ A fungi B plants C animals D bacteria

7. Which provides most of the carbon dioxide that algae need to make food? _____________________________ C animals

8. What is the primary source of energy for producers? ____________________________ A the Sun B the atmosphere C the metabolism of glucose D the decomposition of organic matter

9. What is the primary source of energy for producers? ____________________________ A the Sun

10. A diagram of a forest food web is below. Which organism releases oxygen as a product of photosynthesis? ___________ A aphid B deer C grass D human

11. A diagram of a forest food web is below. Which organism releases oxygen as a product of photosynthesis? ___________ C grass

12. Which best describes the role of most types of bacteria within a food web? _____________________________ A predator B producer C consumer D decomposer

13. Which best describes the role of most types of bacteria within a food web? _____________________________ D decomposer

14. Which process do animals use to obtain nitrogen within their diets? ___________________________ A digestion B respiration C decomposition D photosynthesis

15. Which process do animals use to obtain nitrogen within their diets? ___________________________ A digestion

16. After decomposers break down decaying organisms, which directly uses the resulting nutrients? __________________________________ A animals B fossils C plants D the Sun

17. After decomposers break down decaying organisms, which directly uses the resulting nutrients? __________________________________ C plants

18. Which shows the correct flow of energy through this simple food chain? _____________________________________ A fox → grass → rabbit B grass → fox → rabbit C grass → rabbit → fox D rabbit → grass → fox

19. Which shows the correct flow of energy through this simple food chain? _____________________________________ C grass → rabbit → fox

20. Which best describes the role humans play in the oxygen cycle? ________________________________________ A They combine oxygen with other elements. B They breathe in oxygen and carbon dioxide from the atmosphere. C They breathe in oxygen and convert it to carbon dioxide, which they breathe out into the atmosphere. D They breathe in carbon dioxide and convert it into oxygen, which they breathe out into the atmosphere.

21. Which best describes the role humans play in the oxygen cycle? ________________________________________ C They breathe in oxygen and convert it to carbon dioxide, which they breathe out into the atmosphere.

22. Which is an effect of replanting trees in local communities? ________________________________________ A More carbon dioxide will be removed, and more oxygen will be produced. B More oxygen will be removed, and more carbon dioxide will be produced. C More oxygen and carbon dioxide will be produced. D Less carbon dioxide and oxygen will be produced.

23. Which is an effect of replanting trees in local communities? ________________________________________ A More carbon dioxide will be removed, and more oxygen will be produced.

24. What is the role of photosynthesis in the carbon cycle? __________________________________ A It adds carbon dioxide to water. B It removes carbon dioxide from plants. C It adds carbon dioxide to the atmosphere. D It removes carbon dioxide from the atmosphere.

25. What is the role of photosynthesis in the carbon cycle? __________________________________ D It removes carbon dioxide from the atmosphere.

26. Which best describes how energy from the sun relates to the energy a cow gets from eating grass in a field? ________________________________________ A The cow absorbs energy from the sun, and stores the energy in its body. B The cow absorbs energy from the sun, and uses this energy to break down the grass it eats. C The grass absorbs energy from the sun; the cow eats the grass and releases additional energy to the grass. D The grass uses energy from the sun to make food; the cow eats the grass and breaks it down to release energy for the cow to use.

27. Which best describes how energy from the sun relates to the energy a cow gets from eating grass in a field? ________________________________________ D The grass uses energy from the sun to make food; the cow eats the grass and breaks it down to release energy for the cow to use.

28. Through which do animals release most nitrogen from their bodies? ________________________________ A blood B saliva C sweat D urine

29. Through which do animals release most nitrogen from their bodies? ________________________________ D urine

30. In a marine ecosystem, which gas is needed by algae to produce oxygen? _____________________________ A chlorine B nitrogen C hydrogen D carbon dioxide

31. In a marine ecosystem, which gas is needed by algae to produce oxygen? _____________________________ D carbon dioxide

32. Which factor would most likely have a negative effect on the rate at which photosynthesis occurs in a bean plant? _________________________________ A a lack of water B a shortage of oxygen C an increase in temperature D an abundance of carbon dioxide

33. Which factor would most likely have a negative effect on the rate at which photosynthesis occurs in a bean plant? _________________________________ A a lack of water

34. Which best explains how plants contribute to the water cycle? ___________________________________ A by being the base of all successful food webs B by storing water in their vacuoles C through photosynthesis D through transpiration

35. Which best explains how plants contribute to the water cycle? ___________________________________ D through transpiration

36. Which best describes how green plants obtain the carbon dioxide needed for photosynthesis? ________________________________________ A Carbon dioxide enters the plant through its roots. B Carbon dioxide enters the plant through its leaves. C Carbon dioxide is produced in the leaves using energy from the sun. D Carbon dioxide is produced from stored food in the stem of the plant.

37. Which best describes how green plants obtain the carbon dioxide needed for photosynthesis? ________________________________________ B Carbon dioxide enters the plant through its leaves.

38. Which molecule is necessary in order for respiration to occur in plants and animals? ___________________________ A nitrogen B oxygen C sulfur D water

39. Which molecule is necessary in order for respiration to occur in plants and animals? ___________________________ B oxygen

40. The cycling of oxygen within an ecosystem is shown in the diagram below. Which best describes changes within the ecosystem that will increase the amount of oxygen in the atmosphere? ________________________________________ A increase in the amount of grass, increase in the number of animals B increase in the amount of grass, decrease in the number of animals C decrease in the amount of grass, decrease in the number of animals D decrease in the amount of grass, increase in the number of animals

41. The cycling of oxygen within an ecosystem is shown in the diagram below. Which best describes changes within the ecosystem that will increase the amount of oxygen in the atmosphere? ________________________________________ B increase in the amount of grass, decrease in the number of animals

42. Which consume(s) energy from dead organisms? _________________________________ A the Sun B producers and consumers C trees, grasses, and shrubs D scavengers, fungi, and bacteria

43. Which consume(s) energy from dead organisms? _________________________________ D scavengers, fungi, and bacteria

44. Which best explains what happens to water chemically during the process of photosynthesis? ________________________________________ A Water combines directly with carbon dioxide to produce glucose. B Water reacts with chlorophyll and energy from the sun to produce glucose. C Water breaks apart into oxygen and hydrogen. The hydrogen combines with carbon dioxide to produce glucose. D Water reacts with carbon dioxide, causing oxygen to be released from carbon dioxide. The water combines with the carbon from carbon dioxide to produce glucose.

45. Which best explains what happens to water chemically during the process of photosynthesis? ________________________________________ C Water breaks apart into oxygen and hydrogen. The hydrogen combines with carbon dioxide to produce glucose.

46. Which organism is most likely to use energy to transform atmospheric nitrogen into a more usable form? __________________________________ A humans B soybeans C paramecia D earthworms

47. Which organism is most likely to use energy to transform atmospheric nitrogen into a more usable form? __________________________________ B soybeans