1. acid rain

2. rain that is contaminated with pollutants such as sulfur dioxide and nitrogen oxide gases

3. adapt

4. to change in order to fit a new situation or use

5. aquarium

6. a water filled glass or plastic container where organisms can live and be observed

7. aquatic

8. living in water

9. classify

10. to group things together because they share one or more properties

11. conclusion

12. a decision that is based on observation or on a study of data

13. constant

14. a condition that is not changed in a scientific experiment

15. consumer

16. an organism that feeds on other organisms or organic matter because it cannot make its own food

17. controlled experiment

18. a scientific investigation in which one variable is changed and all the others are kept the same, or constant

19. data

20. information, such as that gathered during an experiment

21. disrupt

22. to upset the development, movement, or organization of someone or some thing

23. ecology

24. the science concerned with the relationships among living things and their environment

25. ecosystem

26. a community that includes all the living and nonliving things found in a certain area

27. entomologist

28. a scientist who studies insect life

29. environment

30. everything that surrounds an organism and influences it

31. evidence

32. something that offers proof

33. experiment

34. a procedure that is carried out to investigate a scientific question

35. fossil fuel

36. fuels formed from plant or animal remains, such as coal, gas, and oil

37. germination

38. the process by which seeds swell up and begin to sprout and develop roots

39. habitat

40. a place that is natural for an organism to live

41. hypothesis

42. a prediction about how something works or how two variables are related

43. live-bearer

44. an animal that gives birth to live, fully formed offspring

45. opinion

46. an expression of how one thinks or feels about something, based on personal views and not necessarily on facts

47. photosynthesis

48. the process by which green plants and blue-green algae, in the presence of light, make food out of carbon dioxide and water

49. pollutant

50. anything that spreads harmful or unpleasant substances into the air, water, or ground

51. procedures

52. a set of steps that explains how to do something

53. producer

54. an organism that can make its own food through the process of photosynthesis

55. respiration

56. the processes by which an organism takes in and processes oxygen and releases carbon dioxide

57. scavenger

58. an organism, also known as a decomposer, that eats dead or decaying organic matter

59. sediment

60. small pieces of rock, plant, and animal material that are carried by water, wind, or ice

61. stable

62. steady, balanced

63. system

64. a number of objects or units that move or work together as a whole

65. terrarium

66. a closed glass or plastic container where organisms can live and be observed

67. terrestrial

68. of or related to the land

69. trade-off

70. the act of giving up one thing in order to get another

71. variable

72. an element in an experiment that can be changed

73. water pollution

74. condition that exists when harmful materials have entered the water and made it harmful to organisms

75. watershed

76. an area of land that is drained by a stream or river and its branches

77. weight

78. a measurement of the force of gravity on an object

79. algae

80. nonvascular plants that are often found in aquatic or marine environments and provides both food and a place for organisms to live

81. crickets

82. land-dwelling arthropods that have six legs (insects), make a chirping song by rubbing their legs together, and are known for their ability to jumparthropods

83. elodea

84. a genus of aquatic plants often called the water weeds

85. guppy

86. small fish

87. interdependence

88. being mutually responsible to and sharing a common set of principles with others

89. snails

90. members of the molluscan class Gastropoda which have coiled shells in the adult stagemolluscanGastropodashells

91. co-exist

92. exist together

93. decomposers

94. members of an ecosystem that break down organic material so it may be used again (or recycled) by the ecosystemecosystem organic

95. dependent

96. to depend on something else for survival

97. oxygen

98. an element that is normally colorless, odorless and tasteless and which is the most abundant element and is essential to life

99. protection

100. anything that helps ward off some threat

101. climate

102. the average and variations of weather in a region over long periods of time

103. pH

104. a term that refers to the relative concentration of hydrogen ions (H+) in a solution, and therefore whether the solution is acid or base solutionacidbase

105. soil

106. the top layer of earth, composed of organic materials (humus), inorganic materials (sand, silt, and clay), water, and air.

107. temperature

108. a measurement of the amount of heat a substance contains

109. thermometer

110. a device for measuring temperature

111. nutrients

112. food for plants

113. toxins

114. a poisonous substancepoisonous

115. decay

116. the process where bacteria and other decomposers break down dead thingsbacteria decomposers

117. food chain

118. the ways in which the organisms in an ecosystem interact with one another according to what they eat

119. recycle

120. to take something that would otherwise be thrown away and make it into something that can be used again

121. water cycle

122. the ongoing process in nature that recycles fresh water