Grade 12 · Science review

Grade 12 Science review — Environmental science questions and answers

Climate, carbon cycle, and ecosystems. Written in American English for students, parents, and teachers in the United States.

Practice quiz

Question and answer list

Each item is a 4-option MCQ. Open a question, tap A–D. Green is correct, red is wrong. Original US classroom practice — not a state test copy.

1. Grade 12 science — environmental: practice check 45 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

2. Grade 12 science — environmental: practice check 46 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

3. Grade 12 science — environmental: practice check 47 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

4. Grade 12 science — environmental: practice check 48 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

5. Grade 12 science — environmental: practice check 49 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

6. Grade 12 science — environmental: practice check 50 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

7. Grade 12 science — environmental: practice check 51 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

8. Grade 12 science — environmental: practice check 52 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

9. Grade 12 science — environmental: practice check 53 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

10. Grade 12 science — environmental: practice check 54 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

11. Grade 12 science — environmental: practice check 55 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

12. Grade 12 science — environmental: practice check 56 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

13. Grade 12 science — environmental: practice check 57 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

14. Grade 12 science — environmental: practice check 58 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

15. Grade 12 science — environmental: practice check 59 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

16. Grade 12 science — environmental: practice check 60 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

17. Grade 12 science — environmental: practice check 61 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

18. Grade 12 science — environmental: practice check 62 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

19. Grade 12 science — environmental: practice check 63 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

20. Grade 12 science — environmental: practice check 64 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

21. Grade 12 science — environmental: practice check 65 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

22. Grade 12 science — environmental: practice check 66 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

23. Grade 12 science — environmental: practice check 67 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

24. Grade 12 science — environmental: practice check 68 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

25. Grade 12 science — environmental: practice check 69 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

26. Grade 12 science — environmental: practice check 70 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

27. Grade 12 science — environmental: practice check 71 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

28. Grade 12 science — environmental: practice check 72 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

29. Grade 12 science — environmental: practice check 73 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

30. Grade 12 science — environmental: practice check 74 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

31. Grade 12 science — environmental: practice check 75 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

32. Grade 12 science — environmental: practice check 76 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

33. Grade 12 science — environmental: practice check 77 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

34. Grade 12 science — environmental: practice check 78 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

35. Grade 12 science — environmental: practice check 79 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

36. Grade 12 science — environmental: practice check 80 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

37. Grade 12 science — environmental: practice check 81 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

38. Grade 12 science — environmental: practice check 82 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

39. Grade 12 science — environmental: practice check 83 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

40. Grade 12 science — environmental: practice check 84 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

41. Grade 12 science — environmental: practice check 85 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

42. Grade 12 science — environmental: practice check 86 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

43. Grade 12 science — environmental: practice check 87 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

44. Grade 12 science — environmental: practice check 88 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

45. Grade 12 science — environmental: practice check 89 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

46. Grade 12 science — environmental: practice check 90 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

47. Grade 12 science — environmental: practice check 91 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

48. Grade 12 science — environmental: practice check 92 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

49. The carbon cycle includes

Tap A, B, C or D.

Answer: D) photosynthesis, respiration, and fossil-fuel burning

CO₂ is a key greenhouse gas.

50. Biodiversity means

Tap A, B, C or D.

Answer: A) variety of life in an ecosystem

More diversity often means more resilience.

51. A carbon sink

Tap A, B, C or D.

Answer: A) stores more carbon than it releases, like a healthy forest

Oceans and forests can act as sinks.

52. Eutrophication is often caused by

Tap A, B, C or D.

Answer: B) excess fertilizer runoff that overfeeds algae

Algal blooms can steal oxygen when they decay.

53. An invasive species

Tap A, B, C or D.

Answer: C) spreads in a new habitat and can harm natives

Zebra mussels in the Great Lakes are a US example.

54. Renewable energy examples include

Tap A, B, C or D.

Answer: A) wind, solar, and hydro

They replenish on a human timescale.

55. The ozone layer

Tap A, B, C or D.

Answer: B) blocks much harmful UV from the Sun

Stratospheric ozone is helpful; ground-level ozone is a pollutant.

56. A keystone species

Tap A, B, C or D.

Answer: D) has an outsized effect on its ecosystem

Sea otters and wolves are textbook cases.

57. Grade 12 science — environmental: practice check 1 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

58. Grade 12 science — environmental: practice check 2 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

59. Grade 12 science — environmental: practice check 3 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

60. Grade 12 science — environmental: practice check 4 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

61. Grade 12 science — environmental: practice check 5 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

62. Grade 12 science — environmental: practice check 6 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

63. Grade 12 science — environmental: practice check 7 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

64. Grade 12 science — environmental: practice check 8 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

65. Grade 12 science — environmental: practice check 9 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

66. Grade 12 science — environmental: practice check 10 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

67. Grade 12 science — environmental: practice check 11 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

68. Grade 12 science — environmental: practice check 12 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

69. Grade 12 science — environmental: practice check 13 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

70. Grade 12 science — environmental: practice check 14 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

71. Grade 12 science — environmental: practice check 15 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

72. Grade 12 science — environmental: practice check 16 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

73. Grade 12 science — environmental: practice check 17 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

74. Grade 12 science — environmental: practice check 18 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

75. Grade 12 science — environmental: practice check 19 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

76. Grade 12 science — environmental: practice check 20 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

77. Grade 12 science — environmental: practice check 21 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

78. Grade 12 science — environmental: practice check 22 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

79. Grade 12 science — environmental: practice check 23 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

80. Grade 12 science — environmental: practice check 24 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

81. Grade 12 science — environmental: practice check 25 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

82. Grade 12 science — environmental: practice check 26 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

83. Grade 12 science — environmental: practice check 27 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

84. Grade 12 science — environmental: practice check 28 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

85. Grade 12 science — environmental: practice check 29 — the reliable next step is

Tap A, B, C or D.

Answer: C) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

86. Grade 12 science — environmental: practice check 30 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

87. Grade 12 science — environmental: practice check 31 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

88. Grade 12 science — environmental: practice check 32 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

89. Grade 12 science — environmental: practice check 33 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

90. Grade 12 science — environmental: practice check 34 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

91. Grade 12 science — environmental: practice check 35 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

92. Grade 12 science — environmental: practice check 36 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

93. Grade 12 science — environmental: practice check 37 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

94. Grade 12 science — environmental: practice check 38 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

95. Grade 12 science — environmental: practice check 39 — the reliable next step is

Tap A, B, C or D.

Answer: D) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

96. Grade 12 science — environmental: practice check 40 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

97. Grade 12 science — environmental: practice check 41 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

98. Grade 12 science — environmental: practice check 42 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

99. Grade 12 science — environmental: practice check 43 — the reliable next step is

Tap A, B, C or D.

Answer: B) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.

100. Grade 12 science — environmental: practice check 44 — the reliable next step is

Tap A, B, C or D.

Answer: A) try the item, then read the tip

Original GKSchools practice — not a state exam leak. Come back tomorrow; order rotates.