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Decomposers, decay rates and recycling nutrients

10th grade (Year 11 in England) · 16 questions · Common Core: NGSS.HS-LS2-3, NGSS.HS-LS2-5 · England: GCSE Combined Science: Ecology

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  1. Question 1

    A bag of grass clippings had a mass of 100 g. After 10 days in a compost bin its mass was 85 g. What was the mean rate of decay, in g per day?

    Answer

  2. Question 2

    Why do gardeners turn their compost heaps regularly?

    • A. to dry it out completely
    • B. to kill all the microorganisms
    • C. to cool the heap to 0 °C
    • D. to add oxygen for the decomposers' aerobic respiration
  3. Question 3

    Decay: which statement is NOT true?

    • A. Decay returns mineral ions to the soil.
    • B. Decay is faster when it is warm and moist.
    • C. Decomposers create new atoms of carbon.
    • D. Compost can be used as a natural fertiliser.
  4. Question 4

    A bag of grass clippings had a mass of 150 g. After 12 days in a compost bin its mass was 114 g. What was the mean rate of decay, in g per day?

    Answer

  5. Question 5

    Why do gardeners turn their compost heaps regularly?

    • A. to dry it out completely
    • B. to cool the heap to 0 °C
    • C. to add oxygen for the decomposers' aerobic respiration
    • D. to kill all the microorganisms
  6. Question 6

    Decay: which statement is NOT true?

    • A. Compost can be used as a natural fertiliser.
    • B. Decay returns mineral ions to the soil.
    • C. Decomposers need no oxygen at all.
    • D. Decomposers include bacteria and fungi.
  7. Question 7

    A bag of grass clippings had a mass of 150 g. After 10 days in a compost bin its mass was 100 g. What was the mean rate of decay, in g per day?

    Answer

  8. Question 8

    What role do decomposers play in the carbon cycle?

    • A. They lock carbon away forever
    • B. They photosynthesise
    • C. They respire, releasing carbon dioxide from dead material back into the air
    • D. They turn carbon into oxygen
  9. Question 9

    Decay: which statement is NOT true?

    • A. Compost can be used as a natural fertiliser.
    • B. Decay is faster when it is warm and moist.
    • C. Decomposers need no oxygen at all.
    • D. Decay returns mineral ions to the soil.
  10. Question 10

    A bag of grass clippings had a mass of 200 g. After 5 days in a compost bin its mass was 180 g. What was the mean rate of decay, in g per day?

    Answer

  11. Question 11

    What role do decomposers play in the carbon cycle?

    • A. They turn carbon into oxygen
    • B. They respire, releasing carbon dioxide from dead material back into the air
    • C. They lock carbon away forever
    • D. They photosynthesise
  12. Question 12

    Decay: which statement is NOT true?

    • A. Decomposers include bacteria and fungi.
    • B. Compost can be used as a natural fertiliser.
    • C. Decomposers need no oxygen at all.
    • D. Decay returns mineral ions to the soil.
  13. Question 13

    A bag of grass clippings had a mass of 100 g. After 10 days in a compost bin its mass was 60 g. What was the mean rate of decay, in g per day?

    Answer

  14. Question 14

    What role do decomposers play in the carbon cycle?

    • A. They lock carbon away forever
    • B. They turn carbon into oxygen
    • C. They respire, releasing carbon dioxide from dead material back into the air
    • D. They photosynthesise
  15. Question 15

    Decay: which statement is NOT true?

    • A. Decay returns mineral ions to the soil.
    • B. Decay is fastest when everything is frozen.
    • C. Decay is faster when it is warm and moist.
    • D. Decomposers include bacteria and fungi.
  16. Question 16

    A bag of grass clippings had a mass of 120 g. After 10 days in a compost bin its mass was 105 g. What was the mean rate of decay, in g per day?

    Answer

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  1. 1.5
  2. to add oxygen for the decomposers' aerobic respiration
  3. Decomposers create new atoms of carbon.
  4. 3
  5. to add oxygen for the decomposers' aerobic respiration
  6. Decomposers need no oxygen at all.
  7. 5
  8. They respire, releasing carbon dioxide from dead material back into the air
  9. Decomposers need no oxygen at all.
  10. 4
  11. They respire, releasing carbon dioxide from dead material back into the air
  12. Decomposers need no oxygen at all.
  13. 4
  14. They respire, releasing carbon dioxide from dead material back into the air
  15. Decay is fastest when everything is frozen.
  16. 1.5