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Environmental Issues — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYEnvironmental Issues2 Marks
Question
Study the graph given below and answer the questions that follow:
  1. What is the relationship between dissolved oxygen and biochemical oxygen demand (BOD)?
  1. Mention their effect on aquatic life in the river.
✓

Answer

  1. When BOD is high, dissolved $O_2$ is less/ inversely proportional.
  2. If dissolved $O_2$ is less and BOD is high, aquatic organisms die.
If dissolved $O_2$ is more and BOD is low, fresh water organisms reappear.

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