Multiple choice

Consider the following statements:

(1) A river with high BOD (Biological Oxygen Demand) is comparatively less polluted. (2) Eutrophication leads to the decrease in concentration of CO2 in water bodies.

Which of the given statements is/are correct?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement 1 is incorrect. BOD - Standard method for indirect measurement of the amount of organic pollution in a sample of water. Thus, high BOD means high pollution. Statement 2 is also incorrect.             Eutrophication - The process by which a water body acquires high concentration of nutrients, especially phosphates and nitrates. It promotes growth of algae and the decomposing organisms deplete the available oxygen in water. Thus, there is a decrease in concentration of oxygen and increase in concentration of carbon dioxide.

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