Read the following statements carefully and find the incorrect statements: A. More than 1 percent impurities make domestic sewage unfit for human use. B. Less BOD causes mortality of fish and other aquatic creatures. C. Presence of large amounts of nutrients in water also causes excessive growth of planktonic algae, called an algal bloom. D. Algal bloom causes deterioration of the water quality and decreases fish mortality. E. Some bloom-forming algae are extremely toxic to human beings and animals. F . Eichhornia crassipes is the world's most problematic aquatic weed.

Question

Read the following statements carefully and find the incorrect statements: A. More than 1 percent impurities make domestic sewage unfit for human use. B. Less BOD causes mortality of fish and other aquatic creatures. C. Presence of large amounts of nutrients in water also causes excessive growth of planktonic algae, called an algal bloom. D. Algal bloom causes deterioration of the water quality and decreases fish mortality. E. Some bloom-forming algae are extremely toxic to human beings and animals. F . Eichhornia crassipes is the world's most problematic aquatic weed. (A) A, C, E and F (B) C, E and F (C) A, B and D (D) All are correct

Tardigrade Admin · Accepted Answer

A mere 0.1 per cent impurities make domestic sewage unfit for human use. BOD (Biochemical Oxygen Demand) is considered a measure of the amount of organic matter present in polluted water. So if BOD is more then fishes and aquatic creatures cannot survive. Algal bloom causes deterioration of the water and increase their mortality.