Q. Which regions of seas/oceans are the most polluted ? EstuarineCoastalSea depthsCoral reefs Answer: Coastal

Q. Which of the following does not occur when the sewage is discharged into water? Increase in O2Cyanophycean blooms occurDepletion of O2 layersEutrophication Answer: Increase in O2

Q. Fishes die by sewage because Of its bad smellIt replaces food material of fishesIt increases oxygen competition among fishesCO2 is mixed in large amount in water Answer: Of its bad smell

Q. Foul smell in the water of tanks, ponds etc. is due to AnaerobiosisAerobiosisBiological magnificationPsammophytes Answer: Anaerobiosis

Q. Minamata disease is a pollution related disease results from Oil spills into seaAccumulation of arsenic into atmosphereRelease of industrial waste mercury into fishing waterRelease human organic waste into drinking water Answer: Release of industrial waste mercury into fishing water

Q. The excessive discharge of fertilizers into water bodies results in Growth of fishDeath of hydrophytesEutrophicationSilt Answer: Eutrophication

Q. Water pollution can be stopped best by Treating effluents to remove injurious chemicalsRearing more fishesCultivating useful water plantsSpraying with DDT Answer: Treating effluents to remove injurious chemicals

Q. When Chloride is added to sewage both at the beginning as well as at the end of the treatment process, the phenomenon is called: Post chlorinationSuper chlorinationSplit chlorinationNone of these Answer: Split chlorination

Q. In the treatment of waste water discharge, which treatment stage involves biological treatment Primary treatmentSecondary treatmentTertiary treatmentReverse osmosis stage Answer: Secondary treatment

Q. Thermal pollution of water bodies is due to Discharge of heat (hot water) from power plantsDischarge of chemicals from industriesDischarge of waste from miningDischarges of agricultural run off Answer: Discharge of heat (hot water) from power plants