Reducing deforestation, cutting down use of fossil fuel results into reduction into one of the green house gas, i.e., CO2. Answer:(a)

Air prevention and Control of Pollution protection act – 1981 Environmental protection act– 1986 Water (Prevention and Control of Pollution) act – 1974 Answer:(b)

Biochemical Oxygen Demand (BOD) is not a good index for checking the pollution levels of water bodies receiving effluents from petroleum industry, This is because such effluents contain waste which rs non-biodegradable Answer:(a)

lakes in many parts of the earth have been severely eutrophied by sewage and agricultural and industrial wastes. The prime contaminants are nitrates and phosphates, which act as plant nutrients. They overstimulate the growth of algae, causing unsightly scum and unpleasant odours, and robbing the water of dissolved oxygen vital to other aquatic life. At the same time, other pollutants flowing into a lake may poison whole populations of fish, whose decomposing remains further deplete the water’s dissolved oxygen content. In such fashion, a lake can literally choke to death. Answer:(b)

Seagulls are fish eating birds. Concentration of DDT is increased at successive trophic levels; say if it starts at 0.003 ppb (ppb = parts per billion) in water, it can ultimately reach 25 ppm (ppm = parts per million) in fish-eating birds, through biomagnification. Answer:(d)

Aerosols can cause various problems to agriculture through its direct or indirect effects on plants. However continually increasing air pollution may represent a persistent and largely irreversible threat to agriculture in the future. Answer:(c)

Primary treatment is a physical process which involves sequential filtration and sedimentation Answer:(c)

lakes in many parts of the earth have been severely eutrophied by sewage and agricultural and industrial wastes. The prime contaminants are nitrates and phosphates, which act as plant nutrients. They overstimulate the growth of algae, causing unsightly scum and unpleasant odours, and robbing the water of dissolved oxygen vital to other aquatic life. At the same time, other pollutants flowing into a lake may poison whole populations of fish, whose decomposing remains further deplete the water’s dissolved oxygen content. In such fashion, a lake can literally choke to death. Answer:(a)

Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide (SO2) and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain. Answer:(b)

Biomagnification, also known as bioamplification or biological magnification, is any concentration of a toxin, such as pesticides, in the tissues of tolerant organisms at successively higher levels in a food chain. Answer:(b)

Lichens also absorb sulphur dioxide dissolved in water. Lichens are widely used as environmental indicators or bio-indicators. If air is very badly polluted with sulphur dioxide there may be no lichens present, just green algae may be found. If the air is clean, shrubby, hairy and leafy lichens become abundant. Answer:(b)

CFCs discharged in the lower part of atmosphere move upward and reach stratosphere. In stratosphere, UV rays act on them releasing Cl atoms. Cl degrades ozone releasing molecular oxygen, with these atoms acting merely as catalysts; Cl atoms are not consumed in the reaction Answer : (b)

Ground-level ozone is a colorless and highly irritating gas that forms just above the earth's surface. It is called a "secondary" pollutant because it is produced when two primary pollutants react in sunlight and stagnant air. These two primary pollutants are nitrogen oxides (NOx) and volatile organic compounds (VOCs). Answer : (d)

September 16 was designated by the United Nations General Assembly as the International Day for the Preservation of the Ozone Layer. Answer : (c)