The chemical, which kills or inhibits the growth of insects is called insecticide. These chemicals control insects by acting upon the respiratory system or nervous system. Answer : (c)

SO2 hinders with stomata which affects gaseous exchange and transpiration. Its most hazadous effect is on process of photosynthesis. Chlorophyll present in chloroplast is responsible for photosynthesis. Thus SO2 pollution affects chloroplast. Answer : (b)

A greenhouse gas is a gas that absorbs and emits radiant energy within the thermal infrared range. Greenhouse gases cause the greenhouse effect on planets. The primary greenhouse gases in Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Answer : (b)

Pesticides are substances that are meant to control pests, including weeds. They are generally insoluble in water and non-biodegradable. Therefore, these chemicals will not gradually decompose and keep on accumulating in the soil. Therefore, the concentration of these chemicals will increase when the transfer of these chemicals take place from lower to higher trophic level via the food chain. Answer : (c)

The Bhopal disaster, also referred to as the Bhopal gas tragedy, was a gas leak incident on the night of 2–3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh, India. It is considered among the world's worst industrial disasters. Over 500,000 people were exposed to methyl isocyanate (MIC) gas. n 2008, the Government of Madhya Pradesh had paid compensation to the family members of 3,787 victims killed in the gas release, and to 574,366 injured victims. Answer : (a)

Bacterial contamination in water is measured using indicator organisms, notably Escherichia coli and Enterococci which are used as primary indicators of contamination in fresh and marine water quality, respectively, rather than the total coliforms present Answer : (a)

World Environment Day (WED) is celebrated on 5 June every year, and is the United Nations' principal vehicle for encouraging awareness and action for the protection of the environment. Answer : (c)

The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere. Radiatively active gases in a planet's atmosphere radiate energy in all directions. It is related to global warming. Answer : (b)

Benzene is carcinogenic and hence long exposure to benzene and other carcinogenic. black lung disease is caused by long exposure to coal dust. It is a common in coal miners and others who work with coal. Substantial exposure to organophosphate pesticides (e.g., diazinon, parathion) doubles the risk of non-Hodgkins lymphoma. Answer : (d)

Water pollution can cause the outbreak of jaundice. Jaundice is caused by the organism Seriola quinqueradiata. The disease is characterised by yellow colorations of the skin, these yellow colourations are majorly due to the build-up of bilirubin in the blood. Answer : (a)

electrostatic precipitator, which can remove over 99 per cent particulate matter present in the exhaust from a thermal power plant. According to Central Pollution Control Board (CPCB), particulate size 2.5 micrometers or less in diameter (PM 2.5) are responsible for causing the greatest harm to human health. Answer : (a)

Eutrophication, distrophication or hypertrophication, is when a body of water becomes overly enriched with minerals and nutrients which induce excessive growth of algae. This process may result in oxygen depletion of the water body. Answer : (b)

Ozone depletion in stratosphere shall lead to UV-B radiation to reach the earth. UV radiation leads to skin related disease and skin cancer. Answer : (b)

Carbon monoxide combines with hemoglobin to form carboxyhemoglobin at any or all of the oxygen-binding sites of hemoglobin, and also acts to increase the stability of the bond between hemoglobin and oxygen, reducing the ability of the hemoglobin molecule to release oxygen bound to other oxygen-binding sites. Answer : (a)

Secondary pollutants are the pollutants formed by the chemical reaction between primary pollutants in the presence of sunlight e.g., sulphuric acid, nitrogen dioxide and ozone. Nitric oxides, when dissolved in water, produces nitric acid. Hence, nitric acid (HNO3) is a secondary air pollutant. It is responsible for acid rains. Answer : (c)

Turbidity is caused by particles suspended or dissolved in water that scatter light making the water appear cloudy or murky. Particulate matter can include sediment - especially clay and silt, fine organic and inorganic matter, soluble colored organic compounds, algae, and other microscopic organisms. Due to pollutant BOD is high and thus increased deoxygenation. Answer : (b)

Decibel (dB), unit for expressing the ratio between two physical quantities, usually amounts of acoustic or electric power, or for measuring the relative loudness of sounds. Noise is a particular pollutant. Answer : (a)

The Kyoto Protocol is an international agreement that aimed to manage and reduce carbon dioxide emissions and greenhouse gases. The Protocol was adopted at a conference in Kyoto, Japan, in 1997 and became international law on February 16, 2005. Answer : (a)

Dental fluorosis is a common disorder, characterized by hypomineralization of tooth enamel caused by ingestion of excessive fluoride during enamel formation. It appears as a range of visual changes in enamel causing degrees of intrinsic tooth discoloration, and, in some cases, physical damage to the teeth. Answer : (b)

Cyclonic separation is a method of removing particulates from an air, gas or liquid stream, without the use of filters, through vortex separation. When removing particulate matter from liquid, a hydrocyclone is used; while from gas, a gas cyclone is used. Answer : (b)

Silicosis is a lung disease. It usually happens in jobs where you breathe in dust that contains silica. That's a tiny crystal found in sand, rock, or mineral ores like quartz. Over time, silica can build up in your lungs and breathing passages. This leads to scarring that makes it hard to breathe. Answer : (c)

Carbon dioxide is a green house gas. Green house gases trap infra red radiation and this increases temperature of earth. Answer : (c)

PANs are secondary pollutants, which means they are not directly emitted as exhaust from power plants or internal combustion engines, but they are formed from other pollutants by chemical reactions in the atmosphere. Free radical reactions catalyzed by ultraviolet light from the sun oxidize unburned hydrocarbons to aldehydes, ketones, and dicarbonyl compounds, whose secondary reactions create peroxyacyl radicals, which combine with nitrogen dioxide to form peroxyacyl nitrates. Answer : (c)

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. High concentrations of DDT disturb calcium metabolism in birds, which causes thinning of eggshell and their premature breaking, eventually causing decline in bird populations. Answer : (c)

The domestic waste comprises of 67% organic, 13% plastic, 2% glass, 9% paper and paper products, 2% metals, 1% rubber and leathers, 1% textile and 5% others. It si biodegrable pollution Answer : (b)

The Plecoptera are an order of insects, commonly known as stoneflies. All species of Plecoptera are intolerant of water pollution, and their presence in a stream or still water is usually an indicator of good or excellent water quality. they are not bioindicator of water pollution. 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. Hence, whatever CFCs are added to the stratosphere, they have permanent and continuing affects on Ozone levels. Answer : (b)

Organochlorine pesticide is an organic compound containing at least one covalently bonded atom of chlorine as the dominant functionality, of which chloroalkane and chlorinated solvent as examples are major members. Assertion is true Fenitrothion (IUPAC name: O,O-dimethyl O-(3-methyl-4-nitrophenyl) phosphorothioate) is a phosphorothioate (organophosphate) insecticide that is inexpensive and widely used worldwide. Reason is false Answer : (c)

herbicides inhibit photosynthesis by binding to D1 proteins of the photosystem II complex in chloroplast thylakoid membranes. Herbicide binding at this protein blocks electron transport and stops CO2 fixation and production of energy needed for plant growth. Organochlorine compounds work on insects by opening what's known as the sodium ion channel in the neurons or nerve cells of insects, causing them to fire spontaneously. The insect will go into spasms and eventually die. Answer : (c)

The Kyoto Protocol was adopted at the third session of the Conference of Parties to the UNFCCC (COP 3) in 1997 in Kyoto, Japan. Answer:(a)