Answer : (d)

A hyperaccumulator is a plant capable of growing in soil or water with very high concentrations of metals, absorbing these metals through their roots, and concentrating extremely high levels of metals in their tissues. These hyperaccumulation genes (HA genes) are found in over 450 plant species, including the model organisms Arabidopsis and Brassicaceae. Answer : (c)

Answer : (c)

The Bhopal gas tragedy, was a gas leak incident in India, considered the world's worst industrial disaster. It occurred in December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate (MIC) gas and other chemicals. The Chernobyl disaster was a catastrophic nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine. An explosion and fire released large quantities of radioactive particles into the atmosphere, which spread over much of the western USSR and Europe. Answer : (c)

Minamata disease was first discovered in Minamata City in Kumamoto prefecture, Japan in 1956. It was caused by the release of methylmercury in the industrial wastewater (point source pollution) from the Chisso Corporation's chemical factory, which continued from 1932 to 1968. Answer : (a)

Carbon dioxide(CO2), methane (CH4), chlorofluorocarbons (CFCs) and N2O are green house gases. Answer : (a)

Lindane, also known as gamma-hexachlorocyclohexane, gammaxene, Gammallin and sometimes incorrectly called benzene hexachloride (BHC), is an organochlorine chemical. Lindane is a persistent organic pollutant: it is relatively long-lived in the environment, hence non-biodegradable pollutant. Anthropogenic contamination is a form of pollution. produced directly by human activities primary pollutants are substances directly emitted from a process, such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories. In traffic-congested city air, nitrogen oxides produce brown air or reddish-brown haze. Answer : (b)

The carotenoids are the antioxidants which are present as the pigments in the plant cells. The antioxidants scavenge the effect of the oxygen radicals and protect the cell from UV damage. Answer : (c)

BOD is used, often in wastewater-treatment plants, as an index of the degree of organic pollution in water. High BOD indicates highly polluted water. Answer : (a)

Eutrophication is the natural aging of a lake by nutrient enrichment of its water Components like phosphate and nitrates in fertilizers accelerates this process. This phenomenon is called cultural or accelerated eutrophication. Answer : (d)

2,4-D and pesticides run-off with rainwater in nearby water bodies and pollute it. smoke ash, automobile exhausts are air pollutant and aeroplanes contribute to noise pollution. Answer : (d)

The Earth's oceans contain a large amount of CO2 in the form of bicarbonate and carbonate ions—much more than the amount in the atmosphere. The bicarbonate is produced in reactions between rock, water, and carbon dioxide. Answer : (a)

The World Summit on Sustainable Development (Johannesburg, South Africa, August 26 - September 4, 2002) was an unprecedented opportunity to strengthen the role of health in sustainable development. Answer : (a)

DDT cannot be metabolized or excreted. It gets stored in fat tissue and hence biomagnify. Biomagnification refers to increase in concentration of the toxicant at successive trophic levels Answer : (a)

Ingestion of excess fluoride, most commonly in drinking-water, can cause fluorosis which affects the teeth and bones. Moderate amounts lead to dental effects, but long-term ingestion of large amounts can lead to potentially severe skeletal problems. Answer : (c)

2,4-D (2,4-dichlorophenoxyacetic acid) is a herbicide in the phenoxy or phenoxyacetic acid family that is used postemergence for selective control of broadleaf weeds. 2,4,5-Trichlorophenoxyacetic acid, a synthetic auxin, is a chlorophenoxy acetic acid herbicide used to defoliate broad-leafed plants. DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. Peroxyacetyl nitrate is a peroxyacyl nitrate. It is a secondary pollutant present in photochemical smog. Answer : (c)

Cultural or anthropogenic eutrophication is the process that speeds up natural eutrophication because of human activity. Due to clearing of land and building of towns and cities, land runoff is accelerated and more nutrients such as phosphates and nitrate are supplied to lakes and rivers, and then to coastal estuaries and bays. Extra nutrients are also supplied by treatment plants, golf courses, fertilizers, farms (including fish farms), as well as untreated sewage in many countries. Answer : (c)

Ozone acts as a shield absorbing ultraviolet radiation from the sun. Ozone hole enhances UV reaching earth. UV radiation of wavelengths shorter than UV-B, are almost completely absorbed by Earth’s atmosphere, given that the ozone layer is intact. But, UV-B damages DNA and mutation may occur. It causes aging of skin, damage to skin cells and various types of skin cancers. In human eye, cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of cornea, called snow-blindness, cataract, etc. Such exposure may permanently damage the cornea. Answer : (d)

Eutrophication 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. One example is an "algal bloom" or great increase of phytoplankton in a sandy body as a response to increased levels of nutrients. Answer : (b)

Major water pollutants are pathogen, domestic waste, industrial waste and plastics. Most abundant water pollutant is industrial waste. Answer : (c)

Plants form the base of the food level for all organisms. They require atmospheric gases for photosynthesis. Thus any change in the atmosphere due to pollution is first observed in plants. Answer : (b)

An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog, mist, dust, forest exudates and geyser steam. Examples of anthropogenic aerosols are particulate air pollutants and smoke.The liquid or solid particles have diameters typically less than 1 µm. Answer : (c)

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 : (d)

DDT, plastics, polythene, bags, insecticides, pesticides, mercury, lead, arsenic, metal articles like aluminum cans, synthetic fibres, glass objects, iron products and silver foils are non-biodegradable pollutants. Answer : (c)

chlorofluorocarbons (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 : (a)

Chlorofluorocarbons (CFCs) known as freons are used as coolant in refrigerators and air conditioners. 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 : (d)

Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide 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 : (a)

Nitrogen oxides and flurocarbons are chief pollutant which is likely to deplete ozone layer Answer : (d)

BOD of Distillery (DE) is above 90,000mg/L BOD of sewage(S) is above 600mL/lit BOD of Paper mill(PE) is above 170mL/lit BOD of sugar mill(SE) is above 2200mL/lt Answer : (b)

Minamata disease, sometimes referred to as Chisso-Minamata disease, is a neurological syndrome caused by severe mercury poisoning. Symptoms include ataxia, numbness in the hands and feet, general muscle weakness, narrowing of the field of vision and damage to hearing and speech. Answer : (c)