31 Years NEET Previous Year Questions: Environmental Issues - 2 (Old NCERT)

Stone flies are not bio indicators. Bioindicators provide a range of techniques to assess the impcts of air pollution from reactive nitrogen (N) compounds on statutory nature conservation sites. They complement physical monitoring of atmospheric concentrations and deposition and risk assessment based on the critical loads approach by providing sitebased information on atmospheric N concentrations, N deposition and/or ecological impacts.

Pollution) Act 1974. Further, CPCB was entrusted with the powers and functions under Air (prevention and control of pollution) Act, 1981. It serves as a field formation and also provides technical services to the Ministry of Environment and Forest, of the provisions of the Environments (protection)  Act, 1986. Principal functions of the CPCB, as spelt out in the water (prevention and control of pollution) act, 1974, and the Air (prevention and control of pollution) Act, 1981.
(i) to promote cleanliness of streams and wells in different areas of the states by prevention, control and abatement of water pollution.
(ii) to improve the quality of air and to prevent, control or abate air pollution in the country. According to CPCB, 2.5 or less particulate size in diameter (in micrometers) of the air pollutants is responsible for greatest harm to human health. 

Biofuels are substances of biological origin which are used for the production of heat and another form of energy. Often biologically generated hydrogen, methane, ethanol, butanol and diesel are referred to as biohydrogen, biomethane, bioethanol, biobutanol and biodiesel respectively. Petro plans are the plants which can yield a large amount of latex having long chained liquid hydrocarbon, eg, Jatropha, Euphorbia (family-Euphorbiaceae) and other members of Euphorbiaceae, Asclepiadaceae, Apocyanaceae. 

The wood used as a source of energy is called fuel wood. The good fuelwood should be free from resin, much smoke and offensive odours. Hardwood is generally good fuel wood, Casuarina, Azadirachta, Dalbergia, Terminalia.

Due to heavy industrialization and transportation (modernization), CO₂ concentration is increasing day by day in the atmosphere. CO₂ has capacity of absorbing heat radiations and thus increases temperature. This increase in global temperature (global warming) is mainly due to CO₂ concentration and is called 'green house effect'. Besides CO₂ other important gases associated with green house effect are CH₄ (methane), oxides of nitrogen (NOv), CFCs (chlorofluorocarbons) and O₃ (ozone) and these are called 'green house gases'. Relative contribution of these gases to global warming are: CO₂ (50%), CFCs (20%), CH₄ (16%), O₃ (8%), nitrous oxide (6%).

World Summit on sustainable development (2002) was held in Johannesburg, South Africa, 190 countries pledged their commitment to achieve by 2010, a significant in reduction the current rate of biodiversity loss at global, regional and local levels. 

Global agreement in specific control strategies to reduce the release of ozone depleting substances was adopted by the Montreal protocol. The treaty was originally signed in 1987 and substantially amended in 1990 and 1992. The Montreal protocol stipulates that the production and consumption of compounds that deplete ozone in the stratosphere-chlorofluoro-carbons (CFCs), halogens, carbon tetrachloride, and methyl chloroform– are to be phased out by 2000 (2005 for methyl chloroform).

Biochemical Oxygen Demand (BOD) in a river water increases when sewage gets mixed with river water. Biochemical oxygen demand or biological oxygen demand (BOD) is a chemical procedure for determining how fast biological organisms use up oxygen in a body of water. It is used in water quality management and assessment, ecology and environmental science. BOD considered as an indication of the quality of a water source.

Jatropha is useful for production of bioethanol. Jatropha is a genus of approximately 175 succulent plants, shrubs and trees (some are deciduous, like Jatropha curcas L.), from the family Euphorbiaceae.The hardy Jatropha is resistant to drought and pests, and produces seeds containing 27-40% oil. Currently the oil from Jatropha curcas seeds is used for making biodiesel fuel in Philippines and in Brazil, where it grows naturally and in plantations in the southeast, and the north/northeast Brazil. Likewise, Jatropha oil is being promoted as an easily grown biofuel crop in hundreds of projects throughout India and other developing countries.

The step taken by Government of India to control air pollution include compulsory PUC (pollution under control) certification of petrol driven vehicles which tests for carbon monoxide and hydrocarbons.

The aim of Montreal protocol was to protect the ozone layer in the stratosphere by decreasing and eventually eliminating the use of of ozone depleting substances like CFCS.

DDT residues are rapidly passed through  food chain causing biomagnification because DDT is lipo soluble. Biomagnification, also known as bioamplification or biological magnifica-tion, is the increase in concentration of a substance, such as the pesticide DDT, that occurs in a food chain as a consequence of:

• Persistence (slow to be broken down by environmental processes) 
• Food chain energetics 
• Low (or non-existent) rate of internal degradation/excretion of the substance (often due to water-insolubility)

Chipko movement was launched for the protection of forests. The Chipko movement refers to the unique form of protest adopted by the rural people in the himalayan region of India in the 1970s and 80s, against the indiscriminate logging and felling of trees that spelt the destruction of their environment. The first Chipko action occurred in April 1973. Over the next five years, the movement spread to several hill districts in Uttar Pradesh. In 1980, Chipko activists won a fifteen-year ban on green felling in the himalayan forests.

The bacterium Bacillus thuringiensis is widely used in contemporary biology as insecticide. Bacillus thuringiensis (also known as Bt) is a Gram-positive, soil dwelling bacterium of the genus Bacillus. Bacillus thuringiensis produces a parasporal insecticidal crystal protein.

Exhaustible resources are those natural resources that are likely to be exhausted due to their continuous use. Forest is a renewable exhaustible resource that can be again and again produced. Coal, petroleum and minerals are nonrenewable exhaustible natural resources that cannot be again produced.

Noise pollution is a physical form of pollution that affects the receiver directly. dB (decibel) is a standard abbreviation used for the quantitative expression of noise. Noise or pollutant sound has a value of 80 dB and above, it harms hearing system. The WHO has fixed 45 dB as the safe noise level for city

The gases that makes highest relative contribution to the green house gases are carbon dioxide (CO₂) and methane (CH₄).

The correctacronymis IUCN , International Union for Conservation of Nature and Natural resources.

The phenomenon of keeping the earth's surface warm is due to the presence of certain gases in the atmosphere that are called greenhouse gases. The name is based after a similar warmer interior in a glass-enclosed greenhouse where glass panels, CO2 and water vapour allow the solar radiations to enter but prevent the escape of long wave heat radiations. CO2 and N2O are the major cause of 'greenhouse effect'. CO2 contributes 60% of total global warming. N2O contributes 6% to greenhouse effect.

In secondary treatment mainly settled sewage flows to an aerobic biological treatment stage where it comes into contact with micro-organisms which remove and oxidise most of the remaining organic pollutants.

Marsh gas is another term for methane, produced by plants decomposing under water.

The Bhopal gas tragedy was occured on the night of December 2-3 , 1984 at the Union carbide India Limited pesticide plant in Bhopal, M.P.  A leak of methyl isocyanate gas and other chemicals from the plant resulted in the exposure of hundreds of thousands of people. 

Good ozone occurs naturally in the earth’s upper atmosphere 10 to 30 miles above earth’s surface (stratosphere) where it forms a protective layer that shield us from the sun’s harmful ultraviolet rays.

High concentration of DDT disturbs calcium metabolism in birds which caused thinning of eggshell and their premature breaking.

Ozone present in upper par t of the atmosphere ie. stratosphere is benefical for living beings. As it functions as a shield against harmful UV-radiation.