The most common indicator organism that represents polluted water is
E. coli lives in the human intestine. If they are present in water it indicates that the water is polluted. E.coli coliform count test is done.
How does carbon monoxide, a poisonous gas emitted by automobiles, prevent transport of oxygen into the body tissues?
The affinity of the carbon monoxide towards haemoglobin is more compared to the affinity towards oxygen. The increase in the concentration of carbon monoxide in the atmosphere which results in the binding of carbon monoxide with haemoglobin, forming carboxyhemoglobin. There are very less sites for oxygen binding and transport of the oxygen is reduced in the body which is known as carbon monoxide poisoning.
Which one of the following organisms is used as indicator of water quality?
Faecal pollution is indicated by Escherichia coli. MPN is the most probable number of E. coli in a water sample. It is an indicator of water pollution.
Which important green house gas other than methane is being produced from the agricultural fields?
Some of the impor tant g reen house gases are CO2, CFCs, Nitrous oxide, Ozone, Methane etc. Nitrous oxide is produced by denitrifying bacteria acting on artificial fertilisers applied to poorly aerated soil.
DDT causes egg shell thinning in birds because it inhibits
DDT causes egg shell thinning in birds because it inhibits Calcium ATPase.
Which of these is a pollution related to occupational health hazard ?
Silicosis is caused by exposure to dust containing silica.
Maximum bioconcentration of pesticide residues is usually found in birds that exclusively feed on
Biological magnification is the increase in concentration of persistent pollutant per unit weight of the organism with the rise in trophic level.
Which of the following is the use of lichens in case of pollution?
Lichens are sensitive to sulphur dioxide pollution, hence they serve as bioindicators of pollution.
Green house effect refers to
Green house effect is the rise in atmospheric temperature due to increase in concentration of green house gases.
The greenhouse effect, discovered by Joseph Fourier in 1824 and first investigated quantitatively by Svante Arrhenius in 1896, is the process in which the emission of infrared radiation by an atmosphere warms a planet’s surface. In the case of the Earth, without these greenhouse gases its surface would be up to 30°C cooler. The name comes from an incorrect analogy with the way in which greenhouses are heated by the sun in order to facilitate plant growth. In addition to the Earth, Mars and especially Venus have greenhouse effects. The maximum green house gases are emitted by USA.
Which of the following organism is likely to have more concentration of D.D.T. in its body?
Organisms found in the higher trophic level show greater accumulation of pesticides due to the phenomenon of biomagnification - which is defined as the gradual increase in concentration of harmful pesticides in the food chain, with increase in trophic level.
Which of the following is a secondary pollutant?
Primary pollutant is that which persists in the form in which it is released in the environment eg. CO. A secondary pollutant is one which is formed from another pollutant due to change or reaction eg. PAN (Peroxy acytyl nitrate).
DDT cannot be broken down or converted to harmless state by natural processes of oxidation or biological decomposition. Hence it is non biodegradable.
Which of the following is absent in polluted water?
Stoneflies are exopterygote insects with aquatic nymphs; long antennae, biting mouthparts and a weak flight. Adults have the tendency to feed on lichens and unicellular algae. These are good pollution indicators. Stonefly (Plecoptera order) larva requires well-aerated, non-polluted water. It is absent in polluted water.
So, the correct answer is 'Larva of stonefly'.
Escherichia coli is used as an indicator organism to determine pollution of water with
E. coli grows in water polluted by sewage and domestic waste.
A major component of gobar gas is
Methane forms a major part of gobar-gas. Ammonia is toxic. Ethane and butane are not major components of gobar gas.
In 1984, Bhopal gas tragedy took place because methyl isocyanate
In Bhopal gas tragedy methyl isocyanate (MIC) reacted with water to produce a large amount of heat, as it was an exothermic reaction. Due to this increase in pressure the safety valve of the tank bursted and the gas came out.
Lead concentration in blood is considered alarming if it is
Lead (Pb) is released by combustion of petrol as tetra ethyl lead is used as antiknock in petrol. This lead is very harmful and causes plumbism or lead poisoning, which disturbs nervous system, liver, kidneys in adults and also causes brain damage in children. About 150 to 400 mg of lead is stored in the body of an average adult and blood levels average about 25 mg/100 ml. Increase to 70 mg/100 ml of blood is generally associated with clinical symptoms. Hence a level of30 mg/100 ml should be considered alarming.
Recently Govt. of India has allowed mixing of alcohol in petrol. What is the amount of alcohol permitted for mixing in petrol?
Alcohol to the tune of 5% is allowed to be mix in petrol as per the Govt. of India decision.
Prolonged liberal irrigation of agricultural fields is likely to create the problem of
Salinity causes the problem of prolonged liberal irrigation of agricultural fields. As the soil becomes water logged, vegetation and crops die due to the insufficient supply of oxygen.
Which of the following is not used for disinfection of drinking water?
Disinfectants are the antimicrobial agents which are mainly used to stop the growth of pathogens on the non-living organism. It may affect the substances on which it is applied. Phenyl is a disinfectant which cannot be used for purification of drinking water because it will kill the pathogens of the bacteria but the quality of the water will degrade as it is poisonous for the living organisms. It has a pungent odour. All the other options are used as disinfectant because they do not have an adverse effect on the quality of water.
Limit of BOD prescribed by Central Pollution Control Board for the discharge of industrial and municipal waste waters into natural surface waters, is
Biochemical Oxygen Demand (BOD) is the amount of oxygen required to destroy the organic waste by the bacteria. The more oxygen required for bacteria that means there is more organic waste. For pure drinking water it is decided less than 1 ppm and for industrial & municipal waste it is less than 10 ppm. In Yamuna water in Delhi it is about 1000 ppm.
Photochemical smog pollution does not contain
Photochemical smog is made by the deposition of dust & carbon particles on the pollutant gases and water vapours. The gases found in photochemical smog are NO2, PAN, O3 etc.
Montreal protocol which calls for appropriate action to protect the ozone layer from human activities was passed in the year
Montreal protocol which calls for appropriate action (like less production of ozone depleting substances called ODS such as CFCs) to protect the ozone layer was passed by a forum of 27 industralized countries on 16 September 1987. Till now 175 countries have joined this.
In which one of the following the BOD (Biochemical Oxygen Demand ) of sewage (s), distillery effluent (DE), paper mill effluent (PE) and sugar mill effluent (SE) have been arranged in ascending order ?
More value of BOD means the water sample is polluted by organic matter. BOD of distillary effluent is 40000 mg/L and that of paper mill effluent and sewage is 190 mg/L and 30 mg/L respectively.
In a coal fired power plant electrostatic precipitators are installed to control emission of
In recent years, the increases in toxic substances of NOx and/or SPM (Suspended Particulate Matter) from vehicles come to be serious problem. About the correlation between the traffic volume in our model and the real volume, we obtained the correlation coefficient of 0.74. Simultaneously, we got the result that the concentration of NOx was approximately 70 to 230 ppm. That of SPM was approximately 40 to 100 µg/m3.