Multiple Choice QuestionsEutrophication of water bodies leading to killing of fishes is mainly due to non-availability of
food
light
essential minerals
essential minerals
In an area where DDT had been used extensively, the population of birds declined significantly because
birds stopped laying eggs
earthworms in the area got eradicated
cobras were feeding exclusively on birds
cobras were feeding exclusively on birds
D.
cobras were feeding exclusively on birds
DDT, its breakdown products and other chlorinated hydrocarbon pesticides posed an insidious threat to birds. These persistent poisons enter the food chain and they accumulate in the fatty tissues of organisms at lower trophic level and then tend to concentrate as they move through the food chain. This is called biomagnification or bioconcentration. The insidious aspect of this phenomenon is that large concentrations of chlorinated hydrocarbons do not usually kill the bird out right. Rather, DDT and its relatives alter the bird's calcium metabolism in a way that results in thing egg shells which are unable to support the weight of incubating bird. So, many of the birds eggs laid are not hatched. This causes a significant decline in the population of birds.
Which one of the following is a wrong statement
Most of the forests have been lost in tropical areas
Ozone in upper part of atmosphere is harmful to animals
Greenhouse effect is a natural Phenomenon
Greenhouse effect is a natural Phenomenon
Measuring Biochemical Oxygen Demand (BOD) is a method used for
Estimating the amount of organic matter in sewage water
Working out the efficiency of oil driven automobile engines
Measuring the activity of Saccharomyces cerevisae in producing curd on a commercial scale
Measuring the activity of Saccharomyces cerevisae in producing curd on a commercial scale
The zone of atmosphere in which the ozone layer is present is called
ionosphere
mesophere
stratosphere
stratosphere
A scrubber in the exhaust of a chemical industrial plant removes
Gases like sulphur dioxide
Particulate matter of the size 5 micrometre or above
Gases like ozone and methane
Gases like ozone and methane
The domestic sewage in large cities
has a high BOD as it contains both aerobic and anaerobic bacteria
is processed by aerobic and then anaerobic bacteria in the secondary treatment is Sewage Treatment Plants (STPs)
When treated in STPs does not really require the aeration step as the sewage contains adequate adequate oxygen
When treated in STPs does not really require the aeration step as the sewage contains adequate adequate oxygen
The UN Conference of Parties on climate change in the year 2011 was held in
Poland
South Africa
Peru
Peru
High value of BOD (Biochemical Oxygen Demand) indicates that
water is pure
water is highly polluted
water is less polluted
water is less polluted
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