Environmental Engineering

391. The species of plants that play a vital role in controlling the relative abundance of other species in a community are called

1. Edge species
2. Link species
3. Pioneer species
4. Successional species
5. Keystone species

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392. The supersonic jets cause pollution by the thinning of

1. CO2 layer
2. SO2 layer
3. O3 layer
4. O2 layer

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393. The term ‘Biocoenosis’ was proposed by

1. Transley
2. Carl Mobius
3. Warming
4. None of the above

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394. The true statement about ‘green house effect’ is that it is

1. caused by combination of many gases
2. caused by CO2
3. caused only by CO2, CFC, CH4 and NO2 gases
4. None of these

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395. The undesirable change in physical, chemical or biological characteristics of air, land and water is referred as

1. pollutants
2. ecodestructions
3. pollution
4. all of these

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396. The unfavourable alteration of environment due to human activities is termed as

1. ecological disturbance
2. catastrophe
3. ecological degradation
4. pollution

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397. Trophic levels are formed by

1. Only plants
2. only animals
3. Only carnivorous
4. Organisms linked in food chain

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398. Two opposite forces operate in the growth and development of every population. One of them is related to the ability to reproduce at a given rate. The force opposite to it is called

1. fecundity
2. mortality
3. environmental resistances
4. biotic control

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399. Ultraviolet radiation which is not lethal but harm to the organism is

1. 0.1 to 0.28 μm
2. 0.28-0.32 μm
3. 0.32-0.4 μm
4. 0.4-0.5 μm

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400. Upper layer of water in a single body of water is known as

1. Hypolimnion
2. Epilimnion
3. thermocline
4. Hydroline

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