1. | increased population of aquatic food web organisms |
2. | an increased production of fish due to biodegradable nutrients |
3. | death of fish due to lack of oxygen |
4. | drying of the river very soon due to algal bloom |
An increase in the concentration of the toxicant at successive trophic levels is known as:
1. Biomagnifications
2. Biodeterioration
3. Biotransformation
4. Biogeochemical cycling
Eutrophication of water bodies leading to the killing of fishes is mainly due to non-availability of:
1. Food
2. Light
3. Essential minerals
4. Oxygen
The zone of atmosphere in which the ozone layer is present is called:
1. Ionosphere
2. Mesosphere
3. Stratosphere
4. Troposphere
A scrubber in the exhaust of a chemical industrial plant removes:
1. Gases like sulphur dioxide
2. Particulate matter of the size 5 micrometer or above
3. Gases like ozone and methane
4. Particulate matter of the size 2.5 micrometer or less
Global warming can be controlled by:
1. | Reducing reforestation, increasing the use of fossil fuel. |
2. | Increasing deforestation, slowing down the growth of the human population |
3. | Increasing deforestation, reduces the efficiency of energy usage. |
4. | Reducing deforestation, cutting down the use of fossil fuel. |
In an area where DDT had been used extensively, the population of birds declined significantly because:
1. Birds stopped laying eggs
2. Earthworms in the area got eradicated
3. Cobras were feeding exclusively on birds
4. Many of the birds laid eggs, but the eggs did not hatch