Biochemical Oxygen Demand (BOD) may not be a good index for pollution in water bodies receiving effluents from?
1. domestic sewage
2. dairy industry
3. petroleum industry
4. sugar industry
A lake which is rich in organic waste may result in?
1. | increased population of aquatic organisms due to minerals |
2. | drying of the lake due to algal bloom |
3. | increased population of fish due to lots of nutrients |
4. | mortality of fish due to lack of oxygen |
The highest DDT concentration in aquatic food chain shall occur in?
1. phytoplankton
2. seagull
3. crab
4. eel
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