UV rays are highly injurious to living organisms as:
1. they are part of invisible electromagnetic spectrum
2. they cannot be stopped by atmospheric gases
3. they are preferentially absorbed by DNA and proteins
4. they cause dissociation of atmospheric oxygen
The thickness of ozone layer is measured in :
1. Centimorgan (cM)
2. Dobson unit
3. Roentgens
4. Lux
CFC have a continuing effect on ozone layer as:
1. | the Cl atoms formed by them only act as catalysts in reactions causing degradation of ozone |
2. | the Cl atoms formed by them are used up in reactions causing degradation of ozone |
3. | they are being produced in increasing amounts all over the world |
4. | they are efficiently absorbed by the atmospheric water vapours |
Which of the following is implicated in the causation of skin cancers and snow-blindness cataracts in humans?
1. | UV – A | 2. | UV - B |
3. | UV - C | 4. | None of the above |
The normal greenhouse effect is necessary for survival of life on Earth as it has raised the temperature of Earth’s surface by:
1. | - 18°C | 2. | 15°C |
3. | 33°C | 4. | 50°C |
An abnormal warming of surface ocean waters in the eastern tropical Pacific is termed as:
1. | El Nino | 2. | La Nina |
3. | ENSO | 4. | Ocean hazard |
The “Polyblend” developed by Ahmad Khan is a:
1. possible solution to accumulating plastic wastes
2. method for dealing with electronic wastes
3. synthetic fiber produced in India
4. organic farming product
Ecological sanitation, also known as 'Ecosan', is a new paradigm in sanitation that:
1. | eliminates the use of conventional pesticides to decrease environmental insult |
2. | recognises human excreta and household wastewater as resources that can and are recovered, treated, and reused |
3. | emphasises the disposal of solid waste in sanitary landfill sites |
4. | emphasises the need for strict legislation against polluting industries. |
In a water body polluted with biodegradable organic compounds,
1. the BOD and DO content are low
2. the BOD and DO content are high
3. the BOD is low and DO content is high
4. the BOD is high and DO content is low
The world’s most problematic aquatic weed, “The terror of Bengal”, is the name given to:
1. | Zostera | 2. | Ceratophyllum |
3. | Eichhornia | 4. | Parthenium |