1. With reference to ecosystems, consider the following statements:
1. Organisms at higher trophic level receive energy from more than one trophic level.
2. Higher trophic levels tend to be more discrete than the lower ones.
Which of the statements given above is/are correct?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2
Answer & Explanation
a) 1 only. In an ecosystem, organisms at higher trophic level receive energy from more than one trophic level. The best example is man. Humans, for example, are primary consumers when they eat plants such as vegetables. They are secondary consumers when they eat cows. They are tertiary consumers when they eat salmon. So as you can see, humans can obtain energy from more than one trophic level. This statement – “Organisms at higher trophic level receive energy from more than one trophic level.” is one of the fundamental principles of ecology. Further, higher trophic levels tend to be less discrete than the lower ones as they have varied sources of food. They thus, tend to be ‘generalists’ in their feeding habits.
2. Which of the following are required for the formation of Ground-level ozone ( GLO) ?
1. Carbon dioxide
2. Volatile Organic Compounds
3. Sunlight
Select the correct answer using the codes given below.
a) 1 and 2 only
b) 1 and 3 only
c) 2 and 3 only
d) 1, 2 and 3
Answer & Explanation
c) 2 and 3 only. Ground-level ozone is a colorless and highly irritating gas that forms just above the earth’s surface. Ground level or “bad” ozone is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC.
3. Which of the following is/are have been provided for in the Wildlife Protection Act, 1972?
1. National Parks
2. Wildlife Sanctuaries
3. Biosphere Reserves
Select the correct answer using the codes given below.
a) 1 only
b) 1 and 2 only
c) 1 and 3 only
d) 2 and 3 only
Answer & Explanation
b) 1 and 2 only. Both National Parks and Wildlife Sanctuaries have been provided for in the Wildlife (Protection ) Act, 1972. The Act provides for four type of protected areas viz. Wildlife Sanctuaries, National Parks, Conservation Reserves and Community Reserves. National parks and Wildlife sanctuaries are created by state government via a notification. However, alteration of boundaries of a national park can only be done via a legislation passed by the state government.Biosphere Reserves are not provided for under any act.
4. The Montreal Protocol on Substances that Deplete the Ozone Layer aims to control the production and use of :
1. Dichloromethane
2. CFCs
3. HFCs
Select the correct answer using the codes given below.
a) 1 and 2 only
b) 2 only
c) 2 and 3 only
d) 1,2 and 3
Answer & Explanation
b) 2 only. Montreal protocol aims to phase out several groups of halogenated hydrocarbons that have been shown to play a role in ozone depletion. All of these ozone depleting substances contain either chlorine or bromine (substances containing only fluorine do not harm the ozone layer). These include CFCs and HCFCs. HFCs replaced CFCs and HCFCs. HFCs pose no harm to the ozone layer because, unlike CFCs and HCFCs, they do not contain chlorine. The Montreal Protocol therefore does not address HFCs. But HFCs cause global warming. Dichloromethane is a new entry among gases that depletes ozone layer, but at present it has not been included under Montreal Protocol.
5. Endosulphan has been banned under the Stockholm Convention because:
a) it depletes ozone
b) it causes global warming
c) it is an endocrine disruptor
d) none of the above
Answer & Explanation
c) it is an endocrine disruptor. Endosulfan is an off-patent organochlorine insecticide and acaricide that is being phased out globally. Endosulfan became a highly controversial agrichemical due to its acute toxicity, potential for bioaccumulation, and role as an endocrine disruptor.
6. Which of the following Tiger reserves is/are also a National Park ?
1. Manas
2. Indravati
3. Namdapha
4. Sariska
Select the correct answer using the codes given below.
a) 1,2 and 3 only
b) 1,3 and 4 only
c) 2,3 and 4 only
d) 1,2,3 and 4
Answer & Explanation
d) 1,2,3 and 4. Factual question just to make you revise the national parks and tiger reserves of India.
7. Pollutants can be classified as primary and secondary. Which of these is/are primary pollutant?
1. Volatile Organic Compunds
2. Ground Level Ozone
3. Acid Rain
Select the correct answer using the codes given below.
a) 1 only
b) 1 and 2 only
c) 1 and 3 only
d) 1,2 and 3
Answer & Explanation
a) 1 only. A primary pollutant is an air pollutant emitted directly from a source. A secondary pollutant is not directly emitted as such, but forms when other pollutants (primary pollutants) react in the atmosphere. Ground Level Ozone is a “secondary” pollutant because it is produced when two primary pollutants react in sunlight and stagnant air. These two primary pollutants are nitrogen oxides (NOx) and volatile organic compounds (VOCs). Acid rain ofcourse is a secondary pollutant.
8. With reference to eutrophication, consider the following statements:
1. primary productivity becomes low
2. oxygen availability decreases
Which of the statements given above is/are correct ?
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2
Answer & Explanation
b) 2 only. Primary productivity is high in eutrophic water bodies. Due to excessive nutrients, especially nitrogen and phosphorus, these water bodies are able to support an abundance of aquatic plants. thereby leading to a high primary productivity. Because of abundance of aquatic plants and algae, the oxygen availability decreases.
9. Which of the following is/are in-situ methods of conservation?
1. Biosphere Reserve
2. Botanical Garden
3. Zoological Park
Select the correct answer using the codes given below.
a) 1 only
b) 1 and 2 only
c) 1 and 3 only
d) None
Answer & Explanation
a) 1 only. In situ conservation is on-site conservation of genetic resources in natural populations of plant or animal species. It is the process of protecting an endangered plant or animal species in its natural habitat, either by protecting or cleaning up the habitat itself, or by defending the species from predators. National parks, wildlife sanctuaries, biosphere reserves etc are its examples. Ex-situ conservation is the process of protecting an endangered species of plant or animal outside its natural habitat; for example, by removing part of the population from a threatened habitat and placing it in a new location. Botanical Gardens, Zoological Parks, germplasm banks are its examples.
10. Consider the following scenario :
1. Trees at trophic level 1 as primary producers.
2. Parasites at trophic level 2 as primary consumers.
3. Hyperparasites at trophic level 3 as secondary consumers.
The resultant pyramid of numbers would be :
a) erect
b) inverted
c) neither erect nor inverted
d) can be erect or inverted depending on other factors.
Answer & Explanation
b) inverted. This is because one single primary producer ( tree ) can support numerous primary consumers ( parasites ) and secondary consumers ( hyperparasites ). Therfore number of organisms will be highest at trophic level 3 followed by 2 and then minimum at 1 giving rise to an inverted numbers pyramid.
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3. Applying logic in UPSC General Studies Prelims
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