Nios Class 12th Environmental Science Solved Previous Year Question Paper in English Medium
Q.1. Name the planet that is called red planet and contains 95% carbon monoxide and reddish dust.
Answer. The name of the planet that is called red planet the Mars.
Q.2. Which is the site for the Tehri Power Project?
Answer. Tehri Power Project site is at the confluence of river Bhagirathi and Milangna in Tehri Garhwal Distt, Uttara Khand.
Q.3. Write the full form of IUCN.
Answer. The full form of IUCN is International Union for Conservation of Nature and Natural Resources.
Q.4. Name the process of beekeeping for the production of honey.
Answer. The process of beekeeping for the production of honey is known as apiculture.
Q.5. “Growth of industrialization has resulted in exploitation of natural resources since the beginning of the human civilization.” Explain this statement with suitable examples.
Answer. The prehistory human was living like other animals on the earth. But this animal, the human was having big brain. Due to his intelligence, as he got the knowledge of the natural materials, he could turn them into resources Slowly be came to know the utility of different materials occurring around him. he used them. Increase in population and development of senses and then the growth of industrialization resoled in exploitation these natural resources.
- Civilization began with agriculture, to which the man made in industry wring more and more land and depletion of forests.
- Coal, iron and other underground materials, the mining for making new products. An expanding human population resulted into expanding need of man started utilizing more and more natural resource are much large scale with scientific progress and technological development. Thus, growth of industrialization, the exploitation of natural resources because the two face of the same coin.
Q.6.Human activities are devasting the environment to a great extent list four local environment backlashes as caused due to human activities.
Answer. Environment, the sum total of all conditions and influences that affect the development of organisms. The philosophy of conquest of nature, that human being have followed, resulted in a very much degraded environment. Follow ins are the main human activities which may be considered local environmental back lashes:
- Contamination of air dust, smoke and harmful gases released combustion of fossil fuels in various domestic activities and automobile exhaust.
- Industrial waste gases, fly ash, dusts, smoke etc. from factories, industries and small-scale industries.
- One of the most common primary sources of water pollution is the discharge of untreated or partially treated sewage industrial effluents ete in the water bodies.
- Noise, an unwanted sound exposed before birth and throughout the life. Mechanized vehicles truck, buses, scooters, motor driver vehicles, old machine, loud seekers etc. make great noise and pollute the environment.
Q.7. Write a short note on poultry farming.
Answer. Poultry farming: Poultry farming is a term used for rearing and keeping birds such as fowl, duck and hen for eggs and meat. Poultry farming has become popular in a short period because of its comparatively easy start and maintenance.
It gives quick return within one to six months of the investments. It is easily manageable and require less space and labour. Poultry birds and their eggs are rich source of nutrients. Indian poultry provide good quality meat but on the other hand produces small sized eggs.
They have less natural immunity against common disease as compared to exotic varieties. Common exotic birds are Leg horn, Rhode Island Red, Cornish etc. Common Indian breeds are Aseel, Chittagong, Busra etc.
Q.8. Wildlife is important to up for various reasons, but it is threatened. State the important vital function of forests in conservation of fauna and flora of the biosphere.
Answer. Forests and wildlife are essential for ecological balance of an area i.e. the ecosystem, thus on the whole the biosphere. They are important component of our environment and economy. Besides, forests check air pollution, soil erosion, save hill-slopes and attract rain fall. Forests and wildlife serve as gene reserve of important species of the bio diversity. However, they are facing threatened problems.
As the wildlife maintains the ecological balance, checks pollution thus conserves like on the earth’s flora and fauna. It holds the gene reserves which serve vitally for the conservation of fauna and flora.
Q.9. Name any three conventional sources of energy. Why are they regarded as non-renewable?
Answer. Coal, oil and natural gas are the three examples of conventional energy sources. They are in use since the development of human civilization, for this these are known as conventional sources of energy. The reserves of these energy sources are with in limits and are not produced in the geo-biochemical cycles. The formation of these sources takes millions of years. For this they are regarded as the non-renewable energy sources.
Q.10. What are unconditionally renewable resources? Give three examples.
Answer. Unconditionally renewable sources : Renewable resources are those, that are regenerated by natural processes. Air, water, soil vegetation and animals are renewable primary resources because they naturally recycle and reproduce themselves. Renewable resources can be unconditional or partial which will last forever on human time scale and condition renewable recourse which must reproduce And regenerate in order to last forever .
Examples of unconditionally renewable recourses : solar wind and tidal energy are virtually inexhaustible resources on human time scale.
Q.11. India is a tropical country receiving high solar radiation. How can we converse electricity by using solar energy ?
Answer. We can well promote solar energy power to cut off the necessity of electric power by the following means in India . As we are tropical country and get high solar insolation this can be done quite on large scale :
- solar energy may be transformed in electric energy by the us of photovoltaic system this can be well cut off the necessity of electricity.
- it is necessary to promote the use of photovoltaic system by the government and other agencies. Although some confessional helps and incentives have been provided by some agencies like MRNE (New and renewable energy) , IREDA (The Indian renewable energy development agency) etc. However , it is not sufficient , much more has to done for the initiation.
- solar cookers, solar energy based heaters etc in the kitchen, hospitals hotel and any where to save electricity
Q.12. what was the need for legislation for solving environmental problems? In which year the environmental protection act was introduced in india, and when did come into force?
Answer. Legislation is needed in order to prevent misuse and degradation of the environment Major legislation directly dealing with the protection of environment are the wildlife (protection) Act, 1972, The forest (conservation) Act 1980, the water (Prevention and control of pollution) Act 1974, the Air (Prevention and Control of Pollution) Act 1981 were passed, however.
The – Environmental (protection) Act, 1986 is landmark legislation which provides for single focus in the country for the protection of the environment and aims or plugging the loopholes in the existing legislation. This act is an umbrella for legislation designed to provide of framework for central Government, ordination or activities of various central and state authorities established under previous Acts. The Environments (Protection) Act, 1986 was made into force on 23rd may 1986.
Q.13. What technical name is given for the capacity of an ecosystem for self-regulating itself? Talking an example of a pond ecosystem, explain briefly how self-regulation is maintained in such an ecosystem.
Answer. The influence of animals on the ecosystem is mostly destructive. An enormous increase in the number of animals at any trophic level (a stage in a food chain) leads to a large scale destruction of the preceding trophic level.
Similarly, large-scale destruction of a higher trophic level will lead to a great increase in the population of the preceding trophic level. In both cases, the result is that the balance (or equilibrium) in the ecosystem is upset.
This, however, is prevented by the fact that, while a given trophic level is a consumer with respect to the preceding level, it acts as a secondary producer for (and is, in turn, consumed by) the next higher trophic level. This system of checks and balances is an important stabilizing factor in any ecosystem.
It acts as a self-regulating mechanism (i.e., a negative feedback loop), which prevents any large change in the living components of the ecosystem and maintains it in a state of equilibrium. The operation of the this mechanism in nature is known as homeostasis. It may also be called the principles of eco balance.
The fresh water pond represents a complete self maintaining and self-regulating ecosystem. The vegetation is abundant with thousands of micro-organisms. large plants and animals. Thus the eco balance is normally perfect. The green plants provide oxygen and food to the consumers. The CO2 thus produced in respiration by the consumers and plant also is used by the green plants for photosynthesis.
The consumes of first, second and third order depend upon one and the other. The decomposes decompose dead plants and animals and other organic natural. It helps in the cycling of raw materials, needed by the green planets to produce food. This interrelationship keeps balance between biotic components and therefore in the ecosystem.
Q.14. What is rural eco system and characteristics of rural ecosystem.
Answer. Rural ecosystems are midway between natural and urban ecosystems since the exploitation of nature and natural resources by humans is relatively much less. Rural people live relatively close to natural and follow a simple life style.
Characteristics of rural ecosystems:
- Many villages belong to a single family.
- In rural areas people live in small clusters in thatched, mud houses surrounded by farm lands. In rural areas people are directly or indirectly dependent on agriculture and consume locally available resources.
- Drinking water is largely obtained from wells, canals, lakes or rivers.
- Education, healthcare, drainage, sanitation, hygiene and transport etc. inadequate or lacking.
- Rural areas are mostly free from air and noise pollution. The government policies to reduce the migration of people from village to cities are to increase the cost of land in the cities and reduce it in the villages. More employment opportunities should be created in the villages. Some incentives should be given to the people working in the village.
Q.15. What are earthquakes? What instrument is used to measure their intensity? What precautionary measures should be taken in the event of earthquake?
Answer. Earthquakes: An earthquake can be defined as “a rapid and dissemble termer or movement caused by fracturing of the rocks in the earth’s crust.”‘ Large and small internal forces e.g., construction, expansion, uplifting, depression, folding and faulting bring earth movements. India has had its share of destructive earthquakes.
Causes of Earthquakes and its measurements: Earthquakes are caused due to disequilibrium in any part of the curst of the earth. A number of causes have been assigned to cause disequilibrium in the earth’s crust such as volcanic eruptions, faulting and folding, up warping, and down warping, hydrostatic pressure of man-made water bodies like reservoirs and lakes, and of late the plate movements. Earthquakes are measured and recorded on seismograph on Richter scale.
Generally, up to 5.4 Richter scale measure earthquakes are not of much harm, but over this measure these may have drastic effects.
Precautions: Natural disasters like earthquakes cannot be stopped, only we can observe some time bound measures to minimise the loss:
- It is quite useful to keep watch about the unwanted activity in the earth crust with the help of some instrument like seismograph. More over the predictor beside at the time of quake should be modified beforehand.
- Buildings and other infrastructure should be made quake resistant. The designs of these building should be made in view of the quake belts by the experienced engineers.
- At the quake times people should leave the buildings and collect in the open fields.
Q.16. Respiratory bronchitis caused by smoke and SPM is increasing day-by-day due to vehicular pollution. Give various measures you will take to control such pollution.
Answer. Control of vehicular Pollution: Following measures have been suggested to control such pollution:
- By separating pollutants from gases: Some gases which are more soluble in a particular liquid than air, for example, ammonia in water can be separated by dissolving in it.
- By separating particulate matter: Particles larger than 50 mm are separated in gravity settling tanks or porous filters. Fine particles are separated by using cyclone collectors or electrostatic precipitators.
- Cyclone collector consists of a special chamber in which a gas stream containing particulate pollutants is circulated through a spiral. Particles are centrifuged outward and collected.
- Electrostatic precipitation depends on the fact that particles may be electrically charged and that a surface with opposite charge attracts them. The removes up to 95 per cent particles in the diameter range of 5-20 um. These are used in thermal power plants.
- The height of chimneys should be increased to the highest possible levle to reduce pollution at the ground level.
- SO, pollution can be controlled to a great extent by extracting sulphur from the fuel before use.
Q.17. What (X-situ conservation of biodiversity? Name four method cistus conservation of biodiversity. What is the significance of boat, gardens and zoos?
Answer. Ex-situ conservation of Biodiversity: Conservation and protection of threatened/endangered species of plants and animals by removing them from the unsated or threatened habitat and placing them under the ears of humans, in helps in recovering population or preventing their extinction under stimulated conditions that closely resemble their natural habitats.
In the face of increasing human interference, in situ conservation is not a viable option for most of the rare species. In the natural habitats, species mi decline and/or become extinct due to several factors such as genetic drift and inbreeding, deterioration of habitat quality and/or habitat loss, demographic and environmental variations, competition from exotic species, diseases as well as overexploitation. Under such circumstances, alternative method of conservation of species is ex-situ conservation.
Ex-situ conservation includes the following:
- Sacred plants and home gardens.
- Seed banks, field gene banks.
- Botanical gardens, Arboreta, Zoological gardens, Aquaria.
All these approaches help to conserve species and population diversity outside the natural habitats. Here, individuals of the species are maintained in artificial conditions under human supervision. In other words, Ex-situ conservation involves cultivation of rare plants and rearing of threatened animal species in Botanical and Zoological gardens respectively and preserve the former in the form of seeds banks etc. by means of tissue culture techniques.
These methods also include maintaining gene banks and pollens of species. In-vitro conservation, especially cryopreservation is useful technique for preserving vegetatively propagated crops, e.g., potato, seeds of plants, and preserving sperms, eggs, cells and embryonic tissues of animals at 196°C temperature. Endangered animal species are also preserved using similar techniques. The Zoological Society of San Diego has established a frozen zoo to store more than 355 species of different animals form different phylac.
There are nearly 1,500 botanical gardens and arboreta (botanical gardens where specific tree and shrub species are cultivated) in the world wizening more than 80,00 species. Similarly, there are about 800 professionally managed zoos having nearly 3,000 vertebrate species (amphibians, reptiles birds, mammals).
Majority of these zoos have well developed captive breeding programmes. In India, 35 botanical gardens and 275 2005. deer parks, safari parks and aquaria are there. The National Bureau of Plant Genetic resources (NBPGR). New Delhi and The National Bureau of Animal Resources, Kama (Haryana) have been engaged in India for the conservation of plant and animal resources.
The conservation of wild varieties of crop plants and off-site conservation of crop varieties or culture of microorganisms provide opportunities to plant breeders and genetic engineers with a ready source of genetic material. Similarly, animals and plants conserved in zoos, aquaria, botanical gardens and arboreta can be used to reintroduce them into the wild or restock depleted populations and also to restore degraded land.
Q.18. State four factors that have helped in Second Green Revolution. What is the contribution of Dr. M.S. Swaminathan in bringing green revolution in India?
Answer. Specifically the term “green revolution” refers to wheat and rice but some agricultural scientists even include maize, soya bean and sugarcane where spectacular gains in wield have occurred.
The factors which have helped to bring about the green revolution are:
- Introduction of high yielding varieties of crops.
- Multiple cropping, better irrigation and sufficient supply of fertilizer.
- Use of crop protection measures against disease and pest.
- Transfer of the technology of scientific farming from research farms to village farmers.
Spectacular in the yield of crops, particularly cereals, through the application of modern techniques in agriculture is called greed revolution.
In India, DV. M.S. Swaminathan with world envirment Dr. Norien Borlaug developed dwarf of verities for example, across between semi-dwarf Mexican wheat (high yielding and responded to fertilizer and irrigation) and Indian wheat (disease resistant and good grain quality) resulted in high yielding and disease resistant varieties of what.
Some important revolutionary varieties are Sonara-64, Larma Roso-64, Pusa-Levrma K-68, Malvika, Kalyan Sona,
Sonalika and Sharbati Sonara etc. For these development he got Padma Shree in 1967 and Padma Vibhushan in 1972.
Q.19. What are natural ecosystems? Name and define four terrestrial ecosystems.
Answer. A natural ecosystem is an assemblage of plants and animals which functions as a unit and capable of maintaining its identity such as forest, grassland and estuary, human intervention is an example of a natural ecosystem. A natural ecosystem is totally dependent on solar energy.
There are two main categories of ecosystems terrestrial and aquatic Terrestrial ecosystem Ecosystems found on land e.g. forest, grasslands, deserts, tundra. Terrestrial ecosystem are forests, grassland, deserts and tundra.
Forests : Forests are large areas supporting rich growth of trees. Depending on the climate and type of trees they are generally grouped into :
- Tropical rain forests,
- Temperate deciduous forests,
- Boreal or north coniferous forests.
Grasslands: Grasslands are areas dominated by grasses. They occupy about 20% of the land on the earth surface. Grasslands occur in both in tropical and temperate regions where rainfall is not enough to support the growth of trees. Grasslands are known by various names indifferent part of the world.
|Name of the grassland
|Eurasia (Europe and Asia)
Deserts: Deserts are hot and low rain areas suffering from water shortage and high wind velocity. They show extremes of temperature. Globally deserts occupy about 1/7th of the earth’s surface.
Tundra : The word tundra means a barren land since they are found in those regions of the world environmental conditions are very severe. They are two types of tundra arctic and alpine.
Q. 20. The greenhouse effect is a normal phenomenon and has resulted in the origin of life on the earth. The increasing human population in the recent past has hastened this process.
(a) Green House Effect and the green house gases : Sunlight that reaches earth warms both the atmosphere and earth’s surface. The atmosphere then reratiates heat as infrared radiation. Water vapours, carbon dioxide (CO2), nitrous oxide (NO2), methane (CH), chlorofluorocarbons (CFCs) and halocarbons trap some of the heat energy radiating from earth’s atmosphere and re-met it causing warming of the atmosphere. The warming is some what similar to greenhouse, which also traps heat. Thus, the process is called green house effect. The air pollutants responsible for green house effect are called green house gases.
Human activities produce chlorofluorocarbons (CFCs), methane, nitrous oxides and ozone. These account for 40-50 percent green house effect. It is predicted that green house effect will cause rise in global temperature by 0.5°C by 2020 while others expect a rise of as much as 5°C by 2050.
(b) Effects of Global Warming on the environment and the life :
Three major effects of global warming are being considered seriously :
1. Rise in sea level.
2. Changes in climate pattern and
3. Occurrence of large cyclones and tropical disturbances.
Rise in Sea level: Global warming is expected to increases sea level. This rise will be twofold: due to thermal expansion of warming ocean water (the primary cause) and due to melting of glacial ice and polar ice caps (Secondary cause).
The rise is sea level poses following serious problems :
- Coastal flooding : Coastal regions are expected to experience a sea level rise of 45-55 cm by the year 2100. This will cause coastal flooding and coastal erosion. There is fear of disappearance of Bombay in India and New York Boston, Miami etc. in USA. Buildings and other structures in the coastal zone will be exposed to sea waves of high magnitude.
- Change in coastal ecosystem : Costal ecosystem such as marshes, swamps would move inland to higher grounds. This put additional pressure on human population in coastal zone.
- Ground-water supply : Groundwater supplies for coastal communities would be threatened by saltwater intrusion.
- Change in climatic pattern : Global warming is expected to introduce climatic changes that may affect crop production, forestry and human health. Meditational climate zones could shift northwards.
- Grain growing areas may shift northwards towards Canada and Russia.
- Forests may disappear because of drier condition. This may causes disappearance of some tree species.