may 2018 EVS solved paper of Mumbai University part 1

1.A what is meant by E pollution.

Ans:- Electronic waste or e-waste describes discarded electrical or electronic devices. Used electronics which are destined for reuse, resale, salvage, recycling, or disposal are also considered e-waste. Informal processing of e-waste in developing countries can lead to adverse human health effects and environmental pollution. Electronic scrap components, such as CPUs, contain potentially harmful components such as lead, cadmium, beryllium, or brominated flame retardants. Recycling and disposal of e-waste may involve significant risk to health of workers and communities in developed countries and great care must be taken to avoid unsafe exposure in recycling operations and leaking of materials such as heavy metals from landfills and incinerator ashes

1.B explain the concept carbon credit.

Ans:- A carbon credit is a permit or certificate allowing the holder to emit carbon dioxide or other greenhouse gases. The credit limits the emission to a mass equal to one ton of carbon dioxide. The issuance of carbon credits aims to reduce the emission of greenhouse gases into the atmosphere. It is also called as emission permit. Carbon credits are created in many ways – 1. Sequestration:- it means capturing or retaining CO2 from atmosphere like afforestation 2. CO2 saving projects like use of renewable energies. It is the outcome of KYOTO protocol which creates legally binding emission targets foe developing nations to limit CO2 emissions, It creates market by providing monetary values to the cost of polluting the air. It is seen like other inputs like raw material or labor where the credits can be exchanged between businesses and brought and sold in the international markets at prevailing market price. Renewable energy like wind farms, geothermal, biomass energy as well as methane capture from landfills create carbon credits by displacing the fossil fuels.

1.C explain the concept ecological pyramid

An ecological pyramid is a graphical representation of the relationship between different organisms in an ecosystem. Each of the bars that make up the pyramid represents a different trophic level, and their order, which is based on who eats whom, represents the flow of energy. Energy moves up the pyramid, starting with the primary producers, or autotrophs, such as plants and algae at the very bottom, followed by the primary consumers, which feed on these plants, then secondary consumers, which feed on the primary consumers, and so on. The height of the bars should all be the same, but the width of each bar is based on the quantity of the aspect being measured. An ecological pyramid not only shows us the feeding patterns of organisms in different ecosystems, but can also give us an insight into how inefficient energy transfer is, and show the influence that a change in numbers at one trophic level can have on the trophic levels above and below it. Also, when data are collected over the years, the effects of the changes that take place in the environment on the organisms can be studied by comparing the data. Types of Ecological Pyramids Pyramid of numbers This shows the number of organisms in each trophic level without any consideration for their size

Pyramid of biomass This indicates the total mass of organisms at each trophic level. Usually, this type of pyramid is largest at the bottom and gets smaller going up, but exceptions do exist. The biomass of one trophic level is calculated by multiplying the number of individuals in the trophic level by the average mass of one individual in a particular area. Pyramid of productivity The pyramid of productivity looks at the total amount of energy present at each trophic level, as well as the loss of energy between trophic levels. 1.D differentiate between conventional and non conventional energy

1.E explain food chain

A food chain is a linear network of links in a food web starting from producer organisms (such as grass or trees which use radiation from the Sun to make their food) and ending at apex predator species (like grizzly bears or killer whales), detritivores (like earthworms or woodlice), or decomposer species (such as fungi or bacteria). A food chain also shows how the organisms are related with each other by the food they eat. Each level of a food chain represents a different trophic level. A food chain differs from a food web, because the complex network of different animals' feeding relations are aggregated and the chain only follows a direct, linear pathway of one animal at a time. Natural interconnections between food chains make it a food web. A common metric used to quantify food web trophic structure is food chain length. In its simplest form, the length of a chain is the number of links between a trophic consumer and the base of the web and the mean chain length of an entire web is the arithmetic average of the lengths of all chains in a food web. The food chain's length is a continuous variable that provides a measure of the passage of energy and an index of ecological structure that increases in value counting progressively through the linkages in a linear fashion from the lowest to the highest trophic (feeding) levels fig- food chain

1. F explain causes and effects of ozone layer depletion

Causes: Ozone is a triatomic form of oxygen (O3), found in the Earth's atmosphere. A combination of low temperatures, elevated chlorine, and bromine concentrations in the upper stratosphere are responsible for the destruction of ozone. The production and emission of chlorofluorocarbons (CFCs), is the leading cause of ozone layer depletion. CFC's account for almost 80% of the total depletion of ozone. Other ozone-depleting substances (ODS), include hydrochlorofluorocarbons (HCFCs), and volatile organic compounds (VOCs). These are often found in vehicle emissions, byproducts of industrial processes, refrigerants, and aerosols. ODS are relatively stable in the lower atmosphere of the Earth, but in the stratosphere, they are exposed to ultraviolet radiation and thus, they break down to release a free chlorine atom.

Effects of ozone depletion As ozone depletes in the stratosphere, it forms a 'hole' in the layer. This hole enables harmful ultraviolet rays to enter the Earth's atmosphere. Ultraviolet rays of the Sun are associated with a number of health-related, and environmental issues.

Impact on animals

• Skin cancer: Exposure to ultraviolet rays poses an increased risk of developing several types of skin cancers, including malignant melanoma, and basal and squamous cell carcinoma.

• Eye damage: Direct exposure to UV radiations can result in photokeratitis (snow blindness), and cataracts.

• Immune system damage: Effects of UV rays include impairment of the immune system. Increased exposure to UV rays weakens the response of the immune system.

• Accelerated aging of skin: Constant exposure to UV radiation can cause photo allergy, which results in the outbreak of rashes in fair-skinned people.

• Other effects: Ozone chemicals can cause difficulty in breathing, chest pain, throat irritation, and hamper lung functioning.

Impact on Plants

• In some species of plants, UV radiation can alter the time of flowering, as well as the number of flowers produced by a plant.

• Plant growth can be directly affected by UV-B radiation. Despite mechanisms to reduce or repair these effects, physiological and developmental processes of plants are affected.

1.G explain concept of acid rain

any form of precipitation with acidic components, such as sulfuric or nitric acid that fall to the ground from the atmosphere in wet or dry forms. This can include rain, snow, fog, hail or even dust that is acidic.
Acid rain results when sulfur dioxide (SO2) and nitrogen oxides (NOX) are emitted into the atmosphere and transported by wind and air currents. The SO2 and NOX react with water, oxygen and other chemicals to form sulfuric and nitric acids. These then mix with water and other materials before falling to the ground. While a small portion of the SO2 and NOX that cause acid rain is from natural sources such as volcanoes, most of it comes from the burning of fossil fuels. The major sources of SO2 and NOX in the atmosphere are:

• Burning of fossil fuels to generate electricity. Two thirds of SO2 and one fourth of NOX in the atmosphere come from electric power generators.

• Vehicles and heavy equipment.

• Manufacturing, oil refineries and other industries. Winds can blow SO2 and NOX over long distances and across borders making acid rain a problem for everyone and not just those who live close to these sources.

Wet Deposition

Wet deposition is what we most commonly think of as acid rain. The sulfuric and nitric acids formed in the atmosphere fall to the ground mixed with rain, snow, fog, or hail.

Dry Deposition

Acidic particles and gases can also deposit from the atmosphere in the absence of moisture as dry deposition. The acidic particles and gases may deposit to surfaces (water bodies, vegetation, buildings) quickly or may react during atmospheric transport to form larger particles that can be harmful to human health. When the accumulated acids are washed off a surface by the next rain, this acidic water flows over and through the ground, and can harm plants and wildlife, such as insects and fish. The amount of acidity in the atmosphere that deposits to earth through dry deposition depends on the amount of rainfall an area receives. For example, in desert areas the ratio of dry to wet deposition is higher than an area that receives several inches of rain each year.

2A. Explain various modes needed for public awareness to protect earth from environmental degradation

Targeted Efforts According to UNEP, environmental awareness campaigns are most successful when targeted to specific groups or populations. Many people don't pay much attention to environmental problems because they don't understand how the problem would affect them or their lifestyle. One reason that hybrid cars, energy-saving appliances, and solar panels have become so popular in the past few years is because of targeted awareness. Showing people how much money they could save by purchasing a hybrid or installing a solar panel has helped to "convert" people who normally wouldn't have paid much attention to environmental problems.

Local Outreach

Environmental education is just as important in the developing world as it is in industrialized nations; however, reaching out to the people in those countries can be very difficult. Language barriers, illiteracy, and cultural differences can prevent them from learning about environmental issues, particularly in rural or tribal areas. Reaching out to tribal, religious, and community leaders can often help a government organization or non-governmental organization (NGO) educate the people on environmental issues. Community leaders can help ease communication problems and bridge the cultural divide that often stands in the way of outreach efforts.

The Media

In developed countries and urban areas, the use of print, broadcast, and Internet media can be a great way to increase education and awareness. By working with the media, government agencies and nonprofit organizations can help spread their message, either by holding press briefings, issuing printed press releases, or even setting up online databases that can be used as information centers. Information centers can be useful tools to educate both the public and journalists about environmental concerns. Many media outlets may want to increase their coverage of environmental issues, but don't know where to find accurate information. Having a central information clearinghouse that is accessible to journalists and the public can be extremely useful.

Classroom Education

Thirty percent of the world's population is under the age of eighteen, according to UNEP, which is why educating children and young adults about environmental problems is crucial to long-term success. This will help them foster a sense of responsibility and "proactive citizenship," so that when they become adults they will make choices that help the environment rather than harm it. Many schools, however, do not currently teach their students about environmental issues. Integrating environmental education into current science classes or teaching environmental science as a separate discipline is one of the best ways to educate children and teens about environmental problems, particularly if the classes involve some sort of "hands-on" learning, like starting a garden or caring for an animal.

2.B explain the need and importance of environmental studies.

Every organism is surrounded by materials and forces that constitute its environment. It is the environment from where every organism must derive its requirement. The environment creates favourable conditions for the existence and development of living organisms. The survival of any organism requires a steady supply of materials and removal of waste products from its environment. The degradation of the environment has become a serious problem for the existence of human beings. Pollution of soil, water and air causes harm to living organisms as well as loss to valuable natural resources. Environmental studies involves educating the people for preserving the quality of environment.


Increasing population, Urbanization and poverty have generated pressure on the natural resources and lead to a degradation of the environment. TO PREVENT THE ENVIRONMENT FROM FURTHER DEGRADATION, the supreme court has ordered and initiated environmental protection awareness through government and non-government agencies to take part in protecting our environment. Environmental pollution cannot prevented by laws alone. Public participation is equally important with regard to environmental protection.

Environmental Education (EE) is a process of learning by giving an overall perspective of knowledge and awareness of the environment. It sensitizes the society about environmental issues and challenges interested individuals to develop skills and expertise thereby providing appropriate solutions. Climate change, loss of biodiversity, declining fisheries, ozone layer depletion, illegal trade of endangered species, destruction of habitats, land degradation, depleting ground water supplies, introduction of alien species, environmental pollution, solid waste disposal, storm water and sewage disposal pose a serious threat to ecosystems in forest, rural, urban and marine ecosystems. Both formal and informal education on the environment will give the interested individual the knowledge, values, skills and tools needed to face the environmental challenges on a local and global level.

IMPORTANCE OF ENVIRONMENTAL STUDIES In the industrialized era that we live today, every component that we intake - be it, air, water or food are contaminated by industrial activities. THERE IS NO ZERO POLLUTION. To minimize this problem, knowledge of environmental studies is essential. An in-dept study of environmental studies will help us in the following ways:

  1. We will begin to appreciate and adopt the idea of "DEVELOPMENT WITHOUT DESTRUCTION OF THE ENVIRONMENT"


  3. Playing an effective role in protecting the environment by "DEMANDING CHANGES IN LAW AND ENFORCEMENT SYSTEMS".



2.C explain classification of ecosystem

Ecosystems can generally be classified into two classes such as natural and artificial. Artificial ecosystems are natural regions affected by man’s interferences. They are artificial lakes, reservoirs, townships, and cities. Natural ecosystems are basically classified into two major types. They are aquatic ecosystem and terrestrial ecosystem.

Types of Natural Ecosystem An ecosystem is a self-contained unit of living things and their non-living environment. The following chart shows the types of Natural Ecosystem −

Biotic (Living Components)

Biotic components in ecosystems include organisms such as plants, animals, and microorganisms. The biotic components of ecosystem comprise − • Producers or Autotrophs • Consumers or Heterotrophs • Decomposers or Detritus

Abiotic (Non-living Components)

Abiotic components consist of climate or factors of climate such as temperature, light, humidity, precipitation, gases, wind, water, soil, salinity, substratum, mineral, topography, and habitat. The flow of energy and the cycling of water and nutrients are critical to each ecosystem on the earth. Non-living components set the stage for ecosystem operation.

Aquatic Ecosystem An ecosystem which is located in a body of water is known as an aquatic ecosystem. The nature and characteristics of the communities of living or biotic organisms and non-living or abiotic factors which interact with and interrelate to one another are determined by the aquatic surroundings of their environment they are dependent upon.

Aquatic ecosystem can be broadly classified into Marine Ecosystem and Freshwater Ecosystem.

Marine Ecosystem

These ecosystems are the biggest of all ecosystems as all oceans and their parts are included in them. They contain salt marshes, intertidal zones, estuaries, lagoons, mangroves, coral reefs, the deep sea, and the sea floor. Marine ecosystem has a unique flora and fauna, and supports a vast kingdom of species. These ecosystems are essential for the overall health of both marine and terrestrial environments. Salt marshes, seagrass meadows, and mangrove forests are among the most productive ecosystem. Coral reef provides food and shelter to the highest number of marine inhabitants in the world. Marine ecosystem has a large biodiversity.

Freshwater Ecosystem

Freshwater ecosystem includes lakes, rivers, streams, and ponds. Lakes are large bodies of freshwater surrounded by land. Plants and algae are important to freshwater ecosystem because they provide oxygen through photosynthesis and food for animals in this ecosystem. Estuaries house plant life with the unique adaptation of being able to survive in fresh and salty environments. Mangroves and pickle weed are examples of estuarine plants. Many animals live in freshwater ecosystem. Freshwater ecosystem is very important for people as they provide them water for drinking, energy and transportation, recreation, etc.

Terrestrial Ecosystem

Terrestrial ecosystems are those ecosystems that exist on land. Water may be present in a terrestrial ecosystem but these ecosystems are primarily situated on land. These ecosystems are of different types such as forest ecosystem, desert ecosystem, grassland and mountain ecosystems. Terrestrial ecosystems are distinguished from aquatic ecosystems by the lower availability of water and the consequent importance of water as a limiting factor. These are characterized by greater temperature fluctuations on both diurnal and seasonal basis, than in aquatic ecosystems in similar climates. Availability of light is greater in terrestrial ecosystems than in aquatic ecosystems because the atmosphere is more transparent on land than in water. Differences in temperature and light in terrestrial ecosystems reflect a completely different flora and fauna.


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