Environmental Science Past Paper PDF

Environmental Science Pattern of Examination:  Total marks – 100  Internal Assessment - 20 marks (test – 10 marks. Attendance – 5 marks, Assignment – 5 marks )  Final Examination - 80 marks Term End Examination: Paper will be for maximum of 80 marks. The minimum mark to pass the examination is...

Environmental Science Pattern of Examination:  Total marks – 100  Internal Assessment - 20 marks (test – 10 marks. Attendance – 5 marks, Assignment – 5 marks )  Final Examination - 80 marks Term End Examination: Paper will be for maximum of 80 marks. The minimum mark to pass the examination is 40% (32 marks).  Section – A: Short Answer questions  Section – B: Medium Answer Questions  Section – C: Long Answer Questions Duration of the examination: 3 hours Unit 1 - Introduction to Environmental Studies: Multidisciplinary nature of environmental studies, Scope and importance; Concept of sustainability and sustainable development, SDG Goals Ecosystem: Structure and function of ecosystem; Energy flow in an ecosystem: food chains, food webs and ecological succession. Terrestrial Ecosystems: Forest ecosystem, Grassland ecosystem, Desert ecosystem, Aquatic ecosystems; ponds, streams, lakes, rivers, oceans, estuaries Unit 2 - Ecosystem: Natural Resources: Renewable and Non- Renewable Resources: Land resources: Land-use and land cover change; Land degradation, Soil erosion, and desertification. Forest Resources: Types and scope; Deforestation: Causes and impacts due to mining, dam building on environment, forests, biodiversity, and tribal populations. Water Recourses: Use and over-exploitation of surface and ground water, floods, droughts, conflicts over water (international & interstate). Energy resources: Renewable and non- renewable energy sources, use of alternate energy sources, growing energy needs, case studies. Biodiversity and Conservation: Levels of biological diversity: Genetic, species and ecosystem diversity; Biogeographic zones of India Biodiversity patterns and global biodiversity hot spots. India as a mega-biodiversity nation; Endangered and endemic species of India. Threats to biodiversity: Habitat loss, poaching of wildlife, manwildlife conflicts with case studies, biological invasions; Conservation of biodiversity: In-situ and Ex-situ conservation of biodiversity. Unit 3 - Environmental pollution: types, causes, effects and controls; Air, water, soil and noise pollution, nuclear hazards and human health risks, Solid waste; management and control measures of urban and industrial waste with case studies. Environmental Policies and Practices: Climate change, global warming, ozone layer depletion, acid rain and impacts on human communities and agriculture. Environment Laws: Environment Protection Act; Air (Prevention & Control of Pollution) Act; Water (Prevention and control of Pollution) Act; Wildlife Protection Act; Forest Conservation Act. International agreements: Montreal and Kyoto protocols and Convention on Biological Diversity (CBD). Nature reserves, tribal populations and rights, and human wildlife Unit 4 - Human Communities and the Environment: Human population growth: Impacts on environment, human health and welfare. Resettlement and rehabilitation of project affected persons; case studies. Disaster management: floods, earthquake, cyclones and landslides with case studies. Environmental movements: Chipko, Silent valley, Bishnois of Rajasthan Environmental ethics: Ecological, economic, social, ethical, aesthetic and Informational value. Role of Indian and other religions and cultures in environmental conservation Environmental communication and public awareness, case studies - CNG vehicles in Delhi). Environmental studies is a multidisciplinary academic field which systematically studies human interaction with the environment. Environmental studies connects principles from the physical sciences, commerce/economics, the humanities, and social sciences to address complex contemporary environmental issues. It is a broad field of study that includes the natural environment, the built environment, and the relationship between them. Multidisciplinary Nature of Environmental studies  Importance and Need for public awareness The study creates awareness among the people to know about various renewable and non-renewable resources of the region. The pattern of utilization and the balancing of various resources available for future use in the state of a country are analysed.  Provides the knowledge about ecological systems and cause and effect relationships.  Provides information about biodiversity richness and potential dangers to the species of plants/animals/microorganism.  To understand the causes and consequences due to natural and induced disaster, pollutions and measure to minimise the effects. ECOSYSTEM  The term ‘Ecosystem’ is coined by A.G Tansley in 1935.  Structure of an Ecosystem: Abiotic and Biotic  Ecosystem - is a community of living organism interacting with each other and their non living environment. Ecosystem is classified into two categories Abiotic an Biotic group Abiotic group – all non-living elements fond on the earth (i) Physical Factors - Temperature - useful to sustain life on earth, metabolic activity, growth etc, Water – the type of nature/quality of water determine the type of vegetation and life. It exists in forms –vapour, ice, snow in water bodies. , Light – main source of energy, helps in photosynthesis, oxygen for humans, Air – contains number of gases, oxygen important for life, Topography – varies from place to place, soil and vegetation, hills, valleys plains, mountain. (ii) Inorganic Substances – Carbon dioxide, nitrogen, oxygen, phosphorus, water etc. (iii) Organic Compounds – Carbohydrates, proteins, lipids, human substances- they are building blocks of living systems are found in the cells of living organisms. Biotic group - it composes of all living organism found on the earth. It is classified into three categories i.e producers , consumers and decomposers. (i) Producers/Autotrophs – green plants generates their own energy requirement through photosynthesis (ii) Consumers/heterotrophs - which depends on producers for food and energy, primary consumers are herbivores and secondary consumers are carnivores. (iii) Decomposer/Saprotrophs –these are bacteria/fungi that feed on organic matter of the producers and consumers.  Types of consumers – Biotic Group Consumers are organisms within food chains that survive by eating other organisms. (i) Primary Consumers /First Order Consumers/Herbivore – the animals which feed on plants/producer. Example- rabbit (ii) Secondary Consumers/ Second order Consumers– the animals which feed on the herbivores. Example- Foxes (iii) Tertiary Consumers/ Third Order Consumers – these are large carnivores which feed on the primary/secondary consumers. Example- lion (iv) Quaternary consumers / Fourth order consumers – these are largest carnivores which feed on the tertiary consumers and are not eaten up any other animal. Example - hawk Food Chain Transfer of food energy from green plants (producers) through a series of organisms with repeated eating and being eaten is called a food chain. Each step in the food chain is called trophic level. Consumers Trophic level Grazing food Chain - it begins with green plants, then moves on to grazing herbivores and finally to carnivores. It utilises energy from the environment. e.g Grass –Rabbit – Fox – tiger Parasitic Food Chain – a type of food chain that starts from herbivores, but the food energy transfer from larger organism to smaller organism without killing. e.g Trees – fruit eating birds – bugs Detritus Food Chain – it starts with dead organic matter that are decomposed by microorganism(detritivores/decomposers) and then the predators. Release of nutrients held inside the organic matter back into the ecosystem- soil/water. e.g Dead leaves – woodlouse- blackbird  Food Web – is the interconnection of food chains and a graphical representation of what – eats-what in an ecological community. Ecological Pyramid  An Ecological pyramid is a graphical representation of the relationship between the different living organisms at different trophic levels within a food chain.  Environment Components   Physical/Abiotic-- Lithosphere/Hydrosphere/Atmospheres  Environment Biological/Biotic - flora/fauna  Social/cultural /manmade – Physical/Social /Economic Lithosphere  The lithosphere is the rocky outer part of the Earth. It is made up of the brittle crust and the top part of the upper mantle. The lithosphere is the coolest and most rigid part of the Earth. Hydrosphere  A hydrosphere is the total amount of water on a planet. The hydrosphere includes water that is on the surface of the planet, underground, and in the air. A planet's hydrosphere can be liquid, vapor, or ice. On Earth, liquid water exists on the surface in the form of oceans, lakes and rivers.  Atmosphere  The atmosphere is a mixture of gases that surrounds the planet. On Earth, the atmosphere helps make life possible. Besides providing us with something to breathe, it shields us from most of the harmful ultraviolet (UV) radiation coming from the Sun, warms the surface of our planet by about 33° C (59° F) via the greenhouse effect.  Nitrogen – 78.084%, Oxygen – 20.9476% Structure of Atmosphere  Troposphere -  Stratosphere  Mesosphere  Thermosphere  Exosphere Troposphere is the atmospheric layer closest to the planet.  Temperature and water vapor content decrease with increase in altitude.  Water vapor plays a major role in regulating air temperature because it absorbs solar energy and thermal radiation from the planet's surface.  The air in the troposphere is 78% nitrogen and 21% oxygen. Only 1% of the air is made up of water vapor, argon, and carbon dioxide.  All weather phenomena occur within the troposphere  The upper boundary of the layer, known as the tropopause. Stratosphere  The stratosphere is located above the troposphere and below the mesosphere.  It extends above the tropopause to an altitude of about 30 miles (50 km).  The stratosphere is very cold, temperature increases with altitude in the stratosphere, which is opposite from the troposphere.  The stratosphere contains ozone layer. The ozone layer helps to protect us from ultraviolet radiation (UV) from the sun.  Pilots wanting to create a smooth ride for their passengers, they fly above the tropopause in the stratosphere, where there are no thunderstorms or rain, air is thinner and free of turbulence. Mesosphere  The mesosphere is the third and coldest layer of Earth's atmosphere, extending approximately from 30 to 50 miles (80 to 90 km) above the surface, is characterized by decreasing temperatures.  The mesosphere is just above the stratosphere and meteors can burn up in this layer.  The boundary between the mesosphere and the thermosphere is called the mesopause. Thermosphere  The layer present right above the mesosphere extending to a height of 800km is the thermosphere.  As solar radiation travels from the sun to the earth , it passes through the exosphere and enters the thermosphere it has approximately 3500 degree Fahrenheit, this heat is what gives the thermosphere it’s name – Thermo means HEAT (Greek word)  This layer is composed of electrically charged ions that are responsible for reflecting the radio waves back to the Earth's surface.  Radio waves are a type of electromagnetic radiation best-known for their use in communication technologies, such as television, mobile phones and radios.  Due to the presence of these ions, thermosphere is also known as Ionosphere. Exosphere  The exosphere is the uppermost region of Earth's atmosphere as it gradually fades into the vacuum of space. "Exo" means outside.  The lower boundary of the exosphere, where it meets the thermosphere, is called the thermopause.  The thermopause is called the exobase, exopause, or critical altitude.  The particles in the exosphere are moves very quickly, so the temperature there is quite hot.  The Earth's exosphere consists mainly of hydrogen, helium, carbon dioxide, and atomic oxygen. Ecological Succession  It is the process of by which mix of species and habitat in an area changes over time.  In primary succession, newly exposed or newly formed rock is colonized by living things for the first time (100 yr). In secondary succession, an area previously occupied by living things is disturbed—disrupted—then recolonized following the disturbance (150 yrs and above).  climax community or climatic climax community is a historic term for a community of plants, animals, and fungi which, through the process of ecological succession in the development of vegetation in an area over time, have reached a steady state. Natural Ecosystem Forest Ecosystem - #Forest ecosystems are areas of the landscape that are dominated by trees and consist of biologically integrated communities of plants, animals and microbes, together with the local soils (substrates) and atmospheres (climates) with which they interact. #depending on the climate and the type of forest ecosystem is grouped into Tropical Rain Forest  Distribution - found in higher rainfall areas on either side of equator. Western coast of India, south East Asia, Parts of Africa, South America.  Rainfall – 200cm per year  Temperature - High temperate and humidity  Soil – rich in humus  Flora and Fauna – Vines, creepers, orchid, Monkeys, flying squirrels, snails Temperate Deciduous Forest Distribution – North west central Europe, Eastern north America, North China, Korea, Japan Trees shed their leaves in autumn and leaves grows in spring. These forests are also known as deciduous forests because the trees have flat and wide leaves. Rainfall – 75 to 150 cm per year Soil – Brown soil Flora and Fauna – Oak, Pine, chestnut, Deer, Bison, Wild cat, fox, Hibernation /Winter Sleep North Coniferous Forest /Boreal /Taiga Forest  Distribution: North America and Eurasia  Climate – Cold with long duration, harsh winter, temperature below Zero degree Celsius.  Soil – Acidic in nature, poor in nutrients  Flora and Fauna – Pines, spruces, Firs, Red squirrel, deer, goat, robin Desert Ecosystem  Climate – Hot and low rain areas, high wind velocity, extreme temperature.  Distribution Globally deserts occupy 1/7th of the earths surface.  Flora & fauna – Cacti, Acacia, Euphorbia, Prickly Pears (desert plants). Shrew, fox, wood rats, rabbits, camel Adaptation Plants – Shrubs, leave absent/reduced, stem and leaves store water. Animals – Fast runner, Nocturnal – Avoid heat during the day, have long legs – protect body from hot ground. Grassland Ecosystem  Non woody plants (Herbaceous), few trees, Shrubs.  Distribution – Grassland are areas dominated by grasses. 20% of land on earth surface is occupied by them. It is found in Tropical and Temperate Region.  Grassland are known by various names in different parts of the world. Place North America Prairies Eurasia(Europe & Steppes Asia) South America Pampas Africa Savanna India Grassland, Savanna Flora and Fauna - Grasses, Thorny trees Badgers, Fox, Zebra  Aquatic Ecosystem  Aquatic ecosystem refers to plant and animal communities occurring in water bodies.  The aquatic ecosystem is the habitat for water-dependent living species including animals, plants, and microbes. Types :  Fresh water ecosystem  Marine Water ecosystem  Fresh Water Ecosystem Fresh Water Ecosystem are the subset of earth’s aquatic ecosystem and has low salt content, study of freshwater ecosystem is called limnology. (i) Static or still water (Lentic) example: pond, lake, bogs and swamps (ii) Running Water (Lotic) example : Springs, mountain brooks, stream and rivers. LAKE ECOSYSTEM The different zones are as follows: Littoral zone – It is the shallow water region occupied by rooted plants. Limnetic-zone- ranges from the shallow to the depth of effective light penetration and associated organisms are small crustaceans, rotifers, insects, and their larvae and algae. Pro-fundal zone- It is the deep-water parts where there is no effective light penetration. The associated organism are mussels, crab, worms etc. Many Lakes undergoes Eutrophication which is the process in which a water body becomes overly enriched with nutrients, leading to the plentiful growth of simple plant life. The excessive growth (or bloom) of algae and plankton in a water body are indicators of this process. Pond Ecosystem  A pond ecosystem refers to the freshwater ecosystem where there are communities of organisms that are dependent on each other and with the prevailing water environment for their nutrients and survival. Usually, ponds are shallow water bodies in which sunlight can reach to its bottom, permitting the growth of the plants that grow there. Producers The producer includes species of rooted and floating (algae) aquatic plant life that intakes sunlight, air, water, nutrients. The floating organisms are called plankton. The minute plants of plankton type are known as phytoplankton. Primary Consumers The primary consumers consist of small herbivorous animals that feed on producers. Primary consumers are snails, insects, tadpoles, and small fish. They also include various microscopic animals that are called zooplankton. Secondary Consumers secondary consumers feeds on the primary consumers. They are frogs, fish, crayfish, other amphibians, and reptiles like water snakes and turtles. Tertiary Consumers Tertiary consumers eat primary and secondary level animals. The third level consumer includes water birds, hawks, small mammals. Decomposers Bacteria, scavengers, and fungi are the last consumers of the Pond’s food web. They break down decaying and dead aquatic plants and animals. The recycling of elemental nutrients by decomposers makes available the nutrients to new generations of plants.  Wetland – are the areas that periodically overloaded with water and support a flourishing community of aquatic organisms. E.g Swamps, marshes and mangroves Marine Ecosystem Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. Distribution – Marine ecosystem covers 71% of the earths surface with an average depth of 4000m. It pertains to seas and oceans including marine organism. Salinity of open sea is 3.6%.  The marine environment provides a diverse range of habitat for flora and fauna of the marine aquatic system, ranging from seashores to the deep seafloor. It is home to millions of species.  SARGASSU M RED ALGAE KELP  Plant habitat in a maritime ecosystem includes kelp, red algae, sargassum, and mangrove. Fauna includes Blue Whale, Dolphin, Whale, Shark and Sea Otter other animals  Marine water has an average temperature of 30 degrees Fahrenheit.  However, depending on its location on the Earth's surface, its temperature may change (becoming cooler or warmer).  The marine ecosystems around the equator have relatively warm water temperatures, whereas those towards the poles have frigid water temperatures. Estuary – it is a partly enclosed body of water with one or more rivers or streams flowing into it and with a free connection to the open sea. Example Thane creek. Mangrove – is a grouping of semi-submerged trees that have been flooded with water. They are characterized by halophytic (salt loving) trees, shrubs and other plants growing in brackish to saline tidal waters. Example Sunderbans Coral Reef – it is one of the richest aquatic ecosystem of the planet, Coral reefs are made up of colonies of hundreds to thousands of tiny individual corals, called polyps. These marine invertebrate animals have hard exoskeletons made of calcium carbonate, and are sessile, meaning permanently fixed in one place.. Example Coral reef of Andaman and Nicobar island Mangrove ESTUARY Coral Reef Bog swamp Marshes Eutrophication is the process in which a water body becomes overly enriched with nutrients, leading to the plentiful growth of simple plant life. The excessive growth (or bloom) of algae and plankton in a water body are indicators of this process. Sustainable Development United Nations Conference on Environment and Development (UNCED) NITI ( National Institution for Transforming India) Aayog, new commission for coordinating SDGs in India.  The United Nations Conference on Environment and Development (UNCED), also known as the 'Earth Summit', was held in Rio de Janeiro, Brazil, from 3-14 June 1992.  The Rio de Janeiro conference highlights different social, economic and environmental factors  The 'Earth Summit' concluded that the concept of sustainable development was an attainable goal for all the people of the world, regardless of whether they were at the local, national, regional or international level.  One of the major results of the UNCED Conference was Agenda 21, a daring program of action calling for new strategies to invest in the future to achieve overall sustainable development in the 21st century. Its recommendations ranged from new methods of education, to new ways of preserving natural resources and new ways of participating in a sustainable economy.  Sustain – supportable, maintainable  UNCED defines Sustainable development “Sustainable Development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs”. Three pillars of Sustainable Development  SDG (17 Goals) 1. No Poverty - in all its forms everywhere. Promoting access to sustainable jobs and equality to eradicate extreme poverty by year 2030. 2. Zero hunger - Many still suffer from hunger and malnutrition around the world, mostly women and children. The food and agriculture sector offers key solutions for development and is central for hunger and poverty eradication. This goal include ending malnutrition, protecting small famers, investing in research to make farming more productive. 3. Ensure healthy lives and promote well being for all at all ages. This goals calls for universal health coverage, increasing healthcare workforce, reducing illness and death by pollution, tackling global health challenges such as AIDS, Malaria, tuberculosis. Vaccinating to protect and improve public health. 4.Equitable quality education for all. - this goal include the need for access to university level education, vocational training and entrepreneurial skills. Helping children in our community to acquire education. 5. Gender equality , empower all women and girls – gender equality is not only a fundamental human right, but is a necessary foundation for a peaceful, prosperous and sustainable world. Target include freedom from discrimination and violence, ensuring equal share of leadership opportunities and responsibilities for women as well as property ownership. 6. Clean Water and Sanitation – Clean accessible water for all. This goal include programs that provide access to basic needs like toilets or latrines as well as protecting ecosystem that provide water. 7. Affordable and Clean Energy – about 1.3 billion people globally have no access to electricity. Target for this goals emphasize a conversion to renewable sources and a dramatic improvement in efficiency everywhere. 8. Decent Work and Economic Growth - Sustainable economic growth will require societies to create the conditions that allow people to have quality jobs. About 75 million people between ages 15 and 24 are estimated to be unemployed and out of school globally. This goal targets closing that gap using innovation as well as separating growth from ecosystem degradation. 9. Industry, Innovation and Infrastructure - Investment in infrastructure are crucial to achieve sustainable development. This goals target in fostering a more innovative and environmentally sound approach in industrial development. 10. Reducing inequalities – Target for this goal include financial market regulation to make the playing field more equal, to ensure equal opportunity and reduce inequalities of outcome, through eliminating discriminatory laws, policies and practices and promoting appropriate legislation, policies and actions in this regard. 11. Sustainable cities and communities – this goals targets to address the issues like transportation, basic service, energy, housing, preservation of the worlds cultural and natural heritage. 12. Responsible consumption and production - this goal targets topics like reducing food wastage, corporate sustainability practice and educating people on the impact of their lifestyle on the environment. 13. Climate Action - Urge to take action to combat climate change and its impacts. To educate young people on climate change to put them on sustainable path early. 14. Life below water - Conserve and sustainably use of the marine resources. The target is to find out better ways to save the life beneath the water and protect them from pollution. 15. Life on Land - Managing forests sustainably, halting and reversing land and natural habitat degradation, successfully combating desertification and stopping biodiversity loss. 16. Peace, justice and strong institution : Promotion of peaceful and inclusive societies for sustainable development, the provision of access to justice for all, and building effective, accountable institutions at all levels. Target is to reduce violence, reduction of corruption, creating institutions and governments that work for everyone.  17. Global partnership for sustainable development - SDG 17 refers to the need for cross sector and cross country collaboration in pursuit of all the goals by the year 2030. It is a call for countries to align policies. It is about strengthening and streamlining cooperation between nation-states, both developed and developing, using the SDGs as a shared framework and a shared vision for defining that collaborative way forward.