JKBOSE 12th Class Bi-Annual Private 2026 EVS Guess Paper PDF Download
In this article, I will provide the most important and expected questions for the JKBOSE 12th Class Environmental Science (EVS) Bi-Annual Private Examination 2026. These guess questions are prepared according to the latest JKBOSE syllabus and model paper pattern to help students focus on high-weightage topics and improve their exam preparation. JKBOSE has also updated Environmental Science among the revised Class 12 subjects for recent sessions.
1. Name two gases that are considered major air pollutants and state their primary sources.
Two major air pollutants are sulfur dioxide (SO₂) and carbon monoxide (CO). Sulfur dioxide is mainly released from the burning of coal and petroleum in thermal power plants and industries. Carbon monoxide is produced by the incomplete combustion of fuels in motor vehicles, factories, and domestic heating systems. These gases contribute significantly to environmental pollution and can cause serious health problems in humans.
2. What is the key difference between primary and secondary sewage treatment?
Primary sewage treatment is a physical process in which large suspended particles are removed from wastewater through screening and sedimentation. Secondary sewage treatment is a biological process that uses microorganisms to decompose and remove dissolved organic matter from sewage. Thus, primary treatment removes physical impurities, while secondary treatment removes biodegradable organic pollutants.
3. Explain the process of eutrophication in a water body, detailing the sequence of events.
Eutrophication is the excessive enrichment of water bodies with nutrients such as nitrates and phosphates. These nutrients promote rapid growth of algae and aquatic plants, resulting in algal blooms. When the algae die, bacteria decompose them and consume large amounts of dissolved oxygen. This depletion of oxygen causes the death of fish and other aquatic organisms, leading to deterioration of water quality and imbalance in the aquatic ecosystem.
4. Differentiate between sheet erosion and gully erosion.
Sheet erosion is the uniform removal of a thin layer of topsoil from a large area by running water. It occurs gradually and often goes unnoticed. Gully erosion, on the other hand, occurs when running water creates deep channels or gullies in the soil due to severe erosion. Gully erosion causes greater damage to land and makes agricultural activities difficult.
5. What are the three 'R's of solid waste management?
The three 'R's of solid waste management are Reduce, Reuse, and Recycle. Reduce means minimizing the generation of waste by using resources efficiently. Reuse involves using items multiple times instead of discarding them after a single use. Recycle refers to processing waste materials into new products. Together, these practices help conserve resources and reduce environmental pollution.
6. What is the main advantage of a sanitary landfill over an open dump?
A sanitary landfill is designed to safely dispose of waste by compacting and covering it with layers of soil, preventing the spread of foul odors, pests, and disease-causing organisms. Unlike open dumps, sanitary landfills reduce groundwater contamination and environmental pollution. They provide a more hygienic and environmentally friendly method of waste disposal.
7. Describe briefly various categories of threatened species recognized by IUCN.
The International Union for Conservation of Nature (IUCN) classifies threatened species into three main categories: Vulnerable, Endangered, and Critically Endangered. Vulnerable species face a high risk of extinction in the wild. Endangered species face a very high risk of extinction, while Critically Endangered species face an extremely high and immediate risk of extinction. These categories help prioritize conservation efforts.
8. What are the impacts of climate change on ecosystem?
Climate change affects ecosystems by altering temperature, rainfall patterns, and seasonal cycles. It can lead to habitat loss, species migration, reduced biodiversity, and increased frequency of natural disasters such as floods and droughts. Many plants and animals struggle to adapt to these changes, resulting in ecosystem imbalance and disruption of ecological processes.
9. What does EIA stand for? What are its key elements?
EIA stands for Environmental Impact Assessment. It is a process used to evaluate the environmental consequences of a proposed project before its implementation. The key elements of EIA include screening, scoping, impact assessment, mitigation measures, public participation, and monitoring. It helps ensure that development projects are environmentally sustainable.
10. What are the three salient features of Air (Prevention and Control of Pollution) Act, 1981?
The Air (Prevention and Control of Pollution) Act, 1981 was enacted to prevent and control air pollution in India. It empowers Pollution Control Boards to monitor and regulate air quality. The Act allows the government to declare air pollution control areas and establish emission standards for industries and vehicles. It also provides penalties for violating pollution control regulations.
11. What are the main sources and types of air pollution? Describe the harmful effects of air pollution on environment and human health.
Air pollution originates from both natural and human-made sources. Natural sources include volcanic eruptions, forest fires, and dust storms, while human-made sources include vehicles, industries, power plants, and burning of fossil fuels. Air pollutants may be gaseous, such as sulfur dioxide and nitrogen oxides, or particulate, such as dust and smoke. Air pollution causes respiratory diseases, asthma, and heart problems in humans. It also damages crops, forests, buildings, and contributes to global warming, acid rain, and climate change.
12. What is noise pollution? How does it affect the living organisms? How can it be controlled?
Noise pollution refers to unwanted and excessive sound that disturbs normal activities and affects health. Major sources include vehicles, industries, loudspeakers, and construction activities. Excessive noise can cause hearing loss, stress, hypertension, sleep disturbances, and reduced productivity in humans. It also affects wildlife by disturbing communication, breeding, and migration patterns. Noise pollution can be controlled through proper urban planning, use of silencers, soundproofing, plantation of trees, and enforcement of noise regulations.
13. "Soil pollution is a silent crisis affecting India's environment and economy". In light of this statement explain the various sources of soil pollution in India. Suggest effective solutions to mitigate them.
Soil pollution refers to the contamination of soil by harmful substances that reduce its fertility and quality. In India, major sources of soil pollution include excessive use of chemical fertilizers and pesticides, industrial wastes, municipal solid waste, mining activities, plastic waste, and untreated sewage. These pollutants affect crop productivity, groundwater quality, and human health. Effective solutions include promoting organic farming, proper waste management, recycling, treatment of industrial effluents, afforestation, and creating public awareness about sustainable environmental practices.
14. What is soil erosion? Describe in detail the natural and human induced causes of soil erosion.
Soil erosion is the removal of the fertile top layer of soil by natural agents such as water and wind. Natural causes include heavy rainfall, floods, storms, and strong winds. Human-induced causes include deforestation, overgrazing, improper agricultural practices, mining, construction activities, and excessive irrigation. Soil erosion decreases soil fertility, reduces agricultural productivity, and leads to environmental degradation. Proper land management and conservation practices are necessary to control it
15. What is biodiversity? Explain the different levels of biodiversity and their importance.
Biodiversity refers to the variety of living organisms present on Earth, including plants, animals, and microorganisms. It exists at three levels: genetic diversity, species diversity, and ecosystem diversity. Genetic diversity refers to variations within a species, species diversity refers to the variety of species in a region, and ecosystem diversity refers to different habitats and ecosystems. Biodiversity is important because it maintains ecological balance, supports ecosystem services, provides food and medicines, and enhances environmental stability.
16. What is biodiversity conservation? Discuss the Ex-situ methods of biodiversity conservation with suitable examples.
Biodiversity conservation refers to the protection and management of biological resources to ensure their survival for future generations. Ex-situ conservation involves conserving species outside their natural habitats. Methods include zoos, botanical gardens, seed banks, gene banks, and tissue culture techniques. For example, rare plant species are preserved in botanical gardens, while endangered animals such as tigers and lions are protected in zoos. These methods help safeguard species that are threatened in their natural environments.
17. Write a short note on adsorption as a process to control gaseous air pollutants.
Adsorption is an air pollution control technique in which gaseous pollutants are removed by passing polluted air through a material capable of attracting and holding pollutants on its surface. Activated charcoal is commonly used as an adsorbent because of its large surface area. Harmful gases adhere to the surface of the adsorbent, resulting in cleaner air. This method is widely used in industries to control emissions of toxic gases and volatile organic compounds.
18. How do oil spills affect marine life and the environment?
Oil spills occur when petroleum products are accidentally released into oceans, seas, or rivers. The oil forms a layer on the water surface, reducing oxygen exchange and blocking sunlight penetration. Marine organisms such as fish, birds, and mammals may die due to poisoning, suffocation, or loss of insulation. Oil spills also damage coastal ecosystems, coral reefs, and fisheries, causing long-term environmental and economic losses.
19. Differentiate between Eutrophic and Dystrophic Lakes.
Eutrophic lakes are nutrient-rich water bodies with abundant plant and algal growth. They generally have high biological productivity but may experience oxygen depletion due to excessive decomposition. Dystrophic lakes, on the other hand, contain high amounts of organic matter and humic substances, making the water brownish and acidic. These lakes are usually nutrient-poor and support lower biological productivity compared to eutrophic lakes.
20. Define Soil. Describe briefly the process of pedogenesis.
Soil is the uppermost layer of the Earth's crust composed of minerals, organic matter, water, air, and living organisms. It serves as a medium for plant growth and supports terrestrial life. Pedogenesis is the process of soil formation through the weathering of rocks and the accumulation of organic matter over time. Factors such as climate, organisms, parent material, topography, and time influence soil development and determine its characteristics.
21. What are various characteristics of Hazardous Wastes?
Hazardous wastes are wastes that pose a significant threat to human health and the environment. They are characterized by properties such as toxicity, ignitability, corrosiveness, and reactivity. Toxic wastes can harm living organisms, ignitable wastes can easily catch fire, corrosive wastes can damage materials and tissues, while reactive wastes may explode or produce harmful gases under certain conditions. Proper handling and disposal are essential to minimize risks.
22. Why is biodiversity important for Ecosystems?
Biodiversity is essential for maintaining healthy and stable ecosystems. Different species perform various ecological functions such as pollination, nutrient cycling, decomposition, and regulation of climate. A rich biodiversity increases ecosystem productivity and resilience against environmental changes and natural disasters. It also provides food, medicine, and other resources necessary for human survival and sustainable development.
23. What are the salient features of Environment Protection Act, 1986?
The Environment Protection Act, 1986 was enacted to provide comprehensive protection to the environment in India. It empowers the Central Government to take measures for preventing and controlling pollution. The Act allows the establishment of environmental standards, regulation of industrial activities, and protection of environmental quality. It also provides penalties for violations and serves as a framework for coordinating various environmental laws.
24. Discuss the impacts of air pollution on environment, human health and economy.
Air pollution adversely affects the environment, human health, and the economy. It contributes to acid rain, climate change, ozone depletion, and damage to crops and forests. In humans, it causes respiratory diseases, heart disorders, eye irritation, and reduced life expectancy. Economically, air pollution increases healthcare costs, lowers agricultural productivity, damages infrastructure, and reduces overall workforce efficiency, resulting in significant financial losses.
25. Describe the different types of soils found in India and the regions where they are predominantly found.
India has several major soil types including alluvial, black, red, laterite, desert, and mountain soils. Alluvial soils are found in the Indo-Gangetic plains and are highly fertile. Black soils occur mainly in Maharashtra, Gujarat, and Madhya Pradesh and are suitable for cotton cultivation. Red soils are common in southern and eastern India, while laterite soils are found in regions with heavy rainfall such as Kerala and Karnataka. Desert soils occur in Rajasthan, and mountain soils are found in the Himalayan region.
26. Explain the causes and consequences of ozone layer depletion and discuss global efforts taken to address the issue.
Ozone layer depletion is mainly caused by chlorofluorocarbons (CFCs), halons, and other ozone-depleting substances released into the atmosphere. These chemicals break down ozone molecules, reducing the protective ozone shield. As a result, more harmful ultraviolet radiation reaches the Earth, causing skin cancer, cataracts, weakened immune systems, and damage to plants and marine life. Global efforts such as the Montreal Protocol have successfully reduced the production and use of ozone-depleting substances and helped in the recovery of the ozone layer.
27. How do human activities contribute to desertification in India? What are the remedial measures being taken to address these activities?
Human activities such as deforestation, overgrazing, excessive irrigation, mining, and unsustainable agricultural practices contribute significantly to desertification in India. These activities reduce vegetation cover, degrade soil quality, and increase land vulnerability to erosion. Remedial measures include afforestation, watershed management, controlled grazing, sustainable farming practices, rainwater harvesting, and implementation of government programs aimed at restoring degraded lands and conserving natural resources.
28. How can we control air pollution with the help of electrostatic precipitators?
An electrostatic precipitator is a device used to remove fine particulate matter such as dust, smoke, and ash from industrial exhaust gases. It works by passing polluted air through a chamber where particles receive an electric charge. These charged particles are then attracted to oppositely charged plates and collected on them. The cleaned air is released into the atmosphere while the collected particles are removed periodically. This method is highly efficient and widely used in thermal power plants and industries.
29. Expand BOD. What does an increased BOD in a water body reflect?
BOD stands for Biological Oxygen Demand. It is the amount of dissolved oxygen required by microorganisms to decompose organic matter present in water. An increased BOD indicates a high level of organic pollution in the water body. It means more oxygen is being consumed by bacteria, leaving less oxygen available for aquatic organisms. High BOD is therefore a sign of poor water quality and environmental degradation.
30. How is soil pollution caused?
Soil pollution is caused by the accumulation of harmful chemicals and waste materials in the soil. Major causes include excessive use of fertilizers and pesticides, industrial effluents, mining activities, improper disposal of solid waste, plastic pollution, and sewage discharge. These contaminants alter the physical, chemical, and biological properties of soil, reducing its fertility and affecting plant, animal, and human health.
31. What are the main components of Solid Waste Management?
Solid Waste Management involves the systematic handling of waste from its generation to final disposal. The main components include waste generation, collection, segregation, transportation, treatment, recycling, and disposal. Proper management ensures that waste is handled in an environmentally safe manner, reducing pollution, conserving resources, and protecting public health.
32. What are the hotspots of biodiversity?
Biodiversity hotspots are regions that possess exceptionally high levels of species richness and endemism but are under severe threat from habitat destruction and other human activities. These areas are considered priorities for conservation. India contains parts of four major biodiversity hotspots: the Himalayas, Indo-Burma region, Western Ghats-Sri Lanka region, and Sundaland (Nicobar Islands).
33. Why is Greenhouse effect important?
The greenhouse effect is a natural process in which certain gases in the atmosphere trap heat and keep the Earth warm. It is important because it maintains a suitable temperature for life on Earth. Without the greenhouse effect, the Earth's average temperature would be too low to support most living organisms. However, excessive greenhouse gases can intensify this effect and lead to global warming.
34. What are the impacts of Acid Rain?
Acid rain occurs when sulfur dioxide and nitrogen oxides react with atmospheric moisture to form acidic compounds. It damages forests, crops, lakes, rivers, and buildings. Acid rain lowers the pH of water bodies, harming aquatic life and reducing biodiversity. It also affects soil fertility and can contribute to respiratory problems in humans through the pollutants that cause it.
35. What are the steps towards achieving Sustainable Development?
Achieving sustainable development requires the balanced use of natural resources while meeting present needs without compromising future generations. Important steps include conserving biodiversity, promoting renewable energy, reducing pollution, practicing sustainable agriculture, improving waste management, conserving water resources, and encouraging environmental education and public participation. These measures help ensure long-term environmental, social, and economic well-being.
36. What is the importance of EIA?
Environmental Impact Assessment (EIA) is important because it helps identify and evaluate the potential environmental effects of a proposed project before its implementation. It assists decision-makers in minimizing environmental damage through appropriate mitigation measures. EIA promotes sustainable development, encourages public participation, protects natural resources, and ensures that development projects are environmentally responsible.
37. What are the causes and consequences of marine pollution?
Marine pollution is caused by the discharge of industrial wastes, sewage, plastics, oil spills, agricultural runoff, and chemical pollutants into oceans and seas. These pollutants degrade water quality and harm marine organisms. Consequences include the death of aquatic life, destruction of coral reefs, disruption of food chains, loss of biodiversity, and economic losses to fisheries and tourism industries.
38. Define Soil. Explain any two classes of soil as classified by ICAR.
Soil is the natural upper layer of the Earth's surface composed of minerals, organic matter, water, air, and living organisms that supports plant growth. According to the Indian Council of Agricultural Research (ICAR), soils are classified into several groups. Alluvial soil is highly fertile and found mainly in the northern plains, making it ideal for agriculture. Black soil, rich in clay and moisture-retaining capacity, is found in the Deccan Plateau and is particularly suitable for cotton cultivation.
39. What is Soil Erosion? Describe the various methods for its control.
Soil erosion is the removal of the fertile top layer of soil by wind, water, or other natural agents. It reduces soil productivity and causes environmental degradation. Soil erosion can be controlled through afforestation, contour ploughing, terracing, strip cropping, construction of check dams, and controlled grazing. These measures help conserve soil, reduce runoff, and maintain agricultural productivity.
40. What is the composition of e-waste?
E-waste consists of discarded electronic and electrical devices such as computers, mobile phones, televisions, and household appliances. It contains metals like copper, aluminum, iron, gold, and silver, along with plastics, glass, and electronic components. E-waste may also contain hazardous substances such as lead, mercury, cadmium, and brominated flame retardants, which can pose environmental and health risks if not properly managed.
41. Define Biomedical Waste.
Biomedical waste refers to waste generated during the diagnosis, treatment, immunization, or research activities related to human beings or animals. It includes used syringes, needles, bandages, pathological waste, laboratory waste, and contaminated materials. Improper disposal of biomedical waste can spread infections and pose serious risks to public health and the environment.
42. How is Deep Well Injection used in management of Hazardous Wastes?
Deep well injection is a method of hazardous waste disposal in which liquid hazardous wastes are pumped into deep underground geological formations through specially designed wells. These formations are located far below groundwater sources and are capable of safely containing the waste. This method prevents surface contamination and minimizes environmental risks when properly monitored and managed.
43. What is Photochemical Smog composed of?
Photochemical smog is a type of air pollution formed when sunlight reacts with nitrogen oxides and hydrocarbons released from vehicles and industries. It mainly consists of ozone, peroxyacetyl nitrate (PAN), aldehydes, and other oxidizing pollutants. This smog appears as a brownish haze over urban areas and can cause irritation to the eyes, respiratory problems, and damage to vegetation.
44. Account for Smog and Acid Rain. How do they affect us?
Smog is a mixture of smoke, fog, and harmful pollutants formed in the atmosphere, while acid rain is rainfall containing acids formed from sulfur dioxide and nitrogen oxides. Smog reduces visibility and causes respiratory illnesses, eye irritation, and lung disorders. Acid rain damages crops, forests, water bodies, buildings, and monuments. Both are serious environmental problems that negatively affect human health and ecosystems.
45. How is Biodiversity important for ecosystem functioning?
Biodiversity plays a vital role in maintaining ecosystem functioning by supporting ecological processes such as nutrient cycling, pollination, decomposition, and energy flow. A diverse ecosystem is more stable and resilient to environmental changes and natural disasters. Biodiversity also ensures the availability of food, medicine, and other resources, making it essential for both ecosystem health and human well-being.
46. What are the causes and impacts of loss of biodiversity?
Loss of biodiversity is caused by habitat destruction, deforestation, pollution, climate change, overexploitation of resources, invasive species, and urbanization. The impacts include ecosystem imbalance, extinction of species, disruption of food chains, reduced ecosystem productivity, and loss of valuable genetic resources. Biodiversity loss also affects human livelihoods and the availability of natural resources.
47. What are the causes of Global Warming?
Global warming is mainly caused by the increased concentration of greenhouse gases in the atmosphere. Major causes include the burning of fossil fuels, deforestation, industrial activities, transportation, agricultural practices, and excessive energy consumption. These activities increase the levels of carbon dioxide, methane, and other greenhouse gases, trapping more heat in the atmosphere and raising the Earth's temperature.
48. Discuss the effects of Global Warming.
Global warming leads to a rise in Earth's average temperature, causing melting of glaciers and polar ice caps, sea level rise, and changes in rainfall patterns. It increases the frequency of floods, droughts, heat waves, and storms. Global warming also threatens biodiversity, affects agriculture, and poses serious risks to human health and water resources, thereby impacting both natural and human systems.
49. What are the international efforts for combating Global Warming? Explain salient features of Kyoto Protocol.
Several international efforts have been undertaken to combat global warming, including the United Nations Framework Convention on Climate Change (UNFCCC), Kyoto Protocol, and Paris Agreement. The Kyoto Protocol, adopted in 1997, aimed to reduce greenhouse gas emissions by setting legally binding targets for developed countries. It promoted clean technologies, carbon trading mechanisms, and international cooperation to address climate change and reduce global emissions.
50. What is the difference between gaseous and particulate pollution of air?
Gaseous pollution consists of harmful gases such as carbon monoxide, sulfur dioxide, nitrogen oxides, and ozone present in the atmosphere. Particulate pollution consists of tiny solid or liquid particles such as dust, smoke, soot, and aerosols suspended in the air. While gaseous pollutants affect air chemistry and human health, particulate pollutants can penetrate deep into the respiratory system and cause serious health problems.
51. Differentiate between primary and secondary air pollutants.
Primary air pollutants are pollutants directly released into the atmosphere from sources such as vehicles, industries, and power plants. Examples include sulfur dioxide, carbon monoxide, and particulate matter. Secondary air pollutants are formed in the atmosphere through chemical reactions involving primary pollutants. Examples include ozone, photochemical smog, and peroxyacetyl nitrate (PAN). Thus, primary pollutants are emitted directly, whereas secondary pollutants are produced indirectly.
52. Explain the working of an electrostatic precipitator.
An electrostatic precipitator removes particulate pollutants from industrial exhaust gases by using electrical charges. As polluted air passes through the device, particles receive a negative charge and are attracted to positively charged collecting plates. The particles accumulate on these plates and are periodically removed. The cleaned air is then released into the atmosphere. This method is highly efficient in controlling air pollution from industries and power plants.
53. Define BOD. Why is it important in water quality assessment?
Biological Oxygen Demand (BOD) is the amount of oxygen required by microorganisms to decompose organic matter present in water. It is an important indicator of water quality because it helps determine the level of organic pollution. A high BOD value indicates heavy pollution and low dissolved oxygen availability, which can harm aquatic organisms. Therefore, BOD is widely used to assess the health of water bodies.
54. What are the causes and effects of water pollution?
Water pollution is caused by the discharge of sewage, industrial effluents, agricultural runoff, oil spills, and solid waste into water bodies. These pollutants contaminate water and reduce its quality. The effects include the spread of water-borne diseases, death of aquatic organisms, eutrophication, reduced biodiversity, and scarcity of safe drinking water. Water pollution also disrupts aquatic ecosystems and affects human health.
55. What are the sources of marine pollution?
Marine pollution originates from various sources including industrial discharges, untreated sewage, agricultural runoff, oil spills, plastic waste, and dumping of hazardous chemicals into oceans. Pollutants may also enter marine environments through rivers and coastal activities. These contaminants degrade water quality, harm marine organisms, and disrupt the ecological balance of marine ecosystems.
56. What is water pollution? What are the main causes or sources of water pollution?
Water pollution is the contamination of water bodies by harmful substances that make the water unsuitable for human use and aquatic life. Major sources include domestic sewage, industrial effluents, agricultural chemicals, oil spills, mining activities, and solid waste disposal. These pollutants alter the physical, chemical, and biological characteristics of water, leading to serious environmental and health problems.
57. Differentiate between Genetic diversity and Species diversity.
Genetic diversity refers to the variation in genes among individuals of the same species. It enables species to adapt to environmental changes and resist diseases. Species diversity refers to the variety and abundance of different species present in a particular ecosystem or region. While genetic diversity occurs within a species, species diversity exists among different species and contributes to ecosystem stability.
58. What are the major threats to biodiversity?
Biodiversity is threatened by several human activities such as habitat destruction, deforestation, pollution, overexploitation of natural resources, climate change, and the introduction of invasive species. These factors reduce the population of plants and animals, disturb ecological balance, and increase the risk of extinction. Conservation measures are therefore essential to protect biodiversity and maintain healthy ecosystems.
59. What are endangered and vulnerable species? Give examples.
Endangered species are those that face a very high risk of extinction in the near future due to declining populations and habitat loss. Examples include the Bengal Tiger and Asian Lion. Vulnerable species are those likely to become endangered if the factors threatening their survival continue. Examples include the Snow Leopard and Olive Ridley Turtle. Both categories require conservation efforts for their protection.
60. Why is biodiversity high in the tropics?
Biodiversity is higher in tropical regions because they receive abundant sunlight, high rainfall, and warm temperatures throughout the year. These favorable climatic conditions support continuous plant growth and provide diverse habitats for many organisms. The stable environment and long evolutionary history of tropical regions have allowed a large number of species to develop and survive, resulting in high biodiversity.
61. What is the difference between in-situ and ex-situ conservation methods?
In-situ conservation involves protecting species within their natural habitats through national parks, wildlife sanctuaries, and biosphere reserves. Ex-situ conservation involves conserving species outside their natural habitats in places such as zoos, botanical gardens, seed banks, and gene banks. While in-situ conservation protects entire ecosystems, ex-situ conservation focuses on preserving individual species under controlled conditions.
62. What are the salient features of the Water (Prevention and Control of Pollution) Act, 1974?
The Water (Prevention and Control of Pollution) Act, 1974 was enacted to prevent and control water pollution and maintain water quality. It established Central and State Pollution Control Boards responsible for monitoring water pollution. The Act regulates the discharge of pollutants into water bodies and empowers authorities to take legal action against violators. It also promotes measures for the restoration and protection of water resources.
63. Why is the Environment Protection Act (EPA), 1986 called an umbrella legislation?
The Environment Protection Act, 1986 is called an umbrella legislation because it provides a comprehensive framework for the protection and improvement of the environment. It covers various aspects of environmental management including air, water, soil, and hazardous substances. The Act empowers the Central Government to coordinate activities under different environmental laws, making it an overarching legislation for environmental protection in India.
64. What are the steps/elements of Environmental Impact Assessment (EIA)?
Environmental Impact Assessment (EIA) consists of several important steps including screening, scoping, collection of baseline data, impact prediction, evaluation of alternatives, mitigation planning, public consultation, preparation of the EIA report, decision-making, and post-project monitoring. These steps help identify environmental impacts in advance and ensure that development projects are carried out responsibly and sustainably.
65. What are the advantages of EIA?
Environmental Impact Assessment offers several advantages by identifying potential environmental impacts before a project begins. It helps reduce environmental damage, promotes sustainable development, improves project planning, and ensures compliance with environmental regulations. EIA also encourages public participation and assists decision-makers in selecting environmentally sound alternatives for development projects.
66. Explain in detail the salient features of the Environment Protection Act of 1986.
The Environment Protection Act, 1986 was enacted after the Bhopal Gas Tragedy to strengthen environmental protection in India. It empowers the Central Government to set environmental quality standards, regulate industrial activities, control pollution, and manage hazardous substances. The Act authorizes inspections, collection of environmental information, and enforcement of environmental regulations. It also provides penalties for violations and serves as a comprehensive legal framework for environmental conservation.
67. What are the methods of solid waste disposal? Explain any one.
Solid waste can be disposed of through methods such as sanitary landfilling, composting, incineration, recycling, and vermicomposting. Sanitary landfilling is one of the most commonly used methods, where waste is compacted and covered with soil in specially designed sites. This method minimizes odor, pest infestation, and groundwater contamination, making it safer than open dumping.
68. What is e-waste? Mention any two impacts of e-waste.
E-waste refers to discarded electrical and electronic devices such as computers, mobile phones, televisions, and batteries. Improper disposal of e-waste releases toxic substances like lead, mercury, and cadmium into the environment. These substances contaminate soil and water resources and can cause serious health problems including neurological disorders and respiratory diseases in humans.
69. What is composting? How is it useful?
Composting is the biological decomposition of organic waste such as food scraps, leaves, and agricultural residues by microorganisms under controlled conditions. The process produces nutrient-rich compost that can be used as an organic fertilizer. Composting reduces the amount of waste sent to landfills, improves soil fertility, enhances soil structure, and promotes sustainable agriculture.
70. State the 3R principle with examples.
The 3R principle stands for Reduce, Reuse, and Recycle. Reduce means minimizing waste generation by using resources efficiently, such as avoiding single-use plastics. Reuse involves using products repeatedly, such as reusing glass bottles or cloth bags. Recycle refers to converting waste materials into new products, such as recycling paper, plastic, and metal. This principle helps conserve resources and reduce environmental pollution.
71. Define hazardous waste and mention its characteristics.
Hazardous waste is any waste material that poses a threat to human health or the environment due to its chemical, physical, or biological properties. Its main characteristics include toxicity, ignitability, corrosiveness, and reactivity. Such wastes may cause pollution, fires, explosions, or health hazards if not properly handled, treated, and disposed of.
72. What are solid wastes? What are their main sources and impacts on the environment?
Solid wastes are unwanted solid materials generated from households, industries, commercial establishments, hospitals, and agricultural activities. Major sources include domestic garbage, industrial waste, construction debris, and agricultural residues. Improper disposal of solid waste causes land, air, and water pollution, spreads diseases, attracts pests, and degrades the overall quality of the environment.
73. What are the main characteristics of hazardous waste? How can hazardous waste be disposed of?
Hazardous wastes are characterized by toxicity, corrosiveness, ignitability, and reactivity. These properties make them harmful to living organisms and the environment. Hazardous wastes can be disposed of through methods such as secure landfilling, deep well injection, incineration, chemical treatment, and recycling. Proper disposal is essential to prevent environmental contamination and health risks.
74. Explain in detail the methods of sewage treatment.
Sewage treatment involves the removal of contaminants from wastewater through physical, biological, and chemical processes. Primary treatment removes large solids through screening and sedimentation. Secondary treatment uses microorganisms to decompose organic matter and reduce pollution. In some cases, tertiary treatment is used to remove nutrients, pathogens, and remaining impurities. Treated water can then be safely discharged into the environment or reused.
75. Define Soil. Describe the process of pedogenesis.
Soil is the upper weathered layer of the Earth's crust consisting of minerals, organic matter, water, air, and living organisms. It provides support and nutrients for plant growth. Pedogenesis is the process of soil formation through the weathering of rocks and accumulation of organic matter over long periods. Climate, organisms, parent material, topography, and time are the major factors influencing soil formation.
76. Draw or describe a soil profile.
A soil profile is a vertical section of soil showing different layers known as horizons. The topmost O-horizon contains organic matter and decomposed plant material. Below it lies the A-horizon or topsoil, which is rich in humus and nutrients. The B-horizon contains minerals leached from above, while the C-horizon consists of partially weathered parent material. Beneath these layers lies the bedrock, which forms the foundation of the soil profile.
77. What are the causes of soil erosion? Write two control measures.
Soil erosion is caused by natural factors such as wind, rainfall, floods, and flowing water, as well as human activities like deforestation, overgrazing, mining, and improper farming practices. It removes fertile topsoil and reduces agricultural productivity. Two important control measures are afforestation, which helps bind the soil with roots, and contour ploughing, which reduces surface runoff and prevents soil loss.
78. Define soil degradation. Mention any two causes.
Soil degradation refers to the decline in soil quality and productivity due to physical, chemical, or biological deterioration. It reduces the ability of soil to support plant growth and ecosystem functions. Two major causes of soil degradation are excessive use of chemical fertilizers and pesticides, and deforestation, which exposes soil to erosion and nutrient loss.
79. What is soil pollution? What are its main causes and impacts?
Soil pollution is the contamination of soil by harmful chemicals, wastes, and pollutants that adversely affect its quality and fertility. Major causes include industrial effluents, pesticides, fertilizers, plastic waste, mining activities, and sewage disposal. Soil pollution reduces agricultural productivity, contaminates groundwater, harms organisms living in the soil, and poses serious health risks to humans and animals.
80. What is ozone layer depletion? Mention its effects.
Ozone layer depletion is the thinning of the ozone layer present in the stratosphere due to the release of ozone-depleting substances such as chlorofluorocarbons (CFCs). The depletion allows more harmful ultraviolet radiation to reach the Earth's surface. Its effects include skin cancer, cataracts, weakened immune systems, reduced crop productivity, and damage to aquatic ecosystems.
81. What are the causes of desertification?
Desertification is the process by which fertile land gradually becomes barren and unproductive. Major causes include deforestation, overgrazing, excessive irrigation, mining, soil erosion, and prolonged droughts. Human-induced land degradation reduces vegetation cover and soil fertility, making the land unsuitable for agriculture and other productive uses.
82. Name the greenhouse gases.
Greenhouse gases are atmospheric gases that trap heat and contribute to the greenhouse effect. The major greenhouse gases include carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), water vapour, ozone (O₃), and chlorofluorocarbons (CFCs). An increase in their concentration leads to global warming and climate change.
83. What is global warming? What are its main causes and impacts on the environment?
Global warming refers to the gradual increase in the Earth's average temperature due to the enhanced greenhouse effect. It is mainly caused by the burning of fossil fuels, deforestation, industrial emissions, and agricultural activities. Its impacts include melting glaciers, rising sea levels, extreme weather events, habitat loss, reduced biodiversity, and disturbances in agricultural productivity and water resources.
84. Explain the international efforts taken for combating global warming.
Various international initiatives have been undertaken to combat global warming. These include the United Nations Framework Convention on Climate Change (UNFCCC), Kyoto Protocol, and Paris Agreement. These agreements encourage countries to reduce greenhouse gas emissions, adopt clean energy technologies, and cooperate in addressing climate change. Such efforts aim to limit global temperature rise and promote sustainable development worldwide.
85. What is desertification? Explain the methods to control it.
Desertification is the degradation of fertile land into desert-like conditions due to natural and human-induced factors. It can be controlled through afforestation, controlled grazing, watershed management, rainwater harvesting, sustainable agricultural practices, and soil conservation measures. These methods help restore vegetation cover, improve soil quality, and reduce land degradation.
86. Define Sustainable Development.
Sustainable development is development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs. It emphasizes the balanced use of environmental, economic, and social resources to ensure long-term well-being and environmental protection.
87. What are SDGs (Sustainable Development Goals)? Mention any two.
Sustainable Development Goals (SDGs) are a set of 17 global goals adopted by the United Nations in 2015 to achieve sustainable development by 2030. They aim to address issues such as poverty, inequality, climate change, environmental protection, and education. Two examples of SDGs are Quality Education (Goal 4) and Climate Action (Goal 13).
88. Define BOD and COD. Differentiate between them.
Biological Oxygen Demand (BOD) is the amount of oxygen required by microorganisms to decompose biodegradable organic matter in water. Chemical Oxygen Demand (COD) is the amount of oxygen required to chemically oxidize both biodegradable and non-biodegradable pollutants. BOD measures biological pollution, whereas COD measures the total pollution load and is generally higher than BOD for the same water sample.
89. What is dissolved oxygen (DO)? Why is it important?
Dissolved Oxygen (DO) is the amount of oxygen present in water that is available for aquatic organisms to breathe. It is an important indicator of water quality because fish, aquatic plants, and other organisms depend on it for survival. Higher DO levels indicate healthier water conditions, while low DO levels may lead to the death of aquatic life and poor ecosystem health.
