Environmental Studies (EVS101) Model Questions PDF

Subject: Environmental Studies (EVS101) Model Questions with Answers All the following questions (6 Marks) Q1. What is the atmosphere? Outline its major composition. Discuss briefly the different l...

Subject: Environmental Studies (EVS101) Model Questions with Answers All the following questions (6 Marks) Q1. What is the atmosphere? Outline its major composition. Discuss briefly the different layers of the Atmosphere and draw the altitude vs. temperature profile of atmosphere. (1+2+2+1) Ans. The atmosphere is the layer of gases surrounding the Earth, extending from the surface to the edge of space. It plays a crucial role in supporting life by regulating temperature, providing oxygen, and protecting the planet from harmful solar radiation. Composition of the Atmosphere Nitrogen (N₂): 78% – Nitrogen is the most abundant and inert gas in the atmosphere. Oxygen (O₂): 21% – Oxygen is vital for respiration. Argon (Ar): 0.93% – Argon is an inert gas. Carbon Dioxide (CO₂): 0.04% – CO₂ plays a critical role in the carbon cycle and is a greenhouse gas that traps heat in the atmosphere, contributing to global warming. Other Gases: Trace gases like neon, methane, ozone, and helium make up less than 1% of the atmosphere. Layers of the Atmosphere The atmosphere is divided into distinct layers, each with its own characteristics in terms of temperature, composition, and function: a. Troposphere Altitude: Extends from the Earth's surface up to about 8-15 km (5-9 miles), depending on latitude. Characteristics: This is the lowest layer, where most of the Earth’s weather occurs. The troposphere contains about 75% of the atmosphere's mass and most of its water vapor. As altitude increases, temperature decreases. b. Stratosphere Altitude: Extends from the top of the troposphere to about 50 km. Characteristics: The stratosphere contains the ozone layer, which absorbs most of the Sun’s harmful ultraviolet (UV) radiation. Unlike the troposphere, temperatures in the stratosphere increase with altitude due to the absorption of UV radiation by ozone. c. Mesosphere Altitude: Extends from 50 km to about 85 km. 1 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Characteristics: In the mesosphere, temperatures decrease with altitude because there's less solar radiation absorbed and reemitted, reaching the coldest temperatures in the atmosphere (- 90°C or -130°F). d. Thermosphere Altitude: Extends from 85 km to about 600 km. Characteristics: Temperatures in the thermosphere can rise dramatically, reaching up to 2,500°C (4,500°F) due to absorption of high-energy solar radiation. e. Exosphere Altitude: Extends from about 600 km to 10,000 km. Characteristics: The exosphere is the outermost layer of the atmosphere, gradually transitioning into space. Satellites orbit within this region. Q2. How is environmental science a multidisciplinary study? Discuss briefly some of the key disciplines involved in environmental studies. (1+5) Ans. Environmental Studies is considered a multidisciplinary study because it integrates knowledge, concepts, and methods from various fields of science, social sciences, and humanities to understand the complex interactions between humans and the environment. important disciplines involved in Environmental Studies 1. Natural Sciences: o Chemistry: Focuses on the composition of the atmosphere, water, and soil, the interaction of chemicals in the environment, and the effects of pollution on ecosystems. Eg. acid rain, ozone depletion, and greenhouse effect. o Biology: Studies the life processes of plants, animals, and microorganisms, particularly how they interact with their environment. Eg. ecosystem and biodiversity. 2 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  o Geology: Examines the Earth's physical structure, natural resources, and the processes (such as erosion, earthquakes, and volcanic activity) that shape the environment. o Physics: Provides insights into energy, heat transfer, and environmental processes like the greenhouse effect, climate dynamics, and pollution dispersion. Eg. energy resources. o Geography: Study about earth surface, resource extraction (mining), and natural hazards (earthquakes, volcanoes). 2. Applied Disciplines: o Environmental Engineering: Develops technological solutions to environmental problems, such as water treatment, waste management, and pollution control. Q3. What is deforestation. Mention some of the major causes of deforestation. Explain some potential solutions to deforestation. (1+3+2) Ans. Deforestation, the large-scale removal of forests for agriculture, logging, urbanization, or other purposes, has severe consequences for the environment, biodiversity, and human life. Major causes of Deforestation: Agricultural Expansion: Clearing forests for farming, including large-scale crop plantations and livestock grazing. Wood Logging: Cutting trees for timber, paper, and other wood products, often leading to unsustainable deforestation. Urbanization: Clearing forests to make way for cities, roads, and infrastructure development. Mining: Removing forests for extracting minerals, coal, and oil. Fires: Forest fires, whether natural or caused by human activities, destroy large areas of forests. Population: Increased demand for land, fuelwood, and resources due to population growth. Potential Solutions to Deforestation Degraded land unsuitable for agriculture should be converted into forest land with appropriate species. Trees should be planted along roadsides, near railway tracks, on canal banks, and at farm boundaries. Industries that use wood as a raw material should be required to plant 20 to 50 times the number of trees they cut down. Fuel-efficient stoves should be developed to reduce the amount of firewood used in rural households. Q4. What is a food chain? Mention the breakdown of the typical structure of a food chain. What are different types of food chain with examples. (1+4+1) Ans. The sequence of eating and being eaten in an ecosystem is known as food chain. It is a linear sequence that shows how energy and nutrients flow from one organism to another in an ecosystem. Breakdown of the typical structure of a Food Chain 3 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Primary Producers: These are the base of the food chain and are usually plants or algae that can produce their own food through photosynthesis or chemosynthesis. E.g. Grass, algae, phytoplankton. Primary Consumers: These are herbivores that eat primary producers. E.g. Grasshopper, rabbit, zooplankton. Secondary Consumers: Secondary consumers are carnivores or omnivores that eat primary consumers. E.g. Frog, small fish, mouse. Tertiary Consumers: These are predators that feed on secondary consumers. E.g. Snake, large fish, owl. Quaternary Consumers: Quaternary consumers are apex predators with no natural enemies. They feed on tertiary consumers. E.g. Hawk, shark, lion. Decomposers: They play a crucial role by breaking down dead plants and animals. They recycle nutrients back into the ecosystem, making them available to primary producers. E.g. Bacteria, fungi, earthworms. Types of Food Chain 1. Grazing food chain: It starts with green plants (primary producers) and culminates in carnivores. All the examples cited above show this type of food chain. Other examples could be Grass → Rabbit → Fox Algae → Water flea → Small fish → Tuna 2. Detritus food chain: It starts with dead organic matter which the detritivores and decomposers consume. Leaf litter → Algae → Crabs → Small fish → Tuna Dead organic matter → Insects/Microorganisms → Birds → Cat/Fox → Bear/Crocodile Q5. What is ecological pyramid. Mention different types ecological pyramids with neat diagram. If in an artic area the gross primary production of producers under ideal condition is 5000 KJ in 1 year. Find out the net primary production of the producers for 3 years if the respiration loss is 100 KJ per year. (1+4+1) Ans. Ecological pyramids are graphical representations that show the distribution of energy, biomass, or numbers of organisms across different trophic levels in an ecosystem. Ecological pyramids are of three types: 1. Pyramid of Energy: This pyramid illustrates the flow of energy through each trophic level in an ecosystem, with energy decreasing as it moves from producers up to higher trophic levels. The shape is always upright because the energy available decreases following the 10% rule (only about 10% of the energy at one level is passed to the next level) and huge energy is lost as heat (about 90%) at each trophic level due to metabolism, growth, and reproduction. 4 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand 2. Pyramid of Biomass: This pyramid shows the total mass of living organisms (biomass) at each trophic level in an ecosystem. It is measured in units like g/m2 or kg/m2. The shape is usually upright, but can be inverted in some ecosystems (e.g., in aquatic systems where the biomass of phytoplankton is less than that of zooplankton as phytoplankton are consumed almost as quickly as they are formed). This means that phytoplankton have shorter life spans. m2 m2 m2 m2 3. Pyramid of numbers: This pyramid displays the number of individual organisms at each trophic level in an ecosystem. The shape can be upright or inverted. For example, a single large tree can support many herbivores (inverted pyramid), or a large population of insects might feed on a small number of predators (upright pyramid). 5 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand Sol. GPP = 5000 KJ in 1 year = 15000 KJ for 3 years R for 1 year = 100 KJ = 300 KJ for 3 years Therefore, NPP = GPP – R = 15000 – 300 = 14700 KJ for 3 years Q6. What is nitrogen cycle? Mention the key steps involved in a nitrogen cycle. Draw a neat diagram illustrating the nitrogen cycle. (2+2+2) Ans. The nitrogen is taken up plants and used in metabolism for biosynthesis of amino acids, proteins, vitamins etc. and passes through food chain. Key Steps in the Nitrogen Cycle: Nitrogen Fixation: Nitrogen gas (N2) from the atmosphere is converted into ammonia (NH₃), making nitrogen available to plants. This process is carried out by (a) certain bacteria (e.g., Rhizobium) found in root nodules of leguminous plants, (b) industrial processes (Haber-Bosch process) and (c) lightning. Nitrification: NH3 in the soil is oxidized by nitrifying bacteria (Nitrosomonas) into nitrites (NO2⁻) and then into nitrates (NO3⁻), which plants can readily absorb. Assimilation: Plants take up NO3⁻ from the soil and convert them into organic molecules like amino acids, which are then used to build proteins and other vital compounds. Ammonification: When plants and animals die or excrete waste, decomposers break down the organic nitrogen compounds back into NH3, which returns to the soil. Denitrification: Denitrifying bacteria (Aerobacter) convert NO3⁻ in the soil back into N2, which is released into the atmosphere. Q7. What is phosphorus cycle? Mention the key steps involved in a phosphorus cycle. Draw a neat diagram illustrating the phosphorus cycle. (2+2+2) Ans. The phosphorus cycle is a biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere and biosphere. Key Steps in the Phosphorus Cycle: Weathering: Phosphorus is primarily found in rocks and minerals in the form of phosphate ions (PO43⁻). Over time, weathering processes such as rain, wind, and temperature changes break down these rocks, releasing PO43⁻ into the soil and water bodies. 6 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Absorption by Plants: Plants absorb inorganic PO43⁻ from the soil through their roots. Phosphorus is then used by plants to form vital organic molecules like DNA, RNA, and ATP. Consumption by Animals: Animals obtain phosphorus by eating plants or other animals. The phosphorus is then used to build bones, teeth, and other tissues. Decomposition: When plants and animals die, decomposers break down their organic matter, returning phosphorus to the soil as inorganic PO43⁻ which can then be reused by plants. Q8. Draw a schematic showing values of biodiversity. Briefly describe each of the value with examples. (1+5) Ans. Consumptive use value: These are direct use values where the biodiversity product can be harvested and consumed directly. Fuel, food, drugs, fiber, pulp, wood fall under this group. Plants like neem, Tulsi, and ginger for treating various ailments. Snake venom, bear bile, or parts of certain animals. Insulin, originally extracted from the pancreas of cattle and pigs, is used to manage diabetes. Productive Use Value: These are commercially usable values where the product is marketed and sold. They may include animal products like, tusks of elephants, musk from musk deer, silk from silk-worm, wool from sheep, fur of many animals. Many industries are dependent upon 7 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  the productive use values of biodiversity, e.g., paper and pulp industry, plywood industry, silk industry, textile industry, tannery industry, and pearl industry. Social Value: These are the values associated with the social life, customs, religion and physio- spiritual aspects of the people. Many of the plants are considered holy and sacred in our country like Tusli, Peepal, Mango, Lotus, Bael etc. The leaves, fruits, and flowers of these plants are used in worship or the plant itself is worshiped. Ethical Value: The ethical value means that we may or may not use a species, but knowing the very fact that this species exists in nature gives us pleasure. We are not deriving anything direct from kangaroo, zebra or giraffe, but we all strongly feel that these species should exist in nature. Aesthetic Value: Great aesthetic value is attached to biodiversity as it gives us pleasure, peace of mind, excitement, and a feeling of appreciation. People from far and wide spend a lot of time and money to visit wilderness areas where they can enjoy the aesthetic value of biodiversity and type of tourism is known as “eco-tourism”. Option Value: These include the potentials of biodiversity that are presently unknown and need to be explored. A large number of marine species are believed to possess anti-cancer properties, which are yet to be explored systematically. Ecosystem Value: It is a non-consumptive use value mostly related to the self-maintenance of the ecosystem and various important ecosystem services has been recognized. The services include prevention of soil erosion, nitrogen fixation, water cycling, carbon sequestration, pollution control and reduction of global warming. Q9. What is hotspot of biodiversity? Mention various types of hotspots found in India? Discuss their salient features. (1+5) Ans. Areas which exhibit high species richness as well as high species endemism are termed as Hot spots of biodiversity. To qualify as a biodiversity hotspot, a region must meet two strict criteria It must contain at least 1,500 species of vascular plants as endemics. It must have lost at least 70% of its original habitat. Biodiversity Hot-spots of India 1. Western Ghats Hot Spot: The Western Ghats stretching over 1,600 km along the western coast of India, from Gujarat to Tamil Nadu. Flora: The Western Ghats is home to around 7,400 species of flowering plants, of which about 30% are endemic. Fauna: Mammals: The Western Ghats host 139 species of mammals, with notable endemics like the Nilgiri tahr, lion-tailed macaque, purple frog, Malabar pit viper and Malabar large- spotted civet. Over 500 bird species are found here, including the endangered Nilgiri wood pigeon and the Malabar grey hornbill. 2. Himalayas Hot Spot: The Himalayas stretch across Bhutan, northeastern India, and the Tibetan region of China, encompassing a diverse range of ecosystems. Flora: Notable plant species include, oaks, magnolias, and a variety of orchids. The region is also known for medicinal plants like Himalayan yew. Fauna: The region supports a wide range of mammals, including several endangered species like the snow leopard, red panda, Himalayan black bear, and Bengal tiger. Over 300 bird species 8 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  are found here, with many endemics such as the Himalayan monal, Satyr tragopan, and the critically endangered Bengal florican. 3. Indo-Burma Hot Spot: The Indo-Burma hotspot covers parts of northeastern India, Myanmar, southern China, Laos, Cambodia, Vietnam, Thailand, and parts of Bangladesh and Malaysia. Flora: Notable plant species include various orchids, dipterocarps, and the endangered Vatica, Hopea, and Dipterocarpus trees. Fauna: The region hosts about 430 mammal species, including several endangered species like the Indochinese tiger, Asian elephant, and the critically endangered Asian unicorn. The hotspot is rich in herpetofauna, with numerous endemic species such as the Burmese roofed turtle, the Indochinese box turtle, and the Irrawaddy dolphin. 4. Sundalands Hot Spot: The Sundaland Biodiversity Hotspot is one of the most biologically diverse regions on Earth, encompassing a significant portion of Southeast Asia. Flora: Notable plant species include the Rafflesia (which produces the world's largest flower) and the Titan Arum (known as the "corpse flower"). Fauna: Sundaland has a remarkable diversity of mammals, with over 380 species, including critically endangered species like the Sumatran orangutan, Bornean orangutan, Sumatran rhinoceros, and Malayan tiger. There are more than 770 bird species, with notable endemics such as the hornbills, the Storm's stork, and the Bornean bristlehead. Q10. Differentiate between biosphere reserves, national parks, and wildlife sanctuaries based on their primary objective, structure and zonation, management, and human activity. (6) Ans. There are 18 Biosphere Reserves, 106 National Parks, and 567 Wildlife Sanctuaries are established in India to conserve biodiversity, but they differ in their objectives, management, and levels of human activity permitted. Biosphere Reserve: To promote sustainable development alongside biodiversity conservation by integrating conservation with sustainable use of natural resources. Structure and Zonation: Biosphere Reserves consist of three zones: Core Zone: Strictly protected area where no human activity is allowed, preserving the ecosystem's natural state. Buffer Zone: Surrounds the core area, allowing limited human activities like research, education, and tourism. Transition Zone: The outermost area where sustainable practices like agriculture, settlements, and resource management are encouraged. Human Activity: Encourages sustainable living practices; local communities can reside and practice eco-friendly agriculture or other low-impact activities in designated areas. National Park: Primarily focused on the conservation of wildlife and the preservation of natural ecosystems in their undisturbed state. Structure and Zonation: Typically, no zones; the entire area is protected under strict regulations. Management: Managed by state or national governments with stringent rules to prevent exploitation of natural resources. 9 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Human Activity: No human habitation or exploitation of resources is permitted; limited tourism and research activities are allowed with permissions. Activities like hunting, grazing, and logging are strictly prohibited. Wildlife Sanctuary: To protect specific species of wildlife and their habitats; more flexible than National Parks in terms of human activity. Structure and Zonation: Generally, no specific zonation, but certain areas may be restricted for wildlife breeding and protection. Management: Managed by state governments with regulations that can be modified according to the needs of wildlife conservation. Human Activity: Allows regulated human activities like grazing, firewood collection, and limited tourism. Local communities may reside within or near sanctuaries, and some traditional activities might be permitted if they do not harm the wildlife. Q11. What is indoor air pollution. Briefly describe some major common sources of indoor air pollution. (1+5) Ans. Indoor pollution sources that release gases or particulate matter into the air are the primary cause of indoor air pollution. Many houses in the under-developed and developing countries including India use fuels like coal, dung-cakes, wood and kerosene in their kitchens. Incomplete combustion produces the toxic gas carbon monoxide (CO) and sulphur dioxide (SO2). Major Sources: Fuel-burning combustion appliances Tobacco products Building materials and furnishings as diverse as: o Deteriorated asbestos sheets-containing insulation o Newly installed flooring or carpet o Cabinetry or furniture made of certain pressed wood products Products for household cleaning and maintenance, personal care, or hobbies Central heating and cooling systems and humidification devices Excess moisture Some sources, such as building materials, furnishings and products like air fresheners, can release pollutants more or less continuously. Other sources, related to activities like smoking, cleaning, redecorating or doing hobbies release pollutants intermittently. Q12. Define smog. Mention different types of smog based on formation, components, Conditions Favouring conditions, effects and examples. (1+5) Ans. Smog is a type of air pollution characterized by a mixture of smoke, fog, and various chemical pollutants in the atmosphere. It is commonly associated with urban areas, especially those with high traffic and industrial activity. Smog reduces visibility, harms human health, and affects the environment. Types of Smog a. Photochemical Smog (or Los Angeles Smog): Brownish or yellowish haze 10 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand Photochemical smog forms when sunlight interacts with pollutants like nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the atmosphere. This reaction produces ozone (O₃), peroxyacetyl nitrate (PAN), and other secondary pollutants. 𝑃ℎ𝑜𝑡𝑜𝑙𝑦𝑠𝑖𝑠 NO2 + UV → NO + O O + O2 → O3 RCO3 + NO2 → RCO3NO2 (PAN) Conditions Favouring Formation: Sunny weather, high temperatures, and stagnant air conditions (little wind) enhance the formation of photochemical smog. Common in urban areas with heavy traffic and industrial emissions. Effects: Causes respiratory problems, eye irritation, and aggravates asthma and other lung conditions. Damages crops, trees, and other vegetation. Ozone in photochemical smog also degrades materials like rubber and fabrics. Example: Los Angeles, California, is a classic example where photochemical smog is prevalent, especially during the summer months. b. Sulfurous Smog (or London Smog): Grayish or blackish fog Sulfurous smog, also known as "classic" or "industrial" smog, forms primarily from the burning of fossil fuels, particularly coal. It is characterized by a high concentration of sulfur dioxide (SO₂), particulate matter, and moisture, which combine to form a dense fog. Conditions Favoring Formation: Cold, damp conditions, and high humidity are ideal for the formation of sulfurous smog. Often occurs in areas with significant coal burning, especially during the winter months. Effects: Causes severe respiratory problems, exacerbates lung diseases, and can be fatal during severe episodes. Damages buildings and infrastructure due to the acidic nature of the smog. It can also harm plants and animals. Example: The Great Smog of London in 1952, a notorious event where sulfurous smog caused thousands of deaths and severe public health crises. Q13. What is water pollution. Discuss briefly the point sources and non-point sources of water pollution. (1+5) Ans. Water pollution can be defined as alteration in physical, chemical or biological characteristics of water making it unsuitable for domestic use in its natural state. Major sources of Water Pollution a. Point Sources of Water Pollution: Point sources refer to specific, identifiable locations or sources from which pollutants are discharged directly into a water body. Examples of Point Sources: Industrial discharges: Factories and manufacturing plants that discharge waste directly into rivers, lakes, or oceans. These discharges can include toxic chemicals, heavy metals, oils, and other pollutants. 11 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Sewage treatment plants: Facilities that treat domestic and industrial wastewater before releasing it into water bodies. If not properly treated, sewage can introduce pathogens, nutrients, and organic matter into the water. Oil Spills: Accidental releases of oil from tankers, pipelines, or offshore drilling rigs can cause severe localized water pollution. Combined sewer overflows: In some urban areas, stormwater and sewage are combined into a single sewer system. During heavy rainfall, the system may overflow, discharging untreated sewage and stormwater into rivers and streams. b. Non-Point Sources of Water Pollution: Non-point sources refer to diffuse sources of pollution that are not confined to a single point of origin. Examples of Non-Point Sources: Agricultural runoff: Runoff from farmland can carry fertilizers, pesticides, herbicides, and animal waste into nearby water bodies. Excess nutrients (like nitrogen and phosphorus) can lead to eutrophication, causing algal blooms and oxygen depletion in water bodies. Urban runoff: Rainwater or snowmelt running off urban surfaces such as roads, parking lots, and rooftops can pick up pollutants like oils, grease, heavy metals, litter, and chemicals, which then flow into storm drains and eventually into rivers, lakes, or oceans. Construction sites: Runoff from construction sites can carry sediments, oils, and construction chemicals into nearby water bodies, leading to increased turbidity and pollution. Mining Activities: Runoff from mining operations can carry heavy metals, acids, and other pollutants into water bodies, contaminating them and harming aquatic life. Q14. Draw a schematic of a typical wastewater treatment plant showing primary, secondary and tertiary treatment. Discuss briefly the primary and secondary treatment methods. (3+3) Ans. Primary Treatment of Wastewater The first step is a physical process for removal of debris and large floating/suspended particles with the help of screens. 12 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  The wastewater after screening is passed through grit chamber where inorganic grits (sand, clay, mud etc.) and organic grit (bone chips, egg shells etc.) are removed. The water is them passed to skimming tank to remove the oil and grease from the wastewater. The wastewater is then finally passed through the sedimentation tank (primary clarifier) where most of the suspended solids settle down due to gravity. For better settlement of these solids sometimes polymer chemicals are added (flocculants) to it. About 35% BOD and 60% of suspended solids are removed during primary treatment. Secondary Treatment of Wastewater It is a biological process which involves microorganisms. Here activated sludge process is used to remove mostly the organic matter from wastewater. It removes more than 90% of the BOD and 90% suspended solids from wastewater. Biodegradable organic waste gets oxidized by these microorganisms. After secondary treatment if the BOD of the wastewater becomes less than 20 mg/L, then the wastewater can be released to nearby water bodies. Q15. Discuss the natural formation and occurrence of ozone in the stratosphere. Which are the major agents responsible for ozone depletion. Mention some of the major effects of ozone depletion. (2+2+2) Ans. In the stratosphere ozone (O3) is continuously being formed by the absorption of short wavelength ultraviolet (UV) radiations. UV radiations decompose molecular oxygen (O2) into nascent oxygen (O) by photolytic decomposition (1). The atomic oxygen rapidly reacts with molecular oxygen to form ozone (2). O2 + hv (UV radiation) → O + O 1 O + O2 + → O3 2 Ozone thus formed distributes itself in the stratosphere and absorbs harmful UV radiations and is continuously being converted back to molecular oxygen (3). The net result of the above reactions is an equilibrium concentration of ozone. O3 + hv → O2 + O 3 Major Agents Responsible for Ozone Depletion Chlorofluorocarbons (CFCs) are mainly responsible for ozone depletion in the stratosphere. CFCs are used as coolants in refrigerators and air conditioners, as propellants, cleaning solvents, CFCs released in the troposphere reach the stratosphere and remain there for 65-110 years destroying O3 molecules. Nitrous oxide (N2O) emitted by supersonic aircrafts, during combustion of fossil fuel and use of nitrogen fertilizers breaks ozone molecules. Chlorine liberated from chlorofluorocarbons also break ozone molecules. The chain reaction started in Antarctic Spring i.e. August/ September continues till nitrogen dioxide is liberated from nitric acid formed in the stratosphere by photolysis. Major effects of ozone depletion 13 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Ozone depletion in the stratosphere will result in more UV radiation reaching the earth especially UV-B. The UV-B radiations affect DNA and the photosynthetic chemicals. Any change in DNA can result in mutation and cancer. Easy absorption of UV rays by the lens and cornea of eye will result in increase in incidents of cataract. Phytoplanktons are sensitive to UV exposure. Ozone depletion will result in decrease in their population thereby affecting the population of zooplankton, fish, marine animals, in fact the whole aquatic food chain. Degradation of paints, plastics and other polymer material will result in economic loss due to effects of UV radiation resulting from ozone depletion. Q16. What is meant by acid rain? How does it form? In which regions of India acid rain has been recorded? What are the major impacts of acid rain and how can we control it? (2+2+2) Ans. Acid rain results when sulfur dioxide (SO2) and oxides of nitrogen (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. Formation SO2 and NOX undergo oxidation, and then they react with water resulting in the formation of sulphuric acid and nitric acid, respectively. The following reaction will clarify the acid formation reaction: 2SO2 (g) + O2 (g) + 2H2O (l) → 2H2SO4 (aq) 4NO2 (g) + O2 (g) + 2H2O (l) → 4HNO3 (aq) In India Acid Rain is recorded from certain places: Name of place pH of rainwater Agra 5.02 Kodaikanal 5.18 Minicoy 5.52 Mohanbari 5.50 Major impacts of Acid Rain It causes deterioration of buildings specially made of marble e.g. monuments like Taj Mahal. It damages metals and car finishes. Aquatic life especially fish are badly affected by water bodies acidification. It results in reproductive failure, and killing of fish. It damages the chlorophyl of plant leaves and they are turned pale yellow. Control of Acid Rain Emission of SO2 and NOX from industries, vehicles, and power plants should be reduced by using pollution control equipment. Adding lime (CaCO3) to the lakes and soils should be done to neutralize the water bodies which prevents the adverse effects of acid rain. 14 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  A coating of protective layer of inert polymer should be given in the interior of water pipes for drinking water. Q17. Discuss some of the major factors influencing population size. Discuss briefly the three types of age structure. If a nation has an annual growth rate of 20%, find in how many years its population will double. (2+3+1) Ans. Major factors influencing population size Total fertility rates (TFR): It is one of the key measures of a nation’s population growth. TFR is defined as the average number of children that would be born to a woman in her lifetime if the age specific birth rates remain constant. Infant mortality rate: It is an important parameter affecting future growth of a population. It is the percentage of infants died out of those born in a year. Types of Age structure a) Pyramid shaped: Here the very young population is more, making a broad base and old people are less. This type indicates growing population. India, Bangladesh, Ethiopia, Nigeria are examples of this type. b) Bell shaped: It occurs in countries like France, USA and Canada where birth rates have in the past one or two decades declined resulting in people of almost equal number in age group 0-35 years. c) Urn shaped: Here number of individuals in very young class is smaller than the middle reproductive age class. Germany, Italy, Hungary, Sweden and Japan are examples of this type. Numerical Sol. r = 20% (given), Td = 70/r = 70/20 = 3.5 Therefore, if a nation has an annual growth rate of 20%, its population will double 3.5 years. All the following questions (10 Marks) Q1. What is nuclear energy? Explain its types. Draw a neat diagram of a typical nuclear reactor. Discuss briefly the Chernobyl nuclear disaster. (1+3+2+4) Ans. Nuclear energy is the energy released during nuclear reactions, either through nuclear fission (splitting of atomic nuclei) or nuclear fusion (combining atomic nuclei). It is a powerful and efficient source of energy, with applications primarily in electricity generation. Types of Nuclear Energy 15 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand 1. Nuclear Fission: Nuclear fission is the process of splitting a heavy atomic nucleus, such as uranium-235 or plutonium-239, into smaller nuclei, releasing a large amount of energy. A neutron collides with the nucleus of a heavy atom (e.g., uranium-235), causing the nucleus to split into two lighter nuclei. 2. Nuclear Fusion: Nuclear fusion is the process in which two light atomic nuclei, such as isotopes of hydrogen (deuterium and tritium), combine to form a heavier nucleus, releasing vast amounts of energy. In extremely high-temperature environments (millions of degrees), two light atomic nuclei overcome their repulsive forces and fuse to form a heavier nucleus (e.g., helium). Chernobyl Nuclear Disaster Chernobyl nuclear accident is the worst nuclear disaster in the history of human civilization which occurred at Chernobyl, Ukraine (previously in USSR). On 26 April, 1986 the accident occurred at the reactor of the Chernobyl power plant designed to produce 1000 MW electrical energy. The reactor had been working continuously for 2 years. It was shut down on April 25, 1986 for intermediate repairs. During shutdown control rods were withdrawn and water supply was also reduced so that small amount of water would have produced steam to run the turbine. In the absence of control rods and liquid water coolant the neutron absorption reduced and due to these projectile neutrons fission increased many times resulting in explosions at reactor 4. The explosion was so severe that the 1000-ton steel concrete lid of the reactor 4 blew off. Fire started at the reactor due to combustion of graphite rods. The reactor temperature soared to more than 2000°C. More than 2000 people died. People suffered from ulcerating skin, loss of hair, nausea and anemia. Agricultural produce was damaged for years. Intense radiations destroyed several fields, trees, shrubs, plants etc. Q2. What are renewable energy sources? Briefly discuss any four types of renewable resources. Discuss briefly the Bhopal Gas Tragedy. (1+5+4) Ans. Renewable energy sources are those that can be replenished naturally over short periods of time and are considered sustainable because they do not deplete over time. They are generally more environmentally friendly as they produce little to no greenhouse gas emissions. E.g. Wind energy, solar energy, hydroelectric energy, geothermal energy, and biogas energy. 16 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand 1. Solar Energy: Solar energy is a renewable and sustainable energy source derived from the sun's radiation. Solar energy offers an environmentally friendly alternative to fossil fuels, contributing to reduced greenhouse gas emissions and long-term energy security. Solar energy is harvested in two main ways: 1. Photovoltaic (PV) Systems: These systems use solar panels composed of semiconductor materials, typically silicon, to convert sunlight directly into electricity. 2. Solar Thermal Systems: This method captures the sun’s heat to generate thermal energy, which can be used for heating water, powering turbines for electricity generation, or industrial processes. Examples include solar water heaters, and solar cooker. 2. Hydroelectric Energy: Hydroelectric power is generated by harnessing the kinetic energy of flowing or falling water to produce electricity, typically through a system of dams and turbines. Water stored in a reservoir is released through turbines, turning them and generating electricity. It's one of the most widely used renewable energy sources worldwide. 3. Wind Energy: Wind energy is the process of converting the kinetic energy from wind into usable electrical power. This is typically achieved through the use of wind turbines, which have large blades that rotate when wind passes through them. The movement of these blades drives a generator that produces electricity. 4. Geothermal Energy: Geothermal energy is the heat that comes from the sub-surface of the earth, which is found in the form of steam or hot water. This energy can be harnessed for various applications, including electricity generation, direct heating, and industrial processes. Mostly, the steam or the hot water comes out of the ground naturally through cracks in the form of natural geysers. The Bhopal Gas Tragedy The world’s worst chemical industrial accident occurred in Bhopal, Madya Pradesh, India on late winter night of 2nd and 3rd morning of December, 1984. It happened at Union Carbide Company which is used to manufacture Carbaryl (carbamate) pesticide using Methyl isocyanate (MIC). Due to accidental entry of water in the tank, the reaction got overheated and exploded because its cooling system had failed. Other safety devices also did not work or were not in the working condition. 40 tons of MIC leaked into the atmosphere which might have contained 40 kg of phosgene (very toxic gas). MIC gas at lower concentrations affects lungs and eyes and causes irritation in the skin. Higher amounts remove oxygen from the lungs and can cause death. In the winter night of December there were fog like clouds over south and east of the plant. The gas spread over 40 km area. About 5100 persons were killed (2600 due to direct exposure to MIC and other 2500 due to after effects of exposure) according to Indian officials. Q3. Describe in a tabular form about the 10 major biogeographical regions of India. Include information on biogeographic zones, biotic provinces, climate, and notable flora and fauna found within them. (10) Ans. Major Biogeographical Regions of India 17 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand Sl. Biogeographic Biotic province Climate Important flora and fauna No. zones 1. Trans-Himalayan Northernmost part of Cold desert, with Pine, Deodar, Alpine India, including sparse rainfall, and Ladakh, and parts of extreme temperatures Wild sheep, Yak, Himachal Pradesh Tibetan Antelope, Marmot, snow Leopard, Wolf, Black necked crane 2. Himalayan Extends across Jammu Ranges from Pine, Cork tree, Sal, & Kashmir, Himachal subtropical in the lower Castor, Alpine meadows Pradesh, Uttarakhand, elevations to alpine and Bengal Tiger, Wild Bear, Sikkim, Arunachal tundra in the higher Sambar, Sikkim Stag, Pradesh, and parts of regions. Leopard, Musk Deer Assam 3. Desert Covers the Thar Desert Arid, with extreme Acacia, Zizyphus, in Rajasthan and parts temperatures, scarce Khejri, Date palm of Gujarat rainfall, and sandy soil Camel, Bustard, Ass, Desert cat, Fox, Wolf, Rat, Snakes 4. Semi-arid Spans parts of Gujarat, Semi-arid, with hot Acacia, Date palm, Rajasthan, Madhya summers and moderate Peepal Pradesh, and the rainfall. Gir Lion, Tiger, Deccan Plateau Blackbuck, Wolf, Peafowl 5. Western Ghats Stretches along the Tropical, with heavy Sheesham, Peepal, Tuna western coast of India, rainfall during the Frog, Lion-tailed from Gujarat to Kerala monsoon, high macaque, Malabar Giant humidity, and mild Squirrel, Nilgiri Tahr temperatures 6. Deccan Plateau Covers central and Hot and dry, with Pine, Peepal, Dry southern India, moderate to low deciduous forests, including parts of rainfall. Thorny vegetation Maharashtra, Frog, Indian elephant, Karnataka, Telangana, gaur (Indian bison), and and Andhra Pradesh. sloth bear 7. Gangetic Plains Extends across Humid subtropical, Sal, Acacia, Mango, northern India, from with hot summers, cold Beal Punjab to West Bengal, winters, and moderate Black chinkara, Stag, along the Ganges to heavy rainfall Rhinoceros, Gazzel, River. Alligator, Turtle 8. North-East India Comprising the seven Tropical and Bamboo, Sal, Jack fruit, sister states (Arunachal subtropical, with heavy Chestnut, Castor Pradesh, Assam, rainfall and high Elephant, Rhinoceros, Manipur, Meghalaya, humidity. Yak, Porcupine Mizoram, Nagaland, and Tripura). 9. Coasts Includes the eastern Tropical and humid, Coconut, Banana, and western coastal with high rainfall, Cashew nut regions of India, especially during the Dolphin, Alligator, spanning from Gujarat monsoon. Mollusca to West Bengal. 10. Islands Includes the Andaman Tropical, with high Bahera, Harar, Jack fruit and Nicobar Islands in humidity and Dolphin, Alligator, the Bay of Bengal and significant rainfall. Mollusca the Lakshadweep Islands in the Arabian Sea. 18 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand Q4. What is air pollution. Mention various substances causing air pollution. classify of air pollutants based on origin, physical state, chemical composition, health impact, and source including examples of each. What is the concentration of particulate matter in Birsa area, if the initial weight of filter paper installed in the high air volume sample is 10 gm and the final weight of the filter paper is 11 gm after 5 days. The volume of air sampler is 1000 m3. (1+6+3) Ans. Air pollution is an atmospheric condition in which certain substances (including the normal constituents in excess) are present in concentrations which can cause undesirable effects on man and his environment. These substances include gases, particulate matter, radioactive substances etc. Substances causing air pollution Gaseous pollutants include oxides of sulfur (SO2, SO3), oxides of nitrogen (NO2, NO, and N2O), carbon monoxide, volatile organic compounds (hydrocarbons) etc. Particulate pollutants include smoke, dust, soot, aerosols, pollen grains etc. Classification of Air Pollutants 1. Classification Based on Origin: ▪ Primary Pollutants: Pollutants emitted directly into the atmosphere from sources such as vehicles, industrial processes, and natural events like volcanic eruptions. E.g. carbon monoxide (CO), sulfur dioxide (SO₂), nitrogen oxides (NOx), particulate matter (PM), and volatile organic compounds (VOCs). ▪ Secondary Pollutants: Pollutants formed in the atmosphere through chemical reactions between primary pollutants and other atmospheric components. E.g. ozone (O₃), Smog, and peroxyacetyl nitrate (PAN). 2. Classification Based on Physical State: ▪ Gaseous Pollutants: Pollutants that are present in the atmosphere as gases. Examples: CO, SO₂, NOx, O₃, and NH₃. ▪ Particulate Pollutants: Solid or liquid particles suspended in the air. E.g. dust, smoke, fumes, aerosols, PM10 and PM2.5. 3. Classification Based on Chemical Composition: ▪ Organic Pollutants: Compounds containing carbon, often originating from biological processes or human activities. E.g. benzene (C6H6), toluene, and formaldehyde, and polycyclic aromatic hydrocarbons (PAHs). ▪ Inorganic Pollutants: Pollutants that do not contain carbon, often derived from natural or industrial sources. E.g. SO₂, NOx, and lead (Pb). 4. Classification Based on Health Impact: ▪ Toxic Pollutants: Pollutants that cause serious health effects, including respiratory issues, cancer, and neurological damage. E.g. asbestos, mercury (Hg), and C6H6. ▪ Non-Toxic Pollutants: Pollutants that may not be directly toxic but still have environmental and health impacts. E.g. CO₂. 5. Classification Based on Health Impact: 19 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  ▪ Man-made Pollutants: Pollutants that originate from human activities such as industry, transportation, and agriculture. E.g. industrial emissions (SO₂, NOx, VOCs), vehicle emissions (CO, NOx, PM), and agricultural activities (ammonia, methane). ▪ Natural Pollutants: Pollutants that occur naturally without human intervention. E.g. volcanic eruptions (SO₂, ash, PM), forest fires (CO, PM, VOCs, and pollen. Sol. Given, V = 1000 m3, Winitial = 10 gm, Wfinal = 11 gm 3 [𝑊𝑓𝑖𝑛𝑎𝑙 − 𝑊𝑖𝑛𝑖𝑡𝑖𝑎𝑙 ] 𝑓𝑖𝑙𝑡𝑒𝑟 PM (µg/m ) = × 106 𝑉𝑜𝑙𝑢𝑚𝑒 [11 − 10] × 106 = 1000 × 106 = 1000 = 1000 µg/m3 Q5. What is noise pollution. Discuss briefly the stationary and mobile sources of noise pollution. If the sound pressure level heard by a person at distance 2 m is 100 dB. Find the sound pressure level heard by a another who is standing in the same path but 20 km far from the sound source? (6+4) Ans. A type of sound may be pleasant to someone and at the same time unpleasant to others. The unpleasant and unwanted sound is called noise. Sources of Noise Pollution 1. Mobile Sources: o Road Traffic: Vehicles such as cars, trucks, motorcycles, and buses are major contributors to noise pollution, o Railways: Trains produce significant noise from their engines, horns, and the friction between wheels and tracks. o Air Traffic: Aircraft noise, particularly from takeoffs, landings, and low-altitude flight paths near airports, is a significant source. o Marine Traffic: Ships, especially large vessels like cargo ships and cruise liners, generate noise through their engines, propellers, and other machinery. 2. Stationary Sources: o Factories and Manufacturing Plants: Industrial operations often involve heavy machinery, equipment, and processes that generate high levels of noise. This includes metal fabrication, chemical processing, and other manufacturing activities. o Construction Sites: Construction activities such as drilling, hammering, blasting, and the operation of heavy machinery (e.g., bulldozers, cranes) are significant sources of noise pollution. Construction noise is particularly disruptive in residential areas. 20 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  o Mining and Quarrying: The extraction of minerals and materials from the earth involves drilling, blasting, and crushing, all of which produce considerable noise. Sol. L = 100 db, r = 2 m, r = 20 km =20000 m 1 1 2 r2 L = L1 - 20 log10 r1 2 20000 = 100 - 20 log10 2 = 100 – 20*4 L2 = 20 dB Q6. What is greenhouse effect. Discuss about the major greenhouse gasses? Discuss the potential and contribution of these gases to global warming phenomenon. Discuss briefly the major impacts of enhanced greenhouse effect. Mention some of the measures to mitigate global warming. (4+3+3) Ans. The natural process through which heat is trapped in the lowest layer of atmosphere (troposphere) by a natural process due to the presence of certain gases. This effect is called greenhouse effect. During the day the sun heats up the earth’s atmosphere. At night, when the earth cools down the heat is radiated back into the atmosphere. During this process, the heat is absorbed by the greenhouse gases in the earth’s atmosphere. This is what makes the surface of the earth warmer, that makes the survival of living beings on earth possible. However, due to the increased levels of greenhouse gases, the temperature of the earth has increased considerably. This has led to global warming. Major greenhouse gases: Carbon dioxide (56%) is widely reported as the most important anthropogenic greenhouse gas because it currently accounts for the greatest portion of the warming associated with human activities. Methane (18%) comes from many sources, including human activities such as coal mining, natural gas production and distribution, waste decomposition in landfills, and digestive processes in livestock and agriculture. Nitrous oxide (6%) is emitted during agricultural and vehicle exhaust, as well as during combustion of solid waste and fossil fuels. Various synthetic chemicals gases (13%), such as chlorofluorocarbons (CFCs), perfluorocarbons, sulfur hexafluoride (SF6), and other synthetic gases, are released as a result of commercial, industrial, or household uses. Potential and contribution of these gases to global warming Burning of Fossil Fuels: Burning of fossil fuels releases CO2. With the increase in population, the utilization of fossil fuels has increased. 21 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Deforestation: Plants and trees take in CO2 and release oxygen. Due to the cutting of trees, there is a considerable increase in the greenhouse gases which increases the earth’s temperature. Farming & Automobiles: Nitrogen used in fertilizers and N2O generated in exhaust is one of the contributors to the greenhouse effect in the atmosphere. Industrial Waste and Landfills: The industries and factories produce harmful gases which are released in the atmosphere. Major impacts of enhanced greenhouse effect Global Warming: It is the phenomenon of a gradual increase in the average temperature of the Earth’s atmosphere. Depletion of Ozone Layer: Ozone Layer protects the earth from harmful ultraviolet rays from the sun. It is found in the upper regions of the stratosphere. Smog and Air Pollution: Smog is formed by the combination of smoke and fog. It can be caused both by natural means and man-made activities. Acidification of Water Bodies: The greenhouse gases mix with the rainwater and fall as acid rain. This leads to the acidification of water bodies. Measures to mitigate Global Warming Cutting down the current rate of use of CFCs and fossil fuel. Shifting towards renewable energy resources. Increasing Nuclear Power Plants for electricity production. Shifting from coal to natural gas. Efficiently remove CO2 from smoke stacks. Afforestation/Reforestation i.e., planting more trees. Q7. Write short notes on (2+2+2+2+2) a) Natural gas and its advantages Natural gas is a fossil fuel primarily composed of methane (CH₄) (95%) will small amount of propane and ethane, a colorless and odourless gas. It is found deep beneath the Earth's surface, often in association with other fossil fuels such as oil and coal. Advantages: Cleaner Energy: Emits less carbon dioxide and pollutants compared to coal and oil. Efficient: High energy efficiency for electricity generation and heating. Abundant Supply: Widely available in many regions, ensuring a steady energy source. Cost-Effective: Often cheaper than other fossil fuels. b) Water conflict in the middle-east The Nile River Dispute: The construction of the GER dam by Ethiopia has led to concerns in Egypt, which relies on the Nile for over 80% of its freshwater. Jordan River Basin: The diversion of the Jordan River for agricultural and domestic use has reduced its flow, impacting both Jordan, Syria and Israel. 22 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Tigris and Euphrates: Turkey’s development of the Southeastern Anatolia Project, which includes multiple dams, has raised concerns in Syria and Iraq about reduced water flow. Gaza Strip Water Crisis: The Coastal Aquifer in Gaza is over-extracted and polluted, leading to a severe water crisis. c) Ozone depletion In the stratosphere ozone (O3) is continuously being formed by the absorption of short wavelength ultraviolet (UV) radiations. UV radiations decompose molecular oxygen (O2) into nascent oxygen (O) by photolytic decomposition (1). The atomic oxygen rapidly reacts with molecular oxygen to form ozone (2). O2 + hv → O + O 1 O + O2 → O3 2 d) Sutlej-Yamuna dispute The Sutlej-Yamuna Link (SYL) Canal is a controversial irrigation project in India, designed to connect the Sutlej River in Punjab with the Yamuna River in Haryana. Agreement on SYL Canal: In 1976, the Punjab and Haryana governments signed an agreement to construct the SYL Canal, allowing Haryana to draw water from the Sutlej River. However, the project faced opposition from various groups in Punjab, particularly due to concerns about water availability for agriculture. Supreme Court Involvement: The SYL Canal issue has seen multiple legal battles. In 2002, the Supreme Court of India directed Punjab to complete the construction of the SYL Canal and comply with the 1976 agreement. Current Status: As of now, the SYL Canal remains incomplete, with ongoing disputes between Punjab and Haryana over water sharing. e) Global Information System (GIS) Geographical Information System (GIS) is a computer-based tool that helps us understand and analyze the world around us by mapping and visualizing data. It combines location information (like maps) with other types of data (like population, weather, or traffic) to answer questions and solve problems. For example, GIS can be used to: Find the best route for food delivery agents. Map areas prone to flooding. Track deforestation over time. In simple terms, GIS connects data to a map, allowing us to see patterns, relationships, and trends in a visual and easy-to-understand way. Q8. Write short notes on (2+2+2+2+2) a) Alpha, beta and gamma biodiversity with examples ▪ Alpha Diversity (α-Diversity): Alpha diversity refers to the species richness within a particular homogeneous area, community, or ecosystem. E.g. The number of trees or animal species in a single forest plot or the number of fish species in a particular lake. 23 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  ▪ Beta Diversity (β-Diversity): Beta diversity represents the difference in species richness between different areas or ecosystems. E.g. Comparing a distinct species of plants or animals found in a tropical rainforest versus a temperate grassland. ▪ Gamma Diversity (γ-Diversity): Gamma diversity refers to the total species richness across a larger geographic area that encompasses multiple ecosystems or communities. E.g. The total number of unique plant or animal species in a country or across a mountain range that includes various habitats like forests, grasslands, and rivers. b) Acid rain and its causes Acid rain results when sulfur dioxide (SO2) and oxides of nitrogen (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. Causes: SO2 and NOX undergo oxidation, and then they react with water resulting in the formation of sulphuric acid and nitric acid, respectively. The following reaction will clarify the acid formation reaction: 2SO2 (g) + O2 (g) + 2H2O (l) → 2H2SO4 (aq) 4NO2 (g) + O2 (g) + 2H2O (l) → 4HNO3 (aq) c) Components of nuclear reactor Reactor Core: The heart of the nuclear power plant, where fission reactions occur. The core contains fuel rods made of uranium or plutonium, control rods to manage the fission rate, and a coolant to transfer heat away from the reactor. Control Rods: Made of materials like boron or cadmium, control rods absorb neutrons to regulate the chain reaction. By inserting or withdrawing these rods, operators can control the rate of fission. Moderator: A fluid (often water, heavy water or graphite) that used in the reactor to remove heat generated by fission. The heated coolant is used to produce steam. Steam Generator: Converts the heat from the coolant into steam, which then drives the turbines. d) Environmental Protection Act, 1986 The Environment (Protection) Act, 1986 is one of India's most comprehensive and pivotal environmental laws, enacted in the wake of the Bhopal Gas Tragedy of 1984. It provides a framework for the protection and improvement of the environment. Objectives: Environmental Protection: The primary objective of the Act is to provide for the protection and improvement of the environment. Prevention of Hazards: It seeks to prevent environmental hazards to human beings, living creatures, plants, and property. Coordination of Regulatory Activities: The Act empowers the central government to coordinate actions of various regulatory agencies under existing laws for environmental protection. e) Nalgonda process of defluorination 24 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand The Nalgonda process is a widely used method for defluoridating drinking water, particularly in rural areas and developing countries where fluoride levels in groundwater are high. The Nalgonda process is named after the Nalgonda district in India, where it was first implemented successfully. Alum (Aluminum Sulfate, Al2(SO4)3): The process begins by adding alum to the water. Alum acts as a coagulant, helping to bind fluoride ions to aluminum hydroxide precipitates. Lime (Calcium Hydroxide, Ca(OH)2): Lime is also added to adjust the pH and enhance the coagulation process. The pH is typically adjusted to an optimal level (around 6.5 to 7) to maximize fluoride removal efficiency. Flocculation: As the chemical reactions proceed, flocs (clumps) of aluminum hydroxide form. These flocs trap fluoride ions and other impurities as they settle. Sedimentation: The water is allowed to stand undisturbed so that the flocs, along with the trapped fluoride and other contaminants, settle at the bottom of the tank or container. Q9. Write short notes on (2+2+2+2+2) a) Extinct, endangered, vulnerable and rare species with examples A species is said to be extinct when it is not seen in the wild for 50 years at a stretch. E.g., dodo, passenger pigeon, cheetah, pink headed duck and mountain quail. A species is said to be endangered when its number has been reduced to a critical level or whose habitats, have been drastically reduced. If such species are not protected and conserved, it is in immediate danger of extinction. E.g. Malabar civet. A species is said to be vulnerable category if its population is facing continuous decline due to overexploitation or habitat destruction. E.g. Andaman Hor Shoe Bat. Species which are not endangered or vulnerable at present, but are at risk are categorized as rare species. These are usually localized within restricted areas. b) HIV/AIDS including Indian scenario AIDS (Acquired Immuno Deficiency Syndrome) is not a hereditary disease but is caused by HIV (Human Immunodeficiency Virus). HIV from an infected person can pass to a normal person through: - (a) blood contact generally during unprotected meeting with infected person. (b) sharing needles or syringes contaminated with small quantities of blood from HIV positive person. (c) HIV can also pass from infected mothers to their babies during pregnancy, delivery or breast feeding. c) Major impacts of enhanced greenhouse effect Global Warming: It is the phenomenon of a gradual increase in the average temperature of the Earth’s atmosphere. Depletion of Ozone Layer: Ozone Layer protects the earth from harmful ultraviolet rays from the sun. It is found in the upper regions of the stratosphere. Smog and Air Pollution: Smog is formed by the combination of smoke and fog. It can be caused both by natural means and man-made activities. 25 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Acidification of Water Bodies: Increase in the total amount of greenhouse gases in the air has turned most of the world’s water bodies acidic. The greenhouse gases mix with the rainwater and fall as acid rain. This leads to the acidification of water bodies. d) Major greenhouse gasses Carbon dioxide (56%) is widely reported as the most important anthropogenic greenhouse gas because it currently accounts for the greatest portion of the warming associated with human activities. Methane (18%) comes from many sources, including human activities such as coal mining, natural gas production and distribution, waste decomposition in landfills, and digestive processes in livestock and agriculture. Nitrous oxide (6%) is emitted during agricultural and industrial activities, as well as during combustion of solid waste and fossil fuels. Various synthetic chemicals gases (13%), such as chlorofluorocarbons (CFCs), perfluorocarbons, sulfur hexafluoride (SF6), and other synthetic gases, are released as a result of commercial, industrial, or household uses. e) Activated sludge process The effluent from the primary clarifier goes into the aeration tank. Aeration tank receives microorganisms from the secondary clarifier known as activated sludge. Oxygen is pumped into the aeration tank to maintain aerobic conditions. After 4 to 8 hr of treatment, the wastewater is transferred to the secondary clarifier cum settling tank, where the sludge gets deposited at the bottom of the tank. The excess sludge produced from both the primary and secondary settling tank is dewatered and then disposed after anaerobic treatment. All the following questions (16 Marks) Q1. Write short notes on (any combination of 5 to 6 question will come from below carrying a sum of 16 marks) a. What is nuclear energy? Explain its types 2 Nuclear energy is the energy released during nuclear reactions, either through nuclear fission (splitting of atomic nuclei) or nuclear fusion (combining atomic nuclei). Types of Nuclear Energy Nuclear Fission: Nuclear fission is the process of splitting a heavy atomic nucleus, such as uranium-235 or plutonium-239, into smaller nuclei, releasing a large amount of energy. Nuclear Fusion: Nuclear fusion is the process in which two light atomic nuclei, such as isotopes of hydrogen (deuterium and tritium), combine to form a heavier nucleus, releasing vast amounts of energy. In extremely high-temperature environments (millions of degrees). b. What is soil pollution. Discuss briefly the its major causes. 3 26 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand Contamination of soil with sewage sludge, industrial sludge, solid wastes, dump site leachates, agrochemicals, and radioactive waste is called soil pollution. Major sources of Soil Pollution Domestic wastes include garbage, rubbish material like glass, plastics, metallic cans, paper, fibers, cloth rags, containers, paints, varnishes etc. All these waste releases a slimy liquid known as “leachates”. The leachates from dumping sites and sewage tanks are harmful and toxic, which pollute the soil. Industrial wastes are the effluents discharged from various industries like chemical industries, paper and pulp mills, tanneries, textile mills, steel industries, distilleries, refineries, pesticide and fertilizers industries. Thermal power plant releases a large quantity of dry solid wastes like fly ash, blast furnace slag, steel slag etc. directly dumped onto the soil. Soils also receives urine and excreta from animals and humans (open defecation). These wastes attract many pathogenic bacteria, viruses, and worms into the soil. c. Anaerobic biological process 2 Anaerobic biological treatment is a wastewater treatment process that uses anaerobic bacteria to break down organic matter without oxygen. The process produces biogas, a mixture of methane (CH4) and carbon dioxide (CO2), which can be used as an energy source In anaerobic process bioconversion occurs very slow (30 to 60 days) but produces useful by-products such as methane (have high calorific value used as fuel). Not much sludge is produced. d. If the sound pressure level heard by a person at distance 3 m is 100 dB. Find the sound pressure level heard by a another who is standing in the same path but 3 km far from the sound source? 2 Sol. L1 = 100 db, r1 = 3 m, r2 = 3 km =3000 m r2 L2 = L1 - 20 log10 r1 3000 = 100 - 20 log10 3 = 100 – 20*3 L2 = 40 dB 27 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand e. Alpha, beta and gamma biodiversity with examples 3 ▪ Alpha Diversity (α-Diversity): Alpha diversity refers to the species richness within a particular homogeneous area, community, or ecosystem. E.g. The number of trees or animal species in a single forest plot or the number of fish species in a particular lake. ▪ Beta Diversity (β-Diversity): Beta diversity represents the difference in species richness between different areas or ecosystems. E.g. Comparing a distinct species of plants or animals found in a tropical rainforest versus a temperate grassland. ▪ Gamma Diversity (γ-Diversity): Gamma diversity refers to the total species richness across a larger geographic area that encompasses multiple ecosystems or communities. E.g. The total number of unique plant or animal species in a country or across a mountain range that includes various habitats like forests, grasslands, and rivers. f. Discuss briefly hydroelectricity and its advantages 2 Hydroelectric power is generated by harnessing the kinetic energy of flowing or falling water to produce electricity, typically through a system of dams and turbines. Water stored in a reservoir is released through turbines, turning them and generating electricity. It's one of the most widely used renewable energy sources worldwide. Hydro energy is considered a renewable and clean source of power because it relies on natural water current, does not deplete resources, and produces no harmful emissions during operation. g. What do you mean by i) eutrophic lake and ii) endemic lake 2 Eutrophic lakes which are overnourished by nutrients like nitrogen and phosphorus, usually as a result of agricultural run-off or municipal sewage discharge. They are covered with algal blooms e.g. Dal Lake. Endemic lakes that are very ancient, deep and have endemic fauna which are restricted only to that lake e.g. the Lake Baikal in Russia; the deepest lake, which is now suffering a threat due to industrial pollution. h. Briefly discuss the Cauvery water dispute 2 The Cauvery Water Dispute is a long-standing water-sharing conflict between the Indian states of Karnataka and Tamil Nadu, along with the involvement of Kerala and the Union Territory of Puducherry. 2007 Tribunal Verdict (2007): The Tribunal allocated 419 TMC (thousand million cubic feet) of water to Tamil Nadu, 270 TMC to Karnataka, 30 TMC to Kerala, and 7 TMC to Puducherry. Karnataka was also required to release 192 TMC of water annually to Tamil Nadu. Supreme Court Intervention (2018): In February 2018, the Supreme Court of India delivered its final verdict on the dispute, reducing Tamil Nadu’s share to 404.25 TMC and increasing Karnataka’s allocation to 284.75 TMC. Kerala was allowed 30 TMC and Puducherry 7 TMC. i. Briefly discuss various components of a typical nuclear reactor with a neat diagram 3 Components of a Nuclear Power Plant Reactor Core: The heart of the nuclear power plant, where fission reactions occur. The core contains fuel rods made of uranium or plutonium, control rods to manage the fission rate, and a coolant to transfer heat away from the reactor. Control Rods: Made of materials like boron or cadmium, control rods absorb neutrons to regulate the chain reaction. By inserting or withdrawing these rods, operators can control the rate of fission. 28 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Moderator: A fluid (often water, heavy water or graphite) that used in the reactor to remove heat generated by fission. The heated coolant is used to produce steam. Steam Generator: Converts the heat from the coolant into steam, which then drives the turbines. j. Discuss briefly the Nalgonda process of defluorination 2 The Nalgonda process is a widely used method for defluoridating drinking water, particularly in rural areas and developing countries where fluoride levels in groundwater are high. The Nalgonda process is named after the Nalgonda district in India, where it was first implemented successfully. Alum (Aluminum Sulfate, Al2(SO4)3): The process begins by adding alum to the water. Alum acts as a coagulant, helping to bind fluoride ions to aluminum hydroxide precipitates. Lime (Calcium Hydroxide, Ca(OH)2): Lime is also added to adjust the pH and enhance the coagulation process. The pH is typically adjusted to an optimal level (around 6.5 to 7) to maximize fluoride removal efficiency. Flocculation: As the chemical reactions proceed, flocs (clumps) of aluminum hydroxide form. These flocs trap fluoride ions and other impurities as they settle. Sedimentation: The water is allowed to stand undisturbed so that the flocs, along with the trapped fluoride and other contaminants, settle at the bottom of the tank or container. k. Discuss briefly the stationary and mobile sources of noise pollution 3 Sources of Noise Pollution 1. Mobile Sources: Road Traffic: Vehicles such as cars, trucks, motorcycles, and buses are major contributors to noise pollution, Railways: Trains produce significant noise from their engines, horns, and the friction between wheels and tracks. Marine Traffic: Ships, especially large vessels like cargo ships and cruise liners, generate noise through their engines, propellers, and other machinery. 2. Stationary Sources: 29 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand  Factories and Manufacturing Plants: Industrial operations often involve heavy machinery, equipment, and processes that generate high levels of noise. This includes metal fabrication, chemical processing, and other manufacturing activities. Construction Sites: Construction activities such as drilling, hammering, blasting, and the operation of heavy machinery (e.g., bulldozers, cranes) are significant sources of noise pollution. Construction noise is particularly disruptive in residential areas. Mining and Quarrying: The extraction of minerals and materials from the earth involves drilling, blasting, and crushing, all of which produce considerable noise. l. If in an artic area the gross primary production of producers under ideal condition is 2000 KJ in 2 years. Find out the net primary production of the producers for 1 years if the respiration loss is 50 KJ per year. 2 Sol. GPP = 2000 KJ in 2 year = 1000 KJ for 1 year R for 1 year = 50 KJ, Therefore, NPP = GPP – R = 1000 – 50 = 950 KJ for 1 years m. Define smog. Mention different types of smog based on formation, components, Conditions Favouring conditions, effects and examples. If a nation has an annual growth rate of 5%, find in how many years its population will double. 4 Smog is a type of air pollution characterized by a mixture of smoke, fog, and various chemical pollutants in the atmosphere. It is commonly associated with urban areas, especially those with high traffic and industrial activity. Smog reduces visibility, harms human health, and affects the environment. Types of Smog Photochemical Smog (or Los Angeles Smog): Photochemical smog forms when sunlight interacts with pollutants like nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the atmosphere. This reaction produces ozone (O₃), peroxyacetyl nitrate (PAN), and other secondary pollutants. 𝑃ℎ𝑜𝑡𝑜𝑙𝑦𝑠𝑖𝑠 NO2 + UV → NO + O O + O2 → O3 RCO3 + NO2 → RCO3NO2 (PAN) Conditions Favouring Formation: Sunny weather, high temperatures, and stagnant air conditions (little wind) enhance the formation of photochemical smog. Common in urban areas with heavy traffic and industrial emissions. Effects: Causes respiratory problems, eye irritation, and aggravates asthma and other lung conditions. Damages crops, trees, and other vegetation. Ozone in photochemical smog also degrades materials like rubber and fabrics. Sulfurous Smog (or London Smog): Sulfurous smog, also known as "classic" or "industrial" smog, forms primarily from the burning of fossil fuels, particularly coal. It is characterized by a high concentration of sulfur dioxide (SO₂), particulate matter, and moisture, which combine to form a dense fog. 30 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand Conditions Favoring Formation: Cold, damp conditions, and high humidity are ideal for the formation of sulfurous smog. Often occurs in areas with significant coal burning, especially during the winter months. Effects: Causes severe respiratory problems, exacerbates lung diseases, and can be fatal during severe episodes. Damages buildings and infrastructure due to the acidic nature of the smog. It can also harm plants and animals. Sol. r = 5% (given), Td = 70/r = 70/5 = 14 Therefore, if a nation has an annual growth rate of 5%, its population will double 14 years. End-Sem Question Pattern Attend any 4 questions out of 5 questions of 6 marks each (24 Marks) Attend any 2 questions out of 2 questions of 10 marks each (20 Marks) Compulsory question (16 Marks) Total 60 Marks and Time duration: 3 hours 31 This document belongs to Dr. Vishal Kumar Parida, Amity University Jharkhand