JKBOSE Environmental Science: Solved Model Question Paper for Class 12th Environmental Science NCERT (2023)

JKBOSE Environmental Science: Solved Model Question Paper for Class 12th Environmental Science NCERT (2023)

                                      SECTION A


Q1. Adsorption is the process of controlling which type of air pollutants:

a. Gaseous Air Pollutants b. Particulate Air Pollutants. c. Vehicular Pollution d. None of these

Answer: b. Particulate Air Pollutants.

Q2. When and where was the U.N. Framework Convention on Climate Change Signed?

Answer: The United Nations Framework Convention on Climate Change (UNFCCC) was signed on May 9, 1992, in New York, USA.

Q3. Which step in the Process of EIA helps in determining the key and significant impacts of a developmental activity?

Answer: Impact Analysis.

Q4. When was EPA enacted?

Answer: The Environmental Protection Agency (EPA) was established on December 2, 1970, by President Richard Nixon.

Q5. What is the unit of measurement of Noise?

Answer: The unit of measurement of noise in decibels (dB).

Q6. What is meant by 5R?

Answer: 5R is a framework for waste management. It stands for Reduce, Reuse, Recycle, Recover, and Remanufacture.

Q7. Which method helps to reduce erosion due to water?

 a. Contour farming b. Monoculture c. Tillage d. None of these

Answer: a. Contour farming

Q8. What is deep well injection?

Answer: Deep well injection is a method of disposing of liquid and gaseous waste by pumping it deep underground into a well, typically hundreds to thousands of feet below the surface.

                                 SECTION B


Q9. What were the objectives of the Montreal Protocol?

Answer: The objectives of the Protocol are to reduce the production and consumption of ODS to reduce their presence in the atmosphere, reduce their adverse effects on human health and the environment, and eventually eliminate their use. The Protocol also aims to promote the use of cleaner and more energy-efficient technologies and to promote research into alternative technologies and processes.

Q10. What are soil horizons?

Answer: Soil horizons are layers in the soil that are the result of soil formation processes. Soil horizons are typically divided into three basic categories: A horizon (topsoil), B horizon (subsoil), and C horizon (parent material). The A horizon is the uppermost layer and is usually the most fertile and most heavily used for plant growth. The B horizon is composed of more compacted, less fertile material. The C horizon is composed of the parent material from which the soil was formed. It is usually composed of bedrock or partially decomposed bedrock.

Q11. What are the functions of the Central Pollution Control Board?

Answer: The functions of the CPCB are as follows:

1. To lay down standards for the quality of air and water and for the emission of noise and other forms of pollution.

2. To monitor and control the levels of pollution in the environment.

3. To advise the central and state governments on measures to be taken to prevent and control environmental pollution.

4. To undertake and promote research and investigations in the field of pollution control.

5. To provide technical assistance and guidance to the state pollution control boards for implementing pollution control programmes.

6. To carry out and promote training and awareness programmes on pollution control.

7. To develop and promote cleaner technologies and processes in industry and other sources of pollution.

8. To advise the central and state governments on any other matter relating to environmental pollution.

Q12. Explain the concept of genetic diversity with examples.

Answer: Genetic diversity is the variety of genetic information within a species or population. It is the total number of genetic characteristics in the gene pool of a species. It is the diversity of genes within a species, population, or breed. Examples of genetic diversity include variations in the size, shape, and colour of a species. For example, the difference between a Siamese cat and a tabby cat, or the difference between a petite person and a tall person. Other examples include variations in behaviour, such as the ability to learn or the presence of certain diseases. Variations in genetic code, such as the number of chromosomes, also contribute to genetic diversity.

 Q13. How do sanitary landfills work?

Answer: Sanitary landfills are engineered structures that are used to safely dispose of solid waste. The waste is typically buried in layers that are covered with a layer of soil or other material to contain the waste and to reduce the spread of disease-causing organisms. Liners and leachate collection systems are also used to help prevent contamination of groundwater and surface water. Gas collection systems are also used to help prevent odours, reduce greenhouse gases, and capture methane for energy production. After the landfill has been filled, it is typically capped with a layer of soil and vegetation, to help prevent further contamination of the environment.

Q14. What are the three pillars of Sustainable Development?

Answer: The three pillars of Sustainable Development are:

1. Economic Development: The production and use of resources in a manner that sustains economic growth.

2. Social Development: The promotion of equitable access to resources and services, and the protection of human rights.

3. Environmental Protection: The conservation and management of natural resources in a manner that preserves their ecological integrity.

Q15. Explain the concept of Biomagnification.

Answer: Biomagnification is the process by which toxins such as pesticides, herbicides, and other chemicals accumulate in the tissues of organisms at higher levels than what is found in the environment. These chemicals can be taken up by organisms at the lower trophic levels in the food chain, such as plankton or fish, and as they move up the food chain, they are accumulated in higher concentrations, becoming more and more concentrated in the higher order predators. This process can have dangerous effects on organisms, as the higher concentrations of these toxins can cause illness, death, or reproductive failure.

Q16. What are the direct and indirect values of biodiversity?

Answer: Direct values of biodiversity refer to the tangible benefits that humans gain from nature, such as food, medicine, clean water, shelter, and beauty. Indirect values of biodiversity refer to the intangible benefits that humans gain from nature, such as spiritual enrichment, recreation, educational opportunities, and scientific knowledge.

Q17. What is Montreal Protocol?

Answer: The Montreal Protocol is an international agreement to phase out the production and use of chemicals that deplete the ozone layer. It was originally signed in 1987 and has since been amended several times. The agreement is designed to reduce the emissions of ozone-depleting substances, such as chlorofluorocarbons (CFCs), halons, and methyl bromide. The Protocol has been widely successful, with most of the ozone-depleting substances now banned or being phased out.

Q18. Name some ozone-depleting substances.

Answer: Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, carbon tetrachloride, methyl bromide, methyl chloroform.

                                    SECTION C


Q19. Differentiate between in-situ and ex-situ conservation methods.

Answer: In-situ conservation is the conservation of species in their natural habitat. This method is often used to protect species from extinction, as well as to protect their habitats from destruction. In-situ conservation can include setting up protected areas such as national parks, establishing laws to protect certain species, and controlling hunting and fishing activities.

Ex-situ conservation is the conservation of species outside of their natural habitat. This method is often used to preserve species that are endangered or threatened in their natural habitat. Ex-situ conservation can include capturing species and relocating them to a safe habitat, breeding programs, and maintaining gene banks for species.

Q20. Explain the concept of Photochemical Smog. What are its impacts?

Answer: Photochemical smog is a type of air pollution that is created when sunlight reacts with certain pollutants in the atmosphere. It is created by the reaction of nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. The most dangerous components of photochemical smog are ozone (O3) and particulate matter, which can both cause a range of health and environmental problems.

 The impacts of photochemical smog include respiratory problems such as asthma, bronchitis, and emphysema. It can also cause eye irritation and damage to plants, animals, and crops due to the presence of ozone, particulate matter, and other air pollutants. Additionally, photochemical smog can have a negative effect on the climate, reducing visibility and contributing to global warming.

Q21. What are the different types of Soil found in India?

Answer: The different types of soil found in India are:

1. Alluvial Soil: These are rich in humus and are found in the plains of the major river systems.

2. Black Soil: Also known as Regur, this soil is rich in calcium carbonate and is found in the Deccan Plateau.

3. Red Soil: This soil is largely composed of ferric oxide and is found in the areas of the Eastern and Western Ghats.

4. Laterite Soil: This soil is rich in iron and is found in the Eastern and Western Ghats.

5. Mountain Soil: This is found in the Himalayas and the hilly areas of Northeast India.

6. Arid Soil: This type of soil is poor in fertility and is found in the desert areas of Rajasthan.

Q22. How do habitat fragmentation and invasion of exotic species affect biodiversity?

Answer: Habitat fragmentation and invasion of exotic species can have serious impacts on biodiversity. Fragmentation reduces the amount of suitable habitat and resources available for native species, making it harder for them to survive and reproduce. This can also lead to genetic isolation and inbreeding, which can further reduce genetic diversity and reduce the species’ chances of adaptation and survival. The invasion of non-native species can lead to competition for resources, predation of native species and hybridization, which can also threaten the diversity of native species and disrupt the balance of an ecosystem.

Q23. How does Eutrophication affect aquatic water bodies?

Answer: Eutrophication is an unnatural process of enrichment of water bodies with excessive nutrients like nitrogen, phosphorous, etc., which leads to an imbalance in the aquatic ecosystem. It can lead to algal blooms, decreased oxygen levels, and loss of aquatic animal life. Eutrophication reduces biodiversity, disrupts the food chain, and can make the water unsuitable for recreational activities like swimming, fishing, and boating. It also affects the aesthetics of the water body by turning the water green and murky.

Q24. Explain in short the impact of Carbon monoxide on human health.

Answer: Carbon monoxide is an odourless, colourless, and toxic gas that can be deadly when inhaled. It can reduce the amount of oxygen reaching the body’s organs and tissues and can cause flu-like symptoms, headaches, dizziness, nausea, confusion, unconsciousness, and even death. Long-term exposure can lead to permanent brain and organ damage.

Q25. What are the causes and impacts of Soil pollution?

Answer: Soil pollution is caused by a variety of factors, including industrial activities, agricultural practices, inadequate waste management, and accidental spills. Common sources of soil contamination include hazardous waste sites, septic tanks, landfills, and agricultural runoff.

The impacts of soil pollution can be wide-ranging and far-reaching. It can affect the quality of crops and plants, contaminate groundwater, and harm wildlife. It can also lead to respiratory problems, skin infections, and other health problems for people who come into contact with contaminated soil. Soil pollution can also cause long-term damage to the environment, such as reduced fertility and lower soil productivity.

Q26. What are the key elements of EIA?


1. Scoping: Identifying the potential impacts of the proposed project, including the physical, social, economic and environmental factors.

2. Impact Analysis: Evaluating the potential impacts of the proposed project, and identifying the possible mitigation measures.

3. Public Participation: Involving the public in the EIA process to ensure their interests and concerns are taken into account.

4. Documentation: Preparing and submitting a detailed report of the EIA process, including all relevant data, analysis and recommendations.

5. Decision Making: Making a decision based on the results of the EIA process, taking into account the public’s views and the potential impacts of the proposed project.

Q27. What is global warming? What are its causes?

Answer: Global warming is an increase in the average temperature of the Earth’s climate system.

The primary cause of global warming is the burning of fossil fuels, such as coal, oil, and gas, which release greenhouse gases into the atmosphere. The burning of these fuels emits more carbon dioxide into the atmosphere, which traps heat and causes the Earth’s temperature to rise. Human activities such as deforestation, land-use changes, and livestock production also contribute to global warming by increasing the number of greenhouse gases in the atmosphere.

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