Environmental Science Solved Question Paper 2024 [Dibrugarh University BCOM 2nd SEM NEP Syllabus]

Environmental Science Solved Question Paper 2024 
[Dibrugarh University BCOM 2nd SEM NEP Syllabus]
ENVIRONMENTAL SCIENCE (Value Added Courses)

Paper: VAC3

Full Marks: 40

Pass Marks: 12

Time: 2 hours

The figures in the margin indicate full marks for the questions

1. Answer the following questions: 1x5=5

(a) What do you mean by ‘environment’?

Ans: The word environment is derived from the French word “environ” meaning surroundings. Hence, everything surrounding us is called environment. Every living beings is surrounded by materials and forces such as social, economical, biological, physical or chemical factors that constitute its environment.

(b) What is global warming?

Ans: Global warming means increase in the average temperature of the Earth’s near-surface air and the oceans.

(c) What is the relation between ‘Red Data Book’ and ‘IUCN’?

Ans: Red Data Book is a catalogue (a complete list) that is published by the International Union for Conservation of Nature (IUCN). The Red Data Book keeps a record of all the endangered biological species.

(d) What do you mean by wildlife conservation?

Ans: Conservation of wildlife refers to the management and protection of biodiversity and its natural resources.

(e) Mention the date on which World Earth Day is celebrated.

Ans: 7 April is World Health Day. The date of 7 April marks the anniversary of the founding of WHO in 1948.

2. Answer the following questions in short (any four): 2x4=8

(a) What is rainwater harvesting?

Ans: Rain water harvesting is one of the most effective methods of water management and water conservation. Rainwater harvesting is the system of collection, accumulation and deposition of rain water with the help of artificially designed system rather than allowing it to run off. It can be collected from rivers or roofs and in many places, the water collected is redirected to a deep pit reservoir with percolation. The harvested water can be used as drinking water, irrigation activities, industrial use, and ground water recharge.

(b) Write ex-situ conservation with a suitable example.

Ans: Ex-situ conservation refers to the conservation of biodiversity outside its natural habitats. It involves the conservation of species in areas such as zoos, botanical gardens, seed banks, and gene banks. Some methods of ex-situ conservation are:

a) Captive breeding: Captive breeding involves breeding endangered species in captivity to increase their population size.

b) Seed banks: Seed banks store seeds of endangered plant species for future use.

(c) What do you mean by waste management?

Ans: Waste management involves the activities required to manage waste from its inception to its final disposal. This includes the collection, transport, treatment and disposal of waste, together with monitoring and regulation of the waste management process. Waste management is intended to reduce adverse effects of waste on human health, the environment and aesthetics.

(d) What is greenhouse effect?

Ans: Forest converts carbon dioxide into carbon and oxygen. Loss of forest covers due to release of carbon dioxide and other gases due to industrialization, contributes to ‘Green House Effect’. This leads to Global warming which results in raise in sea-level submerging the low-lying areas in the world and causing atmospheric changes.

(e) What is Red Data Book?

Ans: The IUCN Red List of Threatened Species also known as the IUCN Red List or Red Data List. The Red Data Book is the state document established for documenting rare and endangered species of animals, plants and fungi as well as some local sub-species that exist within the territory of the state or country. It uses a set of criteria to evaluate the extinction risk of thousands of species and subspecies.

3. Write short notes on (any three):        4x3=12

(a) Climate change.

Ans: Climate change is a change in the global or regional climate patterns. It is caused by factors such as biotic processes, variations in solar radiation received by the earth, platonic and volcanic eruptions. Certain human activities have also been identified as significant causes of climate change often referred to as ‘Global Warming’.

According to Intergovernmental Panel on Climate Change(IPCC) Fourth Assessment, climate change will create more stress on the sustainable development capabilities of countries like India. IPCC studies shows that in near future, the global mean surface temperature will rise by 1.4° to 3.8°C. Warming will be greatest over land areas and at high latitudes. The projected rate of warming is greater that has occurred in last 10,000 years.

Causes of climate change:

a) Burning of fossil fuels such as coal, oil, and gas

b) Deforestation and land-use changes

c) Agriculture and livestock production

d) Industrial processes and transportation

(b) In-situ conservation.

Ans: In-situ conservation refers to the conservation of ecosystems and natural habitats in which species live. It involves the protection and preservation of natural ecosystems, such as forests, wetlands, grasslands, and marine habitats, in their original habitats. Some methods of in-situ conservation are:

a) Protected Areas: Protected areas such as national parks, wildlife sanctuaries, and biosphere reserves are established to conserve the natural habitats and biodiversity of a region.

b) Habitat restoration: Restoration of degraded ecosystems and habitats can help to conserve biodiversity.

c) Community-based conservation: Involving local communities in conservation activities can help to conserve biodiversity and promote sustainable use of natural resources.

d) Sustainable use of resources: Sustainable management and use of natural resources, such as forests, can help to conserve biodiversity.

(c) Land degradation.

Ans: Land degradation takes place when land use exceeds the carrying capacity of a system. It is a process in which the value of the biophysical environment is affected by a combination of human induced processes acting upon the land.

During the last few decades, there has been tremendous pressure on land in India due to increase in population. As urban centers grow and industrial expansion occurs, the agricultural land and forests shrink.

Causes of land degradation:

a) Soil erosion: Loss of top soil due to water and wind.

b) Water Logging: Accumulation of excess water under the ground.

c) Salinization: It is the accumulation of soluble salts of sodium, magnesium and calcium in soil to the extent that soil fertility is severely affected.

d) Contamination of soil with industrial waste like heavy metals, pesticides, fertilizers etc.

e) Overgrazing: Increase in livestock population results in overgrazing in pastures land.

(d) Scopes of environmental studies.

Ans: Scope of Environmental studies

Ans: Because of environmental studies has been seen to be multidisciplinary in nature so it is considered to be a subject with great scope. Environment is not limited to issues of sanitation and health but it is now concerned with pollution control, biodiversity conservation, waste management and conservation of natural resources. This requires expert eyes and hence is creating new job opportunities. The opportunities in this field are immense not only for scientists but also for engineers, biologists. There is a good chance of opportunity to find a job in this field as environmental journalists. Environmental science can be applied in the following spheres:

1. Ecosystem Structure and Function: The study of ecosystems mainly consists of the study of the processes that link the leaving organism or in other words biotic component to the non-living organism or a biotic component. So for the study of environment we should aware with biotic and abiotic components.

2. Natural Resource Conservation: For managing and maintenance of forests which are natural resources and for the maintenance of wildlife forms task under natural resource conservation. It is also a scope of environmental studies

3. Environmental Pollution Control: With the knowledge of environmental science everybody can control the pollution. He/she can handle the waste management and also look for ways to control pollution on the aspect of pollution control.

4. Environmental management: There are several independent environmental consultants who are working with Central and State pollution control Board. They offer advice to solve the problems of environment the optimum solution for the upcoming problems. They give direction for controlling pollution due to industrial development.

5. The scope of environmental studies in industry: Environmental scientists work towards maintenance of ecological balance, they also work towards conservation of biodiversity and regulation of natural resources as well as on preservation of natural resources. Most of the industries have a separate environmental research and development section. These sections govern the impact that their industry has on the environment.

(e) Air pollution.

Ans: We all breathe in air, we can feel, and even smell the air and say whether it is fresh or stale. The pollution in air may not be noticed until we see smoke coming out from some source. All human activities from cooking at home to activities in highly mechanized industries contribute to air pollution.

The World Health Organization defines air pollution as “the presence of materials in the air in such concentration which are harmful to man and his environment.”

In Simple words, it is the occurrence or addition of foreign particles, gases and other pollutants into the air which have an adverse effect on human beings, animals, vegetation, buildings, etc.

Sources and causes of Air Pollution

The sources of air pollution are classified into two groups: Natural and Man- made sources.

(a) Natural sources:

1)    Volcanic eruption: releasing poisonous gases like SO2, H2S, CO etc.

2)    Forest fires: Very large quantities of smoke and particulate matter are liberated during their breakout.

3)    Decomposition of organic and inorganic substances: Methane gas, carbon dioxide is released into the air.

4)    Dust: Dust is always present in the atmosphere in varying amount.

(b) Manmade sources:

1)    Deforestation.

2)    Burning of fossil fuels.

3)    Emission from vehicles.

4)    Rapid industrialization.

5)    Modern agricultural practices.

4. Explain about the strategies of sustainable development.       5

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5. Explain the importance of surface water and causes for its pollution. 5

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Or

Explain various sources of waste in urban and industrial sectors and how they can be properly managed.

Ans: Sources of Urban Waste

- Domestic wastes: It includes a variety of materials thrown out from homes.

- Food waste, Cloth, Waste paper, Glass bottles, Polythene bags, Waste metals, plastic containers, scrap, paints etc.

- Commercial wastes: It includes wastes coming out from shops, markets, hotels, offices, institutions, etc.

- Waste paper, packaging material, cans, bottle, polythene bags, etc.

- Construction wastes: It includes wastes of construction materials. • Wood, Concrete, Debris, etc.

- Horticulture waste and waste from slaughter houses include vegetable parts, residues and remains of slaughtered animals, respectively.

- Biomedical wastes: It includes mostly waste organic materials

- Anatomical wastes, Infectious wastes, glass bottles, plastic, metal syringe, etc.

- Mining waste: A large amount of solid waste is released from the mining activities. The increase in solid waste is due to overpopulation, affluence and technological advancement.

Sources of Industrial Waste

The main source of industrial wastes are chemical industries, metal and mineral processing industries.

- Nuclear plants: Generate radioactive wastes

- Thermal power plants: Produce solid waste in the form of fly ash 3

- Chemical Industries: Produce large quantities of hazardous and toxic materials.

- Other industries: Other industries produce packing materials, rubbish, organic wastes, acid, alkali, scrap metals, rubber, plastic, paper, glass, wood, oils, paints, dyes, etc.

Measures to Control Solid Waste

i) Sanitary Landfill: This is the most popular solid waste disposal method used today. Disposing of waste in a landfill involves burying the waste, in abandoned or unused places. In this method garbage is spread out in thin layers, compacted and covered with clay, sand or plastic liner. The liners protect the ground water from being contaminated. When the landfill is full, it is covered with layers of sand, clay, top soil and gravel to prevent seepage of water.

ii) Incineration: It is the hygienic way of disposing solid waste. It is a thermal process (controlled combustion) in which the waste material is converted to heat, gas, steam and ash, which can be used for electrical generation and domestic heating. It is suitable for hazardous, organic and medical wastes. Combustible substance should be separated and removed before incineration process. Wet municipal waste should be preheated before incineration process. It reduces the volume of waste up to 20 or 30% of the original volume.

iii) Composting: It is a popular method by which bulk organic matter is converted into fertilizer by biological action. Microorganisms like fungi, bacteria convert degradable organic waste into broken, odourless mass called humus, which is a good fertilizer. Separated compostable waste is dumped in underground trenches in layers of 1.5m and finally covered with soil of 20 cm and left for decomposition. Sometimes, actinomycetes are introduced for active decomposition. Biological action will start within two to three days. Good quality environmental friendly manure is formed from the compost and can be used for agricultural purpose.

iv) Vermi Composting: It has become very popular in the last few years. In vermi composting, earthworms are added to the compost. These help to break the waste and the added excreta of the worms makes the compost rich in nutrients. It is very useful biofertilizer and soil conditioner.

6. Discuss various methods to protect wildlife and their conservation.   5

Ans: Methods of Conservation of biodiversity

There are two main methods of conservation - in-situ and ex-situ conservation.

1. In-situ conservation:

In-situ conservation refers to the conservation of ecosystems and natural habitats in which species live. It involves the protection and preservation of natural ecosystems, such as forests, wetlands, grasslands, and marine habitats, in their original habitats. Some methods of in-situ conservation are:

a) Protected Areas: Protected areas such as national parks, wildlife sanctuaries, and biosphere reserves are established to conserve the natural habitats and biodiversity of a region.

b) Habitat restoration: Restoration of degraded ecosystems and habitats can help to conserve biodiversity.

c) Community-based conservation: Involving local communities in conservation activities can help to conserve biodiversity and promote sustainable use of natural resources.

d) Sustainable use of resources: Sustainable management and use of natural resources, such as forests, can help to conserve biodiversity.

2. Ex-situ conservation:

Ex-situ conservation refers to the conservation of biodiversity outside its natural habitats. It involves the conservation of species in areas such as zoos, botanical gardens, seed banks, and gene banks. Some methods of ex-situ conservation are:

a) Captive breeding: Captive breeding involves breeding endangered species in captivity to increase their population size.

b) Seed banks: Seed banks store seeds of endangered plant species for future use.

c) Gene banks: Gene banks store genetic material from endangered species for future use.

d) Botanical gardens: Botanical gardens conserve and propagate rare and endangered plant species.

Examples of in-situ and ex-situ conservation:

1. In-situ conservation examples:

a) Protected areas: Periyar National Park in Kerala, Keoladeo National Park in Rajasthan, Sunderbans National Park in West Bengal.

b) Habitat restoration: Restoration of mangrove ecosystems in Sundarbans.

c) Community-based conservation: Joint Forest Management (JFM) in Gujarat, Maharashtra, and Madhya Pradesh.

d) Sustainable use of resources: Forests managed by indigenous communities in the Northeastern states of India.

2. Ex-situ conservation examples:

a) Captive breeding: Breeding of Great Indian Bustard in the captive breeding center at Rajasthan.

b) Seed banks: National Bureau of Plant Genetic Resources (NBPGR) in New Delhi.

c) Gene banks: National Bureau of Fish Genetic Resources (NBFGR) in Lucknow.

d) Botanical gardens: Botanical Garden of Indian Republic (BGIR) in Noida.

Or

What are the ways to mitigate human-wildlife conflict?

Ans: As human populations continue to grow, there is an increasing likelihood of conflicts between humans and wildlife. As humans continue to encroach on wildlife habitats, the animals are often forced to come into human settlements, which can lead to conflicts. To protect biodiversity, it is essential to implement measures to address these threats, such as:

1. Conservation of natural habitats: Conserving natural habitats like forests, wetlands, and grasslands is essential to protect biodiversity. Protected areas like national parks and wildlife sanctuaries can also help in conserving biodiversity.

2. Law enforcement: Strict law enforcement and penalties for poaching and illegal wildlife trade can help reduce the threat to biodiversity.

3. Sustainable development practices: Sustainable development practices that prioritize the conservation of natural resources can help reduce habitat loss and pollution.

4. Education and awareness: Education and awareness programs can help people understand the importance of biodiversity and the threats facing it, leading to increased public support for conservation efforts.

5. Human-wildlife conflict management: Effective management of human-wildlife conflicts can help reduce the likelihood of conflicts and protect both humans and wildlife. This can include measures such as the creation of wildlife corridors, fencing, and relocation programs.

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