Environmental Studies PYQs

• Biodiversity is a term used to describe the enormous variety of life on Earth.
• Biodiversity refers to every living thing, including plants, bacteria, animals and humans.
• Scientists have estimated that there are around 8.7 million species of plants and animals in existence out of which only 1.2 million have been identified.

Key Points

Silent Valley:

• The Silent Valley, situated in the southern Western Ghats, is one of the world's ten "Hottest Biodiversity Hot Spots" and is believed to be the sole surviving bit of virgin tropical rain forests in India.
• It is located about 80 km northeast of Palakkad, Kerala.
• The 8952 sq km forest was declared a National park on 14 November 1984 and now forms part of the core of Nilgiris Biosphere Reserve.
• It is among the most biodiversity-rich forests.
• The topographical isolation facilitated by the surrounding steep ridges, hills and escarpments has helped the forests to develop into a rich biodiversity reserve untouched hitherto by humans.
• It has over 960 species of flora with 17 among them coming under the International Union for the Conservation of nation's (IUNC) Red List.
• Of the 315 species of fauna found here, the valley's flagship species is the lion-tailed macaque.

Thus, we can say that most biodiversity is found in Silent Valley.

Additional Information

• Valley of Flowers National park is an Indian National Park, located in Chamoli in the state of Uttarakhand and is known for its meadows of endemic alpine flowers and the variety of flora.

The correct answer is It is methane emitting.

Key Points

• Cooking gas is also called LPG (Liquified Petroleum Gas).
• Liquefied petroleum gas (LPG) is a colourless odourless liquid which readily evaporates into a gas.
• LPG (cooking gas) is a mixture of  Butane and propane.
• LPG (cooking gas) is a flammable mixture of hydrocarbon gases that include propane, butane, isobutene, and mixtures of the three LPG gases.
• On liquefaction, petroleum gas changes into a liquid which is called liquefied Petroleum Gas (LPG).
• The main constituent of LPG is butane though it contains smaller amounts of ethane and propane also.
• LPG (cooking gas) is stored in steel vessels ranging from small BBQ gas bottles to larger gas cylinders and tanks.
• When a valve provided in the cylinder is opened with the help of a regulator; due to a decrease in pressure, LPG changes into a vapour.
• This vapour flows to the burners through a rubber tubing attached to the regulator.
• They are commonly used for generating heat for the home.
• For example- heating, hot water, cooking including boilers, etc.

Important Points 

Characteristic of LPG:

• It is a clean fuel
• It has a high calorific value
• It burns with a blue flame
• It is composed of propane and butane.
• It is easily transported in a cylinder or tanks.
• It is a good substitute for petrol in spark-ignition engines.

Mistake Points

• Natural gas is composed of methane.
• LPG is not a natural gas so it can’t be methane emitting.

Concept:

Ecosystem: 

• All organisms such as plants, animals, microorganisms and human beings as well as the physical surroundings interact with each other and maintain a balance in nature.
• All the interacting organisms in an area together with the non-living constituents of the environment form an ecosystem.
• The term ecosystem was coined by Tansley.

Explanation:

Components of an ecosystem:

Biotic Components: 

• It includes producers, consumers and decomposers.
• All living things have a direct or indirect influence on other organisms in an environment.
• Example: plants, animals, humans, microorganisms etc.

Abiotic components: 

• All the inorganic components of the ecosystem, non-living physical and chemical composition of nature are abiotic components.
• Example: land, stones, water, humus (organic waste), air etc.

Thus, biotic and abiotic substances are components of the environment.

Additional Information

​Autotrophs:

• A food chain always starts with the producers as the primary source of food, by the process of photosynthesis.
• Autotrophs produce their own food like plants, trees, and some algae.
• They are also called Producers.

Heterotrophs:

• These are consumers i.e. animals, man, insects, etc.
• They are on the second level of nutrition.
• Heterotrophs can be of the following type:
• Primary consumer: 
• They are also sometimes referred to as herbivores because they mainly feed on plants i.e. the producers.
• They can also be omnivores (feeding on both plants and animals).
• Secondary consumer: 
• They can either be carnivores (feeding only on animals) or omnivores.
• They feed on the primary consumers.
• Tertiary consumer: 
• They feed on the secondary consumers.
• They occupy the topmost level of an ecosystem because they do not have any predators.

Decomposers:

• Decomposers form the largest population in the food chain.
• These are the organisms that feed on the dead and decaying matter and break down the complex compounds into simpler ones.
• These include bacteria, fungi, and several other microorganisms.
• The decomposers form an important part of the food chain.
• They break down the organic matter releasing carbon and other nutrients that are beneficial for their growth as well as the development of plants.

Key Points

• The Equator:
• It is an imaginary line on the surface of the Earth at the same distance from the North Pole and the South Pole.
• It divides the Earth into the Northern and Southern Hemispheres.
• On the northern side of this line are the Tropic of Cancer at 23½ ° and the Tropic of Capricorn at 23½ ° on the southern side.
• The equator passes through the land or waters of 14 countries.​

​

Additional Information

• The Tropic of Capricorn:
• It is an imaginary line drawn from the west to the east, at 23° 23 '22" parallel to the equator in the southern hemisphere.
• The area to the north of the Tropic of Capricorn and south of the Tropic of Cancer is called the "tropical region".​
• The Tropic of Cancer:
• It is a latitude line drawn from west to east at 23.5 degrees in the Northern Hemisphere, parallel to the equator on the globe.
• It is the northernmost latitude line of the Earth, on which the sun shines vertically in the afternoon.
• The Arctic Circle:
• The position of the Arctic Circle is 66° 33′46.6 ″ north of the equator.
• Its latitude depends on the axial tilt of the Earth

Explanation:

Tropic of Capricorn is 23.5°S above the equator in the Southern hemisphere of Earth where the sun is directly overhead at noon on December 21.

Diagram showing Other important lines:

Explanation:

Ecosystem: 

• All organisms such as plants, animals, microorganisms and human beings as well as the physical surroundings interact with each other and maintain a balance in nature.
• All the interacting organisms in an area together with the non-living constituents of the environment form an ecosystem.
• The term ecosystem was coined by Tansley.

Thus, Tansley coined the term ‘ecosystem’.

Key Points

Components of an ecosystem: 

Biotic Components: 

• It includes producers, consumers and decomposers.
• All living things have a direct or indirect influence on other organisms in an environment.
• Example: plants, animals, microorganisms etc.

Abiotic components: 

• All the inorganic components of the ecosystem, non-living physical and chemical composition of nature are abiotic components.
• Example: stones, water, humus (organic waste), air etc.

Important Points

• Haeckel gave the term ecology.
• Odum is known as the father of modern ecology.

Additional Information

Types of the ecosystem:

• A forest ecosystem is a natural unit that includes animals, plants and microorganisms and their interaction with the abiotic components of the environment. These are further classified as temperate and tropical.
• Grassland ecosystems can be found in steppes, savannas and prairies.
• Tundra ecosystems are treeless regions that are found in windy and cold climatic areas.
• The marine ecosystem is one of the largest aquatic ecosystems on the earth. They have a high salt content.
• Freshwater ecosystems are found in springs, lakes, rivers, ponds, etc.
• Desert ecosystems exist where there is low precipitation.

Key Points

• Water pollution is one of the most serious environmental problems.
• It occurs when water is contaminated by such substances as human and animal wastes, toxic industrial chemicals, agricultural residues, oil, and heat.
• One of the causes of water pollutions is groundwater contamination which poses a serious risk to human health.

Groundwater Contamination:

• It is caused by the introduction of chemicals to the ground all the way down into groundwater.
• Arsenic is a toxic element that has no apparent beneficial health effects for humans. Most waters in the world have natural arsenic concentrations of less than 0.01 mg/litre. It is introduced into soil and groundwater during weathering of rocks and minerals followed by subsequent leaching and runoff.
• Arsenic groundwater contamination has far-reaching consequences including its ingestion through the food chain. Arsenic poisoning leads to potentially fatal diseases like skin and internal cancers.

Hence, it can be concluded that in large parts of Eastern India, the groundwater is contaminated by Arsenic.

• Arsenic is a toxic chemical that contaminates groundwater.
• Arsenic contamination of groundwater has become a serious problem in 9 out of 20 districts of West Bengal.
• It causes skin cancer and other serious health issues.

The correct answer is the rain shadow effect.

Key Points

• A rain shadow effect is a patch of land that has been forced to become a desert because mountain ranges blocked all plant-growing, rainy weather.
• On one side of the mountain, wet weather systems drop rain and snow.
• On the other side of the mountain, the rain shadow side all the precipitation is blocked.
• In a rain shadow, it is warm and dry.
• It is a dry side of a mountain opposite to the wind, it is called the leeward side.
• A rain shadow forms when moist winds head towards a set of mountains and get forced upwards by them.
• This moist air often comes from the sea or from another large body of water.
• The Deccan of the Western Ghats in India receives less rainfall than the coasts.
• As the summer (wet) monsoons approach the West Coast of India, they rise up the Western Ghats and the air cools.
• By the time the winds make it over the Western Ghats, they have lost most of their moisture and very little falls on the Deccan plateau to the east of the Ghats.
• This reduced rainfall on the leeward side of the mountains is called a rain shadow effect.

Thus, we can say that Deccan of the Western Ghats is drier because of the rain shadow effect.

The wildlife protection act was enacted on 9 September 1972 by the parliament of India to protect the animal from being hunted and for the protection of all species of plants.

Other important Environment and biodiversity act Passed by the Indian government:

1. Biological diversity act 2002
2. Environment protection act 1986
3. Air(prevention and control of pollution) Act 1981.
4. Forest conservation act 1980
5. Water prevention and control of pollution Act 1974.

The correct answer is Solar constant.

Key Points

Solar constant:

• Solar constant is the total radiation energy received from the Sun per unit of time per unit of area on a theoretical surface perpendicular to the Sun's rays and at Earth's mean distance from the Sun.
• It is measured by satellites where atmospheric effects are absent.
• The value of the constant is approximately 1.366 kilowatts per square metre.
• Though called a constant, the solar constant is merely relatively constant.
• The relative constant does vary by 0.2% in a cycle that peaks once every eleven years.
• The first attempt at estimating the solar constant was made by Claude Pouillet in 1838 at 1.228 kW/m².

Thus, we can say that the solar constant is the quantity of solar radiation per unit area received at the outer limit of the atmosphere.

Additional Information

• Insolation is a measure of the solar energy that is incident on a specified area over a set period of time.
• It affects the temperature, the more the insolation, the higher the temperature.
• Heat budget is the perfect balance between incoming heat absorbed by Earth and outgoing heat escaping it in the form of radiation.
• If the balance is disturbed, then the earth would get progressively warmer or cooler with each passing year.
• Solar energy is the radiation from the Sun capable of producing heat, causing chemical reactions or generating electricity.
• It is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy including solar water heating, and solar architecture.

Key Points

Fundamental Duties:

• The idea of Fundamental Duties is inspired by the Constitution of Russia.
• These were incorporated in Part IV-A of the Constitution by the 42^nd Constitutional Amendment Act, 1976 on the recommendations of the Swaran Singh Committee.

Important Points

The Soviet Constitution (USSR, now Russia) gave the idea of:

• Fundamental duties of all the citizens
• The ideal of justice on social, economic and political basics in the Preamble of the constitution.

Thus, Fundamental Duties are adopted from the Constitution of USSR.

Additional Information

Another part of the constitution is adopted from:

 US: Ideas taken from the US are:

• Written Constitution
• Impeachment of the President
• Supreme Court.
• Provision of States
• Functions of President and Vice-President
• Removal of Supreme Court and High Court judges
• Fundamental Rights
• Judicial review
• Independence of Judiciary
• The preamble of the Constitution

Ireland: Ideas taken from Ireland are:

• Concept of Directive Principles of State Policy (Ireland had borrowed it from Spain)
• The nomination of members to Rajya Sabha by the President
• Method of election of President

USSR: Ideas taken from USSR are:

• Fundamental duties
• The ideal of justice (social, economic, and political) in the Preamble
• Five-Year Plans

Explanation:

Feeding relation in the natural surrounding:

Food chain: 

• A food chain shows the feeding relationship between different organisms in a particular environment and/or habitat.
• A food chain shows how energy is passed from the sun to producers, from producers to consumers, and from consumers to decomposes such as fungi.
• They also show how animals depend on other organisms for food.

Key Points

Tropic level: 

• Based on the source of their nutrition or food, organisms occupy a specific place in the food chain that is known as their trophic level.
• Producers belong to the first trophic level, herbivores (primary consumer) to the second and carnivores (secondary consumer) to the third. The important point to note is that the amount of energy decreases at successive trophic levels.

Important Points

• Primary producers are at first tropic level - They produce food on their own with the help of photosynthesis. Ex- plants, trees.
• Primary Consumers are the herbivores animals, whose nutrition is directly based on plant products. Ex- Cow, deer, grasshoppers, small insects etc.
• Secondary consumers are carnivorous animals Like- small birds, wolfs etc.
• Tertiary Consumers are also carnivorous but they feed on secondary consumers.

So, In a food chain of the grassland ecosystem, the top consumers are carnivores.

Additional Information

• Producers: Such species that producers their own food from nature. Eg plant, grass.
• Herbivores: Only consume green vegetables and plants they are totally dependent on the earth. Eg- goat, rabbit.
• Carnivorous: They mainly consume secondary consumers such as rabbits, got etc. Eg- lion, tiger.
• Omnivores: These consumers eat both plants and meats. Eg- beer, pig.
• Decomposer: An organism that breaks down dead materials or waste products through decomposition. Eg- bacteria, fungi.

The correct answer is Troposphere.

• Weather is the state of the atmosphere which refers to the day-to-day temperature and precipitation activity.
• For example, the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy.

Key Points

Troposphere: 

• It is the lowest layer of the atmosphere - in which we live.
• It contains most of our weather - clouds, rain, snow.
• The lowest part of the Troposphere is called the boundary layer and the topmost part is called the tropopause.

Additional Information

About Layers of the Atmosphere:

Stratosphere:

• This layer extends upwards from the tropopause to about 50 km.
• It contains much of the ozone in the atmosphere.
• The temperature in Stratosphere is highest over the summer pole and lowest over the winter pole.

Mesosphere:

• Above the stratosphere is the mesosphere. It extends upward to a height of about 85 km above our planet. Most meteors burn up in the mesosphere.
• The coldest temperature in the Earth's atmosphere, about -90 °C is found near the top of this layer.

Thermosphere: 

• This layer is found above Mesopause from 85 to 800 km.
• This the warmest layer of the atmosphere. Aurora and satellites occur in this layer.

Exosphere​:

• ​This is the outermost layer of the atmosphere.
• It contains mainly oxygen and hydrogen atoms they are so few that they rarely collide.
• They follow ballistic trajectories under the influence of gravity, and some of them escape directly into space.

Ionosphere​:

• The ionosphere is a very active part of the atmosphere, and it grows and shrinks depending on the energy it absorbs from the Sun.
• The name ionosphere comes from the fact that gases in these layers are excited by solar radiation to form ions, which have an electrical charge.
• It overlaps the mesosphere, thermosphere, and exosphere.

The correct answer is 11^th December, 2002

Key Points

• Convention on Biological Diversity (CBD) is the international legal instrument for "the conservation of biological diversity, the sustainable use of its components and the fair and equitable sharing of the benefits arising out of the utilization of genetic resources".
• Convention on Biological Diversity covers biodiversity at all levels: ecosystems, species and genetic resources and also covers biotechnology, including through the Cartagena Protocol on Biosafety.
• The Secretariat of the Convention on Biological Diversity is located in Montreal, Canada.
• To meet the obligations under the Convention on Biological Diversity (CBD), India enacted the Biodiversity Act 2002.

Additional Information 

• Biological Diversity Act 2002 was enacted in order to conserve biodiversity, manage its sustainable use, and enable fair and equitable sharing benefits arising out of the use of biological resources with the local communities.
• National Biodiversity Authority (NBA) has been formed under the act and is headquartered in Chennai.

The correct answer is Organic farming.

Key PointsOrganic farming:

• Organic farming is an agricultural system that uses ecologically based pest controls and biological fertilizers derived largely from animal and plant wastes and nitrogen-fixing cover crops.
• Modern Organic farming was developed as a response to the environmental harm caused by the use of chemical pesticides and synthetic fertilizers in conventional agriculture.
• Organic farming has numerous ecological benefits:
• It uses fewer pesticides as compared to conventional agriculture.
• It helps in reducing soil erosion.
• It decreases nitrate leaching into groundwater and surface water.
• It recycles animal waste back into the farm.
• Organic farming is more environmentally friendly than compared to conventional farming.

Thus, we can say that organic farming is an eco-friendly agricultural practice.

Additional Information

• Shifting cultivation is a system of cultivation that preserves soil fertility by plot rotation.
• In this, a plot of land is cleared and cultivated for a short period of time and then left abandoned to revert its natural vegetation while the cultivator moves on to another plot.
• High yielding variety seeds (HYV seeds) are seeds of better quality than normal quality seeds. These seeds are a better option in order to obtain surplus crops.
• Glasshouses are the structures covered with glass used for growing crops under Greenhouse farming.
• Greenhouse farming is the unique farm practice of growing crops within sheltered structures covered by a transparent, or partially transparent material.

Along with harming human health, air pollution can cause a variety of environmental effects that affect the overall environment, acid rain being one of them.

Key Points

Acid Rain:  

• Acid rain means the precipitation of acidic components such as oxides of Sulphur and Nitrogen.
• Sulfur dioxide and oxides of nitrogen get into the upper atmosphere by wind or air currents and get mixed with water.
• The SO2 and NOX react with water, oxygen and other chemicals to form sulfuric and nitric acids.
• Normal rain has a pH value of 5.6.
• It is slightly acidic due to the presence of carbon dioxide which gets dissolved into the water forming weak carbonic acid.
• However, acid rain usually has a pH between 4.2 and 4.4 because of the large number of acids.
• The major sources of sulphuric dioxide and oxides of nitrogen are the burning of fossil fuels, emission from vehicles, oil refineries, etc.

Thus, acid rain is concerned with the presence of sulphuric acid.

Additional Information 

​Controlling Acid rain:

• Reducing the amount of SO2 and NO2 being released into the atmosphere decreases the chances of acid rain.
• The main source of SO2 is coal fuel power plants in which SO2 emission can be reduced by new combustion techniques.
• Whereas the main source of NO2 in the atmosphere is through vehicular exhaust which can be controlled by using internal combustion engines.

The correct answer is the World Wildlife Fund. 

Key Points

• World Wildlife Fund is an international non-government organization established in 1961 and headquartered at Gland, Switzerland.
• It aims at Preservation and reduction of human impact on the environment.
• It is the world's largest conservative organization.
• Its Prime objective is to conserve the world's biological diversity, ensuring the use of renewable resources and promoting the reduction of pollution and wasteful consumption.
• Its logo is a giant panda named after Chi-Chi.

Important Points

• It publishes various reports like the living planet report.
• It is also responsible for the organization of earth hour.
• The living planet report is published biennially since 1998.

The correct answer is Uttarakhand.

Explanation:

• The Valley of Flowers is situated in the Chamoli-Pithoragarh districts of Uttarakhand.
• It is known for the large meadows of alpine flora.
• It is a low lying Himalayan valley and has an alpine temperate climate
• The climate is favourable for the growth of a number of ornamental flowers, hence the name.
• This region got known to the world as late as the 1930s by the British.
• It is also home to a large number of wild animals such as Asiatic black bear, red fox etc
• It has been declared as a world heritage site by UNESCO.
• This region has a great degree of endemism and a large number of species are threatened due to ongoing human activities.

Additional Information

• Chamoli lies in an earthquake-prone zone in the Himalayan belt.
• Chief Minsiter of Uttrakahand: Pushkar Singh Dhami
• Governor: Gurmit Singh

Key Points

• The Central Pollution Control Board (CPCB) is a statutory organization constituted in September 1974 under the Water Prevention and Control of Pollution Act, 1974.
• Further, CPCB was entrusted with the powers and functions under the Air Prevention and Control of Pollution Act, 1981.
• The Central Pollution Control Board is led by its chairman; this chairman is appointed by the Central Government.
• This entire board comes under Central Government.
• According to Section-3, the Central Pollution Control Board can have a maximum of five officials nominated by the Central Government and not more than five persons nominated by the Central Government from amongst the members of State Boards.
• The Central Pollution Control Board is the apex organization in the country in the field of pollution control.
• It is a technical wing of the Ministry of Environment and Forest. It comes under the Government of India.
• It is a government organisation that comes under the Ministry of Environment, Forest and Climate change. It promotes the cleanliness of streams and wells to control water pollution.
• Prakash Javadekar is the current union minister of Environmental, Forest and Climate change.

Thus, Central Pollution Control Board is primarily concerned with the measurement of pollution in India.

Additional Information

• A volcano is an opening in the earth's crust.
• Through it gasses, molten rocks material. ash. stream, etc are emitted outward in the course of an eruption.

​​Volcanoes are also classified as:

• Active volcanoes: An active volcano is a volcano that has had at least one eruption during the past 10,000 years.
• Dormant volcanoes: A dormant volcano is an active volcano that is not erupting but is supposed to erupt again.
• Extinct volcanoes: An extinct volcano has not had an eruption for at least 10,000 years and is not expected to erupt again in a comparable time scale in the future.

Important Points

• Cotopaxi volcano is situated in the Andes Mountains.
• It erupted from August 2015 to January 2016.
• It is the world's largest Mountain range running along with South America and passes through Colombia, Ecuador, Peru, Bolivia, Argentina and Chile.

Thus, ‘Cotopaxi’ is an active volcano situated in Andes.

Additional Information

Other most active volcanoes in India:

Key PointsTsangpo:

• The Brahmaputra River is one of the last largely free-flowing rivers emanating from the Tibetan Plateau.
• Brahmaputra river originated from the Chemayungdung glacier of the Kailash range near the Mansarovar lake.
• Yarlung Zangbo is the Tibetan name for the upper course of Brahmaputra.
• The Yarlung Zangbo also called Yarlung Tsangpo.
• The Yarlung Tsangpo is the deepest canyon created by the Brahmaputra in Tibet.
• In Tibet, Brahmaputra is known by the name Tsangpo.
• In Bangladesh, Brahmaputra is known by the name Jamuna.
• Major tributaries of Brahmaputra are the Subansiri, Kameng, Manas, Lohit, Tista, and Sankosh.
• The river Brahmaputra empties into the Bay of Bengal.
• The Brahmaputra is also known as the 'red river'.
• The tributaries of the Brahmaputra river are Teesta River, Lohit, Danba Qu, Subansiri River.​

​Thus, the Tsangpo river of Tibet, in India, is known as the Brahmaputra.

Additional Information

Other major rivers in India: