Environmental Studies PYQs

• The atmosphere is composed of a mix of several different gases in differing amounts.
• The permanent gases present in the atmosphere are nitrogen, oxygen, carbon dioxide, helium and argon.

Key Points

The atmospheric composition of gases by volume are as follow: 

Thus, oxygen and nitrogen gas makes up approximately 99% of the atmosphere.

Important PointsOzone:

• Ozone is a pale blue gas.
• It is a form of oxygen.
• Ozone is poisonous and explosive.
• It differs from common oxygen in its chemical makeup.
• Each ozone molecule has three oxygen atoms.
• The scientific formula for ozone is O3.
• Ozone is a natural part of Earth’s upper atmosphere.
• This part of the atmosphere, about 15 miles (24 kilometres) above the surface, is called the ozone layer in the stratosphere.

EVS is a subject that is concerned with the development of learners' awareness about environmental issues. It nurtures children's curiosity about the natural environment.

• The teaching of EVS helps students to develop desirable attitudes, values, and behavior patterns necessary for an environment-friendly lifestyle.
• Excursions are activities organized by the school where the students are taken out of the regular classrooms to experience knowledge in the context of real life. For example, a trip to museums, historical monuments, exhibitions, etc.

Key Points

• Educational excursions are powerful, positive teaching tools that help enhance the social, personal, and emotional development of all learners.
• The basic objective of educational excursions in EVS is to provide first-hand experience to the students by engaging them with real situations.
• It is the appropriate tool to engage children effectively in EVS learning due to the active participation of students in the learning process.
• It introduces such concepts, ideas, and hands-on experiences that can't be provided in a classroom environment.
• It provides opportunities to bridge the gap between the theoretical and practical aspects of learning.

Hence, it becomes clear that the basic objective of educational excursion in EVS is to provide first-hand experience to the students;

Key PointsDry Soil:

• Physiologically dry soil means that water is present within the soil but is not accessible to the plants.
• This is either because of higher salt concentration, or lack of water in a liquid state, or poor aeration.
• These conditions appropriately take place in saline marshes, cold deserts, and waterlogged soil.
• Physiologically dry soil possesses a much high concentration of salts.
• It is generally dead soil from lack of oxygen and higher salt content.
• The halophytes are plants of physically moist but found in physiologically dried habitats.
• Such plants are basically present near sea-shores where mesophytes and freshwater hydrophytes cannot thrive well.
• Although these plants grow within the areas which are well saturated with water yet they can't avail of the water due to the high concentration of salts within the soils.

Thus, the characteristic of physiologically dry soil is high salt concentration.

Continuous and Comprehensive Evaluation, commonly know as 'CCE' has been introduced as a school-based system of evaluation by the CBSE in 2009 with the enactment of the Right to Education Act.

• Continuous and Comprehensive Evaluation (CCE) aims to evaluate 'all aspects of the development of the child' as it ensures all-round development of students including cognitive, psychomotor, and affective domains.

Key Points Continuous and comprehensive evaluation is necessary as:

• it reduces stress and anxiety, which often builds up among young students during and after the examination.
• it reduces the dropout rate as there will be less fear and anxiety among learners related to their examination and school performance.
• in CCE, greater focus is given to learning rather than on conducting tests and examinations. It contributes to the holistic development of learners.
• CCE is used as an instrument of preparing learners for future life by making them physically fit, mentally alert, emotionally balanced, and socially adjusted.
• learners get more time to develop their interests, hobbies, and personalities through CCE. It promotes a learner-friendly environment, thereby optimizing student learning.

Hence, it could be concluded that continuous and comprehensive evaluation is necessary as no unnecessary fear of examination is seen among learner by continuous evaluation.

Key Points

Selective grazing:

• Selective grazing involves just what it says, selecting something and then grazing it.
• Selective grazing means that the animals often overgraze the good stuff (as they see it) and undergraze other plants.
• This leaves the least appealing plants to continue growing causing many weed problems in pastures.
• Overgrazing happens one plant at a time.
• Woody weeds take over many rangelands.
• Some animals revisit and regraze a plant, almost the moment a new leaf appears.
• Any animal which is unable to move because of fences, predators etc. is likely to overgraze an area.
• A selective grazer is any animal that is able to aim for and get a particular plant.
• Selective grazing changes the vegetation of the region allowing only weeds or a specific type of plants to grow.

Thus, grazing animals change vegetation by selective grazing.

Confusion Points

• Grazing animals only eat grasses and leaves and not the fruit of the plants.
• Animals that eat the fruits of the plants help in seed dispersal.
• Pollination is also done by small insects that look for nectar and not by grazing animals.

• Vitamins are the essential nutrients that the body needs to function, grow and develop.
• The term vitamin was coined by Casimir Funk.
• Vitamin is the nutrient that is also known as co-enzyme.
• As the body does not produce vitamins itself, it must be acquired through the food we eat or in some cases through supplements.
• There are 13 vitamins - A, C, D, E, K, and B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, B6, B12, and folate), each of them have a different job.
• Vitamin A, D, E, K are fat-Soluble vitamins and are stored in fat cells while Vitamin B and C are water-soluble vitamins that are not stored in your body.
• The liver acts as a storage site for Vitamin A, D, E, K, and B12 for the times when they may be lacking in the diet.

Key Points

Calcium: 

• Calcium forms an integral part of bones.
• Calcium deficiency occurs at any stage.
• It can result in rickets, osteoporosis, and osteopenia.
• It is important for bone health.

Vitamin D:

• It helps our body in absorbing calcium and phosphate from the intestines.
• We can get vitamin D from various food products such as milk, eggs and fish.
• Sunrays are the best source of Vitamin D.
• Vitamin D deficiency makes it difficult for our body to maintain sufficient levels of calcium and phosphate.
• Vitamin D acts as a hormone.
• They are produced by the kidneys it helps to control the concentration of calcium in the blood and is vital for the development of strong bones.

Thus, Calcium and Vitamin D is required for healthy bones.

Additional InformationVitamins and diseases caused by their deficiencies

• The Himalayas: These are geologically young and structurally fold mountains.
• They stretch over the northern borders of India.
• They represent the loftiest and one of the most rugged mountain barriers of the world.
• These mountain ranges run in a west-east direction from the river Indus to the Brahmaputra.
• They form an arc, which covers a distance of about 2,400 Km.
• Their width varies from 400 Km in Kashmir to 150 Km in Arunachal Pradesh.​

Key Points

Mt. Kanchenjunga:

• Kanchenjunga is the world’s third-highest mountain, with an elevation of 28,169 feet (8,586 meters).
• It is situated in the eastern Himalayas on the border between Sikkim state, northeastern India, and eastern Nepal, 46 miles (74 km) north-northwest of Darjeeling, Sikkim.
• The mountain is part of the Great Himalaya Range.
• The Kanchenjunga massif is in the form of a gigantic cross, the arms of which extend north, south, east, and west.
• Kanchenjunga is composed of rocks of Neoproterozoic (late Precambrian) to Ordovician age (i.e., about 445 million to 1 billion years old).
• The mountain and its glaciers receive heavy snow during the summer monsoon season and a lighter snowfall during the winter.
• The individual summits connect to neighbouring peaks by four main ridges, from which four glaciers flow, the Zemu (northeast), the Talung (southeast), the Yalung (southwest), and the Kanchenjunga (northwest).

Thus, Kanchanjunga Peak is the highest peak of the Himalayas in India.

Important Points

Mount Everest: 

• It is located on the border between Tibet and Nepal.
• It is the highest mountain in the world with an elevation of 8848 m.
• It is a peak in the Himalayan mountain range.

Mt. K2:

• K2 is also known as Mount Godwin Austen and locally it is known as Dapsang or Chogori is the world’s second-highest peak.
• K2 is located in the Karakoram Range.
• It was given the symbol K2 because it was the second peak measured in the Karakoram Range.
• It has an elevation of  8611 m.
• It lies in the region of Pakistan-administered Kashmir.

Dhaulagiri:

• Dhaulagiri peak is located in Nepal.
• It is the highest peak of the Dhaulagiri Himal or massif in Nepal.
• It is a sub-range of the Himalaya which rises between the Bheri River on the west and the Kali Gandaki River on the east.
• The word Dhaulagiri is derived from the Sanskrit dhawala Giri, which means “beautiful white mountain".
• It is also the 7^th Highest Mountain in the World.

Teaching methods are the essential tools that can help teachers to make the students achieve success in the classroom. There are a variety of teaching methods that can be used by the teacher for teaching theory and skills in the classroom setting. 

Play-way method of teaching:

• The play-way method is a complete package that enables the overall development of the child by developing in terms of feelings, intellect, and skills parameters.
• It is based upon Psychological principles of development and growth.
• It not only focuses on subjective development but the emotional development of the child as well.
• In this method, playing acts as the driving force as the entire learning method revolves around activity-based learning. It encourages expression and creative skills among children.

Key Points

Psychological principles of development and growth:

• There are three principles of growth and development: the cephalocaudal principle, the proximodistal principle, and the orthogenetic principle.
• These predictable patterns of growth and development allow us to predict how and when most children will develop certain characteristics.
• Growth represents the physical changes of an individual and development represents the overall changes, structure, and shape of an individual.
• Knowledge of the growth and development at various stages is very essential for the teacher.
• The teacher has to stimulate the growth and development of a child. He can do it only if he has proper knowledge of the growth and development at various stages.

Hence, At lower classes, the play-way method of teaching is based on psychological principles of development and growth because the growth (physical changes) and development (overall changes, structure, and shape) of an individual can take place while learning through play.

The atmosphere around the earth:

• The atmosphere consists of different layers with varying densities and temperatures.
• The column of the atmosphere is divided into five different layers depending upon the temperature condition.
• They are troposphere, stratosphere, mesosphere, thermosphere, and exosphere.

Key Points

Layers of atmosphere from bottom up: 

Thus, the troposphere is the lowest layer of the atmosphere.

• Vitamin means 'vital for life'.
• Vitamin is an organic non-protein substance.
• Vitamins are compounds necessary for the healthy functioning of our bodies.
• We need vitamins to help us grow, to see correctly, as well as to help us battle infections.
• It is required by an organism for normal metabolic function but cannot be synthesized in sufficient quantity by that organism.
• They are also required in small quantities to prevent deficiency diseases.​

Key Points

Vitamin C:

• Ascorbic acid is the chemical name of vitamin C.
• Vitamin C is the first artificially synthesized vitamin.
• Vitamin C is essential for the healing of wounds, repair, and maintenance of cartilage, bone, and teeth.
• Vitamin C deteriorated through cooking and canning of food.
• Sources: citrus fruit, such as lemons, oranges and orange juice, amla, peppers, strawberries, blackcurrants, broccoli, sprouted pulses and potatoes.
• Scurvy is caused by the deficiency of Vitamin C
• It is a nutritional disorder mostly characterized by rashes or red spots on the skin.
• Muscle pain, body pain, fatigue and bleeding gums or tooth loss are other common symptoms of scurvy.

Thus, the disease caused due to deficiency of Vitamin C is scurvy.

Additional Information

Key Points

Kiran Bedi:

• Kiran Bedi is a retired IPS Officer, Indian Politician, former tennis player, and social activist.
• Kiran Bedi was the 24^th Lieutenant Governor of Puducherry from 28^th May 2016 to 16^th February 2021.
• She was the first female Indian Police Service (IPS) officer and started her service in 1975.
• She also served as the Director-General of the Bureau of Police Research and Development (2005-2007) and Police Adviser and Director of United Nations Police (2003-2005).
• She got the Ramon Magsaysay award (1994), President's Police Medal (1979), United Nations Medal.

​Thus, Kiran Bedi is the first woman IPS officer in India.

Additional Information

Pratibha Devi Singh Patil: 

• She was the 12^th President of India from 2007 to 2012
• She was the first female President in India.
• She was also a Governor of Rajasthan from 2004 to 2007.
• She was also the first female Governor of Rajasthan.

Padmaja Naidu:

• Padmaja Naidu was the 5^th Governor of West Bengal.
• In 1956 she was appointed the Governor of West Bengal.
• At the age of 21, she co-founded the Indian National Congress in the Nizam ruled the princely state of Hyderabad.
• The Padmaja Naidu Himalayan Zoological Park in Darjeeling is named after her.

​Hansa Mehta:

• Hansa Jivraj Mehta was a reformist, social activist, educator, independence activist, feminist and writer from Baroda.

National Park:

• A national park is an area dedicated to the conservation of wildlife along with its environment.
• It is usually a small reserve covering an area of about 100 to 500 km2.
• Within biosphere reserves, one or more national parks may also exist.

Key Points

• ​Kaziranga National Park is located in Assam.
• Kaziranga National Park is one of India’s oldest reserve areas.
• It is located in Golaghat and Nagaon, in the Karbi Anglong district of Assam in northeast India.
• The park is administered by the forest department of the Assam State Government.
• Kaziranga national park is famous for being the world's largest habitat for the great one-horned rhinos.
• It was declared a World Heritage Site by UNESCO in 1985.

Thus, "Kaziranga" the famous Sanctuary of Assam is famous for one-horned rhinos.

Additional Information The following National parks are most famous in India:

• A rock is any naturally occurring solid mass or aggregate of one or more minerals or mineraloid matter.
• The earth's crust is composed of rocks.
• It is categorized by the minerals included its chemical composition and the way in which it is formed.
• The rock cycle is a basic concept of transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous.
• Each rock type is altered when it is forced out of its equilibrium conditions.

Key Points

Igneous Rocks:

• As igneous rocks form out of magma and lava from the interior of the earth, they are known as primary rocks.
• The igneous rocks, Ignis – in Latin means ‘Fire’ are formed when magma cools and solidifies.
• When magma in its upward movement cools and turns into a solid form it is called igneous rock.
• The process of cooling and solidification can happen in the earth’s crust or on the surface of the earth.
• Igneous rocks are classified based on texture.
• The texture depends upon the size and arrangement of grains or other physical conditions of the materials.
• If molten material is cooled slowly at great depths, mineral grains may be very large.
• Sudden cooling (at the surface) results in small and smooth grains.
• Intermediate conditions of cooling would result in intermediate sizes of grains making up igneous rocks.
• Granite, gabbro, pegmatite, basalt, volcanic breccia and tuff are some of the examples of igneous rocks.

Thus, Basalt is an example of igneous rock.

Additional Information

​Metamorphic Rocks: 

• ​The word metamorphic means ‘change of form’.
• These rocks form under the action of pressure, volume and temperature (PVT) change.
• Metamorphism occurs when rocks are forced down to lower levels by tectonic processes.
• Or when molten magma rising through the crust comes in contact with the crustal rocks.
• Or the underlying rocks are subjected to great amounts of pressure by overlying rocks.
• Metamorphism is a process by which already consolidated rocks undergo recrystallisation and reorganisation of materials within original rocks.
• Common metamorphic rocks include slate, schist, gneiss, and marble.

Sedimentary Rocks:

• ​The word ‘sedimentary’ is derived from the Latin word sedimentum, which means settling.
• Sedimentary rocks are called secondary rocks.
• They are often the result of the accumulation of small pieces broken off of pre-existing rocks.
• In many sedimentary rocks, the layers of deposits retain their characteristics even after deposition.
• Hence, we see a number of layers of varying thickness in sedimentary rocks like sandstone, shale etc.

The atmosphere around the earth:

• The atmosphere consists of different layers with varying densities and temperatures.
• The column of the atmosphere is divided into five different layers depending upon the temperature condition.
• They are troposphere, stratosphere, mesosphere, thermosphere, and exosphere.

Key Points

Layers of atmosphere from bottom up: 

Thus, the ozone layer is found in the earth's stratosphere layer.

The correct answer is Guru Nanak Dev.

Key Points

• Guru Nanak Dev Ji is considered as the founder of Sikhism.
• He was born on 15^th April 1469 in Rai Bhoi ki Talwandi, presently in Pakistan.
• He died at the age of 70 in Kartarpur, Pakistan.

Additional InformationGurus of Sikhism: 

Key Points 

Earthquake:

• An earthquake is a form of energy of wave motion transmitted through the surface layer of the earth.
• The instrument used for recording earthquakes is known as a seismograph.
• The network of seismographic stations all over the world records dozens of earthquakes every day.
• The point within the earth’s crust where an earthquake originates is called the focus.
• It is also referred to as seismic focus.
• It generally lies within a depth of 60 kilometers in the earth crust.
• The point vertically above the focus on the earth’s surface is known as the ‘epicenter’.
• These earthquake waves originating from the focus travel in all directions.
• But their intensity is the highest at the epicenter.
• That is why the maximum destruction occurs at and around the epicenter.
• The intensity of vibrations decreases as one moves away.

Thus, the instrument to record the intensity of the Earthquake is a seismograph.

Additional InformationBarograph:

• Barograph is a barometer that records the barometric pressure over time in graphical form used to make a continuous recording of atmospheric pressure.
• It was invented by Lucien Vidi in 1844.

Cardiograph:

• Cardiograph is an instrument that graphically registers the movements of the heart.

The correct answer is December 22.

Key Points

• December 22 marks the longest day in the southern hemisphere.
• On this day the tropic of Capricorn receives direct rays of the sun as the South Pole tilts towards it.
• A larger portion of the Southern hemisphere gets light as the sun rays fall vertically at the Tropic of Capricorn.
• This position of the earth is called the Winter Solstice.
• Due to this process, it is summer in the Southern Hemisphere with longer days and shorter nights.
• The reverse happens in the Northern Hemisphere with the shortest day and longest night.

Important Points 

• Direct rays of the sun fall on the equator on 21^st March and 23^rd September.
• This position of the earth is called equinox.
• June 21^st marks the shortest day and longest night in the southern hemisphere.
• June 21 marks the longest day and the shortest night in Northern Hemisphere.
• This position of the earth is called the Summer Solstice.

The correct answer is Dayanand Saraswati.

Key Points

• Dayanand Saraswati wrote the book “Satyartha Prakash”.
• Satyarth Bhumika, Rigvedadi Bhashya, Bhumika, Sanskarvidhi are also written by Dayanand Saraswati.
• ‘Back to Vedas’ was said by Dayanand Saraswati.
• Arya Samaj was started by Dayanand Saraswati in Bombay.
• He translated the Vedas and wrote three books named Satyartha Prakash, Veda Bhasya Bhumika, and Veda Bhasya.
• Dayananda Anglo Vedic (D.A.V) schools were established based on his philosophy and teachings.

Additional Information 

The correct answer is Assam.

Key Points

• Bihu dance is an Indigenous folk dance of the Indian state of Assam.
• This dance is usually performed by young men and women.
• The dancing style is characterized by brisk steps and rapid hard movements.
• In this folk dance, the traditional costumes of dancers are colourful and centred around the red colour theme.
• The earliest depiction of Bihu dance is found in the 9^th Century Sculptures.
• This dance is mainly found in the Tezpur and Darrang districts of Assam.
• It is mentioned in the inscriptions of the 14^th Century, Chutia and Laxminarayan as well.
• Bihu dance is performed outdoors, in fields, groves, etc.
• This folk dance takes its name from the Bohag Bihu festival.
• Bohag Bihu festival is celebrated as New year in Assam.

Additional Information

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.
• A simplified food web illustrating a three-trophic food chain (producers-herbivores-carnivores) linked to decomposers.

Key Points

Food Web: 

• A food web is similar to a food chain, but the food web is significantly larger.
• Occasionally, a single organism is eaten by a large number of predators, or it consumes a number of other species.
• As a result, several trophic levels become intertwined, and the food chain fails to accurately depict the flow of resources.
• The food chains are very simple and hence, do not exist in reality,
• Rather, an interconnection of many food chains is seen in nature or in our ecosystem that forms a food web.
• The energy flow is unidirectional.
• In a food web, one organism takes place at different trophic levels in different food chains (which combine to form a complex food web).
• It gives greater stability to the ecosystem.

​Thus, a group of interconnected food chains is called a food web.

Additional Information

Pyramid of Biomass:

• A biomass pyramid is a diagram that compares the biomass of different trophic levels within an ecosystem.
• It shows the mass of producers that are needed to support primary consumers, the mass of primary consumers required to support secondary consumers, and so on.