Keywords To Remember
- Lithosphere
The outermost solid layer of the Earth, consisting of rocks and landforms, including continents and ocean floors. - Hydrosphere
All the water on Earth’s surface, including oceans, seas, rivers, lakes, glaciers, and underground water. - Atmosphere
The layer of gases surrounding the Earth, composed mainly of nitrogen and oxygen, essential for life and weather. - Biosphere
The narrow zone where life exists on Earth, including land, water, and air, where plants, animals, and microorganisms live and interact. - Continent
A large continuous expanse of land above sea level; Earth has seven continents. - Plateau
An elevated flat land with rugged surface, higher than surrounding areas, often rich in minerals. - Mountain
A natural elevation of the earth’s surface with steep slopes, often arranged in ranges and having peaks. - Plain
A large flat or gently rolling area of land, usually low in elevation and fertile. - Relief
The variation in elevation and slope in a particular area of land. - Sea Level
The average level of the ocean’s surface, used as a base to measure the height of landforms. - Isthmus
A narrow strip of land connecting two larger land areas, with water on both sides. - Equator
An imaginary line around the middle of the Earth, dividing it into Northern and Southern Hemispheres. - Tropic of Cancer
An imaginary line of latitude approximately 23.5° north of the equator, marking the northernmost point where the sun can be directly overhead. - Tropic of Capricorn
An imaginary line of latitude approximately 23.5° south of the equator, marking the southernmost point where the sun can be directly overhead. - Arctic Circle
A parallel of latitude located at approximately 66.5° north of the equator, marking the southern boundary of the polar day/night phenomenon in the Arctic. - Antarctic Circle
A parallel of latitude at approximately 66.5° south of the equator, marking the northern boundary of the polar day/night phenomenon in the Antarctic. - Oceans
The largest bodies of saltwater that cover about 71% of Earth’s surface. The five major oceans are the Pacific, Atlantic, Indian, Arctic, and Southern. - Ocean Depth
The vertical distance from the ocean surface to the ocean floor; varies from shallow continental shelves to deep ocean trenches. - Minerals
Natural substances found in the earth’s crust used for economic purposes like iron, gold, coal, etc. - Erosion
The process by which natural forces like wind or water remove soil, rock, or dissolved material from one location on the Earth’s surface. - Flood
An overflow of water that submerges land, often caused by heavy rainfall or river overflow. - Pollution
The introduction of harmful substances or products into the environment, causing adverse effects on air, water, or soil quality. - Ultraviolet Radiation
A form of energy from the sun that can cause damage to living organisms; largely blocked by the ozone layer. - Ozone Layer
A layer in the Earth’s stratosphere (15-30 km above surface) that absorbs most of the sun’s harmful ultraviolet radiation. - Mean Sea Level
The average level of the ocean’s surface between high and low tide, used as a reference point for measuring elevation and depth. - Trans-Siberian Railway
The longest railway line in the world, located in Asia. - Great Wall of China
The longest wall ever built, located in Asia. - Aravalli Range
An example of old mountains located in India. - Himalayas
The highest young mountain range in the world, located in Asia. - Mount Everest
The highest peak in the world, located in the Himalayas, with a height of 8850 metres. - Tibetan Plateau
Also called the “Roof of the World,” it is the highest plateau in the world. - Biosphere Interaction
The interdependence between plants, animals, and microorganisms with their physical environment. - Suez Canal
A man-made waterway in Egypt connecting the Mediterranean Sea to the Red Sea. - Panama Canal
A man-made waterway in Central America linking the Pacific Ocean and Atlantic Ocean. - Research Base
A permanent station established in Antarctica for scientific research. - Islands
Land masses smaller than continents, surrounded by water. - Polar Regions
Areas around the Earth’s poles characterized by extreme cold and ice cover. - Monsoon
Seasonal wind pattern bringing heavy rains, important for climate especially in Asia. - Latitude
Imaginary lines running east-west on the globe used to measure distance north or south of the equator. - Longitude
Imaginary lines running north-south on the globe used to measure distance east or west of the Prime Meridian.
Something To Know
A. Tick (✔ ) the correct option.
- Which one of the following is an old mountain?
(a) The Himalayas
(b) The Aravalli Range
(c) The Andes
(d) The Alps
Answer – (b) The Aravalli Range
- How much surface of the earth is covered by oceans?
(a) 29%
(b) 71%
(c) 60%
(d) 80%
Answer – (b) 71%
- The largest ocean of the world is-
(a) Indian Ocean
(b) Pacific Ocean
(c) Arctic Ocean
(d) Atlantic Ocean
Answer – (b) Pacific Ocean
- Which continent is the most advanced and economically developed continent?
(a) Asia
(b) North America
(c) Australia
(d)Europe
Answer – (d)Europe
- Which one of the following gases has the largest volume in the atmosphere?
(a) Nitrogen
(b) Oxygen
(c) Ozone
(d) Carbon Dioxide
Answer – (a) Nitrogen
B. Fill in the blanks.
- __________ is a narrow belt or zone of the earth where all forms of life exist.
Answer – Biosphere
- An envelope of the air surrounding the earth is called__________ .
Answer – atmosphere
- __________ is the upper surface of the earth consisting of rocks.
Answer – Lithosphere
- A highly elevated land from the surroundings with very steep slopes is known as __________ .
Answer – mountain
- An upland with rugged surface is called __________ .
Answer – plateau
C. Match the following:
- It separates Europe and Asia a. Asia
- It joins North America with South America b. Oxygen
- The largest continent of the world c. Isthmus of Panama
- It helps in burning d. Antarctica
- Continent in the Southern Hemisphere e. Ural mountain and Ural river
Answer –
- It separates Europe and Asia – e. Ural mountain and Ural river
- It joins North America with South America – c. Isthmus of Panama
- The largest continent of the world – a. Asia
- It helps in burning – b. Oxygen
- Continent in the Southern Hemisphere – d. Antarctica
D. Answer the following questions in brief.
- Name the four realms of the earth.
Answer – Lithosphere (land), Hydrosphere (water), Atmosphere (air), Biosphere (life).
- Which four gases constitute only one per cent of the total volume of the atmosphere?
Answer – Carbon dioxide, Ozone, Argon, and other trace gases.
- Which continent Is not inhabited by the people and why?
Answer – Antarctica, because it is covered with thick ice and has extremely cold conditions unsuitable for human habitation.
- Why Is earth known as a ‘unique planet’?
Answer – Because it consists of land, air, water, and life all interacting uniquely to support diverse ecosystems.
- Name three major landforms on the land surface,
Answer – Mountains, Plateaus, and Plains.
E. Answer the following questions.
- What are plains? Explain briefly the formation of plains.
Answer – Plains are large flat or gently rolling areas of land with low elevation. They are mostly formed by the deposition of sediments carried by rivers from mountains.
- Give a brief account of the plateaus of the world.
Answer – Plateaus are elevated flat lands with rugged surfaces, often rich in minerals. Examples include the Tibetan Plateau (the highest), Deccan Plateau in India, Arabian Plateau, and Brazil Plateau.
- Name the two main gases of the atmosphere. Write the significance of each.
Answer – Nitrogen (78%) which is essential for plant growth and forming proteins; Oxygen (21%) is necessary for respiration and combustion.
- What is meant by hydrosphere? Briefly explain the importance of hydrosphere.
Answer – Hydrosphere is all the water on Earth’s surface including oceans, lakes, rivers, and ice. It regulates climate, supports aquatic life, and is vital for human activities.
- How are human activities responsible for causing ecological imbalance?
Answer – Human activities like deforestation, pollution, urbanization, and overexploitation of resources disturb natural habitats, causing soil erosion, floods, and loss of biodiversity.
Value Based Question
House sparrow is gradually vanishing from urban scenario. Our urban lifestyle is responsible for it. Electromagnetic radiation from the mobile towers, shortage of nesting spaces, shortage of insect food, decline of native plants, changes in the architectural designs of buildings, unleaded petrol and use of insecticides are some of the reasons for vanishing of the bird.
Human beings are a part of the ecosystem. They do not have a right to disturb the ecological balance. We all have to take intiative to save sparrows by enhancing awareness about their life and habitat.
- Why some people have become so insensitive towards other species?
Answer – Due to lack of awareness, urbanization, and prioritizing human needs over nature, many people ignore the needs of other species.
- Like the house sparrow, which other birds or animals living around us in the residential areas are on the verge of extinction?
Answer – Pigeons, bees, butterflies, and certain local bird species are also declining.
- Suggest any three effective measures to protect the endangered species.
Answer – (i) Protect and restore natural habitats, (ii) Reduce pollution and use eco-friendly products, (iii) Raise awareness and involve communities in conservation efforts.
Map Skill
Shade and label different continents as well as major oceans on an outline map of the world.
Answer – Continents: Asia, Africa, Europe, North America, South America, Australia, Antarctica.
Oceans: Pacific, Atlantic, Indian, Arctic, Southern.
Something To Do
- Draw a diagram of the biosphere showing its diversity.
Answer – Students will do this at their own.
- Prepare a chart depicting different landforms on the earth and label them.
Answer – Prepare a chart depicting different landforms on the earth and label them (mountains, plateaus, plains).
- Prepare a chart showing interdependence of plants, animals and micro-organisms.
Answer – Prepare a chart showing interdependence of plants, animals and micro-organisms.
Additional Questions And Answers – 01
Fill in the Blanks (with Answers)
- The Earth’s outermost layer of rocks is called the __________.
Answer: Lithosphere - The __________ is the vast layer of air surrounding the earth.
Answer: Atmosphere - The __________ is known as the ‘Roof of the World.’
Answer: Tibetan Plateau - The longest mountain range in the world is the __________.
Answer: Andes - The __________ Ocean is the smallest of the five oceans.
Answer: Arctic - The __________ is the narrow strip of land joining North America and South America.
Answer: Isthmus of Panama - The __________ gas makes up about 21% of the atmosphere.
Answer: Oxygen - __________ is the zone where the lithosphere, atmosphere, and hydrosphere interact and support life.
Answer: Biosphere - Mount Everest is located in the __________ mountain range.
Answer: Himalayas - The average depth of the Pacific Ocean is about __________ metres.
Answer: 7300
Multiple Choice Questions (MCQs) with Answers
- Which continent is called the ‘Island Continent’?
(a) Africa
(b) Australia
(c) Antarctica
(d) Europe
Answer: (b) Australia - What percentage of the Earth’s crust is covered by continents?
(a) 29%
(b) 50%
(c) 71%
(d) 85%
Answer: (a) 29% - Which continent has the largest land area?
(a) Africa
(b) Asia
(c) North America
(d) Europe
Answer: (b) Asia - The Great Wall of China is located in which continent?
(a) Europe
(b) Africa
(c) Asia
(d) South America
Answer: (c) Asia - The Arctic Ocean is mostly __________ for most parts of the year.
(a) Frozen
(b) Warm
(c) Dry
(d) Salty
Answer: (a) Frozen - The process by which rivers deposit silt to form plains is called:
(a) Erosion
(b) Deposition
(c) Volcanism
(d) Sedimentation
Answer: (b) Deposition - The Suez Canal connects which two bodies of water?
(a) Red Sea and Mediterranean Sea
(b) Atlantic and Pacific Oceans
(c) Indian Ocean and Atlantic Ocean
(d) Arctic Ocean and Pacific Ocean
Answer: (a) Red Sea and Mediterranean Sea
True or False (with Answers)
- The Himalayas are considered old mountains.
Answer: False - The biosphere includes all living organisms and their interaction with land, air, and water.
Answer: True - The Indian Ocean is the largest ocean in the world.
Answer: False - The Deccan Plateau is located in Europe.
Answer: False - Nitrogen makes up the majority of gases in the atmosphere.
Answer: True - Antarctica has a very thick ice sheet covering almost all of its surface.
Answer: True - The Arctic Ocean is located around the South Pole.
Answer: False
Short Questions and Answers
- What is lithosphere?
Answer: Lithosphere is the Earth’s outermost layer made of rock, including continents and ocean floors. - Name the seven continents of the world.
Answer: Asia, Africa, Europe, North America, South America, Australia, Antarctica. - What is a plateau?
Answer: A plateau is a flat elevated land with rugged surface and steep slopes. - Why is the Earth called a ‘Watery Planet’?
Answer: Because about 71% of its surface is covered by water. - What role does the atmosphere play?
Answer: It provides gases essential for life and protects Earth from harmful solar radiation. - Define biosphere.
Answer: Biosphere is the zone on Earth where life exists, including land, water, and air. - What is the average height of the Earth’s landmass?
Answer: About 700 meters above sea level. - Name the highest peak in the world.
Answer: Mount Everest.
Competency-Based Reasoning and Assertion Questions
- Assertion: The Himalayas have sharp peaks covered with snow.
Reason: They were formed recently in geological terms.
Answer: Both assertion and reason are correct, and reason explains assertion. - Assertion: The Arctic Ocean remains frozen for much of the year.
Reason: It lies within the Arctic Circle.
Answer: Both assertion and reason are true, and reason correctly explains assertion. - Assertion: The biosphere is limited to a narrow zone on Earth.
Reason: Life can only exist where land, air, and water interact.
Answer: Both assertion and reason are correct, and reason explains assertion. - Assertion: Plateaus are major sources of mineral wealth.
Reason: They have rugged surfaces and rich deposits of minerals.
Answer: Both assertion and reason are true, and reason explains assertion. - Assertion: Oceans cover more than half of Earth’s surface.
Reason: Water is the most abundant natural resource on Earth.
Answer: Both assertion and reason are correct, and reason explains assertion.
High Order Thinking Skill (HOTS) Questions and Answers
- How does the variation in height and slopes of the Earth’s surface affect human settlement?
Answer: Higher elevations and rough slopes make construction and agriculture difficult, leading humans to settle in plains and plateaus with gentler slopes. - Why is the biosphere limited to about 9 km above the surface and 11 km below ocean surface?
Answer: Because life requires specific conditions like temperature, pressure, and oxygen levels, which exist only in this narrow range. - Explain the significance of the ocean currents in regulating climate.
Answer: Ocean currents distribute heat from the equator to poles, regulating temperatures and weather patterns across the globe. - How can human activities disrupt the balance in the biosphere?
Answer: Deforestation, pollution, and urbanization destroy habitats, reduce biodiversity, and cause soil erosion, affecting ecological balance. - Discuss why mountain ranges often run in lines or ranges instead of isolated peaks.
Answer: Mountain ranges form from tectonic plate collisions causing long belts of uplifted land, creating chains rather than isolated mountains.
Long Questions and Answers (40-50 words)
- What is the atmosphere, and why is it important for life on Earth?
Answer: The atmosphere is a layer of gases surrounding the Earth. It contains oxygen and nitrogen essential for breathing and protects living beings from harmful ultraviolet rays, maintaining the planet’s climate and weather. - Describe the significance of the hydrosphere to life on Earth.
Answer: The hydrosphere includes all water on Earth—oceans, lakes, rivers, and ice. It supports aquatic life, influences weather and climate, and provides water vital for drinking, agriculture, and industry. - Explain the differences between old and young mountains with examples.
Answer: Old mountains like the Aravalli are worn down and have gentle slopes. Young mountains like the Himalayas are tall with sharp peaks, formed recently through tectonic activity and often covered with snow. - What are the major features of a plateau, and why are they important?
Answer: Plateaus are elevated flat lands with rugged surfaces and steep edges. They often store minerals like iron and gold, support agriculture due to fertile soils, and are important for human settlement. - How do rivers contribute to the formation of plains?
Answer: Rivers carry sediments from mountains and deposit them in low-lying areas over time, creating flat and fertile plains ideal for agriculture and human settlement.
Additional Questions And Answers – 02
Fill in the Blanks Questions and Answers
- The realm of land is called the __________.
Answer: Lithosphere - The largest continent is __________.
Answer: Asia - The __________ Ocean is the largest ocean on Earth.
Answer: Pacific - The __________ is a narrow strip of land connecting two larger landmasses.
Answer: Isthmus - The highest peak in the world is Mount __________.
Answer: Everest - The __________ Plateau is known as the Roof of the World.
Answer: Tibet - The realm of water is called the __________.
Answer: Hydrosphere - The __________ layer protects Earth from harmful ultraviolet radiation.
Answer: Ozone - The __________ Ocean surrounds Antarctica.
Answer: Southern - The Northern Plains of India were formed by the __________ River system.
Answer: Ganga - The __________ is the second-largest continent.
Answer: Africa - The __________ Canal connects the Pacific and Atlantic Oceans.
Answer: Panama - The __________ is the realm of life where plants and animals interact.
Answer: Biosphere - The __________ Mountains are an example of old mountains in India.
Answer: Aravalli - The __________ gas constitutes 78% of the atmosphere.
Answer: Nitrogen
Multiple Choice Questions (MCQs) and Answers
- What is the realm of land called?
a) Hydrosphere
b) Atmosphere
c) Lithosphere
d) Biosphere
Answer: c) Lithosphere - Which continent is the largest?
a) Africa
b) Asia
c) Australia
d) Europe
Answer: b) Asia - Which ocean is the largest part of Earth’s surface?
a) Indian
b) Atlantic
c) Pacific
d) Arctic
Answer: c) Pacific - What is the highest plateau in the world?
a) Deccan Plateau
b) Tibet Plateau
c) Arabian Plateau
d) Brazil Plateau
Answer: b) Tibet - Which gas forms 21% of the atmosphere?
a) Nitrogen
b) Oxygen
c) Carbon Dioxide
d) Argon
Answer: b) Oxygen - Which continent lies entirely in the Southern Hemisphere?
a) Africa
b) South America
c) Australia
d) Asia
Answer: c) Australia - What connects North and South America?
a) Suez Isthmus
b) Panama Isthmus
c) Bering Strait
d) Gibraltar Strait
Answer: b) Panama - Which mountain range is an example of young mountains?
a) Aravalli
b) Ural
c) Himalayas
d) Appalachians
Answer: c) Himalayas - Which continent is known as the hottest?
a) Asia
b) Africa
c) Australia
d) South America
Answer: b) Africa - Where is the biosphere located?
a) Deep ocean floors
b) Upper atmosphere
c) Zone where land, water, and air interact
d) Polar ice caps
Answer: c) Zone where land, water, and air interact
True/False Questions and Answers
- The lithosphere includes both continents and ocean floors.
Answer: True - Asia is the smallest continent.
Answer: False (It is the largest.) - The Pacific Ocean is the deepest ocean.
Answer: True - The ozone layer is found in the troposphere.
Answer: False (It is in the stratosphere.) - Plains are densely populated due to fertile soil.
Answer: True - Antarctica is inhabited by large human populations.
Answer: False (It is uninhabited by permanent residents.) - The Equator passes through Europe.
Answer: False (It passes through Africa, Asia, and South America.) - Plateaus cover about 40% of Earth’s land surface.
Answer: True - The Arctic Ocean remains frozen for most of the year.
Answer: True - The biosphere exists only on land.
Answer: False (It includes land, water, and air.)
Short Questions and Answers
- What is the lithosphere?
Answer: The lithosphere is the Earth’s upper surface, a thin layer of rock forming continents and ocean floors. - Name the largest continent.
Answer: Asia - What is the hydrosphere?
Answer: The hydrosphere is the realm of water on, below, and above Earth’s surface, including oceans, lakes, and rivers. - What is a mountain range?
Answer: A mountain range is a series of mountains arranged in a line with peaks and valleys. - What is the biosphere?
Answer: The biosphere is the narrow zone near Earth’s surface where plants, animals, and microorganisms interact with land, water, and air. - Name one young mountain range.
Answer: Himalayas - What is the largest ocean?
Answer: Pacific Ocean - Why are plains densely populated?
Answer: Plains have fertile soil, abundant water, and ideal climates, making them suitable for agriculture and settlement. - What is the atmosphere composed of?
Answer: The atmosphere contains gases like nitrogen (78%), oxygen (21%), carbon dioxide, and others. - What is an isthmus?
Answer: An isthmus is a narrow strip of land connecting two larger landmasses, surrounded by water on both sides.
Competency-Based Questions and Answers (Reasoning and Assertion)
- Assertion: The lithosphere includes both continents and ocean floors.
Reason: It is the Earth’s upper rocky layer found above and below sea level.
Answer: Both assertion and reason are true, and the reason explains the assertion. - Assertion: Plains are ideal for human settlement.
Reason: They have fertile soil and gentle slopes formed by river deposits.
Answer: Both assertion and reason are true, and the reason explains the assertion. - Assertion: The Pacific Ocean is the largest and deepest ocean.
Reason: It covers one-third of Earth’s surface with an average depth of 7300 meters.
Answer: Both assertion and reason are true, and the reason explains the assertion. - Assertion: The biosphere is a narrow zone of life.
Reason: It exists where land, water, and air interact, supporting plants and animals.
Answer: Both assertion and reason are true, and the reason explains the assertion. - Assertion: Antarctica has no permanent human inhabitants.
Reason: Its thick ice cover and extreme cold make it unsuitable for human settlement.
Answer: Both assertion and reason are true, and the reason explains the assertion.
High Order Thinking Skill (HOTS) Questions and Answers
- Why are plains more densely populated than mountains?
Answer: Plains have fertile soil, gentle slopes, and abundant water from rivers, ideal for agriculture and settlement. Mountains, with steep slopes and harsh climates, pose challenges for farming and infrastructure, limiting population density compared to plains. - How does the atmosphere support life on Earth?
Answer: The atmosphere provides oxygen for respiration, nitrogen for plant growth, and regulates temperature through gases like carbon dioxide. The ozone layer shields life from harmful UV rays, while air density supports weather patterns essential for ecosystems. - Why is the hydrosphere critical for Earth’s ecosystems?
Answer: The hydrosphere, covering 71% of Earth, supplies water for drinking, agriculture, and habitats. Oceans regulate climate, support marine life, and cycle nutrients, while rivers and lakes sustain terrestrial ecosystems, making water essential for all life forms. - How do human activities disrupt the biosphere’s balance?
Answer: Deforestation, urbanization, and industrialization destroy habitats, reduce biodiversity, and pollute air and water. Overexploitation of resources like forests and minerals disrupts ecosystems, causing soil erosion, floods, and climate change, threatening the interdependent balance of plants and animals. - Why is the Tibet Plateau called the Roof of the World?
Answer: The Tibet Plateau, with an average height of 5000 meters, is the highest plateau globally. Its elevated, rugged terrain and vast expanse above surrounding regions earn it the title “Roof of the World,” distinguishing it from other plateaus.
Long Questions and Answers (40-50 Words)
- Explain the lithosphere and its components.
Answer: The lithosphere is Earth’s upper rocky layer, including continents (29% of the crust) and ocean floors. It features landforms like mountains, plateaus, and plains, varying in height from 8000 meters above to depths below sea level, shaped by natural forces. - Describe the major features of the Pacific Ocean.
Answer: The Pacific Ocean, the largest and deepest, covers one-third of Earth’s surface with an average depth of 7300 meters. Surrounded by Asia, Australia, and the Americas, it supports diverse marine life and influences global climate patterns significantly. - How are plains formed and why are they important?
Answer: Plains are formed by rivers depositing silt and sediments from mountains in low-lying areas. Their fertile soil, gentle slopes, and water availability make them ideal for agriculture and dense human settlements, supporting economies and civilizations globally. - What is the biosphere, and why is it unique?
Answer: The biosphere is the narrow zone where land, water, and air interact, supporting plants, animals, and microorganisms. Its uniqueness lies in the interdependence of life forms with non-living elements like sunlight, sustaining diverse ecosystems across Earth’s surface. - Discuss the impact of human activities on the environment.
Answer: Human activities like deforestation, urbanization, and pollution disrupt ecosystems, causing soil erosion, floods, and biodiversity loss. Overexploitation of resources and air-water pollution exceed sustainable limits, creating environmental imbalances that threaten life and require urgent conservation efforts.