Very Short Answer Questions

Q1. Define: (a) Endogenic Forces (b) Exogenic Forces (c) Lithospheric Plates
Ans 1:
(a) Endogenic Forces: Forces which are working in the interior of the earth leading to earth movements, earthquakes and volcanic eruption are known as endogenic forces.
(b) Exogenic Forces: Forces which are working on the surface of the earth leading to the erosional and depotional features of wind, water and ice are known as exogenic forces.
(c) Lithospheric Plates: The crust of the earth is broken into a number of large and small plates known as the lithospheric plates.

Q2. What is volcano? What are its types?
Ans 2: Natural openings in the earth's crust through which molten materials, rocks, ashes, gases, etc are thrown out are called 'Volcanoes'. Volcanoes are classified into three types:
(a) Active Volcanoes: These volcanoes erupt frequently and give out gases, ash, lava, etc. e.g. Mt. Etna in Italy.
(b) Dormant Volcanoes: These are also known as 'Sleeping Volcanoes'. They erupt after a very long time. E.g. Mt. Vesuvius in Italy.
(c) Extinct Volcanoes: These are also known as 'Dead Volcanoes'. They have been inactive since a very long time. E.g. Mt. Kilimanjaro in East Africa.

Q3. What do you mean by 'Focus' and 'Epicentre'?
Ans 3: Focus: The point of origin of an earthquake is called its Focus.
Epicenter: The point directly/vertically above the focus on the earth's surface is known as Epicenter.

Q4. What are meanders?
Ans 4: Curves and large bends or loops formed by rivers in the plains are known as meanders.

Q5. Define the term 'Aggradation'.
Ans 5: The process of depositing the eroded material is called aggradation.

 

Short Answer Questions

Q6. How does the process of gradation creates various landforms?
Ans 6: The surface of the earth is continuously undergoing changes. Running water, moving ice, wind and waves are the main agents of gradation which continuously wear down the land surface and carry the broken fragments which are deposited in the low lying areas.
The process of reduction of height of landform is called 'degradation'. The process of depositing the eroded material is called 'aggradation'. Aggradation and degradation are the two main ways which as continuously at work creating different landforms on the earth surface.

Q7. What do you mean by erosion? What are the main agents of erosion?
Ans 7: The removal of outer layer of rocks in the natural environment is called erosion. The main agents of erosion are water, wind and ice.

 

Long Answer Questions

Q8. Give a detailed account of the features formed by Wind, Waves and Ice.
Ans 8: The features formed by wind are as follows:
(a) Mushroom Rocks: In deserts you can see rocks in the shape of a mushroom, commonly called mushroom rocks. Winds erode the lower section of the rock more than the upper part. Therefore, such rocks have narrower base and wider top.

(b) Sand Dunes: When the wind blows, it lifts and transports sand from one place to another. When it stops blowing the sand falls and gets deposited in low hill – like structures. These are called sand dunes.
(c) Barkhan: A crescent shaped sand dune is called a barkhan.
(d) Loess: When the grains of sand are very fine and light, the wind can carry it over very long distances. When such sand is deposited in large areas, it is called loess.

The features formed by sea waves in the coastal areas are as follows:
(a) Sea Caves: Sea waves continuously strike at the rocks. Cracks develop. Over time they become larger and wider. Thus, hollow like caves are formed on the rocks. They are called sea caves.
(b) Sea Arches: When these cavities become bigger and bigger only the roof of the caves remain, thus forming sea arches.
(c) Stacks: Further, erosion breaks the roof and only walls are left. These walls like features are called stacks.
(d) Sea Cliff: The steep rocky coast rising almost vertically above sea water is called sea cliff.
(e) Beaches: The sea waves deposit sediments along the shores forming beaches.

The features formed by ice are as follows:
(a) Lakes: Glaciers carve out deep hollows. As the ice melts they get filled up with water and become beautiful lakes in the mountains.
(b) U-Shaped Valley: Formation of "U" shaped valleys, which are deep and have steep sides.
(c) Glacial Moraines: The material carried by the glacier such as rocks big and small, sand and silt gets deposited. These deposits form glacial moraines.

Q9. What are tectonic plates? Why do they cause tremors?
Ans 9: The crust of the earth is not in the form of a continuous plate rather in the form of broken pieces. These pieces of the earth's crust are called tectonic plates. Broadly, there are seven major plates: African Plate, Antarctic Plate, Eurasian Plate, Indo-Australian Plate, North American Plate, Pacific Plate and South American Plate.
According to the theory of continental drift, these tectonic plates are constantly moving. When these plates collide with each other, tremors or earthquakes are caused. Sudden vibration caused by the movement of lithospheric plates is called earthquake.

Q10. How are features formed by a river different from that formed by a river of Ice?
Ans 10: The features formed by a river are as follows:
(a) 'I' & 'V' shaped valley                              (b) Gorges or Canyons (deep valleys)
(c) Waterfalls, etc.                                         (d) Meanders (curves & large bends or loops)
(e) Oxbow Lakes                                          (f) Flood Plains
(g) Levees (slightly raised river banks)            (h) Delta
(i) River breakup into various streams called 'distributaries'.

The features formed by ice are as follows:
(a) ''U' shaped valley                      (b) Lakes                        (c) Glacial Moraines

The course of a river is very large in compression to that of a glacier (river of ice). A river flows from mountains, plains and forms various features before submerging into the sea. Whereas, course of a glacier is confined to the mountains only. River contains water which is in liquid form and Glaciers contain ice which is in solid/semi-liquid for, due to which the features formed are different.

Q11. Why are deltas so fertile?
Ans: A river when approaches towards its last stage of its course before submerging into the seas and oceans becomes very slow. Due to the load of sediments the river is carrying and because of the flat land, it is forced to deposit the sediments near the mouth. The river starts breaking into number of small streams known distributaries. The network of distributaries form a triangular shaped feature called delta. These deltas are most fertile areas in the course of a river. The deposition of sediments in the deltas is a continuous process making these deltas the most fertile areas. Sunderbans delta formed by the Ganga – Brahmputra river is the biggest delta and also is very fertile.

Q12. Name the erosional and depositional features found in coastal areas Explain how they are formed.
Ans: The erosional features formed by sea waves in the coastal areas are as follows:
(a) Sea Caves: Sea waves continuously strike at the rocks. Cracks develop. Over time they become larger and wider. Thus, hollow like caves are formed on the rocks. They are called sea caves.
(b) Sea Arches: When these cavities become bigger and bigger only the roof of the caves remain, thus forming sea arches.
(c) Stacks: Further, erosion breaks the roof and only walls are left. These walls like features are called stacks.
(d) Sea Cliff: The steep rocky coast rising almost vertically above sea water is called sea cliff.

The depotional features formed by sea waves in the coastal areas are as follows: -
(a) Beaches: The sea waves deposit sediments along the shores forming beaches.

 

Give Reasons

Q13. Wind action is prominent in desert area. Why?
Ans 13: Wind action can be best seen in the desert areas. Features like sand dunes, Mashroom rocks, etc. are formed by the wind action. Wind acts as an agent of erosion and deposition which leads to the formations of different features.
In the deserts we don't find lot of vegetation due to which the wind flows without any disturbance or obstruction. Also, because of the lack of vegetation there is no moisture content in the soil and it is not able to hold itself and becomes very loose (sand). In a wide area with barren land the wind blows with great velocity creating new features specially in the deserts.

Q14. Meanders are formed by the rivers in plains. Why?
Ans 14: Rivers are the most important agents of degradation. As the river flows from the mountainous regions, it has great erosive power. Speed and force of water is great, during this course river does lots of erosional work. As the river enters into the plains, all of sudden the speed of flow of water is reduced to a greater extent and the river widens. In the plains river forms curves and large bends or loops called the meanders

 

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Very Short Answer Questions

Q1. Define: (a) Crust (b) Mantle (c) Core (d) Rocks (e) Ore (f) Lava (g) Magma
Ans 1:
(a) Crust: The outermost and thinnest layer of Earth is known as Crust.
(b) Mantle: The middle layer of Earth between Crust and Core is known as Mantle.
(c) Core: The innermost layer, forming the metallic centre of the Earth is known as Core.
(d) Rocks: All solid materials of the earth's crust, whether hard or soft, that make up the earth's crust are called Rocks.
(e) Ore: A rock in which a particular mineral is found in large percentage is called an ore.
(f) Lava: The red molted rock material erupting from the earth in the form of a volcano is known as Lava.
(g) Magma: The molted rock material inside the earth is known as Magma.

 

Q2. What are minerals?
Ans 2: Rocks form the solid mass of the earth's crust. The rock forming materials are known as "Minerals".

 

Long Answer Questions

Q3. Explain the classification and characteristics of rocks.
Ans 3:  Rocks have different colours, mineral composition, hardness, etc. and according to their formation, rocks can be classified into three categories: -
1. Igneous Rocks
2. Sedimentary Rocks
3. Metamorphic Rocks

1. Igneous Rocks: The word 'Igneous' is derived from Latin word "Ignis" meaning "Fire". This is also called Primary rock. These are the first rocks to be formed and are known as the ancestors of all the rocks. Igneous rocks are the hardest rocks available and it is formed by cooling and solidification of the Lava coming out from the interior of the Earth's interior. E.g. Granite, Basalt, etc. Igneous rocks are of two types:
(a) Solidification of rocks below the earth's surface is known "Intrusive rocks".
(b) The magma which reaches the earth's surface and gets solidified is known as "Extrusive Rocks".

Features of igneous rocks are: -
1. These rocks do not form layers.
2. They contain crystals of varying sizes.
3. They do not contain fossils.

2. Sedimentary Rocks: The word 'Sedimentary' is derived from Latin word "Sedimentum" meaning "Settle Down". Particles that form a sedimentary rock by accumulating are called sediments. Before being deposited, sediment was formed by weathering and erosion in a source area, and then transported to the place of deposition by water, wind, ice, mass movement or glaciers which are called agents of denudation.

Features of Sedimentary rocks are: -
1. They are layered, called stratified rocks.
2. They do not contains crystals.
3. They contain fossils embedded in them.
4. They are rich in coal and petroleum deposits.
5. Examples of Sedimentary rocks are: - Sandstone, Clay, Limestone, etc.
6. 70% of the total earth's surface is dominated with these rocks.

3. Metamorphic Rocks: The word 'Metamorphic' is derived from Greek word "Metamorphose" meaning "Change of Form". When igneous or sedimentary rocks are subjected to great heat or pressure, the original character and appearance of the rock change into a new form. Thus, these rocks are formed by the alteration of other rocks. E.g. graphite, slate, Marble, etc.

Features of metamorphic rocks are: -

1. They are hard in nature.
2. Valuable minerals like gold & silver are found in these rocks.

3. They do not contain fossils.

4. Takes a long time to form.

 

 Q4. Describe the rock cycle with a suitable diagram.

Ans 4:  Rocks undergo a cycle of transformation. Change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic rock can change into igneous or sedimentary rock. Hence, this cycle of change from one type of rock to another is called 'rock cycle'.

Rocks are continually being formed, destroyed and reformed due to changing weather conditions and forces of nature (eg. Wind, river, glaciers, earth movements, etc.)

 

Q5. What is the usefulness of rocks and minerals to us?

Ans 5:  Rocks and minerals are very useful to mankind. Following are the usefulness of rocks and minerals:
1. Different vegetations.
2. Different types of minerals for industries.
3. Different rock materials for construction purposes.
4. Different chemicals for medicine and fertilizer industries.
5. Source of fuels like coal and crude oil.
6. Source of precious stones like, gold, silver, etc.

 

Q6. Why do we get both fossils and fossil fuels primarily in the sedimentary rocks?
Ans 6:   Fossils are the preserved remains or traces of animals, plants, and other organisms from the remote past. Fossil fuels are fuels formed by natural processes such as decomposition of buried dead plants and animals.
Amongst the three major types of rock, fossils are most commonly found in sedimentary rock. Unlike most igneous and metamorphic rocks, sedimentary rocks form at temperatures and pressures that do not destroy fossil remnants. Sedimentary rocks are formed by the deposition of sediments layer by layer making it easy to contain fossils and fossil fuels. Sedimentary rocks are soft rocks, thus it dose not destroy the fossils and in a longer run we get the fossil fuels like coal and petroleum products, which are very important for human life.

 

Q7. All the minerals are exhaustible. What would happen if coal, petroleum and few other minerals get exhausted completely? What effect it would have on our life?
Ans 7:  Coal, Petroleum and other minerals are non-renewable resources, they get exhausted when put to use. It takes millions of years to form these minerals. In todays world we cannot imagine human life without coal and petroleum products. coal and petroleum products are used in household sector, industrial sector, electrical sector, transportation sector, etc. making our life easy. But the usage of these products are increasing very fast day-by-day and if we are not serious very soon these minerals will be exhausted.
Human life will be effected very badly if coal and petroleum products get exhausted completely. If such a situation occurs we won't get proper electricity, transportation will be a great problem, all household items will become very costly, Food items will not be available on time, in short the survival of human life will be very difficult.

 

Q8. Differentiate between: (a) Crust and Mantle (b) Igneous and Sedimentary Rocks
Ans 8:
(a) Crust and Mantle

 

 

 

 

 

 

 

 

 

 

 

 

(b) Igneous and Sedimentary Rocks

                    

 

 

 

 

 

 

 

 

 

 

 

 

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Very Short Answer Questions

Q1.  Define the term Environment.

Ans: The immediate natural surroundings of man is called environment. E.g.: Plants, Air, Water, Landforms, Wildlife, etc.......

The word Environment has been derived from a French word "Environner" which means "Neighborhood".

 

Q2.  What do you mean by Ecology?

Ans: The Science with studies the relationship between living and non-living environment is termed as Ecology.

 

Q3.  Why is an ecosystem considered as the central feature of ecology?

Ans: The Interrelation between plants and animals in the natural environment is called Ecosystem.

The Science with studies the relationship between living and non-living environment is termed as Ecology. Thus, Ecology helps us to understand how a large variety of life forms depend upon the non living things and are influenced by their interaction with their environment.

 

Short Answer Questions

Q4.  What are the different components of the environment?

Ans: Different components of the environment are:

(a) Natural Environment            (b) Human Environment        (c) Human Made Environment

Q5. Why is lithosphere important?

Ans: The hard outermost solid layer of the earth which is made up of rock material is called crust. This solid crust of the earth is called Lithosphere. On this lithosphere we find different landforms such as the mountains, plateaus and plains. It provides us land where we live and also, it is a great source of vegetation, wildlife and mineral wealth. The crust is covered by a thin layer of soil which is of great importance for life. Lithosphere provides us the three basic necessities of life, i.e. Food, Cloth and Shelter.

 

Q6.  Define atmosphere. Why is it important?

Ans: The layer of air around us is called Atmosphere. Following is the importance of atmosphere: -

(a)    It gives us life giving gases like oxygen for breathing of animal kingdom and carbon dioxide is inhaled by plant kingdom.

(b)   It has Ozone layer which protects us from the harmful ultraviolet rays of the sun.

(c)    There are tiny dust particles in the atmosphere which helps in the formation of the rain droplets.

(d)   It acts as a blanket which prevents the earth from becoming too hot during day and too cold during night.

(e)    It protects us from falling meteors and other cosmic dusts. They burn when coming in contact with the atmosphere.

(f)    Presence of gases, dust particles and water vapours lend colours to the sky.

 

Long Answer Questions

Q7.  What efforts must be made to protect the environment?

Ans: Following are some of the efforts which must be made to protect the environment: -

(a)     Encourage / motivate others to be more sensitive towards environment.

(b)     Plant more trees (Aforestation)

(c)    Protest / control Deforestation.

(d)    Reduce, Reuse, Recycle.

(e)     Conserve every drop of water.

(f)     Cut Energy Consumption.

(g)     Support Climate Change Initiatives. E.g. reducing CO2 emissions

(h)     Buy Energy-efficient and Eco-friendly electrical appliances.

(i)      Drive Less and Drive Smart.

 

Q8.  "The environment gives us life and protection in various ways and maintain balance on its own". Enlist the human activities that cause imbalance in the environment.

Ans: Following are few of the human activities that have caused imbalance in the environment: -

(a)     Deforestation

(b)     Overgrazing

(c)     Pollution (Air, Water, Land and Noise)

(d)    Casual and careless attitude towards the environment.

(e)     Destroying the animal habitats

(f)     Hunting

(g)     Urbanization

(h)     Industrialization

(i)      Overpopulation

 

Q9.  Biosphere is the right combination of the three sphere or realms – Atmosphere, Lithosphere and Hydrosphere. Do you think that the biosphere can exist in the absence of anyone of them? Give reason for your answer.

Ans. Plant and animal kingdom together make Biosphere or the living worlds. It is a narrow zone of the Earth where Air (Atmosphere), Water (Hydrosphere) and Land (Lithosphere) interact with each other to support life.

There will be no existence of biosphere incase any one of the three sphere or realms is missing.

For example, to survive a human being requires oxygen to breathe (i.e Atmosphere), food cloth and shelter, the three basic necessities of life are provided by the Lithosphere and without water there is no survival.

Thus, we can understand that all the three spheres are equally important for the existence of life or the Biosphere.

 

Q10. We, the humans are an integral part of the environment but we are a bit different from other creatures. How? What makes us different?

Ans. There are a number of different things that make humans different from other creatures. Human beings adapt themselves to the natural environment by making modifications in their food, cloth and shelter. They also modify their natural environment to suit their social, biological, cultural and economic needs.

The early human beings slept on trees and caves, they used to roam around in search of food as that of other creatures but with the passage of time, with the help of their mind, thinking skills, ability, knowledge, hard work, etc. they have changed themselves drastically. Now, the modern man is far more organized, skilled, well mannered and cultured. They live in houses, eat cooked food, travel from one place to another by various means of transportation, etc.

The biggest difference is that the humans have the ability to create but in case of animals or other creatures, they cannot create. They must depend on whatever is available around them to survive.

 

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Short Answer Questions

Q1. What do you understand by Environment?
Ans: The immediate natural surroundings of man is called environment. E.g.: Plants, Air, Water, Landforms, Wildlife, etc.......
The word Environment has been derived from a French word "Environner" which means "Neighborhood".

Q2. Write a short note on Biosphere.
Ans: Plant and animal kingdom together make biosphere or the living world. It is a narrow zone of the earth where Land (Lithosphere), Water (Hydrosphere) and Air (Atmosphere) interact with each other to support life. Biosphere makes the earth a unique planet in the solar system.

Q3. Describe ecosystem.
Ans: The Interrelation between plants and animals in the natural environment is called Ecosystem. There could be an ecosystem of large rain forest, grassland, desert, mountains, lake, river, ocean and even a small pond.

Q4. Explain the composition of the air.
Ans: Atmosphere is composed of various gases. Major gases present are: Nitrogen – 78%, Oxygen – 21%, Argon - .93%, Carbon Dioxide – 0.03%, Other Gases – 0.04% (like – helium, hydrogen, methane, ozone, etc. and water vapours & dust particles.

 

Long Answer Questions

  Q5. What are the major components of environment?

Ans: Different components of the environment are:
(a) Natural Environment (b) Human Environment (c) Human Made Environment

 

Q6. Discuss lithosphere as one of the domains of the earth.
Ans: The hard outermost solid layer of the earth which is made up of rock material is called crust. This solid crust of the earth is called Lithosphere. On this lithosphere we find different landforms such as the mountains, plateaus and plains. It provides us land where we live and also, it is a great source of vegetation, wildlife and mineral wealth. The crust is covered by a thin layer of soil which is of great importance for life. Lithosphere provides us the three basic necessities of life, i.e. Food, Cloth and Shelter.

Q7. How do plants and animals depend on each other?
Ans: All plants, animals and human beings depend on their immediate surroundings. Often they are also interdependent on each other. "This relation between the living organisms, as well as the relation between the organisms and their surroundings form an ecosystem". There could be an ecosystem of large rain forest, grassland, desert, mountains, lake, river, ocean and even a small pond. In every ecosystem, there is a perfect balance in the transfer of energy and matter among the different components. This is known as Ecological Balance.
To maintain the balance "Food Chain" is the best example, in the process plants produce food for themselves and the plants are consumed by herbivores and herbivores by carnivores, (Omnivores eat both plants and animals) and ultimately, when these plants and animals die they are decomposed by the decomposers and thus, the dead matter of plants and animals is converted into simple compound which then enter the soil and air.

Q8. Discuss the interdependence of human world and environment.
Ans: Human world entirely depends on the environment for their survival. The basic needs of life (i.e. food, cloth and shelter) are fulfilled by the environment. But in the current scenario few of the human activities have caused great imbalance in the environment, for e.g. Deforestation, Overgrazing, Pollution, Casual & careless attitude towards the environment, Urbanization, Industrialization, Overpopulation, etc.
Now, a perfect balance is required between the natural and human environment. Survival of human being is not possible without the natural environment. Thus, we should always try and protect our environment and human beings live a long and healthy life.

 

HOTS (High Order Thinking) Questions

Q9. Why would the earth be barren without the atmosphere?
Ans: The layer of air around us is called Atmosphere. Following is the importance of atmosphere: -
(a) It gives us life giving gases like oxygen for breathing of animal kingdom and carbon dioxide is inhaled by plant kingdom.
(b) It has Ozone layer which protects us from the harmful ultraviolet rays of the sun.
(c) There are tiny dust particles in the atmosphere which helps in the formation of the rain droplets.
(d) It acts as a blanket which prevents the earth from becoming too hot during day and too cold during night.
(e) It protects us from falling meteors and other cosmic dusts. They burn when coming in contact with the atmosphere.
(f) Presence of gases, dust particles and water vapours lend colours to the sky.

Thus, atmosphere plays a very vital role and in its absence there won't be any life and earth will be barren.

Q10. Why are human beings the most important part of the human environment?
Ans. There are a number of different things that make humans different from other creatures. Human beings adapt themselves to the natural environment by making modifications in their food, cloth and shelter. They also modify their natural environment to suit their social, biological, cultural and economic needs.
The early human beings slept on trees and caves, they used to roam around in search of food as that of other creatures but with the passage of time, with the help of their mind, thinking skills, ability, knowledge, hard work, etc. they have changed themselves drastically. Now, the modern man is far more organized, skilled, well mannered and cultured. They live in houses, eat cooked food, travel from one place to another by various means of transportation, etc.

 

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Important term to remember:

1.      Environment: The immediate natural surroundings of man is called environment. E.g.: Plants, Air, Water, Landforms, Wildlife, etc.......

The word Environment has been derived from a French word "Environner" which means "Neighborhood".

2.      Components of Environment:

 (a) Natural Environment               (b) Human Environment        (c) Human Made Environment

 

3.      Biotic Components: All living things are known as Biotic Components. E.g.: Plants, Animal Kingdoms including man, etc....

4.      Abiotic Components: All non-living things are known as Abiotic Components. E.g.: Air, Water, Land, etc.....

5.      Ecosystem: Interrelation between plants and animals in the natural environment is called Ecosystem.

6.      Ecology: The Science with studies the relationship between living and non-living environment is termed as Ecology.

7.      Domains of Earth: The Four domains or realms of the Earth which jointly support life are: -

         (a) Atmosphere     (b) Hydrosphere         (c) Lithosphere          (d) Biosphere

8.     Biosphere: Plant and animal kingdom together make Biosphere or the living worlds. It is a narrow zone of the Earth where Air, Water and Land interact with each other to support life.

 

Geography studies the interrelationship between human beings and the environment.

 

Natural Environment:

1. Lithosphere

• It is the solid crust or the hard top layer of the earth.
• It is made up of rocks and minerals and covered by a thin layer of soil.
• It is an irregular surface with various landforms such as mountains, plateaus, plains, valleys, etc. Landforms are found over the continents and also on the ocean floors.
• Lithosphere is the domain that provides us forests, grasslands for grazing, land for agriculture and human settlements. It is also a source of mineral wealth.

2.Hydrosphere

• The water bodies on the earth's surface together form the Hydrosphere. E.g. Seas & Oceans, Rivers, Lakes, etc.
• Earth is also known as "Watery Planet", because 71% of it's surface is covered with water.
• Water is used for various purposes, i.e. domestic, agriculture, industries, transportation, generating electricity, etc.

3.Atmosphere

• The gaseous envelope around the earth's surface consisting of mixture of gases, water vapour and tiny dust particles is called atmosphere.
• Atmosphere is endless with no visible boundary.
• Atmosphere is composed of various gases. Major gases present are: Nitrogen – 78%, Oxygen – 21%, Argon - .93%, Carbon Dioxide – 0.03%, Other Gases – 0.04% (like – helium, hydrogen, methane, ozone, etc. and water vapours & dust particles.
• Ozone layer protects us from harmful ultraviolet rays of the sun.
• It acts as a blanket which prevents the earth from becoming too hot during day and too cold during night.

4.Biosphere

• Plant and animal kingdom together make biosphere or the living world.
• It is a narrow zone of the earth where Land (Lithosphere), Water (Hydrosphere) and Air (Atmosphere) interact with each other to support life.
• Biosphere makes the earth a unique planet in the solar system.

 

 

ECOSYSTEM

• All plants, animals and human beings depend on their immediate surroundings. Often they are also interdependent on each other.
• This relation between the living organisms, as well as the relation between the organisms and their surroundings form an ecosystem.
• There could be an ecosystem of large rain forest, grassland, desert, mountains, lake, river, ocean and even a small pond.
• In every ecosystem, there is a perfect balance in the transfer of energy and matter among the different components. This is known as Ecological Balance. 

 

ELEMENTS OF BIOSPHERE

 1.  Elements of Biosphere:Basically there are three elements of Biosphere: -

(a)  Producers      (b)  Consumers        (c)  Decomposers

(a) Producers: Plant Kingdom.

(b) Consumers:

     (i)   Herbivores: First consumers, plant eating animals. E.g. goat, dear, etc. They are large in number and reproduce faster.

     (ii)  Carnivores: Second level consumers. Flesh eating animals. E.g. lion, tiger, etc. They have sharp teeth and claws and reproduce at a slower rate.

     (iii) Omnivores: Consumers. They eat both plants and animals. E.g. man, ant, etc

(c) Decomposers: Microorganisms like bacteria get their food from dead plants and animals by decomposing them and are known as Decomposers. They keep the natural environment clean because they convert the dead matter of plants and animals into simple compound which then enter the soil and air.

 2.      Food Chain: In the process of consuming plants by herbivores and herbivores by carnivores, there is a transfer of energy from one level to another, which is called Food Chain.

 

 

HUMAN ENVIRONMENT

• Human beings are the most important part of environment. They not only interact with the environment but also modify it according to their needs.
• Early humans adapted themselves to the natural surroundings. They led a simple life and fulfilled their requirements from the nature around them. With time needs grew and became more varied.
• Modifications done by human beings have disturbed our ecosystem. Man is responsible for degrading the environment. Deforestation, Soil Erosion, etc. are some of the important factors.
• Humans must maintain balance between natural and human environment. Resources to be used wisely and should be preserved for future.

 

World Water Day: World Water Day is celebrated on 22 March every year.

World Environment Day: World Environment Day is celebrated on 05 June every year.

 

"LET'S JOIN OUR HANDS TOGETHER TO MAKE OUR ENVIRONMENT CLEAN AND GREEN"

 

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Multiple choice questions:

Q1. Which one of the following is not a determining factor of vegetation (1)
(a) Temperature (b) Rainfall (c) Sunlight (d) Development
Ans: (d) Development

Q2. Earliest settlements grew around (1)
(a) River Banks (b) Forest Areas (c) Plains (d) Foot Hills
Ans: (a) River Banks

Q3. The amount of fresh water present on the earth is (1)
(a) 3% (b) 1% (c) 29% (d) 8%
Ans: (a) 3%

 

Very short answer questions:

Q4. What is normal lapse rate? (1)
Ans: Temperature decreases at the rate of 1 degree Celsius from every 165 mtrs of ascent. This decline is known as normal lapse rate.

Q5. What does the word 'Tsunami' means? (1)
Ans: Tsunami is a Japanese word that means "Harbour waves" as the harbours get destroyed whenever there is tsunami. The term "Tsunami" has been derived from: - "Tsu" – Harbour and "Nami" – Waves. Meaning huge tidal waves.

 

Short answer questions:

Q6. Distinguish between: Tropical and Temperate Grasslands (2)
Ans: (Any two points)

Q7. Distinguish between: Rural and Urban Settlement. (2)
Ans: (Any two points)

Q8. Distinguish between: Spring Tides and Neap Tides. (2)
Ans: (Any two points)

 

Medium answer questions:

Q9. Define the term Communication What are its two categories? What is their importance? (3)
Ans: Communication is the process of conveying messages (sending or receiving) and ideas to others. With the development of technology humans have devised new and fast modes of communication.
The two categories of communication are:
(a) Personal Communication: Postal and telegraph services, telephones, e-mails, etc are personal means of communication.
(b) Mass Communication: Through Newspapers, magazines, radio, television, films, etc. Communication can be done with large no. Of people. This is known as Mass Communication.

With the help of these two means of communications life has become very fast and comfortable. With just one click we can share information throughout the world and also by just sitting at home itself we come to know what is happening in the world. The means of communications have made the world a large global society.

Q10. Explain the three movements of ocean water? (3)
Ans: Waves, Tides and Ocean Currents are the three movements of ocean water.
WAVES
• When the water on the surface of the ocean rises and falls alternately, they are called waves.
• During a storm, the winds blowing at very high speed form huge waves. These may cause tremendous destruction.
• An earthquake, a volcanic eruption or underwater landslides can shift large amounts of ocean water. As a result a huge tidal wave called tsunami originates.
• Tsunami is a Japanese word that means "Harbour waves" as the harbours get destroyed whenever there is tsunami. The term "Tsunami" has been derived from: - "Tsu" – Harbour and "Nami" – Waves. Meaning huge tidal waves.

TIDES
• The rhythmic rise and fall of ocean water twice in a day is called a tide.
• It is high tide when water covers much of the shore by rising to its highest level.
• It is low tide when water falls to its lowest level and recedes from the shore.
• During the full moon and new moon days, the sun, the moon and the earth are in the same line and the tides are highest. These tides are called spring tides.
• But when the moon is in its first and last quarter, the ocean waters get drawn in diagonally opposite directions by the gravitational pull of sun and earth resulting in low tides. These tides are called neap tides.
• High tides help in navigation. This helps the ships to arrive at the harbour more easily.
• The high tides also help in fishing. Also, the rise and fall of water due to tides is being used to generate electricity in some places.

OCEAN CURRENTS
• The horizontal movement of ocean water in the form of streams flowing constantly in definite directions is known as Ocean Currents.
• Factors affecting the Ocean Currents: -
(a) Planetary Winds.
(b) Rotation of the Earth
(c) Variation in the temperature
(d) Density of ocean water
(e) Shapes of the coastlines
• The ocean currents may be warm or cold.
• The warm ocean currents originate near the equator and move towards the poles.
• The cold currents carry water from polar or higher latitudes to tropical or lower latitudes.
• The ocean current influence the temperature conditions of the area.
• The place where warm and cold currents meet, dens fog is produced, reducing the visibility and thus, making it difficult for navigation. But at the same time these are the best fishing grounds of the world.
• The general circulation of ocean currents is clockwise in the Northern Hemisphere and anti-clockwise in the Southern Hemisphere.

Q11. Name the different means of transportation. Explain any two means of transportation (3)
Ans: Different means of transportation are Roadways, Waterways, Railways, Airways. Explain any two.
ROADWAYS
• The most commonly used means of transport are the roads. Especially, for short distances. Roads can be metalled (Pucca) and unmetalled (Kutcha).
• Roads are the best means to link the rural and urban places across the country.
• In developed countries road network is very good.
• The plains have a dense network of roads because it is easy to construct roads in plain than in the mountains.
• In India we have National Highways connecting all major cities of the country. There are state highways and district roads which connects all cities and towns.
• Manali-Leh highway in the Himalayan Mountains is one of the highest roadways in the world.

RAILWAYS
• Railways is the fastest and the cheapest means of land transportation .
• Diesel and electric engines have largely replaced the steam engines.
• Electric engines are fast and eco-friendly and don't cause pollution.
• Factors responsible for the construction of railway lines: - Relief Features, Climatic Conditions, Density of Population and availability of resources.
• Railway network is more developed in the plains than in the mountiains.
• Indian railway network is well developed. It is the largest in Asia.

WATERWAYS
• Waterways are the oldest and the cheapest means of transportation to carry heavy and bulky goods from one country to another.
• Waterways are mainly of two types – inland waterways and sea routes.
• Inland Waterways: Navigable rivers and lakes are used as inland waterways. Some of the important inland waterways are the Ganga-Brahmaputra river system, the Great Lakes in North America and the river Nile in Africa.
• Sea routes and oceanic routes are mostly used for transporting merchandise and goods from one country to another. These routes are connected with the ports. Some of the important ports of the world are Singapore and Mumbai in Asia, New York, Los Angeles in North America, Rio de Janerio in South America, Durban and Cape Town in Africa, Sydney in Australia, London and Rotterdam in Europe.
• Important Sea Routes of the world: North Atlantic Route which connects North America with Europe. Mediterranean Sea – Indian Ocean connecting Europe-East Africa-South Asia-Cape of Good Hope-Australia
• Major sea ports of India: - Mumbai, Kandla, Kochi, Chennai, Vishakhapatnam, Kolkata.

AIRWAYS
• This is the fastest & most comfortable means of transportation and also the most expensive due to high cost of fuels.
• Air traffic is adversely affected by bad weather like fog and storms, etc.
• It is the only mode of transport to reach the most remote and distant areas especially where there are no roads and railways.
• Helicopters are extremely useful in most inaccessible areas and in time of calamities for rescuing people and distributing food, water, clothes and medicines.
• Some of the important airports are Delhi, Mumbai, New York, London, Paris, Frankfurt and Cairo.
• Air Services are of two types:
(1) Domestic Airways: Fly within the boundaries of a country.
(2) International Airways: Fly abroad and connects major cities of the world.

 

Long answer questions:

Q12. With a suitable diagram explain the structure of the atmosphere. (5)
Ans. Structure of Atmosphere: Atmosphere is divided into five different layers (Troposphere, Stratosphere, Mesosphere, Ionosphere and Exosphere). It extends upto 500 kms.

1. Troposphere:
• This layer is next to earth surface. It Extends upto 15 kms from the earth's surface.
• Temperature decreases at the rate of 1 degree Celsius from every 165 mtrs of ascent. This decline is known as normal lapse rate.
• Average height: 13 kms at poles and 18 kms over the equator.
• All weather changes take place in this layer. Oxygen exists in this layer.
• The boundary separating troposphere and stratosphere is known as tropopause.

2. Stratosphere:
• This layer is next to troposphere and it extends from 15 kms to 50 kms.
• This layer is free from weather changes, cloud formation and dust particles. Hence, this layer is ideal for the air transportation.
• Ozone layer is present here. Ozone layer absorbs/reflects the harmful ultraviolet rays of the sun.
• The boundary separating stratosphere and mesosphere is known as stratopause.

3. Mesosphere:
• This layer is next to stratosphere and it extends from 50 kms to 80 kms.
• Temperature again drops in this layer and can reach upto -100 degree Celsius at the upper boundary layer.
• The boundary separating mesosphere and ionosphere is known as mesopause.

4. Thermosphere:
• This layer is next to mesosphere and it extends from 80 kms to 400 kms.
• This layer contains electrically charged particles called ions, which are found at a height of 250 kms. Due to presence of these ions, this layer is also known as ionosphere.
• This layer protects us from the harmful radiation. Temperature increase with increase in height.

5. Exosphere:
• This is the uppermost layer above the ionosphere and it extends from 400 kms onwards and there is no end. It is a very thin layer and it merges with the space.
• This layer protects us from the harmful radiation.
• Temperature is very high. Light gases like hydrogen and helium float into space from here.

Q13. What do you mean by natural vegetations? How natural vegetation of the world has been classified? Describe the characteristics of forests (any three). (5)
Ans: Plants which grow naturally without any human interference, covering a large area is known as natural vegetation.
Natural vegetation of the world has been classified into three types: Forest, Grasslands and Desert Shrubs.
Characteristics of the forests (any three).

Tropical Rainforests:
These forests are also called Tropical Evergreen.

Location:
• Forests found near the Equator (10° North to 10° South) in Amazon & Zaire Basin and Southeast Asia.
Climate:
• These regions are hot and receive heavy rainfall throughout the year.
Characteristics:
• As there is no particular dry season, the trees do not shed their leaves altogether. This is the reason they are called evergreen.
• Maximum varieties of trees are found. Trees are tall with large trunks.
• The thick canopies of the closely spaced trees do not allow the sunlight to penetrate inside the forest even in the day time. Thus, grass is not found in these forests.
• Hardwood trees like rosewood, teak, sal, ebony, and mahogany are the common trees found here.
• Here the population found is very less. Due to dense forests commercial exploitation of these forests has not be possible, making them economically backward.
Wildlife:
• Large variety and most colourful animals are found here.
• Monkey, Ape, Birds, Hippopotamus, snake, python, Frog, Crocodile, etc. Anaconda, world's largest snake is also found in these areas.

Tropical Deciduous Forests:
These forests are also called Monsoon Forests.

Location:
• Forests found in large part of India, Northern Australia and in Central America.
Climate:
• These regions are warm and receive rainfall less than 200 cms.
Characteristics:
• These regions experience seasonal changes. Trees shed their leaves in the dry season to conserve water.
• Trees like sandalwood, teak, sal, ebony, bamboo, etc. are the common trees found here.
• Forests are not very dense thus; commercial exploitation of these forests is possible.
Wildlife:
• Tigers, lions, elephants, langoors and monkeys are the common animals of these regions.

Temperate Evergreen Forests:
These forests are also called Mixed Forests.
Location:
• Forests found in South-eastern parts of USA, Australia, Brazil and China.
Climate:
• These regions have cool winters and receive rainfall throughout the year.

Characteristics:
• They comprise both hard and soft wood trees like oak, pine, eucalyptus, etc.
• They look like Tropical Forest in thickness and variety.
• Timber (wood) from these forests is used for commercial purpose.
Wildlife:
• Deer, Wolves, Bears, Wild Boar, Foxes, Squirrels, Badgers, Skunks, Owls, Finches, etc. are the common animals of these regions.

Temperate Deciduous Forests:
These forests are also called Monsoon Forests.

Location:
• As we go towards higher latitudes, there are more temperate deciduous forests. These are found in the north eastern part of USA, China, Japan, New Zealand, etc.
Climate:
• These regions have cool winters and receive moderate rainfall.
Characteristics:
• Trees shed their leaves in autumn season and remain leafless through winters.
• The common trees are oak, ash, beech, etc.
• Forests are not very dense thus; commercial exploitation of these forests is possible.
Wildlife:
• Deer, foxes, wolves are the animals commonly found. Birds like pheasants, monals are also found here.

Mediterranean Forests:

Location:
• Found in areas around Mediterranean Sea, Central Chile, South-West USA, Australia, Africa.
Climate:
• These regions have hot & dry summers and mild & wet winters.
Characteristics:
• Mediterranean trees adapt themselves to dry summers with the help of their thick barks and wax coated leaves which help them reduce transpiration. Also, here the plants have long tap roots to reach underground water, called "Xerophytic Plants".
• Mediterranean regions are known as 'Orchards of the world' for their fruit cultivation.
• Citrus fruits such as oranges, figs, olives and grapes are commonly cultivated here because people have removed the natural vegetation in order to cultivate what they want to.
Wildlife:
• There isn't much wildlife here.

Coniferous Forests:
These forests are also called "Taiga Forest".

Location:
• Found in the higher latitudes (50° – 70°) of Northern hemisphere.
Climate:
• These regions have cool & short summers and cold & long winters. These forests are also seen in the higher altitudes. Norway, Sweden, Finland, Russia and Canada.
Characteristics:
• Forests consist of tall, softwood evergreen trees.
• Limited species of trees are found. These trees are evergreen and grow apart from each other.
• Trees are conical shaped with needle shaped leaves and trees are found in large groups.
• Chir, pine, cedar are the important variety of trees in these forests. Lumbering is the common activity. Soft wood is used for manufacturing paper.
Wildlife:
Fur-bearing animals like Silver fox, mink, and polar bear are the common animals found here.

 

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