202110247-TRIUMPH-STUDENT-WORKBOOK-SOCIAL_STUDIES-G09-PART1

CHAPTER 2-THE NATURAL REALMS OF THE EARTH - LITHOSPHERE (v) is the head land cutting out in to the sea. (A) Bay (B) Gulf (C) Cape (D) Gorge (vi) The source of a river is in the__________ . (A) High mountains (B) Lakes (C) Sea (D) Ocean (vii) Deep valleys are developed by of a river. (A) Shallow (B) Swift flow (C) Widths (D) Bank (viii) are suitable for construction of dam. (A) Gorges (B) Canyons (C) Valleys (D) Plains (ix) forms a V shaped valley. (B) River (A) Glaciers (C) Plateau (D) Forest (x) The eruption of the ridge creates the new ocean floor of rocks. (A) Igneous (B) Basalt (C) Sedimentary (D) Granite CHAPTER 2. THE NATURAL REALMS OF THE EARTH - LITHOSPHERE 49

SESSION 1 3. HYDROSPHERE 1.1 Mind Map HYDROLOGICAL CYCLES 1.2 Terminology 1. Stream: The ocean water current which flows speedily is called a ‘stream’. 2. Drift: The ocean water current which flows slowly is called a ‘drift’. 1.3 Improve Your Learning Conceptual Understanding Q1. Find the odd one out and give explanation for your choice. [Refer to TB page 34 Q1] i) a) Evaporation b) Condensation c) Salination d) Precipitation ii) a) Tectonics b) Centrifugal force c) Solar energy d) Precipitation A. i) In the above series, option c) salination is the odd one. SESSION 1. HYDROLOGICAL CYCLES 50

CHAPTER 3- HYDROSPHERE a) evaporation b) condensation and d) precipitation are the various stages in the water cycle. Whereas salination is a term used to define the total content of dissolved salt in sea water. So, this term is the odd one. ii) In this question the term a) tectonics is the odd one from other three terms i.e., b) centrifugal force c) solar energy and d) precipitation are related to ocean currents. The term tectonic plates is related to the movement of the earth plates. Q2. Why are there differences in the salinity of oceans ? [Refer to TB page 34 Q4] A. The differences in the salinity of oceans is due to the following reasons : 1. Evaporation and precipitation 2. Fresh water flow from rivers into oceans and freezing and thawing of ice. 3. Winds by transferring water to other areas. 4. The ocean currents 1.4 Key Concepts 1. The hydrological cycles describes the movement of water on, in and above the earth. 2. Hydrological cycle is the circulation of water in different forms. 3. Evaporation is the process by which water changes from a liquid to gas. 4. Transportation is the movement of water through the atmosphere specifically from over the ocean to over land in the form of a cloud. SESSION 1. HYDROLOGICAL CYCLES 51

SESSION 2 OCEANS - RELIEF AND SALINITY 2.1 Mind Map 2.2 Improve Your Learning 52 Conceptual Understanding Q1. Correct the false statements: [Refer to TB page 34 Q2] a) Ocean trenches can be located near the continents. b) Relief features of the oceans are like plains. c) Most salt in the seas are washed into it from the land over centuries. d) Temperature of ocean water remains the same across the globe. A. a) True b) True SESSION 2. OCEANS - RELIEF AND SALINITY

CHAPTER 3- HYDROSPHERE c) True d) False.The temperature of the ocean water varies from place to place so it is the false statement. 2.3 Key Concepts i. Continents and oceans are the first order relief features of the earth. ii. The huge water bodies are called oceans. iii. A sea is a body of saline water, partly or fully enclosed by land. iv. The continental shelf with a depth up to 200 metres occupies about 7.6% of the ocean area. v. The Siberian shelf in the Arctic Ocean is the largest continental shelf. vi. Continental slopes are formed by erosion process of glaciers and rivers. vii. Submarine canyons are observed in continental slope region. viii. In oceans trenches are found close to the continents. ix. Isohaline is a joining point in the ocean having the same degree of salinity. SESSION 2. OCEANS - RELIEF AND SALINITY 53

SESSION 3 OCEANS - TEMPERATURE AND CURRENTS 3.1 Mind Map 3.2 Terminology 1. Ocean currents: The ocean current is the general movement of a mass of water in fairly defined direction over great distance. SESSION 3. OCEANS - TEMPERATURE AND CURRENTS 54

CHAPTER 3- HYDROSPHERE 3.3 Key Concepts i. An ocean current is the general movement of a mass of water in a defined direction over great distance. ii. The ocean water current which flows speedily is called a stream. iii. Drift is the slow flow of the ocean water current. iv. Warm currents flow towards the poles. v. Cold currents flow towards the equator. vi. The variation of the centrifugal force makes the equatorial water move towards the poles. SESSION 3. OCEANS - TEMPERATURE AND CURRENTS 55

SESSION 4 OCEAN AS A RESOURCE 4.1 Mind Map 4.2 Terminology 1. Transpiration: A considerable proportion of water vapour is released into the atmosphere by plants, through a process called “Transpiration”. 4.3 Improve Your Learning Conceptual Understanding Q1. Do you think that the description of blue planet is accurate? Describe any one way in which your activity impacts its oceans. [Refer to TB page 34 Q3] A. The earth justifies the name given to it as it is the only planet where there is more than twice as SESSION 4. OCEAN AS A RESOURCE 56

CHAPTER 3- HYDROSPHERE much water (71%) as land (29%). The blue planet or water planet –earth, is the third planet in distance from the Sun and the fifth largest in the Solar System. Our Earth is unique as it is the only planet that supports life in the solar system. Oceans are suffering from our activities too. Our land practices cause agricultural run–off, sewage, and litter to end up in the oceans daily. Today oceans have also fallen victim to our exploitation. Many large fishes like whales have been disappearing. Damage to oceans is damage to our livelihoods, well–being and nourishment. Reading the Text, Understanding and Interpretation Q1. Read the para “ocean as a resource” on page 33 and comment on it. [Refer to TB page 34 Q7] A. Student Activity Mapping Skills Q1. Observe the map 1 on page 35 and write down the names of a few warm and cold currents. [Refer to TB page 34 Q6] SESSION 4. OCEAN AS A RESOURCE 57

CHAPTER 3- HYDROSPHERE A. Students activity. Appreciation and Sensitivity Q1. How is human life dependent on oceans ? [Refer to TB page 34 Q5] A. Human life is dependent on oceans in the following ways : 1. Food resources like fish and salt 2. Sand, gravel for housing or industries 3. Extract minerals like chlorine, fluorine and iodine. 4. Waves are used for generating power. 5. Oil is mined from the floor of oceans 6. They provide us with gems and pearls. 7. Livelihood is created along the shore and travel to other countries on the oceans. 4.4 Key Concepts i. Chlorine, fluorine, bromine and iodine are some of the minerals which are found in oceans. ii. Dogger bank, North sea, Grand Bank and Newfound Land are famous fishing regions. iii. Oceans are storehouses for fish. iv. Rock petroleum and natural gas are extracted from under the ocean. v. Oceans are mined for minerals like salt, sand, gravel, manganese, copper, nickel etc. SESSION 4. OCEAN AS A RESOURCE 58

CHAPTER 3-HYDROSPHERE —— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. State true or false. (i) Ocean floor is divided into 2 parts—run off and ground water. [ ] ] (ii) Salinity is expressed in ppt. ] ] [ (iii) Sodium chloride alone constitutes for 78.8% of the sea water. [ (iv) Lake Van, Turkey has a high salinity of 330%. [ 2. Match the following. Column A Column B i. Evaporation a. Most of the water which returns to land flows ii. Transportation down the hills iii. Condensation b. This means that the vapour condenses iv. Precipitation to form tiny droplets and clouds c. Water changes to gas through this process d. This process shows the movement of water from ocean to over land in the form of clouds v. Run off e. When clouds meet cool air over land, pre- cipitation occurs CHAPTER 3. HYDROSPHERE 59

CHAPTER 3-HYDROSPHERE 3. Match the following. Column A Column B i. Panthalsa a. America–Europe–Africa ii. Continental Shelf b. Super ocean iii. Atlantic c. Common salt iv. Sodium Chloride d. Challenger v. British expedition e. 7.6% of ocean area 4. Answer the following questions in one sentence. (v) What is hydrological cycle? (vi) Name the ocean that separates America from Europe and Africa. (vii) Why is centrifugal force greater at the equator? (viii) What are depth contours? 60 CHAPTER 3. HYDROSPHERE

CHAPTER 3-HYDROSPHERE (ix) Today oceans have become victims to our exploitation. Comment on it. (x) What is left behind when water evaporates from the surface of the ocean? (xi) What are the first order relief features of the earth? (xii) How can you differentiate a drift from a stream? 5. Fill in the blanks. (xiii) and are the first order relief features of the earth. (xiv) Most of the salt in the oceans comes from . CHAPTER 3. HYDROSPHERE 61

CHAPTER 3-HYDROSPHERE (xv) The words ‘sea’ and are used interchangeably. (xvii) Water is a cyclic resource. (xviii) The largest continental shelf is . (xix) has six stages. (xx) cover about 76.2% of the ocean basin. (xxi) The greatest portion of fresh water is in the form of . (xxii) led the Dandi march. Short Answer Type Questions 6. Answer the following questions in 3-4 sentences. (i) What are the factors that affect the salinity on the surface layers of the ocean? (ii) What do you know about oceanic deeps? What are they called? CHAPTER 3. HYDROSPHERE 62

CHAPTER 3-HYDROSPHERE Long Answer Type Questions 7. Answer the following questions in 6-8 sentences. (i) What are the relief features of ocean? Explain. (ii) Write a note on water salinity. 63 CHAPTER 3. HYDROSPHERE

CHAPTER 3-HYDROSPHERE AS3-Information Skills Short Answer Type Questions 8. Answer the following questions in 3-4 sentences. (i) Arrange the information given below in the following table: The Challenger or Mariana is one of the major ocean trenches found in the Pacific Ocean and is 11,022 m deep. The next deepest trench is Puertorico or Naves in the Atlantic ocean of 10,475 m depth. The Java found in the Indian Ocean is of 7,450 m deep and is comparatively less deep than the former two trenches. (ii) Read the passage and answer the following questions: Ocean water is processed to extract commercially valuable minerals such as salt, bromine, and magnesium. Although nearly 60 valuable chemical elements have been found dissolved in ocean water, most of them are in such dilute concentrations that commercial extraction is not profitable. In a few arid regions of the world, such as Ascension Island, Kuwait and Israel, ocean water is desalinated to produce freshwater. Ocean pollution, meantime, has escalated dramatically as those who use the oceans for recre- ational and commercial purposes, as well as those who live nearby, have disposed of more and more wastes there. 1. What are the minerals that can be extracted from the oceans? 2. Why is it not profitable to commercially extract them? CHAPTER 3. HYDROSPHERE 64

CHAPTER 3-HYDROSPHERE 3. What do you mean by arid regions? Give examples. 4. What type of pollution has escalated in the recent times? 5. What are the causes that contribute to the pollution of oceans? AS5-Mapping Skills Long Answer Type Questions 9. Answer the following questions in 6-8 sentences. (i) Study the map and answer the following questions: CHAPTER 3. HYDROSPHERE 65

CHAPTER 3-HYDROSPHERE i. Which are the continents that are separated by the Indian Ocean? ii. By which ocean are Europe and North America divided? iii. Name the two continents that are separated by the South Atlantic Ocean. iv. Where is the largest continental shelf found? (ii) Note down your observations about the following image: CHAPTER 3. HYDROSPHERE 66

CHAPTER 3-HYDROSPHERE Objective Questions AS1-Conceptual Understanding 10. Choose the correct answer. (i) is the circulation of water in different forms –liquid, solid and gaseous phases. (A) Evaporation (B) Transportation (C) Hydrosphere (D)Hydrological cycle (ii) Hydrological cycle is sometimes expressed as __________. (A) RA = RO + ET (B) ET = RF + RA (C)RF = RO + ET (D)RO = ET + RF (iii) The primary mechanism for transporting water from the atmosphere to the surface of the earth is . (A) Precipitation (B) Dissipation (C) Evaporation (D)None of these (iv) of water is saline ocean water and is fresh water. (A) 98.52% , 2.50% (B) 95.08%, 2.67% (C) 97.05%, 2.56% (D) 97.21%, 2.78% (v) is a body of saline water, partly or fully enclosed by land. (A) Sea (B) Canyon (C)Continental Shelf (D) Plain CHAPTER 3. HYDROSPHERE 67

CHAPTER 3-HYDROSPHERE (vi) Submarine canyons are found in region. (A) continental slope (B) oceans (C) plateaus (D)ocean floor (vii) The total content of dissolved salts in sea water is called (A) Sodium Chloride (B) Hydro thermal vents (C)Salt (D) Salinity (viii) is the general movement of a mass of water in a fairly defined direction over a great distance. (A) Warm currents (B) Cold currents (C)Ocean currents (D)Stream currents (ix) Oceans have become a dumping ground for and . (A) plastic, toxic waste (B) mineral, metal wastes (C)paper, chemical waste (D)effluents, industrial wastes (x) A line joining all points in the ocean having the same degree of salinity is called (A) Is line (B) Is–hyaline (C) Isohaline (D) Isotopes CHAPTER 3. HYDROSPHERE 68

SESSION 1 4. ATMOSPHERE 1.1 Mind Map STRUCTURE OF ATMOSPHERE 1.2 Terminology 1. Convectional currents: Due to intense heating of the surface, the surface air gets heated and ex- pands and rises up convectionally holding moisture. There winds are known as convectional currents. It is there by cooled and its temperature falls below the dew point forming clouds. SESSION 1. STRUCTURE OF ATMOSPHERE 69

CHAPTER 4- ATMOSPHERE 1.3 Improve Your Learning Conceptual Understanding Q1. Explain the composition of the atmosphere. [Refer to TB page 50 Q1] A. i. The atmosphere is a sea of gases surrounding earth. ii. When we compare it with the size of earth, the atmosphere is a very thin blanket surrounding the earth. iii. The atmosphere is about 1,000 km thick. iv. If the earth is the size of a basketball, the atmosphere would be like a thin sheet of plastic wrapped around it. v. There are many gases in the atmosphere, but oxygen (21% by volume) and nitrogen (about 78% by volume) dominate. vi. Other gases are in very small percentages these include argon, neon, carbon dioxide, methane, ammonia, ozone etc. constitute about 1% of atmosphere. vii. Apart from these gases, the atmosphere also has fine dust particles, these are called par- ticulates. viii. Particulates may come from natural processes and from human activity. ix. These particulates can change atmospheric conditions that may be beneficial to life on earth. x. These particulates also can cause problems by altering temperature and rainfall patterns. . Q2. Discuss the structure of the atmosphere with a diagram. [Refer to TB page 50 Q2] SESSION 1. STRUCTURE OF ATMOSPHERE 70

CHAPTER 4- ATMOSPHERE A. Atmosphere is the sea of gases surrounding our Earth. On the basis of chemical composition: The atmosphere is divided into two broad layers: 1) Homosphere and 2) Heterosphere. 1) Homosphere: The homosphere extends upto a height of 90 kms. It consists of three layers - Troposphere, Stratosphere and Mesosphere. It is characterised by uniformity in composition of gases like nitrogen, oxygen, argon and carbon dioxide. 2) Heterosphere : The layer above 90 kms of the atmosphere is called heterosphere. It has het- erogenous composition and hence the name heterosphere. It has two layers called Thermosphere and Exosphere. Atmosphere can also be divided into various layers based on density and temperature: i) Troposphere: The troposphere is the lower–most layer of the atmosphere. Its average height is 13 kms and extends roughly to a height of 8 kms near the poles and about 18 kms at the equator. It SESSION 1. STRUCTURE OF ATMOSPHERE 71

CHAPTER 4- ATMOSPHERE contains about 75% of the total gaseous mass of the atmosphere and practically all the moisture and dust particles. The entire weather phenomenon happens in this sphere. The temperature in this layer decreases as we go higher which is known as Normal Lapse Rate. Condensation, evaporation, precipitation, rainfall, cyclones etc. occur in this layer. ii) Stratosphere : This layer extends upto a height of 50 kms. This layer is almost free from clouds and associated weather phenomenon, which is ideal for flying Jet aircrafts. It also contains ozone layer. The temperature increases with the increase in altitude. iii) Mesosphere: It extends upto a height of 80kms. Meteorites burn up in this layer on entering from the space. Temperature starts decreasing with the increase in altitude. iv) Thermosphere: It extends upto 400 kms. In thermosphere, temperature rises rapidly with in- crease in height. It contains electrically charged particles known as ions. Radio waves transmitted from the earth are reflected back to the earth by these ions. It is also known as Ionosphere. v) Exosphere: It is the uppermost layer of the atmosphere. This is the highest layer and very little is known about it. 1.4 Key Concepts i. Atmosphere is the gaseous envelope, surrounding the earth’s surface. ii. There are many gases in the atmosphere, Oxygen (21%) and Nitrogen (78% by volume) etc.. iii. The atmosphere also has fine dust particles called particulates. They can change atmospheric conditions that may be beneficial to life on earth. iv. The particulates can cause problems by altering temperature and rainfall patterns. v. On the basis of chemical composition the atmosphere is divided into two broad layers: i) Homosphere and ii) Heterosphere. vi. Homosphere consists of three layers: i) Troposphere, ii) Stratosphere and iii) Mesosphere. vii. Heterosphere has two layers called i) Thermosphere and ii) Exosphere. SESSION 1. STRUCTURE OF ATMOSPHERE 72

SESSION 2 PRESSURE BELTS 2.1 Mind Map 2.2 Terminology 1. Inter–tropical convergence zone: Winds are moving all over the world. At the equator, the high temperature heats up the earth’s surface around the equator. This low pressure belt is called equatorial low pressure belt or the Inter–tropical convergence zone (ITCZ). SESSION 2. PRESSURE BELTS 73

CHAPTER 4- ATMOSPHERE 2.3 Improve Your Learning Conceptual Understanding Q1. What is coriolis force? And explain its effects. [Refer to TB page 50 Q9] A. i. Because of the impact of Earth’s rotation on its own axis, the winds move slightly to the right in the northern hemisphere, and to the left in the southern hemisphere. This effect is called Coriolis effect. ii. At the equator the Coriolis effect is ‘0’ and at the poles it is maximum. The most important effects of Coriolis force are: i. The deflection of winds and currents in the ocean. ii. It has significant effect on planes and missiles also. iii. In the northern hemisphere these winds move to the right and in the southern hemisphere to the left. This usually creates the westerly winds moving from the subtropical areas to the poles. iv. The Coriolis effect also affects the movement of ocean currents. 2.4 Key Concepts i. The air around us is composed of gas molecules. When the gas molecules are heated up, they get a lot of energy and start moving very fast. ii. The earth’s surface does not get heated uniformly. Land heats up faster than the sea. iii. Winds are moving all over the world. At the equator, the high temperature heats up the atmo- sphere and the hot air rises, creating lower pressure at the earth’s surface around the equator. This low pressure belt is called Equatorial low pressure belt or ITCZ. iv. The wind moves slightly to the right (towards east) in the northern hemisphere and to the left (towards the west) in the southern hemisphere. This is because of the impact of the earth’s rotation on its own axis. v. If the earth did not rotate on its axis, winds would follow the direction of the pressure gradient. Instead, earth’s rotation produces the Coriolis force or effect which tends to turn the flow of air. The coriolis force is absent at the equator, but increases as we go towards the poles. SESSION 2. PRESSURE BELTS 74

SESSION 3 CLASSIFICATION OF WINDS 3.1 Mind Map 3.2 Terminology 1. Coriolis effects: Actually the winds move slightly to the right (towards east) in the northern hemisphere and to the left (towards the west) in the southern hemisphere. This is because of the impact of earth’s rotation on its own axis. This effect is called “Coriolis effect”. SESSION 3. CLASSIFICATION OF WINDS 75

CHAPTER 4- ATMOSPHERE 3.3 Improve Your Learning Conceptual Understanding Q1. Differentiate between weather and climate. [Refer to TB page 50 Q3] A. Weather: When we describe the condition of the atmosphere for small period of time (usually about 10 days at most) we call it weather. Weather can change daily, even within a day. Climate : Climate is a description of the average atmospheric conditions for areas over a long period of time, description of a long-term pattern of weather in a particular area. Climatic descriptions are based on decades of atmospheric data and finding the averages of them. Climate descriptions tell us what conditions are for a given time of year, but not for specific days. Q2. Explain relative humidity. [Refer to TB page 50 Q7] A. i) Humidity is the amount of water vapour present in the air. ii) Relative humidity is the ratio between two things: 1. The maximum water vapour that the air can hold at a given temperature and pressure, 2. The actual amount of water vapour it holds at any given time. iii) For example, at 20°C temperature, air can contain 80 gms of water vapour per cubic meter. If the actual water vapour present is only 40 gms, the relative humidity is 50%. iv)If atmosphere has 100% relative humidity, it is known as saturation level. v) RH decreases with increase of temperature and decrease of water vapour. vi) In high humidity, our sweat doesn’t cool us because it cannot evaporate. In low humidity, we also feel more thirsty. Relative humidity decreases with increase of temperatures and decrease of water vapour. Reflection on Contemporary Issues and Questioning Q1. How do the climatic changes influence the human life? [Refer to TB page 50 Q6] A. Due to climatic changes the following changes are taking place. SESSION 3. CLASSIFICATION OF WINDS 76

CHAPTER 4- ATMOSPHERE i. The climatic changes lead to the emergence of large scale environmental Hazards such as global warming, increase of greenhouse gases etc. ii. Development of planet’s flora and fauna is mainly due to climatic changes. iii. Globally the average sea level has risen by 17cm in the 20th century. iv. Climatic changes are affecting food habits and culture of people of everywhere. v. Due to global warming both the Greenland and Antarctic ice sheets have lost significant amounts of ice. vi. Thus the climatic changes are influencing human life significantly. Mapping Skills Q1. Identify the given local winds in the world map. [Refer to TB page 50 Q10] a) Chinook b) Loo c) Simoon d) Yoma e) Norwester f) Mistral g) Puna h) Pampero A. SESSION 3. CLASSIFICATION OF WINDS 77

CHAPTER 4- ATMOSPHERE 3.4 Key Concepts 1. Depending upon the wind speed, their features, their directions, the way they occur, winds are classified into three types: i) Planetary winds ii) Seasonal winds and iii) Local winds. 2. The pressure and wind systems are actually the impact of the Lithosphere and the Hydrosphere on the atmosphere. 3. Cold winds bring the temperature of the affected area below the freezing points. 4. The mountains and the valley breezes, as well as sea and land breezes are also types of local winds. SESSION 3. CLASSIFICATION OF WINDS 78

SESSION 4 WEATHER AND FACTORS AFFECTING WEATHER 4.1 Mind Map 4.2 Terminology 1. Relative Humidity: Relative humidity is the ratio between two things: i) The maximum water vapour that the air can hold at a given temperature and pressure, and ii) The actual amount of water vapour it holds at any given time. Relative humidity decreases with increase of temperatures and decrease of water vapour. 4.3 Improve Your Learning Conceptual Understanding Q1. Why does the amount of water vapour decrease rapidly with altitude? [Refer to TB page 50 Q8]. A. Water vapour is a very important component in the atmosphere. It accounts for about 0.4% by volume of the whole atmosphere, but most of it is close to the surface (within 6kms above the earth). The temperature increases as there is increase in altitude. When the temperature increases, the amount of water vapour decreases rapidly with altitude. SESSION 4. WEATHER AND FACTORS AFFECTING WEATHER 79

CHAPTER 4- ATMOSPHERE Reading the Text, Understanding and Interpretation Q1. Read the paragraph under the title “Effects of planetary winds” on page 43 and comment on it. [Refer to TB page 50 Q11] A. Student Activity. 4.4 Key Concepts i. Evaporation is the process by which water changes from liquid to gas. ii. Condensation is the opposite of evaporation, as it involves conversion of water vapour into droplets of water or crystal of ice. iii. With condensation, the droplets get heavy and fall to earth as precipitation. Rain, snow, hail, fog sleet are the various forms of precipitation. SESSION 4. WEATHER AND FACTORS AFFECTING WEATHER 80

SESSION 5 TYPES OF RAINFALL 5.1 Mind Map 5.2 Terminology 1. Leeward side: Opposite of windward side. The windward side of mountain range receives heavy rainfall whereas the leeward side receives less rainfall. 2. Tropical cyclones: A tropical cyclone is a rapidly rotating storm system characterized by a low–pressure center, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. 5.3 Improve Your Learning Conceptual Understanding Q1. Compare and contrast convectional and orographic rainfall. [Refer to TB page 50 Q4] A. Comparison between convectional and orographic rainfall: i. Both types of rainfall are caused by vertical ascent of heated air. SESSION 5. TYPES OF RAINFALL 81

CHAPTER 4- ATMOSPHERE Contrast between convectional and orographic rainfall: i. While orographic rainfall is caused when the mountain forces the air to rise over the mountain or the elevation in its path, the convectional rainfall occurs when moisture over the heated ground becomes warmer than the surrounding air. ii. While convectional rainfall is common on summer days in the interior part of the continents, orographic rainfall occurs in the windward sides of mountains. iii. While the orographic rain occurs in the mountainous regions, the convectional rain takes place in the equatorial regions. Q2. Describe distribution of rainfall across the world. [Refer to TB page 50 Q5] A. Distribution of World Rainfall: 1) Between the latitudes 10° and 30° N and S of the equator, due to the trade winds, rainfall is heavier on the eastern coasts and decreases towards the west. 2) Between the latitudes 40° and 60° N and S of the equator due to the westerlies the rainfall is heavy on the west coast and decreases towards the east. 3) Low pressure areas, especially around the equator, receive higher rainfall than high pressure areas. 4) The rainfall is more over the oceans than on the continent. 5.4 Key Concepts On the basis of its origin, rainfall may be classified into three main types: i) Convectional rainfall which is common in low latitudes. ii) Orographic rainfall is also called ‘orogenic’ rainfall. iii) Cyclonic rainfall is associated with the passage of a cyclone or a depression. SESSION 5. TYPES OF RAINFALL 82

CHAPTER 4-ATMOSPHERE —— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. Match the following. Column A Column B i. Cyclone a. Moves at slow pace b. Moves very fast ii. Breeze iii. Storm c. Very high speed wind iv. Wind d. Short and fast burst v. Gust e. From high to low pressure areas 2. Match the following. Column A Column B i. Foehn a. New Zealand ii. Simmon b. Japan iii. Yoma c. Causes sunstroke iv. Norwester d. Arabian desert v. Loo e. Europe 3. Answer the following questions in one sentence. (i) What do you mean by atmosphere? CHAPTER 4. ATMOSPHERE 83

CHAPTER 4-ATMOSPHERE (ii) Give one reason why atmosphere is important to us. (iii) Name any two gases which are present in smaller percentages in the atmosphere. (iv) What are seasonal winds? (v) What are the two broad layers of the atmosphere? (vi) Explain the term planetary winds. 84 (vii) What happens to pressure when the air is hot? CHAPTER 4. ATMOSPHERE

CHAPTER 4-ATMOSPHERE (viii) Mistral, Puna and Pampero are the names of which type of winds? (ix) State two adverse effects of climatic changes on human life. (x) Define the term humidity. 4. Fill in the blanks. . . (xi) Living beings cannot live without (xii) The colour of sunrise is caused by , use sunlight and water to . (xiii) Green plants take in . (xiv) Troposphere is the thickest at CHAPTER 4. ATMOSPHERE 85

CHAPTER 4-ATMOSPHERE (xv) transport water from the ocean deeps into the continents in the form of rain. (xvi) contains 75% of the total gaseous mass of the atmosphere. (xvii) Atmosphere is a of gases surrounding the earth. (xviii) The entire weather phenomenon happens in the layer. (xix) The full form of NASA is . (xx) When air moves form high to low pressure areas it is called . Short Answer Type Questions 5. Answer the following questions in 3-4 sentences. (i) What is Homosphere? (ii) Why do winds blow from a high pressure area to a low pressure area? CHAPTER 4. ATMOSPHERE 86

CHAPTER 4-ATMOSPHERE (iii) What is climate? Explain. (iv) What is Normal lapse rate? Where is it found? (v) How are winds classified? Long Answer Type Questions 87 6. Answer the following questions in 6-8 sentences. (i) What are the different types of rainfall? Explain. CHAPTER 4. ATMOSPHERE

CHAPTER 4-ATMOSPHERE AS2-Reading the Text, Understanding and Interpretation Short Answer Type Questions 7. Answer the following questions in 3-4 sentences. (i) When heated air rises, it starts losing the energy that it got from the Earth’s surface—explain the effects of such a phenomenon. CHAPTER 4. ATMOSPHERE 88

CHAPTER 4-ATMOSPHERE AS3-Information Skills Long Answer Type Questions 8. Answer the following questions in 6-8 sentences. (i) Read the paragraph and answer the following questions: Condensation is the opposite of evaporation, as it involves conversion of water vapour into droplets of water or crystals of ice. When the relative humidity exceeds 100%, the excess of water vapour present in the atmosphere gets condensed as minute droplets of water. For example, when air at a temperature of 20°C contains 49 g of water vapour per cubic metre and gets cooled to 10°C it can hold only 40 g of water vapour at saturation level. The excess of 9 g of water vapour gets condensed. Condensation can take place only when minute solid particles are present in the atmosphere. Condensation can also take place on a contact surface. For example, have you observed what happens when cold water is filled in a glass? Condensation happens on the outer side of the glass as the moisture in the air comes in contact with a cold surface. When water vapor condenses on surfaces such as plants, dew drops are formed. 1. What is condensation? 2. What happens when the relative humidity is 100 %? 3. What do you observe when you fill a glass with cold water? 4. Where are Cirrus clouds found? 5. What is the Latin name for precipitation? AS5-Mapping Skills 89 Long Answer Type Questions 9. Answer the following questions in 6-8 sentences. (i) Identify the location of the given local winds in the world map: a) Chinook b) Loo c) Simoom d) Yoma e) Norwester CHAPTER 4. ATMOSPHERE

CHAPTER 4-ATMOSPHERE Objective Questions AS1-Conceptual Understanding 10. Choose the correct answer. (i) The atmosphere has of oxygen in it. (A) 78% (B) 21% (C) 0.3% (D) 33% (ii) Which gas dominates in atmosphere by volume? (A) Oxygen (B) Carbon dioxide (C) Nitrogen (D) Argon (iii) Particulates found in the atmosphere are . (A) fine dust particles (B) gas particles found in the atmosphere CHAPTER 4. ATMOSPHERE 90

CHAPTER 4-ATMOSPHERE (C) tiny drops of water (B) Biosphere (D) None of the above (iv) Where is Stratosphere found? (A) Atmosphere (C) Hemisphere (D) Homosphere (v) The uppermost layer of the atmosphere is called . (A) Stratosphere (B) Mesosphere (C) Troposphere (D) Exosphere (vi) layer is almost free from clouds. (A) Troposphere (B) Mesosphere (C) Stratosphere (D) Ionosphere (vii) What is meant by ITCZ? (A) Inter-Tropical Convergence Zone (B) Ionosphere temperate convergence Zone (C) Inter Area Complete Zone (D) Inter Temperate Convergence Zone (viii) Coriolis effect is zero at . (A) Tropic of Cancer (B) Tropic of Capricorn (C) Equator (D) Poles CHAPTER 4. ATMOSPHERE 91

CHAPTER 4-ATMOSPHERE (ix) Coriolis effect is the highest at . (A) Equator (B) Poles (C)Tropic of Cancer (D)Tropic of Capricorn (x) Foehn, the hot winds, blow along the northern slopes of the . (A) Rockies (B) Andes (C) Alps (D) Himalayas CHAPTER 4. ATMOSPHERE 92

SESSION 1 5. BIOSPHERE 1.1 Mind Map NATURAL VEGETATION 1.2 Terminology 1. Food chain: A series of organisms each dependent on the next as a source of food. 1.3 Improve Your Learning Conceptual Understanding Q1. Life itself constitutes a separate sphere called ‘Biosphere’ Explain. [Refer to TB page 58 Q1] A. The earth is a unique planet, which has life thriving on it. It is inhabited by countless forms of life from microscopic bacteria to great banyan trees and animals like elephants, tigers and blue whales to of course human beings. The fact that the earth has a combination of land, air and water and a moderate temperature (due to moderate distance from the Sun) has made life possible on it. Life thrives only in the intersection of the three spheres — lithosphere, atmosphere and hydrosphere. According to many geographers, life itself constitutes a separate sphere called “Biosphere”. SESSION 1. NATURAL VEGETATION 93

CHAPTER 5- BIOSPHERE All forms of life have an integral connection with the land, air, water and sunshine around them. They draw their sustenance from them and, in turn, affect them in significant ways. Various forms of life are not only related to the three spheres around them, but also to each other. They are part of a complex ‘food chain’ – that is, one kind of life becomes food for another kind. Many of the life forms are also symbiotic that is, they live by exchanging essential substances with each other. Q2. Write about different kinds of forests and climatic conditions of their existence. [Refer to TB page 58 Q3] A. a) Tropical Deciduous Forests. i. Tropical deciduous forests are the monsoon forests. ii. These regions experience seasonal changes. iii. Trees shed their leaves in the dry season to conserve water. b) Tropical Evergreen Forest: i. These thick forests occur in the regions near the equator and close to the tropics. ii. These regions are hot and receive heavy rainfall throughout the year. iii. As there is no dry season, these trees do not shed their leaves altogether. iv. This is why they are called evergreen forests. c ) Temperate Evergreen Forests: i. These forests are located in the mid–latitudinal coastal region. ii. They are commonly found along the eastern margin of the continents. d) Temperate Deciduous Forests: i. The temperate deciduous forests are found in higher latitudes. ii. They shed their leaves in the dry season. SESSION 1. NATURAL VEGETATION 94

CHAPTER 5- BIOSPHERE e) Mediterranean Vegetation: i. The west and the south west margins of the continents are covered by these forests. ii. Mediterranean trees adapt themselves to dry summers with the help of their thick barks and wax–coated leaves. These help them reduce transpiration. iii. These regions are marked for hot dry summers and mild rainy winters. f) Coniferous Forests: i. Coniferous forests are found in the higher latitudes of Northern hemisphere. ii. These forests are found in abundance in the Himalayas. g) Tropical Grasslands: i. These forests grow on either side of the equator up to tropics. ii. This vegetation grows in the areas of moderate to low amount of rainfall. h) Temperate Grasslands: i. These are found in mid –latitudinal zones and in the interior part of the continents. ii. Usually the grass is very short and nutritious. i) Thorny Bushes: i. These are found in dry desert–like regions. ii. This vegetation cover is scarce here because of scanty rain and scorching heat. j) Tundra: i. This vegetation is found in the polar region. ii. The growth of natural vegetation is very limited here. iii. Only mosses, lichens and very small shrubs are found here. SESSION 1. NATURAL VEGETATION 95

CHAPTER 5- BIOSPHERE Information Skills Q1. Read the chapter and fill up the table. S.No Type of forest Spread across the countries Trees grown Animals A. Spread across the Trees grown Animals countries S. No. Type of forest 1 Tropical evergreen Near equator and Rosewodd, ebony, Tigers, forests close to tropics mahogany elephants, lions etc 2 India. Australia and Sal, teak, neem and Tropical deciduos central America shisham Tigers, lions, forests elephants, oak, pine, langoors, 3 South east USA, ecualyptus monkeys etc Temparate south china, south evergreen forests east Brazil Oak, ash, beech, Deers, foxes, 4 birch wolfs etc Temparate Deers, foxes, deciduous forests North east USA, wolfs etc China, New zealand, Mediteranian trees 5 Mediteranian Chile, coastal region of western Europe No wildlife Chir, pine, cedar 6 Coniferous forests South west margins of continents, areas around mediteranian Silver fox, mink, sea polar bear Himalayas SESSION 1. NATURAL VEGETATION 96

CHAPTER 5- BIOSPHERE 1.4 Key Concepts i. The earth is an unique planet. It has life thriving on it. ii. All forms of life have an integral connection with the land, air, water and sunshine around them. iii. The primary food producers are the plants which produce food with the help of sunlight. iv. Bacteria and fungi help in decomposition of dead trees and animals. v. Any disturbance in cycle of life is called ecological crisis. vi. Vultures feed upon dead animals like cattle. vii. Tropical evergreen forests are also called tropical rainforests. viii. Rosewood, ebony, mahogany are called hardwood trees. ix. Tropical deciduous forests are the monsoon forests found in large parts of India. x. Mediterranean vegetation is found in West Africa, South America and South–west Australia. xi. Coniferous forests are also called Taiga. xii. Match boxes and packing boxes are made from soft wood. SESSION 1. NATURAL VEGETATION 97

SESSION 2 GRASSLANDS 2.1 Mind Map 2.2 Terminology 1. Hard wood trees: It is a kind of wood that grows in the tropical deciduous forests. 2. Ecological crises: The pollution effect on water, air and soil is called ecological crises.(or) presence poisonous substance in air or water or soil is called ecological crises. 3. Tundra: a small ,shrubby and bushy plants in dry and cold regions. SESSION 2. GRASSLANDS 98