202110221-TRIUMPH-STUDENT-WORKBOOK-SCIENCE-G06-PART1

(xx) Some stems bulge in size due to the storage of food material. [ ] 5. Answer the following questions in one sentence. [Refer to Session 9.3 ] (xxi) Name one plant in which the food is stored in their stem. (xxii) Name one plant in which the food is not stored in their stem. Short Answer Type Questions 6. Answer the following questions in 3-4 sentences. (i) [(Session 9.1)] What are the different parts of a plant? CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 199

(ii) [(Session 9.1)] What are tuberous roots? Give examples. Can they be eaten raw? Long Answer Type Questions 7. Answer the following questions in 6-8 sentences. (i) [(Session 9.1)] In which type of root system are lateral roots absent? What is the relation between the root system and the venation seen in leaves? CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 200

(ii) [(Session 9.1)] Describe different types of roots and write a few lines about them. AS2-Asking questions and making hypothesis Long Answer Type Questions 8. Answer the following questions in 6-8 sentences. (i) [(Session 9.1)] Archana observed that when her brother tied a small polythene bag around the leaves of a plant for a few hours, there were small droplets of water inside bag. What questions might Archana have in her mind? CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 201

AS3-Experimentation and field investigation Short Answer Type Questions 9. Answer the following questions in 3-4 sentences. (i) [(Session 9.1)] Take few seeds of a carrot plant and sow them in the soil. After a few days observe the type of roots the plant has developed. What do you observe? Long Answer Type Questions 202 10. Answer the following questions in 6-8 sentences. (i) [(Session 9.3)] How will you show that stems carry water? CHAPTER 9. PLANTS: PARTS AND FUNCTIONS

CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 203

AS4-Information skills and projects Long Answer Type Questions 11. Answer the following questions in 6-8 sentences. (i) [(Session 9.2)] Collect leaves from five different plants. Draw their structure and make a table noting down their venation, size, shape and root system. CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 204

AS5-Communication through drawing and model making Long Answer Type Questions 12. Answer the following questions in 6-8 sentences. (i) [(Session 9.1)] Observe the given diagram and label its parts. CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 205

AS6-Appreciation and aesthetic sense, Values Short Answer Type Questions 13. Answer the following questions in 3-4 sentences. (i) [(Session 9.2)] Appreciate the role of leaves in plants. AS7-Application to daily life, concern to bio diversity Short Answer Type Questions 14. Answer the following questions in 3-4 sentences. (i) [(Session 9.1)] Give some examples where you come across adaptation in plants. CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 206

Objective Questions AS1-Conceptual Understanding 15. Choose the correct answer. (i) help to fix the plant firmly in the soil. (A) Roots (B) Stem (C) Branches (D) Water (ii) Plants prepare food by a process called . (A) respiration (B) digestion (C) photosynthesis (D) transpiration (iii) Banana oil is made from . (A) bananas (B) flax seeds (C) petroleum (D) potatoes (iv) are swellings on a plant from which a shoot, a leaf or a flower develops. (A) Buds (B) Bulbs (C) Tubers (D) Roots (v) Which of the following does not store food in their roots or stems? (A) Beet root (B) Spinach (C)Sweet potato (D) Carrot (vi) The flat portion of the leaf is called. . . (A) lamina (B) leaf base (C) petiole (D) spores CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 207

(vii) The long vein present in the middle of the lamina is called . (A) petiole (B) leaf base (C) midrib (D) stalk (viii) acts as a skeleton of the leaf. (A) Petiole roots have (B) Midrib (C) Venation (D) Lamina (ix) Plants with venation. (A) Tap, parallel (B) Fibrous, reticulate (C)Fibrous, parallel (D)Tap, fibrous (x) are useful in the exchange of gases between the plant and atmosphere. (A) Lamina (B) Stem (C) Midrib (D) Stomata (xi) In the process of , water is released from plants in the form of vapour. (A) transpiration (B) photosynthesis (C) transportation (D) osmosis (xii) attract insects for pollination. (A) Plants (B) Flowers (C) Stems (D) Leaves CHAPTER 9. PLANTS: PARTS AND FUNCTIONS 208

10. CHANGES AROUND US SESSION 1 WHY DO CHANGES OCCUR, CHANGING OF MILK TO CURD 1.1 Mind Map SESSION 1. WHY DO CHANGES OCCUR, CHANGING OF MILK TO CURD 209

1.2 Terminology i. Change –is the process of causing a function, practice, or thing to become different from what it is at present or what it was in the past. ii. Change in state –refers to the change in the physical form of matter between solid, liquid or gaseous states without any change in their chemical composition. iii. Evaporation –is the process by which a liquid changes its form to a gas. iv. Condensation –refers to the process of change of state from gas to liquid. v. Hazardous –means risky or dangerous. In a science laboratory, testing a chemical without informing the teacher can be hazardous. 1.3 Key Concepts i. In our daily life, we come across many changes that are constantly occurring in nature. ii. A change may be sudden or gradual. Moreover a change may be natural or initiated by humans. iii. A change may cause change in colour, physical properties or state of a substance. iv. Growth of plant is a natural change whereas changes occurring while making tea is human initiated. v. To explain any change, we must think of the possible and most appropriate reasons for it. vi. Changing of milk into curd is a natural process initiated by certain bacteria. SESSION 1. WHY DO CHANGES OCCUR, CHANGING OF MILK TO CURD 210

1.4 Conceptual Understanding Q1. Write various processes involved in making ghee from milk. What changes do you find during this process? [Refer to TB page 104 Q12] A. 1) When milk is heated, it becomes hot. This is a temporary man–made change. 2) When milk is luke warm, a small quantity of curd is added to it for curd formation. 3) Once formed, churn curd when it is still cool. In about 10 to 20 minutes of continuous churning, the butter–fat ‘breaks’ from the yogurt as butter–globules. 4) The butter–globules clump together which is skimmed–off to make Ghee. The changes we find in this process are in the colour, taste, the physical state and chemical changes. 1.5 Experimentation and Field Investigation Q1. Select a plant in your house/school. Observe and record changes keeping in view height of plant, number and size of leaves and flowers etc. over a period of 2 months. Display your observations. [Refer to TB page 103 Q10] A. Students’ Activity • The student can do this field experiment independently by selecting a plant of his choice in his house/school. • The student can display his observations in the class. Q2. What will happen if a decorative coloured paper is dipped in water? Predict the possible changes. Verify your predictions by doing experiments and write down the steps of the process. [Refer to TB page 103 Q11] A. Predictions: • When a decorative coloured paper is dipped in water, the colour of the paper might get dissolved in water as a result of which– SESSION 1. WHY DO CHANGES OCCUR, CHANGING OF MILK TO CURD 211

i. The coloured paper might lose its colour and turn pale. ii. The water will turn coloured. Verification : • Take a glass tumbler half–filled with water and dip a decorative coloured paper in it. • After few minutes, the water gets some colour of the decorative paper. • The decorative paper loses its colour. SESSION 1. WHY DO CHANGES OCCUR, CHANGING OF MILK TO CURD 212

SESSION 2 CHANGING SEASONS 2.1 Mind Map 2.2 Terminology i. Seasonal changes –are changes associated with change in different seasons such as change in clothes, food preference, change in duration of day etc. ii. Duration of day –refers to the period of light between dawn and nightfall, i.e., the interval from sunrise to sunset. iii. Indicators of change –include our preference for type of clothes, food, change in temperature of air, availability of fruits, vegetables and flowers etc. which enable us to see and feel the changes around us. 2.3 Key Concepts i. There are four major seasons that occur periodically in nature. ii. Change in seasons is often associated with many other changes. iii. Changing season may bring about change in our clothes preference and preference for food and drinks. SESSION 2. CHANGING SEASONS 213

iv. It also results in change in direction of sunrise and change in length and direction of shadow. v. In summers, days are longer than nights, and the Sun rises early and sets late. vi. In winters, days are shorter than nights, and the Sun rises late and sets early. vii. There are indicators and cause or reason behind every change. viii. Slight change in direction of sunrise is the reason for change in seasons. 2.4 Conceptual Understanding Q1. Observe the following table and answer the questions given below. [Refer to TB page 104 Q13] Place Rentachintala Month January April August 24◦C Temperature 21◦C 39◦C 34◦C (Min) 27◦C 47◦C 39.12 mm Temperature 2.41 mm 0.01 mm 6.37 (Max) 17.31 Rainfall Sunrise 6.5 6.11 Sunset 17.12 17.47 a) Which month had maximum rainfall? b) Which season occurs in the month of August? How can you support your answer? c) In which month is the duration of day minimum? What could be the reason for this? d) Do you find any relation between sunrise and seasons? e) What changes can you identify from January to August? A. a) We observed maximum rainfall in the month of August. SESSION 2. CHANGING SEASONS 214

b) Rainy season occurs in the month of August. It is clearly evident from the table that the maximum rainfall of 39.12 mm was reported in the month of August in Rentachintala. c) The duration of day is minimum in the month of January. The duration of day is shorter because of change in the direction of Sunrise to slightly south of east. Moreover, January reports a late sun rise and an early sun set which shortens the duration of day. d) Yes, seasons and sunrise are interdependent. Change of seasons is due to change in the direction of sunrise. From the table, we observe that during summers, there is an early sunrise and late sunset. Whereas, in winters, there is a late sunrise and early sunset. e) From January to August, we can identify the following changes from the table: i) Variation in temperature ii) Variation in rainfall iii) Change in duration of the day 2.5 Asking Questions and Making Hypothesis Q1. Farah wondered “how it could be possible for nature to bring changes in seasons peri- odically”? Can you add some changes like this? How will you explain them? [Refer to TB page 104 Q14] A. i. The slight change in the direction of sunrise is one of the reasons for change in seasons. ii. The changes that repeat after a fixed interval of time are called as periodic changes. They are continuous in nature. iii. Some examples of periodic changes include: Occurrence of day and night, change in phases of moon, heartbeat, rotation of fan, falling of tree leaves etc. iv. Since all these changes repeat after a particular time period, they are all periodic changes. 2.6 Appreciation and Aesthetic Sense, Values Q1. Sita wondered and felt very happy to see the beauty of the fields and insects like twin- SESSION 2. CHANGING SEASONS 215

kling beetle (Arudra) during rainy season in their village. Can you list some such changes which make you wonder and feel happy? [Refer to TB page 104 Q15] A. Every season in the nature has its own charm and special characteristic that make us wonder and feel excited. i. During summers, it is wonderful to see how plants protect themselves from ex- cessive heat and water loss by shedding their leaves and reducing the rate of transpiration. Some summer–blooming varieties with colourful flowers add to the beauty of this season. ii. It is amazing to see change in the length, direction and position of shadow through- out the day and with change in seasons. iii. Availability of a variety of fruits and vegetables specific to specific seasons is yet another wonder of the nature. iv. Availability and preference of different types of fabrics and clothes for different season add variety and beauty to life. SESSION 2. CHANGING SEASONS 216

SESSION 3 COMPARE THE CHANGE OF MILK TO CURD WITH CHANGE OF SEASONS 3.1 Mind Map 3.2 Terminology i. Slow changes –are those changes that take place in longer duration of time. For eg., Rusting of iron. ii. Fast changes –are the changes that take place in small durations of time. For eg., Switching on and off an electric bulb. iii. Natural changes –are those changes that take place in nature without human inter- vention. For eg., Change in seasons. iv. Man–made changes –are those changes which occur due to human activity or are influenced by human intervention. For eg., Changing of raw vegetables to cooked vegetables. v. Temporary changes –are those changes which can be reversed to their original form. For eg., Change in seasons. vi. Permanent changes –are those changes which cannot be reversed. For eg., Curd cannot be changed to milk. 3.3 Key Concepts i. Different types of changes occur around us continuously. ii. A change may be sudden or gradual, slow or fast, temporary or permanent and natural or initiated by humans. iii. Whether a change is slow or fast is relative in nature. SESSION 3. COMPARE THE CHANGE OF MILK TO CURD WITH CHANGE ... 217

iv. Change of milk to curd is a permanent, man–made and fast change as compared to change of seasons. v. Change of seasons is a temporary, natural and slow change when compared to for- mation of curd from milk. vi. Various parameters act as an indicator of changes such as change in color, state, smell etc. 3.4 Conceptual Understanding Q1. Is the change of ice into water a temporary or permanent change? [Refer to TB page 103 Q1] A. i. Change of ice into water is a temporary change. ii. By cooling the water to 0o C, we can get ice from water. iii. Similarly, on increasing the temperature, ice can again melt to form water. iv. This is an example of change in state of ice from solid to liquid, and is a temporary change. Q2. a) If raw egg is boiled in water, what changes do you notice in it? b) If you are given two eggs, can you determine which one is boiled and which one is not? Explain. [Refer to TB page 103 Q3] A. a) On shaking a raw egg, we can feel the liquid content spinning inside it. However, if the egg is boiled in water, the matter inside the egg will solidify. And on shaking the egg, we will not be able to feel the liquid rotating inside it. b) Yes, we can distinguish between a raw and boiled egg by a simple test. When the given egg is made to rotate on a table, the raw egg spins slowly and wobbles, whereas the hard–boiled egg will spin faster and will come to rest sooner when stopped by the index finger. SESSION 3. COMPARE THE CHANGE OF MILK TO CURD WITH CHANGE ... 218

Q3. Name five changes you notice in your surroundings. Classify them as natural or man–made changes. [Refer to TB page 103 Q4] A. S.No. Change Natural / Man–made 1. Ripening of mango Natural 2. Changing of season Natural 3. Switching on a fan Man–made 4. Preparation of sambar from daal Man–made and vegetables 5. Germination of seed Natural Q4. Choose incorrect statements from the following and rewrite them correctly. [Refer to TB page 103 Q5] a) Boiled egg is a temporary change. b) An electric bulb going on and off is a permanent change. c) There is a cause for every change. d) There is a change in state when ice–cream melts. e) The coldness in air during winter is a permanent change. A. a) Boiled egg is a permanent change. b) An electric bulb going on and off is a temporary change. c) This statement is correct. d) This statement is correct. e) The coldness in air during winter is a temporary change. SESSION 3. COMPARE THE CHANGE OF MILK TO CURD WITH CHANGE ... 219

Q5. Some changes are listed below; classify them as temporary and permanent. a) Souring of curd b) Ripening of oranges c) The sawing of a piece of wood into two d) Cooking of food e) Heating of milk – [Refer to TB page 103 Q6] A. a) Souring of curd –Permanent change b) Ripening of oranges - Permanent change c) The sawing of a piece of wood into two - Permanent change d) Cooking of food - Permanent change e) Heating of milk - Temporary change Q6. We use clay to make idols. Can we get back clay from the Idol? What type of change is it? Explain. [Refer to TB page 103 Q7] A. • Yes, we can get back unbaked clay from idols. • When immersed in water, the clay dissolves and gets back to its original form. • Thus, making idols with clay is a temporary change. Q7. Carpenter made a chair using wood, what type of change is it? [Refer to TB page 103 Q8] A. Making a chair with wood is a permanent change as we cannot get back the wood pieces from the chair in their original shape and form. Q8. Rafi said that “Flour from rice/wheat is a man–made change.” He wants to make a list of examples of this kind of change, help him expand his list. [Refer to TB page 103 Q9] A. Some more examples of man–made changes for Rafi to expand his list of these kind of changes include: Flour from rice/wheat i. Sawing a piece of wood ii. Dissolving sugar in water iii. Cooking of food SESSION 3. COMPARE THE CHANGE OF MILK TO CURD WITH CHANGE ... 220

iv. Woollen yarn to knitted sweater v. Cold milk to hot milk vi. Production of biogas from cow–dung vii. Coiled string to straight string Q9. How do you know that rusting of iron is a change? [Refer to TB page 103 Q2] A. • Rust is a form of powder that forms over articles made up of iron when they come into contact with air or water. • Iron reacts with atmospheric oxygen and forms iron oxide which is called as rust. • Iron is hard and cannot be broken easily, while a rusted iron object is weaker. • Thus rusting leads to changes in physical and chemical properties of iron, and thus is a type of slow change. —— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. State true or false. [Refer to Session 10.1 ] (i) The change of state from liquid to gas is called boiling. [] (ii) In our daily life, we do not notice any sort of change around us. [ ] (iii) We notice a lot of changes taking place in our environment as well as in our body. [] CHAPTER 10. CHANGES AROUND US 221

2. Answer the following questions in one sentence. [Refer to Session 10.1 ] (iv) What is the change of state from gas to liquid called? (v) Is there any change of state during change from milk to curd? 3. State true or false. [Refer to Session 10.3 ] (vi) Fuel cannot be extracted later to perform mechanical work. [ ] (vii) Change in taste, smell and colour can be identified during the change of milk to curd. [] (viii) There is a slight change in the direction of sunrise during the change of seasons. [] 4. Answer the following questions in one sentence. [Refer to Session 10.3 ] (ix) Give an example of a slow change. CHAPTER 10. CHANGES AROUND US 222

(x) Give an example for a fast change. (xi) During which season are the days shorter? (xii) Give an example for a natural change. (xiii) Give an example for a permanent change. 5. State true or false. [] [Refer to Session 10.2 ] [] (xiv) Seasons change every week. 223 (xv) People prefer to wear light cotton clothes during summer. CHAPTER 10. CHANGES AROUND US

(xvi) There are mainly 4 seasons in India. [] (xvii) Eating spicy food during winters helps to keep ourselves warm with the heat generated from the spices. [] 6. Answer the following questions in one sentence. [Refer to Session 10.2 ] (xviii) Do we prefer to change the type of clothes every season? (xix) Should we change our eating habits with the change in seasons? (xx) When winter comes, what kind of clothes do we wear? (xxi) What do most kids love eating during the summer season? CHAPTER 10. CHANGES AROUND US 224

(xxii) What happens to the pressure when there is a lot of heat? (xxiii) What happens during the autumn season? Short Answer Type Questions 7. Answer the following questions in 3-4 sentences. (i) [(Session 10.1)] List a few changes you observe that are taking place in and around you and also mention the change of state. (ii) [(Session 10.1)] What are the changes you observe when there is change of milk to curd? CHAPTER 10. CHANGES AROUND US 225

8. Answer the following questions in 3-4 sentences. (i) [(Session 10.3)] Write a few differences between slow and fast changes you observe in your daily life. (ii) [(Session 10.3)] Differentiate between: 226 a) Permanent change and Temporary change b) Natural change and Man–made change CHAPTER 10. CHANGES AROUND US

9. Answer the following questions in 3-4 sentences. (i) [(Session 10.2)] What do we observe when there is a change of seasons? CHAPTER 10. CHANGES AROUND US 227

(ii) [(Session 10.2)] Why do seasons change? Name the four main seasons observed in India. Long Answer Type Questions 10. Answer the following questions in 6-8 sentences. (i) [(Session 10.1)] Give examples for five permanent and five temporary changes. CHAPTER 10. CHANGES AROUND US 228

11. Answer the following questions in 6-8 sentences. (i) [(Session 10.2)] What are the different ways in which changes can be classified? Ex- plain. AS2-Asking questions and making hypothesis Long Answer Type Questions 12. Answer the following questions in 6-8 sentences. (i) [(Session 10.3)] Amita saw her mother preparing lemon tea. She noticed that as soon as her mother added lime juice to the black tea, it turned a light brown. What questions do you think Amita might have? CHAPTER 10. CHANGES AROUND US 229

AS3-Experimentation and field investigation Short Answer Type Questions 13. Answer the following questions in 3-4 sentences. (i) [(Session 10.1)] Go to a nearby field and a dairy farm and observe all the different changes that are taking place in the respective areas. Make a note of these changes. Long Answer Type Questions 230 14. Answer the following questions in 6-8 sentences. CHAPTER 10. CHANGES AROUND US

(i) [(Session 10.3)] How will you find the conditions required for setting of curd from milk? AS4-Information skills and projects Long Answer Type Questions 15. Answer the following questions in 6-8 sentences. (i) [(Session 10.2)] Collect information about the changes in plants during all the seasons. What changes do you see in a pine tree? CHAPTER 10. CHANGES AROUND US 231

AS5-Communication through drawing and model making Long Answer Type Questions 16. Answer the following questions in 6-8 sentences. (i) [(Session 10.2)] Observe the images given below. What can you tell from the images? CHAPTER 10. CHANGES AROUND US 232

AS7-Application to daily life, concern to bio diversity Long Answer Type Questions 17. Answer the following questions in 6-8 sentences. (i) [(Session 10.2)] Discuss in details how changing seasons affect our life? CHAPTER 10. CHANGES AROUND US 233

Objective Questions AS1-Conceptual Understanding 18. Choose the correct answer. . (i) The change of state from liquid to gas is called (A) Freezing (B) Evaporation (C) Melting (D) Condensation (ii) is a temporary change. (A) Growth in plants (B) Change of ice into water (C)Boiling of egg (D)Burning of paper (iii) is a dairy product obtained by curdling of milk. (A) Curd (B) Rasmalai (C)Gulab jamun (D)Kheer (payasam) (iv) When a place is hot, the pressure gets . (A) increased (B) remains unchanged (C) lowered (D)cannot tell (v) The seasons and changes in weather occur due to . (A) the Earth revolving around the Sun on a tilted axis (B) the Moon revolving around the Earth (C)the Earth rotating on its axis (D)the Moon rotating on its axis CHAPTER 10. CHANGES AROUND US 234

(vi) Conversion of milk into curd is a change as compared to the changing of seasons. (B) natural (A) fast (D) temporary (C) slow (vii) The change of state from gas to liquid is called . (A) melting (B) solidification (C) boiling (D) condensation (viii) Which of the following correctly shows the phase change that happens in evapo- ration? (A) Solid → Liquid (B) Solid → Gas (C)Liquid → Solid (D)Liquid → Gas (ix) If the winter season changes to summer season, we observe change in our . (A) mood (B) growth (C)clothes preference (D)skin colour (x) is the mechanical and chemical breakdown of food. (A) Digestion (B) Excretion (C) Evaporation (D) Solidification CHAPTER 10. CHANGES AROUND US 235

11. WATER IN OUR LIFE SESSION 1 WATER AND ITS USES, MEASURING VOLUME OF WATER 1.1 Mind Map SESSION 1. WATER AND ITS USES, MEASURING VOLUME OF WATER 236

1.2 Terminology i. Volume –is the amount of space that a substance or object occupies, both in air or when enclosed within a container. ii. Units of measurement – is a definite magnitude of a physical quantity used as a stan- dard of measurement by convention or by law. iii. Milli litres –is a unit of volume defined as one–thousandth of a litre. iv. Litres – is an SI unit of volume equal to 1 cubic decimetre (dm3 ), 1,000 cubic cen- timetres (cm3 ) or 1/1,000 cubic metre (m3 ). v. Gallon –is a unit of volume used in the US and British systems of measurement. It is generally used to measure liquids such as gasoline, water, milk etc. and equals to 4 quarts (3.785 liters). vi. Cusec –is a unit used to measure the level of water released from dams and projects during floods. vii. Reservoirs – is an enlarged natural or artificial lake, storage pond or impoundment created using a dam or lock to store water. 1.3 Key Concepts i. Water is used for different purposes like washing, cooking, agricultural purposes, in industries etc. ii. Wells, canals, tanks, ponds, rivers etc. are the main sources from where we get water. iii. Unit of measurement of liquids is litres and millilitres denoted as l or ml. iv. Although different measurements are there to measure very large quantity of water such as water stored in tanks are measured in gallons, water level in reservoirs is measured in feet. v. The water released from dams and projects during floods is measured in cusecs. 1.4 Conceptual Understanding Q1. How can you say that water is necessary for us? [Refer to TB page 112 Q1] A. Water is a very essential part of our everyday life and is required for our various day to day activities. SESSION 1. WATER AND ITS USES, MEASURING VOLUME OF WATER 237

• We require water for drinking, cooking, bathing, washing etc. • Plants need water to grow and in turn, we get fruits, vegetables and grains from the plants. • Water is also used to generate electricity. • Moreover, three–fourth of our body contains water and it is essential for proper functioning of our body. Q2. Ravi wants to know the measuring units of water. What will you tell him? [Refer to TB page 112 Q2] A. 1) Water and most liquids are generally measured in litres and millilitres. 2) Gallon is also a measure of the volume of water used for large volumes. The water tanksin some villages and most towns and cities have the capacity to store gallons of water. 3) The water level in the reservoirs is measured in feet. 4) Water released from dams and projects during floods is measured in the unit called cusecs (cubic meters/sec). SESSION 1. WATER AND ITS USES, MEASURING VOLUME OF WATER 238

SESSION 2 WATER ON EARTH 2.1 Mind Map SESSION 2. WATER ON EARTH 239

2.2 Terminology i. Drought –refers to a prolonged period of abnormally low rainfall, leading to a shortage of water. ii. Flood –refers to an overflow of a large amount of water beyond its normal limits, especially over a usually dry land. iii. Migration –is the seasonal movement of birds and animals from one region to another to avoid harsh and unfavourable conditions. iv. Fluorosis –is a chronic condition caused by excessive intake of fluorine compounds through intake of polluted ground water with high levels of fluorine. It causes mottling of teeth and calcification of ligaments. 2.3 Key Concepts i. Three–fourth of the earth’s surface is occupied by water, of which only 1% is available to us as fresh water. ii. We use fresh water from sources like ponds, puddles, rivers, tubewells and taps for our daily purposes. iii. The water level in the various water resources in our surroundings depends upon rainfall. iv. If there is less or no rainfall for considerably longer periods, scarcity of water may occur resulting in droughts. v. Excessive rainfall over long periods causes floods which affects human life. vi. We must use water judiciously and preserve it not only for us but for our future gener- ations as well. 2.4 Conceptual Understanding Q1. Why do people need protected drinking water scheme? [Refer to TB page 112 Q3] A. i. We require fresh water for drinking, cooking and many other purposes. ii. Ground water may contain various harmful microbes and high levels of chlorides, fluorides, nitrates and calcium salts. iii. Consumption of impure water leads to ill health and many diseases and conditions such as diarrhoea, fluorosis etc which may even lead to death. SESSION 2. WATER ON EARTH 240

iv. We, therefore, need a protected drinking water scheme through which people will get potable water. v. Potable water refers to water that is fit for drinking. vi. Under this scheme, water free from harmful disease–causing organisms is supplied to people. vii. The supplied water is also colourless, odourless and free from suspended impurities. viii. Thus, through protected drinking water scheme, we are provided with safe and pure water which prevents us from various illnesses. Q2. In season, we face severe water scarcity. Give your reason. [Refer to TB page 112 Q5] A. • We face severe water scarcity in summer season. • Due to high temperature, rate of water loss from our body through sweating and in plants through transpiration is higher. • To compensate for this loss, consumption of water is also high. • Rate of evaporation of water from the water resources like wells, rivers, ponds, puddles etc. is also high. • With low or no rainfall and high consumption during summers, the level of ground water is not replenished at same level. • This leads to scarcity of water. • Low or no rainfall for a long period of 4 to 5 years leads to drought. • During this period, the soil becomes dry and there is scarcity of water for irrigation as well as for drinking and other purposes in daily life. • Leaching of impurities like harmful microbes and chemicals like fluorides etc in ground water also lead to scarcity of drinking water. Q3. The nature of sea water is [Refer to TB page 112 Q6] A) Salty B) Tasteless C) Odourless D) Sweet A. (A) Salty The nature of sea water is salty. SESSION 2. WATER ON EARTH 241

Q4. If we use water in the same way what will happen in future? Write your suggestions to prevent water wastage? [Refer to TB page 112 Q7] A. i. Using water in the same manner will lead to scarcity of water in the future. ii. We should take precautions not to waste water while using it. iii. For watering the plants in our garden, we should avoid using drinking water. iv. Water used in kitchen for washing vegetables and fruits etc should not be thrown, instead can be used for watering plants, or for flushing in toilets. v. We should take care not to allow overflow of water in tanks or buckets when filled. vi. While brushing our teeth, we should not keep the tap open. vii. Using water stored in a mug will prevent wastage of nearly 16 litres of water while brushing. viii. Using stored water for various activities that require use of water will help in saving water scarcity in the future. Q5. Find out the relationship between water shortage and drought. [Refer to TB page 112 Q11] A. i. Excessive use and wastage of water in an area may lead to lowering of level of ground water in those areas. ii. With low rainfall, the ground water level may not get replenished. iii. This leads to low supply of water for various day to day activities leading to water shortage. iv. No rainfall in areas of water shortage for long periods of 4 to 5 years lead to droughts. v. Droughts severely affect the livelihood of people as there is no or low supply of food, fodder, drinking water, and agriculture and cultivation also become difficult. SESSION 2. WATER ON EARTH 242

Q6. Justify the statement ‘droughts and floods are a result of actions made by man.” Investi- gate your reasons. [Refer to TB page 112 Q12] A. • Ever since the start of human civilization, man has been manipulating environment for his own needs. • Indiscriminate deforestation, drilling of borewells, air pollution etc. due to human activities cause disturbances in the weather patterns. • In nature, water lost from water bodies during high temperatures in summers is replenished by rainfall during rainy season. • However, disturbance in weather pattern due to human activities may lead to late arrival of rains, that too, sometimes amount of rainfall is low and insufficient to support human survival. • Excessive usage and wastage of water by man causes scarcity of water. • Low or no rainfall in areas of water shortage may lead to water in rivers and ponds to dry up and in such conditions, crops cannot grow properly. Such a condition is called a drought. • In some parts of our country, heavy rains during monsoon may cause water in the rivers to rise above their banks which flows to nearby land. Such condition is known as flood. • Man’s selfish and indiscriminate actions cause disturbances in the nature in this way leading to such problems. 2.5 Information Skills and Projects Q1. Make a pamphlet on ‘Do not waste water’. Display it on wall magazine. [Refer to TB page 112 Q9] A. Students’ Activity Hints / Suggestions: • Find out the activities of people which lead to wastage of water. • Make a pamphlet mentioning these activities. • Write the slogan ” Water is precious –Use judiciously ” or ” Save water –Stop wast- ing it ” or ” Do not waste water” on it. • Your pamphlet is ready for display on your school’s wall magazine. SESSION 2. WATER ON EARTH 243

Q2. Collect information about water related games and make a scrap book. [Refer to TB page 112 Q10] A. Some water–related games are: i. Swimming in water ii. Jumping into water from a height called Cliff–diving or Cliff–jumping iii. Boat competitions iv. Diving v. Yachting vi. Jet skiing vii. Joy rides in water parks etc. • Using internet and help from your teachers and parents, you can write about more games. • Also collect and paste pictures and newspaper articles on these games in your scrapbook. 2.6 Communication Through Drawing and Model Making Q1. Prepare a map of your village showing different water resources. [Refer to TB page 112 Q8] A. Students’ Activity • Water resources differ from place to place. • The student is, therefore, advised to observe the water sources available in his or her area and prepare a map accordingly. 2.7 Application to Daily Life, Concern to Bio Diversity Q1. If people are suffering due to severe floods, what would you do to help them? [Refer to TB page 112 Q14] A. i. At the time of severe floods, we should first try to evacuate the people from flooded regions to safer places. SESSION 2. WATER ON EARTH 244

ii. Essential items like food, clothes, medicines etc. should be collected and dis- tributed to people suffering from floods. iii. In case prior information is available, we should help them to collect and keep their valuables safely, and move to safer regions. iv. At the time of floods, basic facilities like availability of clean drinking water, food supply, electricity etc are also affected. So we should try to make these necessary items and their alternatives reach the people affected by floods. Q2. Aravind never forgot to switch off water pumping motor in time. Do you support him? Why? [Refer to TB page 112 Q13] A. Yes, we support and appreciate Aravind for always switching off the water pump motor in time because of the following reasons: i. Water is precious and very essential for us for our daily life activities. ii. We need water for cooking, drinking, washing, agriculture and many other pur- poses. iii. Our body also consists of 70% water by weight and it is required for proper func- tioning of our body. iv. Over–use and excessive wastage may lead to decrease in ground water level, especially in areas with low rainfall. Therefore, we must use water judiciously and preserve it not only for us but also for our future generations. Q3. List out the activities that we perform in our daily life that consume water. [Refer to TB page 112 Q4] A. In our daily life, we consume water for the following activities: i. We use water for drinking, cooking, bathing, washing, cleaning of vessels, toilets, flushing etc. ii. It is used for irrigation of crops. iii. In power plants, water is used for generating electricity. iv. Water is also used in many industries. SESSION 2. WATER ON EARTH 245

—— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. State true or false. [Refer to Session 11.1 ] (i) Water is an essential part of our life. [ ] ] (ii) Water doesn’t have many uses in our day to day life. ] [ (iii) If there is no water, we cannot wash our clothes, wash our utensils etc. [ 2. Answer the following questions in one sentence. [Refer to Session 11.1 ] (iv) How is water level in reservoirs measured? (v) How is the water released from dams measured? 246 (vi) Name one use of water. CHAPTER 11. WATER IN OUR LIFE

(vii) Name a measure of volume of liquids, other than litres and millilitres. 3. State true or false. [Refer to Session 11.2 ] (viii) There are many different sources of water present on the earth. [ ] ] (ix) Certain fruits and vegetables also carry a large of amount of water in them. ] [ ] ] (x) 1/4th of the earth’s surface is covered with water. ] ] [ (xi) There would be severe drought if there wasn’t any rainfall for a year. [ (xii) When we drink polluted ground water, we are affected by fluorosis. [ (xiii) Constructing a well is a good way to save water. [ (xiv) Human body contains 70% of water. [ CHAPTER 11. WATER IN OUR LIFE 247

4. Answer the following questions in one sentence. [Refer to Session 11.2 ] (xv) Why should we save water? (xvi) In case of a rainfall, what measures can we take to save the rain water? (xvii) How much water is present on the earth’s surface? (xviii) What are the sources of fresh water? (xix) How can we avoid polluting the water around us? CHAPTER 11. WATER IN OUR LIFE 248