202110224-TRIUMPH-STUDENT-WORKBOOK-SCIENCE-G07-PART2

Science Workbook_7_P_2.pdf 1 11/5/19 6:21 PM Name: ___________________________________ Section: ________________ Roll No.: _________ School: __________________________________

Table of Contents 1 16 13 SEED DISPERSAL 45 14 WATER 75 15 SOIL:OUR LIFE 98 16 FOREST:OUR LIFE 126 17 CHANGES AROUND US PROJECT BASED QUESTIONS TABLE OF CONTENTS

SESSION 1 13. SEED DISPERSAL 1.1 Mind Map WHY AND HOW ARE SEEDS DISPERSED 1.2 Terminology i. Seed dispersal – Seed dispersal is the movement or transport of seeds away from the parent plant. ii. Propagation – Propagation is the reproduction or spreading of something. iii. Ovules –Some ball like structure present in ovary. iv. Fibrous seed –Seed which consists of fibres 1.3 Key Concepts i. Dispersal: To scatter or break up. ii. Seeds are carried from one place to another so that they get suitable conditions to grow. This is called seed dispersal. SESSION 1. WHY AND HOW ARE SEEDS DISPERSED 1

iii. Seed dispersal is essential for propagation of plants and survival of the species. iv. Seeds are of different shapes, sizes and structures that help in dispersal. 1.4 Conceptual Understanding Q1. What happens if seeds are not dispersed? [Refer to TB page 128 Q1] A. i. If seeds are not dispersed, they fall under the parent plant. ii. The baby plants sprouting from seeds do not get sufficient sunlight, water and nutrients to grow. iii. They do not have sufficient place to grow. iv. So, the baby plants will soon perish and after a long time the species of the parent plant will be extinct. Q2. Ravalli said, “Dispersal of seeds is very important in nature”. Is she correct? Why do you support her? [Refer to TB page 124 Q5] A. i. If the dispersal of seeds is not facilitated, the seeds would have fallen under the tree. ii. Such seeds do not have enough sunlight, water, nutrients and air to grow healthy. iii. Soon they perish and if such condition prolonged, the species of the parent plant would soon be extinct. iv. So the nature itself has incorporated factors into seeds as to carry away seeds far from the parent plant. SESSION 1. WHY AND HOW ARE SEEDS DISPERSED 2

SESSION 2 AGENTS OF SEED DISPERSAL 2.1 Mind Map 2.2 Terminology i. Seed dispersal – Seed dispersal is the movement or transport of seeds away from the parent plant. ii. Propagation – Propagation is the reproduction or spreading of something. iii. Ovules –Some ball like structure present in ovary. iv. Fibrous seed –Seed which consists of fibres. 2.3 Key Concepts i. The agents that help in seed dispersal: (a) wind (b) water (c) animals and (d) birds. ii. Seeds which are dispersed by wind are light and some of them possess wing-like structures. SESSION 2. AGENTS OF SEED DISPERSAL 3

iii. Seeds dispersed by water have fiber–like structures so as to make them float on water. iv. Animals and birds disperse seeds in two ways: (i) They eat the fruit and the seeds are carried away to distant places where they are deposited through excreta. (ii) Some of the seeds stick to the bodies because they have thorns or hooks. They are carried away by animals where the animal gets rid of them. v. Seeds dispersed by wind are produced in large number. vi. Seeds dispersed by water have fibrous growth on them with air spaces. vii. Fruits of lady’s finger, Ruellia balsam explode when they are in contact with moisture and the seeds are scattered away from the parent plant. viii. Seed dispersal helps the plants to prevent overcrowding. ix. Seed dispersal avoids competition among plants for sunlight, water and minerals. x. Fleshy fruit: Fruits containing pulpy part. 2.4 Conceptual Understanding Q1. Why do most of the coconut trees grow along the sea shores? [Refer to TB page 128 Q3] A. i. The coconut fruits are dispersed by water. ii. The outer covering of its seed has empty air spaces, fibrous and light. iii. The entire coconut fruit floats on water and moves from one place to another. iv. When it is washed aside to the sea shore it germinates. v. So we usually find many coconut trees growing near sea shores. Q2. Do you find any relationship between the weight of the seeds and the dispersal mecha- nism? Discuss with suitable examples. [Refer to TB page 128 Q4] A. i. Yes, there is a relationship between the weight of the seeds, and the dispersal mechanism. ii. The seeds dispersed by wind have light weight and have wings or hair to fly in air. iii. E.g. the seeds of calotropis, drumstick, silk cotton etc. are lightweight so that they can float in air and are carried away to distant places and germinate under favor- able conditions. iv. Where as the seed of coconut is heavy which is dispersed by water. SESSION 2. AGENTS OF SEED DISPERSAL 4

Q3. How are seeds dispersed in calotropis? [Refer to TB page 128 Q2] A. i. The seeds of calotropis have light and hairy structure at one end. ii. They rise up and travel with the wind and settle at a suitable place to germinate. 2.5 Information Skills and Projects Q1. Collect the information in the following table and discuss the reason. [Refer to TB page 128 Q6] A. Agents of Name of the Reasons dispersal seed or fruit Are light in weight and have hairy or wing structures. So they By wind Calotropis, travel with wind and settle at a cotton, silk suitable place. cotton, Madar (oak) By water Coconut Has an outer covering which has empty spaces. Seed is covered by fibre and has air spaces. So it can float in water and travel to a distant place. By animal Xanthium It has spines and hooks and so gets attached to the animal’s skin and is carried to distant place. The animal sheds at different place and the seed grows into a plant. By bird Castor seed Castor seed appears like a worm and the bird carries it away mistaken. Then it leaves at a distant place where the seed grows into a baby plant. By man Custard Their juicy part along with the apple, seeds is eaten by humans and jambu fruit the seeds are dropped on the and guava, surface with their excreta. tomato These seeds get favourable conditions to grow. SESSION 2. AGENTS OF SEED DISPERSAL 5

SESSION 3 WHY PLANTS PRODUCE A LARGE NUMBER OF SEEDS 3.1 Mind Map 3.2 Terminology i. Germination –The process by which a plant grows from a seed. ii. Maturation –The process of maturing or ripening. 3.3 Key Concepts i. Fruits and vegetable plants produce large number of seeds. ii. Some fruits grow singly whereas some are in bunches. iii. Some fruits have single seeds in them whereas some have a large number of seeds. iv. Germination: The process by which a plant grows from a seed. v. All the seeds of a fruit should be able to germinate to produce new seeds. vi. Some seeds never germinate to produce new plants. SESSION 3. WHY PLANTS PRODUCE A LARGE NUMBER OF SEEDS 6

vii. Some seeds germinate but plants die before maturation. viii. To overcome these problems plants produce a large number of seeds. 3.4 Conceptual Understanding Q1. Nowadays people want to eat sprouts. List out the reasons why they take sprouts as food. [Refer to TB page 128 Q8] A. i. Sprouts contain carbohydrates, proteins and fats, mineral salts and vitamins in large proportions. ii. So eating such natural and nutritious food is good for health. iii. The nutrients present in sprouting seeds can be digested easily. iv. The sprouting seeds are fresh and healthy food. Q2. Some seeds like soapnuts have a very hard shell. Why is it so? [Refer to TB page 128 Q7] A. i. Seeds like soapnuts and gallnuts have very hard shells. ii. If birds or animals want to eat these nuts it would be difficult to break the hard shell. iii. So the birds and animals carry them to a distant place, but leave them without eating. iv. So the soap nuts enter the soil and germinate under favourable condition. v. They will have plenty of sunlight, water, nutrients and air and grow strong. 3.5 Information Skills and Projects Q1. Collect some seeds and sow them in a particular place in your school garden. Observe how many days each seed needs to germinate. Tabulate your observation. [Refer to TB page 128 Q9] A. Students’ activity. (Hint: Collect seeds like mustard, coriander which are short term, easy to observe the growth. Measure the plant each day and till-tabulte, till the maturitylevel is reached) Q2. Collect Toddy Palm seeds and make a model. Display them in your school. [Refer to TB page 128 Q10] A. Students’ activity. SESSION 3. WHY PLANTS PRODUCE A LARGE NUMBER OF SEEDS 7

—— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. Fill in the blanks. . [Refer to Session 13.2 ] (i) Seeds of coconut are heavy but float in water due to (ii) Seeds adapted to float on water are usually in weight. 2. Match the following. Column B [(Session 13.1)] a. Light and flat Column A b. Light, round and fibrous c. Light and round i. Bhindi d. Light and hairy ii. Coconut e. Heavy, round and fibrous iii. Milk weed iv. Cotton v. Sesame 3. Answer the following questions in one sentence. [Refer to Session 13.1 ] (iii) Why is seed dispersal necessary? CHAPTER 13. SEED DISPERSAL 8

(iv) How do plants germinate? (v) What is the advantage of seed dispersal from one place to another? (vi) Why do you think that shapes of different seeds are different? (vii) What do you mean by seed dispersal? Short Answer Type Questions 4. Answer the following questions in 3-4 sentences. (i) [(Session 13.2)] What are the characteristics of seed that is dispersed through wind? CHAPTER 13. SEED DISPERSAL 9

(ii) [(Session 13.2)] How are seeds dispersed by water? Long Answer Type Questions 5. Answer the following questions in 6-8 sentences. (i) [(Session 13.3)] Why do you think plants produce a large number of seeds? CHAPTER 13. SEED DISPERSAL 10

6. Answer the following questions in 6-8 sentences. (i) [(Session 13.1)] What is seed dispersal? Why is it important? AS4-Information skills and projects Long Answer Type Questions 7. Answer the following questions in 6-8 sentences. (i) [(Session 13.2)] Collect information about different types of seeds you find across in your surroundings. CHAPTER 13. SEED DISPERSAL 11

8. Answer the following questions in 6-8 sentences. (i) [(Session 13.3)] Fill the empty spaces in the table given below by collecting correct information: Name of seeds Agents of seed dispersal Animals Human Bird CHAPTER 13. SEED DISPERSAL 12

Objective Questions AS1-Conceptual Understanding 9. Choose the correct answer. (i) An example of a seed that is dispersed through wind is (A) Calotropis (B) Coconut (C)Neem seed (D) Bhindi (ii) An example of a seed that is dispersed through water is (A) Cotton (B) Caltropis (C) Coconut (D) Maple (iii) Dandelion seeds disperse through (A) birds (B) animals (C) wind (D) water (iv) Seeds are carried from one place to another by (A) Wind (B) Animals (C) Birds (D)All of the above (v) Seed dispersal is necessary because it: (A) Prevents overcrowding (B) Avoid competition for sunlight, water and nutrients (C)Invade new habitats (D)All of the above (vi) The seeds of which of the following get dispersed by bursting? CHAPTER 13. SEED DISPERSAL 13

(A) Coconut (B) Mango (C) Grape (D) Balsam (vii) Which of the following seeds have a hard shell? (A) Soap nut (B) Mustard (C) Pea (D) Bean (viii) Example of seed which have hooks on their body: (A) Xanthium (B) Maple (C) Coconut (D) Dandelion (ix) Which of the following get dispersed by wind? (A) Maple (B) Coconut (C)Spear grass (D)All of the above (x) An example of light weight fibrous seed (A) Coconut (B) Cotton (C)Spear grass (D) None (xi) Which of this is not a fibrous seed: (A) Apple (B) Coconut (C) Mango (D) Coffee (xii) Example of seed dispersion by explosion (A) Maple (B) Apple (C) Coffee (D) None CHAPTER 13. SEED DISPERSAL 14

(xiii) Choose the correct statement: Why do plants produce a large number of seeds? (A) To avoid overcrowding (B) They get dispersed to different places (C)To avoid competition for sunlight and nutrients (D)To produce large numbers of their own species CHAPTER 13. SEED DISPERSAL 15

SESSION 1 14. WATER 1.1 Mind Map SOURCES OF WATER 1.2 Terminology i. Fresh water – Fresh water is naturally occurring water on Earth’s surface in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers and streams, and underground as groundwater. ii. Conserve –To use or manage wisely preserve, or save. iii. Water purification –Water purification is the process of removing undesirable chemi- cals, biological contaminants, suspended solids and gases from contaminated water. SESSION 1. SOURCES OF WATER 16

1.3 Key Concepts i. Only 1% of water available on earth is fresh water. ii. Due to over extraction of fresh water, underground reserves are falling rapidly. iii. Water has become a precious resource now. iv. Water should be saved for the sake of future generations. v. Wasting water: Using water needlessly. vi. Waste water is generated at homes, industries etc. by different human activities. SESSION 1. SOURCES OF WATER 17

SESSION 2 SEWAGE WASTES AND TREATMENT 2.1 Mind Map SESSION 2. SEWAGE WASTES AND TREATMENT 18

2.2 Terminology i. Sewage – All the wastewater released by home, industries, hospitals, offices and other users are collectively called Sewage. Sewage is a liquid waste. ii. Contaminants – A contaminant is any undesirable substance (physical, chemical or biological). iii. Septic tank – A tank, typically underground, in which sewage is collected and allowed to decompose through bacterial activity before draining by means of a soakaway. iv. Activated sludge – Activated sludge refers to a mass of microorganisms cultivated in the treatment process to break down organic matter into carbon dioxide, water, and other inorganic compounds. 2.3 Key Concepts i. Sewage: Waste matter carried by sewers. ii. Contaminants: Substances which lead to contamination. A contaminant is any poten- tially undesirable substance (physical, chemical or biological). iii. Contaminants are of 3 types: Organic impurities, inorganic impurities and bacteria and other microbes. iv. Treatment of waste water involves physical, chemical and biological process. v. Septic tank: An underground tank in which waste matter is putrefied and decomposed through bacterial action. vi. Activated sludge: Heavy, slimy sludge purified by aeration. vii. Percolation tank: Tank in which water passes through a porous substance. viii. All the waste water released by homes, industries, hospitals, offices and other users is collectively called sewage. ix. Sewage is a liquid waste. Most of it is water, which has dissolved and suspended impurities, disease causing bacteria and other microbes. x. The waste water is processed to get fresh water at the waste water treatment plant. xi. Chlorine kills harmful disease-causing organisms present in waste water. xii. Aeration allows growth of microbes that help in the breakdown of waste. xiii. Untreated water becomes a cause for several diseases. 2.4 Conceptual Understanding 19 Q1. Fill in the blanks and give reasons: [Refer to TB page 136 Q1] SESSION 2. SEWAGE WASTES AND TREATMENT

(A) Clearing of water is a process of removing . (B) Waste water released by houses is called . (C) Dried is used as a manure. (D) Drains get blocked by and . A. (A) Pollutants Reason: Pollutants affect the taste of water and impart a bad smell and cause dis- eases. (B) Sewage Reason: Sewage is liquid waste carried by drains. (C) Sludge Reason: Sludge contains animal and human excreta. On the other hand, it contains organic matter that helps plants to grow. (D) Plastic bags, vegetable wastes. Reason : Plastic bags take a long time to degrade. Vegetable wastes are organic matter which blocks the flow of water. Q2. What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas. [Refer to TB page 136 Q2] A. i. Sewage: All the waste water released from houses, industries, hospitals, offices and other users is collectively called sewage. ii. Sewage is a liquid waste. iii. Sewage water contains inorganic, organic, bacterial and other microbial contami- nants. iv. If the sewage water directly joins the fresh water sources the aquatic animals such as the fish, prawns etc. will perish due to the presence of industrial wastes in the sewage. v. It is harmful to the entire ecosystem. SESSION 2. SEWAGE WASTES AND TREATMENT 20

Q3. Why should oils and fats not be released into the drain? Explain. [Refer to TB page 136 Q3] A. i. Oils and fats released into the drain float on sewage water. ii. Bacteria and microbes float on the oil creates froth like substance which keeps on accumulating substances and blocks the drains. iii. These microbes are also carriers of several diseases and epidemics. iv. Fats and oils can harden and block the pipes. v. It also decreases the porosity of soil which affects its water filtering system. vi. So oils and fats should not be released into the drain. Q4. Describe the steps involved in getting clarified water from waste water. [Refer to TB page 136 Q4] A. Steps involved in getting clarified water from waste water: Step 1: Waste water is passed through bar screens to remove rags, sticks, cans, plastic packets etc. Step 2: Water is allowed to flow into a grit and sand removal tank. The speed of incoming water is decreased to allow sand, grit and pebbles settle down. Step 3: The water is then allowed to settle in a large tank which is sloped towards the middle. Solids like feces settle at the bottom and are removed by a scraper. These are the sludge. A skimmer removes the floatable solids. Water thus cleared is called clarified water. Q5. What is sludge? Explain how it is treated? [Refer to TB page 136 Q5] A. Sludge: After removing rags, sticks and plastic packets, the waste water is allowed into a large tank sloped towards the middle. Solids like faeces settle at the bottom and are removed with a scraper. The remaining material is called sludge. Treatment of sludge: i. Sludge is transferred to a separate tank where it is decomposed by anaerobic bacteria. ii. The biogas produced is used to generate electricity. iii. The microbes that settle at the bottom of the tank is called activated sludge. The activated sludge is about 97% water. iv. The water is removed by sand drying beds or machines. Dried sludge is used as manure, returning organic matter back to the soil. SESSION 2. SEWAGE WASTES AND TREATMENT 21

Q6. Name two chemicals used to disinfect water. [Refer to TB page 136 Q7] A. Two chemicals used to disinfect water are: (1) Chlorine or bleaching powder and (2) Ozone. Q7. Explain the function of bar screens in a wastewater treatment plant. [Refer to TB page 136 Q8] A. i. The function of bar screen in a wastewater treatment plant is to remove coarse solids and other large materials often found in sewage. ii. Removal of these materials in necessary to enhance the operation and main- tainance of subsequent units. iii. In a waste water treatment plant, the waste water is passed through bar screens. iv. Large objects like rags, sticks, cans, plastic packets, disposal glasses etc. are removed here. 2.5 Asking Questions and Making Hypothesis Q1. What would happen if there were no microbes that breakdown wastes in sewage? (TB–Pg 137:Q12) A. i. If there were no microbes that break down wastes in sewage, all such wastes will accumulate and it will create health hazards. ii. If the wastes are dumped in sewage, it will be a breeding place for houseflies and mosquitoes, epidemics might break out. 2.6 Information Skills and Projects Q1. Go to a nearby railway station/ bus station/ hospital/ industry. What type of sewage is released? List out where and how. [Refer to TB page 137 Q14] A. Students’ activity. Given below is a sample answer. SESSION 2. SEWAGE WASTES AND TREATMENT 22

The sewage a hospital releases is: 1. Water from bathrooms / toilets. 2. Wastewater coming from outlets of rooms after they are cleaned. 3. Used up injection syringes, cotton plugs, injection vials. 4. Removed cloth bandages, used cloth with blood stains and traces of pus. 5. Peeled skins of fruits, waste food materials, rotten pieces of bread. 2.7 Application to Daily Life, Concern to Bio Diversity Q1. Outline your role as an active citizen in relation to sanitation. [Refer to TB page 136 Q10] A. As an active citizen my role in keeping sanitation is: i. I will form a ‘sanitation volunteers association’ in my school. ii. On every Sunday we will collect all the garbage by going through the streets and deposit it at an uninhabited place. iii. I will take the help of sanitary department authorities from a nearby city and edu- cate my neighbors on how to degrade the garbage. iv. With the help of local self-government authorities of my locality, I will try to improve the sanitation of my village / town. v. I will undergo training as to how we can make good use of degraded wastage and how it can be used to generate electricity or biogas. vi. With the help of my village elders, I will explain the present sanitary condition of my village to the M.L.A.s and Ministers of our district and ask them to lend a helping hand to improve the sanitary conditions of my village. vii. I will see that bleaching powder and lime are sprinkled over places where unsani- tary conditions exist. viii. I believe in the concept of “clean and green” and so plant some seedlings along the sides of village lanes and water them by turn, sharing the duties with my class fellows. Q2. What will you do to motivate people in your street to utilize toilets? [Refer to TB page 136 Q11] A. To motivate people in my street to utilize toilets: i. I will convince people not to use streets and open grounds as public latrines. SESSION 2. SEWAGE WASTES AND TREATMENT 23

ii. With the help of Health and Sanitation officials, I will organize a public meeting where the learned people explain the advantage of using toilets. iii. I will ask the civic representatives of my area to explain people how the government gives financial aid if septic tank latrines are proposed to be constructed by villagers. iv. Also, I will take part in “Dharma” programmed to prevent people using streets as public latrines. v. Explain people about the diseases if they use steets and open ground as public latrines. Q3. What point would you like to address in the letter to your Panchayat Officer about drainage system in your village/ town? [Refer to TB page 137 Q13] A. I would like to address the Panchayat / Municipal Officer of my village town drawing his attention on the following points: i. The present drainage system in our village/town is out fashioned. It has been introduced twenty years ago when there were no sufficient funds in our Panchayat. ii. The gutters are filled with all sorts of wastes from houses and agricultural fields. The open drains are inundated and the sewage is let out into the streets. iii. During rainy season the waste water is entering the villagers’ houses and causing epidemics. So, I request you to convert open drainage system in our village to closed system by arranging R.C.C pipes along the sides of roads. I came to know that our Panchayat/ local body has collected 100% taxes and stands first in sufficiency of funds. On the other hand our State Government is providing grants and other subsidies to improve drainage system. With the help of our village elders and local leaders you may tap those resources and improve the sanitary conditions of the village. SESSION 2. SEWAGE WASTES AND TREATMENT 24

SESSION 3 DISEASES CAUSED BY UNTREATED WATER AND OTHER WAYS OF SEWAGE DISPOSAL 3.1 Mind Map SESSION 3. DISEASES CAUSED BY UNTREATED WATER AND ..... 25

3.2 Terminology i. Drainage system –Drainage systems are the patterns formed by the streams, rivers, and lakes in a particular drainage basin. ii. Disease – A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. iii. Stagnation – Stagnation is the state of being still, or not moving, like a sitting puddle of water where stagnation attracts mosquitoes. iv. Sewage disposal –The process of removing and destroying or converting the poi- sonous substances of sewage. 3.3 Key Concepts i. If waste water is not tested, it becomes a cause for a large number of diseases. ii. To prevent stagnation of water, human and animal excretions, proper drainage system is to be used. iii. Untreated water becomes a cause for several diseases. iv. Some of the diseases caused by untreated drinking water are diarrhoea, malaria, typhoid and cholera. v. Proper drainage system is necessary to prevent foul smell from waste water. vi. Septic tanks are units of waste disposal used at homes in villages/ towns and in some individual houses in cities. vii. Water should be treated before being released into water bodies. SESSION 3. DISEASES CAUSED BY UNTREATED WATER AND ..... 26

3.4 Conceptual Understanding Q1. Untreated human excreta is a health hazard. Explain. [Refer to TB page 136 Q6] A. i. Untreated human and animal excretions mix with water as rain water carries them into water sources. ii. We get a foul smell when we walk near those areas. iii. These human excreta are the breeding places of mosquitoes and houseflies. iv. Such insects carry microbes which cause epidemics such as malaria, chikun- gunya, dengue fever, cholera etc. v. Pigs swarm to eat the human excreta. Those pigs spread brain fever. Q2. Explain the relationship between sanitation and disease. [Refer to TB page 136 Q9] A. i. There is a direct relationship between sanitation and disease. Poor sanitation and contaminated drinking water is the cause for a large number of disease. ii. Under poor sanitation people may resort to defecate in the open, river beds, near fields. iii. If unsanitary conditions prevail in a locality, bacteria and viruses which cause dis- eases and epidemics breed around there. iv. These microbes are carried by mosquitoes and houseflies, which breed in stag- nating water and faeces. v. So, people become ill and various diseases are contracted by them, which might spread to even more people. 3.5 Asking Questions and Making Hypothesis Q1. Have you any doubts about diseases caused by untreated water? List them out. [Refer to TB page 137 Q19] A. Doubts about diseases caused by untreated water: SESSION 3. DISEASES CAUSED BY UNTREATED WATER AND ..... 27

• What are the diseases caused by drinking unprotected water? • What is diarrhoea? How is it a dreadful disease? • How is malaria spread by a mosquito and where do mosquitoes breed in large number? • What are the symptoms of cholera and how is housefly a carrier of the bacteria that cause cholera? SESSION 3. DISEASES CAUSED BY UNTREATED WATER AND ..... 28

SESSION 4 CONSERVATION OF WATER 4.1 Mind Map 4.2 Terminology i. Check dam – A check dam is a small, sometimes temporary, dam constructed across a swale, drainage ditch, or waterway to counteract erosion by reducing water flow velocity. ii. Rock fill dam –A dam built mainly of rocks of various sizes fitted compactly together. iii. Contour trenches – Contour trenches are ditches dug along a hillside in such a way that they follow a contour and run perpendicular to the flow of water. iv. Conservation –The action of protecting something. v. Percolation tank – Percolation tanks are the structures for recharging ground water. SESSION 4. CONSERVATION OF WATER 29

4.3 Key Concepts i. Conservation: Protecting natural resources. ii. Water can be conserved by adopting good practices. iii. Conservation of water increases the socio–economic conditions of the locality. iv. Dams can be built to conserve water. v. Check dam: A strong wall built to restrain water. vi. Rock fill dam: A dam constructed by using large masses of stones vii. Water must be conserved by individual efforts as well as through efforts made by community. viii. Percolation tanks, contour trenches should be constructed to harvest the rain water. 4.4 Information Skills and Projects Q1. Make a write up for your project on preservation of rain water. [Refer to TB page 137 Q17] A. Students’ activity. (Hint: Steps to conserve and preserve rain water. Can make use of rain water harvesting system) Q2. Is there a check dam or any other water conservation unit in your village? Write a note on it. [Refer to TB page 137 Q18] A. Students’ activity. (Hint: Water conservation unit such as Check dams, Rock fill dams etc. in your village. You can write the how dams are constructed and how helpful it is inthe process of conservation of water) Some points are given. Students can make use of these points. i. A check dam is a small, sometimes temporary, dam constructed across a swale, drainage ditch, or waterway to work against erosion by reducing wa- ter flow velocity. ii. Most check dams are constructed of rock, but hay bales, logs and other materials may be acceptable. SESSION 4. CONSERVATION OF WATER 30

iii. A check dam placed in the ditch, swale, or channel interrupts the flow of water and flattens the gradient of the channel, thereby reducing the velocity. iv. In turn, this obstruction induces infiltration rather than eroding the channel. They can be used not only to slow flow velocity but also to distribute flows across a swale to avoid preferential paths and guide flows toward vegetation. v. Check dams could be designed to create small reservoirs, without possibility of silting 4.5 Application to Daily Life, Concern to Bio Diversity Q1. Fresh water is scarce. What is your contribution to make your family members aware of the need to save water? [Refer to TB page 137 Q15] A. i. In near future,fresh water will become scarce. Even drinking water is to be pur- chased at a high price. ii. We read in daily newspapers how the village people walk kilometers and kilometers to fetch a pitiful bucket or two of drinking water. iii. So, I will educate my family members by explaining to them the need to save water. iv. I will convince them to use small quantities of water to wash clothes, to clean the utensils and to bathe. v. I will ask my mother to mop the floor in my house instead of washing it. vi. I will convince my family members to store rain water in soak pits and overhead tanks and use it for other purposes except for drinking. vii. I will make sure that there is no leaks in the taps. if there is any, it will fixed immediately. viii. Watering our garden with a watering can rather than a hosepipe. Q2. Prepare at least 5 slogans on “Don’t waste water”. [Refer to TB page 137 Q16] A. Five slogans on “Don’t waste water” are: i. “Save water, save for our future generation”. ii. A drop of water you save will quench the thirst of a child of future India. iii. “Water is more precious and useful than the gold we buy”. iv. “A cup of water offered to a thirsty person is better than a quintal of gold”. v. “Store water in a soak pit and it will save the lives of people in need of water”. SESSION 4. CONSERVATION OF WATER 31

Q3. If you see water runoff from a public tap, what would you do about it? [Refer to TB page 137 Q20] A. If I see water runoff from a public tap • I would immediately close the tap. • If the water is still leaking, I would call a plumber or municipal water works super- visor to repair any leakages and prevent the wastage of water. —— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. State true or false. [Refer to Session 14.1 ] (i) Only 5% of water on earth is freshwater. [] (ii) Sea water is freshwater. [] (iii) 2% of freshwater is in glaciers and poles as ice. [] (iv) We do not use sea water for drinking. [] (v) Sea water is salty in nature. [] 2. Answer the following questions in one sentence. [Refer to Session 14.3 ] (vi) How is waste water released? CHAPTER 14. WATER 32

(vii) How does waste water cause disease? 33 (viii) What is the use of drainage in villages? (ix) How is a closed drainage system advantageous? (x) What is a septic tank? 3. State true or false. [Refer to Session 14.2 ] CHAPTER 14. WATER

(xi) Dried sludge can be used as manure.. [] (xii) Anaerobic microorganisms are used in sewage treatment process.. ] [ (xiii) When the speed of incoming water increases, sand and grit settles down. ] [ (xiv) Contaminated water contains nitrates, phosphates and metals as inorganic impurities. [] (xv) Cholera, typhoid, dysentery are caused due to bacteria and other microbes. ] [ 4. Match the following. Column B [(Session 14.2)] a. Chemical treatment Column A b. Removes floatable solids c. Used as manure i. Biogas d. Consume waste products ii. Sludge e. Fuel and electricity iii. Aerobic bacteria iv. Chlorine v. Skimmer 5. Answer the following questions in one sentence. [Refer to Session 14.2 ] (xvi) What is sewage? CHAPTER 14. WATER 34

(xvii) What do you mean by contaminants? (xviii) Enumerate different contaminants. (xix) What are the three processes by which water is treated? (xx) How are large visible objects removed during sewage treatment? Short Answer Type Questions 6. Answer the following questions in 3-4 sentences. (i) [(Session 14.2)] How are grit and sand separated from water during treatment? CHAPTER 14. WATER 35

(ii) [(Session 14.2)] What is sludge? How is it removed? Long Answer Type Questions 7. Answer the following questions in 6-8 sentences. (i) [(Session 14.1)] How can you say that water is a precious resource? CHAPTER 14. WATER 36

8. Answer the following questions in 6-8 sentences. (i) [(Session 14.3)] What are the different types of drainage systems we observe? 9. Answer the following questions in 6-8 sentences. 37 CHAPTER 14. WATER

(i) [(Session 14.2)] How is clarified water treated further? AS3-Experimentation and field investigation Long Answer Type Questions 10. Answer the following questions in 6-8 sentences. (i) [(Session 14.1)] Write an experiment to explain what really happens to the wastewater at the treatment plants. CHAPTER 14. WATER 38

AS4-Information skills and projects Long Answer Type Questions 11. Answer the following questions in 6-8 sentences. (i) [(Session 14.2)] Collect information about the different sources of water available on the earth and write the percentage of water available in them. 12. Answer the following questions in 6-8 sentences. 39 CHAPTER 14. WATER

(i) [(Session 14.4)] Collect information about the various techniques used during the pro- cess of water purification in the waste water treatment. AS5-Communication through drawing and model making Short Answer Type Questions 13. Answer the following questions in 3-4 sentences. (i) [(Session 14.1)] With the help of a pie diagram describe the distribution of water on earth? CHAPTER 14. WATER 40

AS6-Appreciation and aesthetic sense, Values Long Answer Type Questions 14. Answer the following questions in 6-8 sentences. (i) [(Session 14.4)] How do you appreciate water? Write slogans to help save it. CHAPTER 14. WATER 41

AS7-Application to daily life, concern to bio diversity Long Answer Type Questions 15. Answer the following questions in 6-8 sentences. (i) [(Session 14.4)] How can you conserve water at your home? Objective Questions AS1-Conceptual Understanding 16. Choose the correct answer. (i) What is the percentage of water in Sea/Ocean? (A) 97% (B) 91% (C) 2% (D) 95% CHAPTER 14. WATER 42

(ii) Glaciers and poles constitute of total water available on the earth. (A) 1% (B) 2% (C) 3% (D) 0.1% (iii) Inorganic impurities found in waste water are . (A) Nitrate (B) Grit (C)Food particles (D) Bacteria (iv) Drinking waste water will cause (A) Typhoid (B) Malaria (C) Dengue (D)Small pox (v) Waste water released by home, industries, hospitals, offices and other users are collectively called as (A) Drain water (B) Sewage (C) Garbage (D) None (vi) kills all the harmful disease causing microorganisms present in water. (A) Nitrate (B) Phosphate (C) Chlorine (D) Detergent (vii) What is added to waste water during the chemical treatment of sewage water? (A) Phosphorus (B) Chlorine (C) Sugar (D) Urea (viii) The correct order of steps involved during wastewater treatment: (A) Chemical process–>Biological Process–>Physical process (B) Physical process–>Biological process–>Chemical process CHAPTER 14. WATER 43

(C)Chemical process–>Biological process–>Physical process (D)Biological process–>Physical process–>Chemical process (ix) During the biological process of waste water treatment, aeration helps in . (A) Removal of microorganisms (B) Growth of microorganisms (C)Separation of suspended particles (D)All of the above (x) from waste water is used as manure. (A) Dried sludge (B) Activated sludge (C) Nitrates (D) Phosphates CHAPTER 14. WATER 44

SESSION 1 15. SOIL: OUR LIFE 1.1 Mind Map USEFULNESS OF SOIL IN OUR LIFE 1.2 Terminology i. Humus – Humus is dark, organic material that forms in the soil when plant and animal matter decays. ii. Mineral salts –Mineral salts are Inorganic salts that need to be ingested or absorbed by living organisms for healthy growth and maintenance. iii. Organic matter – Organic matter is anything that contains carbon compounds that SESSION 1. USEFULNESS OF SOIL IN OUR LIFE 45

were formed by living organisms. iv. Habitat –It is the natural home or environment of an animal, plant, or any organism. 1.3 Key Concepts i. Soil is used for different purposes in our daily life. ii. Soil is one of the most important resources, just like air and water. iii. Almost all things in our surroundings directly or indirectly depend on soil. iv. We depend on soil for agriculture, construction purposes, making utensils, toys etc. v. Soil is the uppermost layer of the earth’s crust. vi. It is formed of rock particles and organic matter called humus. vii. The soil supports all plants, animals and microorganisms. viii. We find different kinds of animals whose habitat is soil. ix. Soil is a good habitat. We depend on it for agricultural and construction purposes. x. Plants depend on soil for nutrients like mineral salts and also water. 1.4 Conceptual Understanding Q1. How can you say soil is a precious resource? Give reasons. [Refer to TB page 148 Q1] A. i. Soil is the uppermost layer of earth’s crust. ii. Soil supports plants, animals and microorganisms. iii. Almost all the things in our surroundings directly or indirectly depend on soil. iv. Soil is good habitat. We depend on it for agricultural and construction purposes, making utensils, toys etc. v. So, we can say that soil is a precious resource. Q2. Nazmal’s grandmother said, “Human beings always depend on soil”. Is she correct? How do you support her statement? [Refer to TB page 149 Q12] A. i. Nazmal’s grandmother is absolutely correct in saying “Human beings always de- pend on soil”. ii. Plants that give us food grow in the soil. SESSION 1. USEFULNESS OF SOIL IN OUR LIFE 46

iii. Plants which give us firewood and wood charcoal are also grown in the soil. iv. The furniture and wooden fittings such as doors, windows and cupboards are made of wood which is a plant derivative. v. Cotton fiber is obtained from cotton plant. Silk and wool are natural fibers which we get from silkworm and sheep. These animals get their food from plants which are soil derivatives. vi. Water, another important basic need of humans is trapped in between the soil layers which is used by humans. vii. The most important factor is, we can’t live more than a few minutes without oxygen, which is released into the atmosphere by green plants growing on soil. Q3. Do you find any relationship between the chapters “Soil” and “Nutrition in plants”? What are they? [Refer to TB page 149 Q16] A. i. There is certainly a strong relationship between “Soil” and “Nutrition in Plants”. ii. For example: Soils such as loamy soils and clayey soils contain large proportion of Nitrogen, Phosphorus and Potassium (N,P,K) which are the essential nutrients for the healthy growth of crops. iii. Loamy soils and clayey soils retain more water which is one of the components for photosynthesis to take place. iv. Some soils hold nutrients at the roots of plants growing in them and thus hold large amounts of nutrients in them. SESSION 1. USEFULNESS OF SOIL IN OUR LIFE 47

SESSION 2 SOIL FROM DIFFERENT PLACES IS DIFFERENT 2.1 Mind Map 2.2 Terminology i. Sandy soil – Sandy soils are granular soils that contain small rock and mineral parti- cles. ii. Clay soil – Clay soil is composed of tiny particles that are hard and able to become easily compacted. iii. Loam soil – Soil composed of a mixture of sand, clay, silt, and organic matter. SESSION 2. SOIL FROM DIFFERENT PLACES IS DIFFERENT 48