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This book is part of a package of books and is not meant to be sold separately. For MRP, please refer to the package price. This practice book is designed to support you in your journey of learning Science for Class 7. The contents and topics of this book are entirely in alignment with the NCERT syllabus. For each chapter, a concept map, expected objectives and practice sheets are made available. Questions in practice sheets address different skill buckets and different question types, practicing these sheets will help you gain mastery over the lesson. The practice sheets can be solved with the teacher’s assistance. There is a self-evaluation sheet at the end of every lesson, this will help you in assessing your learning gap.

TABLE OF CONTENT • Assessment Pattern: 40 Marks • Assessment Pattern: 80 Marks • Syllabus & Timeline for Assessment • Guided Writing Page 1: 1. Nutrition in Plants Page 8: 2. Nutrition in Animals Page 15: 3. Fibre to Fabric Page 23: 4. Heat Page 32: 5. Acids, Bases and Salts Page 39: 6. Physical and Chemical Changes Page 48: 7. Weather, Climate and Adaptations of Plants and Animals to Climate Page 55: 8. Winds, Storms and Cyclones Page 65: 9. Soil Page 74: 10. Respiration in Organisms Page 82: 11. Transportation in Animals and Plants Page 90: 12. Reproduction in Plants Page 98: 13. Motion and Time Page 112: 14. Electric Current and its Effects Page 120: 15. Light Page 127: 16. Water: A Precious Resource Page 136: 17. Forests : Our Life Line Page 144: 18. Wastewater Story

ASSESSMENT PATTERN Marks: 40 ASSESSMENT PATTERN Marks: 40 Grade 7 / Science

Beginner Paper: (Easy: 50%, Medium: 40%, Difficult: 10%) Proficient Paper: (Easy: 40%, Medium: 40%, Difficult: 20%) Easy Question: Remembering questions directly from the text or from the given exercises. (Mostly from content of book or end of chapter exercise). Medium Difficulty Question: In-depth understanding of questions, not necessarily from the text. (Slightly modified concepts or end of chapter questions). Difficult Question: Question involving creativity like story writing, analysis question like character analysis, justification of title or extracts (mostly requires creative and thinking skills). ASSESSMENT PATTERN Marks: 80 ASSESSMENT PATTERN Marks: 80 Grade 7 / Science

PAPER: BEGINNER PAPER: PROFICIENT Max Internal Q.No Difficulty Level Difficulty Level Mark Option Skill Level Skill Level Easy Medium Difficult Easy Medium Difficult Section A (Question Type: VSA) 11 Remembering • Remembering • 21 Remembering • Remembering • 3 1 Remembering • Remembering • 41 Remembering • Remembering • 5 1 Remembering • Remembering • 6 1 Understanding • Understanding • 71 Understanding • Understanding • 8 1 Understanding • Understanding • 91 Understanding • Understanding • 10 1 Understanding • Understanding • 11 1 • Remembering • Remembering • 12 1 Remembering • Remembering • 13 1 Remembering • Remembering • 14 1 Understanding • Understanding • 15 1 Understanding • Understanding • 16 1 Applying • Applying • 17 1 • Applying • Applying • 18 1 Applying • Applying • 19 1 • Applying • Applying • 20 1 Applying • Applying • Section B (Question Type: SA) 21 3 Remembering • Remembering • 22 3 Remembering • Remembering • 23 3 Understanding • Understanding • 24 3 • Understanding • Understanding • Section C (Question Type: LA) 25 5 Remembering • Remembering • 26 5 • Remembering • Remembering • 27 5 Understanding • Understanding • 28 5 • Remembering • Remembering • 29 5 Remembering • Remembering • 30 5 • Understanding • Understanding • Section D (Question Type: SA) 31 3 • Applying • Applying • 32 3 Applying • Applying • 33 3 • Analysing • Analysing • 34 3 Analysing • Analysing • 35 3 • Analysing • Analysing • 36 3 Analysing • Analysing • SYLLABUS FOR ASSESSMENT

CHAPTERS PT-1 TE-1 PT-2 TE-2 1. Nutrition in Plants ✓ ✓ 2. Nutrition in Animals ✓ ✓ ✓ 3. Fibre to Fabric ✓ ✓ 4. Heat ✓ ✓ 5. Acids, Bases and Salts ✓ 6. Physical and Chemical Changes ✓ ✓ 7. Weather, Climate and Adaptations of Plants and Animals to Climate ✓ ✓ 8. Winds, Storms and Cyclones ✓ 9. Soil ✓ ✓ 10. Respiration in Organisms ✓ 11. Transportation in Animals and Plants ✓ 12. Reproduction in Plants ✓ 13. Motion and Time ✓ 14. Electric Current and its Effects ✓ ✓ 15. Light ✓ 16. Water: A Precious Resource ✓ ✓ 17. Forests : Our Life Line ✓ 18. Wastewater Story ✓

Assessment Timeline

Periodic Test - 1 22nd July to 12th August

Term Exam - 1 23rd September to 21st October

Periodic Test - 2 16th December to 13th January

Term Exam - 1 1st March to 30th March

1. Nutrition in Plants

Learning Outcome

By the end of this chapter, you will be: • Explain different modes of heterotrophic • Classify plants as autotrophs and heterotrophs nutrition. based on their nutrition. • Cite examples for autotrophs and heterotrophs • Explain photosynthesis in plants. in plants. • Differentiate an autotroph from a heterotroph. Concept Map

NUTRITION IN PLANTS

AUTOTROPHIC HETEROTROPHIC

Prepares food through Saptrophytes Parasites Insectivorous Symbionts photosynthesis

Keypoints • Living organisms obtain energy from the food they • Saprophytes depend on dead and decaying matter eat. for their food. Example: Bacteria and fungi • Based on the mode of obtaining food, organisms • Insectivorous plants trap insects to meet their ni- are classified into two major groups- Autotrophs trogen demands. Example: Pitcher plant. and Heterotrophs. • Symbionts: Organisms live together, helping each • Autotrophs can prepare their own food either by other to obtain food. Example: Lichen-a symbiotic photosynthesis or chemosynthesis. relationship between an algae and a fungus. • Oxygen is released and carbon dioxide is taken up by plants during photosynthesis. Keywords: Autotrophic, chlorophyll, • Heterotrophs depend on autotrophs directly or in- heterotrophic, host, insectivorous, nutrients, directly for food. nutrition, parasite, photosynthesis, saprotrophs, • Parasites depend on other organisms for their food saprotrophic, stomata. requirements. Example: Cuscuta

1 1. Nutrition in Plants

Work Plan

CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SHEET SIMULATION/ VIDEO

Prepares food through photosynthesis PS-1 Autotrophic PS-2 Demonstration of photosynthesis • Saprotrophs PS-3 • Parasites Study of different Heterotrophic • Insectivorous modes of nutrition PS-4 • Symbionts in plants

Worksheet for “Nutrition in Plants” PS-5 plant showing lid and pitcher Evaluation with self- Self-evaluation Sheet check or Peer check*

2 PRACTICE SHEET - 1 (PS-1)

I. Say True Or False: 1. In parasitic nutrition, both the organisms are benefitted. 2. Plants that do not contain chlorophyll will not be able to carry out photosynthesis. 3. Insectivorous plants are photosynthetic plants. 4. Mushroom is a parasite. 5. In a symbiotic relationship, both the organisms benefit from each other.

II. Fill in the blanks: 1. The ______hair absorbs water and minerals from the soil. 2. Carbon dioxide enters the leaf through ______. 3. Cuscuta is an example of a ______plant. 4. ______is an insectivorous plant.

III. Match the following: COLUMN A COLUMN B ANSWER 1. Autotrophs Water 2. Stomata Photosynthesis 3. Xylem Carbon dioxide 4. Chlorophyll Symbiosis 5. Lichens Mango tree

PRACTICE SHEET - 2 (PS-2)

I. Give two examples for each of the following: 1. Parasitic plants: 2. Saprophytes: 3. Autotrophs: 4. Insectivorous plants: 5. Organisms that make up lichen: II. Write one word for the following: 1. Plants that depend on other organisms for food. 2. Plants that trap insects for their nitrogen requirement. 3. A relationship between two organisms where one is benefitted while the other is harmed. 4. A relationship between the organisms where both the organisms are mutually benefitted. 5. A process by which the solar energy is converted to chemical energy by plants using chlorophyll. III. Spot as many organisms as possible in the puzzle given by encircling them. Write the names and categorize them into autotrophs and heterotrophs. Classify the heterotrophs into herbivores, carnivores, omnivores and saprophytes. B R O S E A T C R O W A A G N B H I N D I B N B N G I N G E R C L Y B A N H B E C O W F A I M U S H R O O M F N T G B E R M W F I O E L E P H A N T S C X T S A E Y N P H B E E C A R R O T U L S I X 3 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option: 8. In the absence of which of the following, will 1. Which of the following is/are needed for photosynthesis not occur in leaves? photosynthesis? a. Guard cells a. Chlorophyll b. Chlorophyll b. Sunlight and water c. Vacuole c. Carbon dioxide d. Space between cells d. All of these 9. Which of the following statements is/are 2. Which of the following is an insectivorous correct? plant? i. All green plants can prepare their own food. a. Cuscuta ii. Most animals are autotrophs. b. Mushroom iii. Carbon dioxide is not required for c. Pitcher plant photosynthesis. d. Mistle toe iv. Oxygen is liberated during photosynthesis. 3. Plants obtain carbon dioxide from the Choose the correct answer from the options atmosphere through below: a. Leaf (a) (i) and (iv) (b) (ii) only b. Stomata (c) (ii) and (iii) (d) (i) and (ii) c. Stem 10. Pitcher plant traps insects because it d. Chloroplast a. is a heterotroph. 4. Food is stored in plants as b. grows in soils which lack in nitrogen. a. Glucose c. does not have chlorophyll. b. Starch d. has a digestive system like human beings. c. Sugar 11. The term that is used for the mode of d. Proteins nutrition in yeast, mushroom and bread- 5. Pea plants form a symbiotic association with mould is a/an a. autotrophic a. Fungus b. insectivorous b. Algae c. saprophytic c. Virus d. parasitic d. Bacteria 6. Ashoka tree is a. Photosynthetic b. Parasitic c. Saprophytic d. Symbiont 7. Organisms which prepare food for themselves using simple naturally available raw materials are referred to as a. heterotrophs b. autotrophs c. parasites d. saprophytes

4 PRACTICE SHEET - 4 (PS-4)

I. Answer the following: 1. Potato and ginger are both underground parts that store food. Where is the food prepared in these plants? 2. Photosynthesis requires chlorophyll, and a few other raw materials. Add the missing raw materials to the list given below: Water, minerals, sunlight/light energy, carbon dioxide. 3. A goat eats away all the leaves of a small plant (balsam). However, in a few days, new leaves could be seen sprouting in the plant again. How did the plant survive without leaves? 4. Nitrogen is an essential nutrient for plant growth. But farmers who cultivate pulse crops like green gram, bengal gram, black gram, etc. do not apply nitrogenous fertilizers during cultivation. Why? 5. Wheat dough, if left in the open, after a few days, starts to emit a foul smell and becomes unfit for use. Give reason. 6. Sunlight, chlorophyll, carbon dioxide, water and minerals are raw materials essential for photosynthesis. Do you know where they are available? Fill in the blanks with the appropriate sources. a. Available in the plant: ______b. Available in the soil: ______c. Available in the air: ______d. Available during day: ______

5 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 8. When you observe leaves of plants, you find water droplets on them. Thus, loss of 1. ______is present in green leaves. this excess water from plant body is called a. Oxygen ______. b. Carbon dioxide a. photosynthesis c. Chlorophyll b. transpiration d. Air c. respiration 2. Guard cells are ______in shape. d. assimilation a. Cylindrical 9. Pitcher plant can prepare its own food using b. Bean chlorophyll. Even then it feeds on insects. What c. Spherical could be the reason? d. Irregular a. It has weak roots. b. It grows in a place where there is no sunlight. 3. ______mode of nutrition is observed in Cuscutaplant; hence it is called ______. c. It has inefficient leaves to prepare food. a. Autotrophic, algae d. The soil in which they live do not have enough b. Heterotrophic, insectivore minerals and nutrients. c. Heterotrophic, parasite 10. What is the main difference between Algae and Cascuta? d. Autotrophic, fungi a. Algae cannot prepare food and cascuta prepare 4. Pipe like structure called vessels are present in food for algae which of the following to transport minerals and water to the leaves of a plant? b. Cascuta does not have leaves, but algae have a. Roots c. Algae prepare their own food, but cascuta depend on others for its food b. Stem d. Both are insectivorous plants c. Branches d. All of these II. Short answer questions 5. Carbon dioxide + water ______+ ______. 1. What plant is shown in the image? What are a. Glucose + Oxygen such plants called? Give reason. b. Glucose + Ozone c. Sucrose + Oxygen d. Sucrose + Ozone 6. Plants take water and air through their ______and ______. a. stem, stomata b. roots, stem c. lenticels, loose tissues 2. When you look at a leaf through microscope, d. roots, stomata how does it look like? Represent section of a leaf in the form of a neat labelled diagram. 7. If you leave pickles, leather,clothes and other articles in hot and humid weather for long time, 3. If suppose, there are no plants on earth. What then ______grow on them. happens to the life on earth? a. Algae III. Long answer questions b. Fungi 1. Write a short note on symbiotic relationship c. Moth present in some organism. d. Lichens 2. Plants require nitrogen for their growth. Nitrogen is present in abundance in air. Explain how this nitrogen is made available for plants.

6 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Fill in the blanks: (4 Marks) 2. Why are green plants called autotrophs? Leaves have a green pigment called (a)______which captures (b)______from sunlight. This (c)______is used in the process of (d)______

3. How is an insect digested in the pitcher plant?

II. Can you give me a name: (3 Marks) a. I am tall tree but I cannot move. I am green and can prepare my own food. 4. How is a farmer benefitted from symbiotic relationship between rhizobium bacteria and legumes?

b. I am small and I can fly. I disturb your sleep, bite you and suck your blood which is my food.

c. I am white and soft. I grow well in the rainy season. Children pluck me from the ground and admire me. I absorb nutrients from decomposed dead parts of plants and animals in the soil.

III. Answer the following questions: (8 Marks) 1. Wild animals like tiger, wolf, lion and leopard do not eat plants. Does this mean that they can survive without plants? Can you provide a suitable explanation?

7 2. Nutrition in Animals

Learning Outcome

By the end of this chapter, you will be: • Illustrate human alimentary canal. • State the importance of digestion to an organism. • Describe the structure of alimentary canal in rumi- • Explain the structure of alimentary canal in man. nants. • Describe the process of digestion. • Explain the process of rumination. • Explain the process of digestion in amoeba.

Concept Map

NUTRITION IN ANIMALS

Digestion in Digestion in Digestion in man ruminants amoeba

Digestive Process of Digestive Process of Process of system digestion system digestion digestion

Keypoints • The main steps of nutrition in animals are ingestion, • The stomach of ruminating animals has four digestion, absorption, assimilation and egestion. chambers that help in digestion of cellulose. • Human digestive system comprises of main organs and accessory organs. Keywords: Absorption, amino acid, amoeba, • Mouth, oesophagus, stomach, small intestine, assimilation, bile, buccal cavity, canine, cellulose, large intestine, rectum and anus are main organs. digestion, egestion, fatty acid, food vacuole, gall Liver and pancreas form the accessory glands. Bladder, glycerol, incisor, Ingestion, liver, milk • Digestion of food begins in the mouth. teeth, molar, permanent teeth, oesophagus, • Mouth has salivary glands that secrete saliva. pancreas,premolar, pseudopodia, rumen, • Stomach has hydrochloric acid to kill microbes in ruminant, rumination, salivary glands, villi, saliva. food and digestive juices help in digesting proteins. • In the small intestine, digestive juices of small intestine, pancreas and bile from liver are poured. So complete digestion of carbohydrates, fats and proteins occur in small intestine. • Digested foods are absorbed by the finger like projections called villi in small intestine. • In the large intestine, water is reabsorbed along with useful substances. • Undigested food matter as feces is ejected through anus.

8 2. Nutrition in Animals

Work Plan

CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SHEET SIMULATION/ VIDEO

Digestion in man Digestive system PS-1 Process of digestion Human digestive Digestion in ruminants Digestive system PS-2 system with teeth Process of digestion

Digestion In amoeba Process of digestion PS-3 Structure of PS-4 digestive system in grass eating Worksheet for “Nutrition in Animals” PS-5 animals

Evaluation with self- Self-evaluation Sheet check or Peer check*

9 PRACTICE SHEET - 1 (PS-1)

I. Fill in the blanks: 1. ______secretes bile juice. 2. The food is completely digested in ______. 3. ______teeth are used for biting and cutting food in humans. 4. Digestion of proteins begin in ______. 5. Stomach secretes ______acid. II. Say True or False. If false corrrect the statement. 1. Amoeba has special digestive organs for digestion. 2. Cow stores food in rumen. 3. Grass is rich in cellulose. 4. Digestive enzymes, present in the sac like structure between small intestine and large intestine, digest cellulose. 5. Digestion of protein starts in buccal cavity.

PRACTICE SHEET - 2 (PS-2)

I. Select appropriate terms for the description given below from the box: 1. Taking of digested food material by the walls of the small intestine. 2. End product of protein digestion. 3. The process where in absorbed substances are taken by different organs of the body to build up complex substances needed by them. 4. A juice that helps in emulsification of fats. 5. Mouth with salivary glands and dentition form this. 6. Teeth used for tearing food. 7. A type of carbohydrates found in plants. 8. Process of breaking down complex food into simpler ones. 9. The process of eliminating waste from the body. 10. End products of fat digestion. 11. A temporary structure that forms around the food in amoeba and helps in digestion. 12. Organ that stores bile juice. 13. Biting or cutting teeth. 14. Process of taking in food by the organisms. 15. Organ that secretes bile.

10 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option. 7. Read the following statements with reference 1. Given below from (i) to (iv) are some food to the villi of small intestine. items. i. They have very thin walls. i. Boiled and mashed potato ii. They have a network of thin and small ii. Glucose solution blood vessels close to the surface. iii. A slice of bread iii. They have small pores through which food iv. Mustard oil can easily pass. iv. They are finger-like projections. Which of the above will give blue-black colour when tested with iodine? Identify those statements which enable the a. i and ii villi to absorb digested food. b. i and iii a. i, ii and iv c. ii and iii b. ii, iii and iv d. iii and iv c. iii and iv 2. Which of the following pair of teeth differ in d. i and iv structure but are similar in function? 8. The false feet of amoeba are used for a. Canines and incisors. a. Movement only. b. Molars and premolars. b. Capture of food only. c. Incisors and molars. c. Capture of food and movement. d. Premolars and canines. d. Exchange of gases only. 3. Read carefully the terms given below. 9. The enzymes present in the saliva convert Which of the following set is the correct a. Fats into fatty acids and glycerol. combination of organs that do not carry out b. Starch into simple sugars. any digestive functions? c. Proteins into amino acids. a. Oesophagus, large intestine, rectum d. Complex sugars into simple sugars. b. Buccal cavity, oesophagus, rectum 10. Cud is the name given to the food of c. Buccal cavity, oesophagus, large intestine ruminants which is d. Small Intestine, large intestine, rectum a. Swallowed and undigested. 4. The swallowed food moves downwards in b. Swallowed and partially digested. the alimentary canal because of c. Properly chewed and partially digested. a. Force provided by the muscular tongue. d. Properly chewed and completely digested. b. The flow of water taken with the food. 11. Choose the correct order of terms that c. Gravitational pull. describes the process of nutrition in d. The contraction of muscles in the wall of ruminants. food pipe. a. Swallowing → partial digestion → chewing 5. The acid present in the stomach of cud → complete digestion a. Kills the harmful bacteria that may enter b. Chewing of cud → swallowing → partial along with the food. digestion → complete digestion b. Protects the stomach lining from harmful c. Chewing of cud → swallowing → mixing with substances. digestive juices → digestion c. Digests starch into simpler sugars. d. Swallowing → chewing and mixing → partial d. Makes the medium alkaline. digestion → complete digestion 6. The finger-like outgrowths of amoeba helps 12. Cellulose-rich food substances are good to ingest food. However, the finger-like source of roughage in human beings because outgrowths of human intestine helps to a. Human beings do not have cellulose- a. Digest the fatty food substances. digesting enzymes. b. Make the food soluble. b. Cellulose gets absorbed in the human c. Absorb the digested food. blood and converts into fibres. d. Absorb the undigested food. c. The cellulose-digesting bacteria convert cellulose into fibres. d. Cellulose breaks down into smaller components which are egested as roughage.

11 PRACTICE SHEET - 4 (PS-4)

I. Answer the following: 1. You were blindfolded and asked to identify the drinks provided in two different glasses. You could identify drink A as lime juice and B as bitter gourd juice. How could you do it inspite of being blindfolded? 2. Boojho took some grains of boiled rice in test tube ‘A’ and Paheli took boiled and chewed rice in test tube ‘B’. Both of them poured 1 – 2 drops of iodine solution into the test tube and observed the colour change. What colour change would they have observed? Give reasons for your answer. 3. ‘A’ got her gall bladder removed surgically as she was diagnosed with stones in her gall bladder. After the surgery, she faced problems in digestion of certain food items when consumed in bulk. Can you tell which kind of food items would they be and why? 4. Ruminants such as cows and buffaloes swallow their food hurriedly and then sit restfully and chew their food. Can you reason why? 5. Boojho and Paheli were eating their food hurriedly so that they could go out and play during the recess. Suddenly, Boojho started coughing violently. Think of the reasons why he was coughing.

12 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 8. Different organisms use different mode of feeding. Which of the following organism uses 1. The breakdown of complex components of food its sticky tongue to catch the prey? into simpler substances is called ______. a. Bird a. Respiration b. Snake b. Digestion c. Frog c. Feeding d. Monkey d. Swallowing 9. After completion of digestion in small intestine, 2. Which of the following teeth are associated with the proteins are broken into ______. chewing? a. Glucose a. Molars b. Amino acids b. Canines c. Fatty acids c. Incisors d. Glycerol d. Wisdom teeth 10. Choose the correct matching considering the 3. Which of the following plays an important role lower jaw of human: in the digestion of fats?

a. Saliva Type of teeth Their Number i) Canines a) 4 b. Bile juice ii) Molars b) 2 c. Mucous iii) Incisors c) 6 d. Pancreatic juice a. i) – c); ii) – b); iii) – a) 4. Which of the following is not a part of human digestive system? b. i) – a); ii) – c); iii) – b) a. Buccal cavity c. i) – b); ii) – c); iii) – a) b. Oesophagus d. i) – b); ii) – a); iii) – c) c. Lungs II. Short answer questions d. Anus 1. How are milk teeth different from permanent 5. What is ingestion? teeth? a. Undigested food 2. Why do we get hiccups of cough while eating b. Taking food into the body food? c. Absorption of digested food 3. Compare the teeth incisors and canines. d. Rejecting food III. Long answer questions 6. Which part of digestive system secrets mucous? 1. What is amoeba? What is the mode of feeding in a. Mouth amoeba? b. Stomach 2. What would happen if a person does not have a c. Liver tongue? How is tongue useful for us? Discuss. d. Pancreas 7. The stomachof which organism pops out through its mouth while feeding? a. Starfish b. Whale c. Octopus d. Python

13 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Fill in the blanks: (3 Marks) IV. Label the parts in the diagram. Use the clues 1. Digestion of all food components is given below. (4 Marks) completed by the ______juice.

2. Large intestine absorbs ______and some ______from the undigested food.

a. The largest gland in our body. II. Match the following: (4 Marks) COLUMN A COLUMN B a. Housefly i. Biting and chewing b. Cockroach ii. Suckling b. The organ where protein digestion starts. c.o Mosquit iii. Sponging d. Infants iv. Sucking

c. The organ that releases digestive juice into the small intestine.

III. Choose the odd one out from each group and give reasons: (2 Marks) 1. Liver, salivary gland, starch, gall bladder. d. The organ where bile juice gets stored.

V. Answer in complete sentences: (2 Marks) 1. How is food digested in amoeba? 2. Stomach, liver, pancreas, salivary gland

14 3. Fibre to Fabric

Learning Outcome

By the end of this chapter, you will be: • Describe the life cycle of a silk moth. • State the animals that yield wool. • Explain the process of obtaining silk from silk • Define selective breeding. moth. • Define sericulture. • Differentiate between a natural fibre and an • Explain the process of obtaining wool from fibre. artificial fibre.

Concept Map

FIBRE TO FABRIC

WOOL SILK

Animals that From fibres to Life cycle of From cocoon yield wool wool silk moth to silk

Rearing and Processing Rearing silk breeding of fibres into Processing silk worms sheep wool

Keypoints

• Wool and silk are two natural fibres obtained from animals. • Wool fibers are obtained from sheep, goats, alpacas and even camel. • Wool fabric is soft to touch and provides warmth. • Silk is a natural fibre made from the cocoons of silk worms. • Silk moth is a large, white insect which passes through different stages in its life cycle-eggs, larva, pupa and moth. • Silk is smooth, soft and lustrous.

Keywords: Cocoon, fleece, reeling, scouring, sericulture, shearing, silk moth, silkworm, sorting.

15 3. Fibre to Fabric

Work Plan

CONCEPT COVERAGE CONCEPT DETAILS PRACTICE SHEET

Wool • Animals that yield wool PS-1 • Rearing and breeding of sheep • Processing fibres into wool PS-2

Silk • Life cycle of silk moth PS-3 • Rearing silk worms • Processing silk PS-4

Worksheet for “Fibre to Fabric” PS-5

Evaluation with self- check or Self-evaluation Sheet Peer check*

16 PRACTICE SHEET - 1 (PS-1)

I. Fill in the blanks: 1. Wool is actually the ______on the body of some animals. 2. A larva transforms into a/an ______. 3. ______are placed in hot water to loosen the silk filaments. 4. The process of washing the skin in tanks to remove grease, dust and dirt is called ______.

II. Match the terms with their meanings: Terms Meanings ANSWER 1. Shearing a. Joining thin fibres together by machines to form one strand of yarn. 2. Scouring b. Washing wool with water containing soap/detergent and small amount of alkali like soda as to remove dust and grease. 3. Sorting c. Rearing of silkworms for production of silk. 4. Spinning d. The stage in silkworm’s life cycle in which larva spins silk like threads around itself. 5. Sericulture e. Separating wool or fibres of different texture. 6. Cocoon f. Removing wool from an animal by scissors, hand blades or electric machines.

PRACTICE SHEET - 2 (PS-2)

I. Say True or False: 1. Wool burns easily. 2. Silk is a plant fibre. 3. Amount of air trapped by wool is more than cotton fibres. 4. Longer fibres are made into wool for sweaters. 5. Rearing of silk worms for commercial purpose is called pisciculture. II. The pictures depict the life cycle of a silk moth. Rearrange the pictures in an appropriate order and select appropriate descriptions for the pictures and rewrite them in correct order.

A B C D

Male Female

17 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option: 9. Which of the following is not a type of silk? 1. Which of the following fibres is used for a. Mulberry silk making camel wool? b. Tassar silk a. Coarse beard hair c. Mooga silk b. Soft undercoat d. Moth silk c. Coarse under coat 10. Paheli wanted to buy a gift made of animal d. None of these. fibre, obtained without killing the animal. 2. In which of the following states of India, are Which of the following would be the right gift sheep reared? for her to buy? a. Uttarakhand a. Woollen shawl b. Himachal Pradesh b. Silk scarf c. Sikkim c. Animal fur cap d. All of the above. d. Leather jacket 3. The main source of wool is 11. Wool fibre cannot be obtained from which of a. Alpaca the following? b. Angoara goat a. Goat c. Sheep b. Llama d. Angora rabbit c. Alpaca d. Moth 4. The stage in which silk thread is obtained from silkworm is 12. Selective breeding is a process of a. Egg a. Selecting the offsprings with desired b. Larva properties. c. Pupa b. Selecting the parents with desired d. Adult properties. c. Selecting an area for breeding. 5. The food of silkworms is leaves of d. Selecting fine hair for good quality wool. a. Maple b. Mulberry 13. The general process that takes place at a c. Neem sheep shearing shed is d. All of these. a. Removal of fleece. b. Separating hair of different textures. 6. Wool is obtained from c. Washing of sheep fibre to remove grease. a. Sheep d. Rolling of sheep fibre into yarn. b. Goat c. Camel d. All of these. 7. Silk fibre is obtained from a. Sheep fleece b. Cocoon c. Cotton boll d. Jute stalk 8. The process of rearing silkworms for obtaining silk is called a. Silviculture b. Sericulture c. Silk culture d. Vermiculture

18 PRACTICE SHEET - 4 (PS-4)

I Answer the following: 1. How does the hair of animals help in keeping their body warm? 2. Various steps involved to obtain wool from fleece are given below: i. Picking out burrs ii. Dyeing in various colours iii. Shearing iv. Scouring v. Sorting. Write the steps in correct sequence in which they are carried out. 3. Some words related with silk are jumbled up. Write them in their correct form. a. Tureculrise b. Wilsmork c. Belmurry d. Ringlee 4. Figure shows three rings of circles with letters in them. Some of these letters in each ring can form the name of one wool yielding animal. Find the names of these animals.

5. Steps for the production of silk are given below in a jumbled order. Arrange them in their proper sequence. a. Eggs are warmed to a suitable temperature for the larvae to hatch from eggs. b. Fibers are taken out from the cocoon. c. After 25 to 30 days, the caterpillars stop eating and start spinning cocoons. d. The larvae/caterpillars or silkworms are kept in clean trays along with freshly chopped mulberry leaves. e. Female silk moths lay eggs. f. Cocoons are kept under the sun or boiled in water.

19 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 8. At which of the following stages of silk moth, silk fibre is obtained? 1. Which of the following animals yield wool for us? a. Eggs a. Sheep b. Cocoon b. Goat c. Silk moth c. Yak d. Silkworm d. All of these 9. Choose the correct matching: 2. What is the process of taking out threads from A B the cocoon for use as silk called? i) Fleece called Mohair is a) Llamaand Alpaca a. Reeling the silk obtained from b. Rearing ii) Fine shawls of Kashmiri b) Angora goats c. Shearing goats are called d. Scouring iii) Camel fur as wool is c) Pashmina 3. Silk yarn yielded by silk moth can be in used in ______texture. a. i) – b); ii) – a); iii) – c) a. Coarse b. i) – b); ii) – c); iii) – a) b. Smooth c. i) – c); ii) – a); iii) – b) c. Shiny d. i) – a); ii) – c); iii) – b) d. All of these 10. Which of the following is the correct flow chart 4. Which of the following countries lead the world of processing of fibre into wool? in silk production? a. India a. Shearing Sorting Scouring Cleaning of burrs b. China Rolling Dyeing c. Australia d. New Zealand b. Scouring Shearing Sorting Cleaning of burrs 5. Which of the following processes is shown in the image? Rolling Dyeing a. Shearing c. Shearing Scouring Sorting Cleaning of burrs

b. Rolling Rolling Dyeing c. Scouring d. Shearing Scouring Sorting Cleaning of burrs d. Dyeing Dyeing Rolling

6. The number of days for which caterpillars eat mulberry leaves is _____. a. 15 to 20 days b. 15 to 30 days c. 20 to 35 days d. 25 to 30 days 7. In India, women are significantly involved in which kind of industries related to silk production among the given? a. Rearing of silkworms b. Reeling of silk from cocoons c. Processing of raw silk into fabrics d. All of these

20 PRACTICE SHEET - 5 (PS-5)

II. Short answer questions 1. Mark the states in the given India map; i) Rajasthan and Gujarat where you find camel ii) Himachal Pradesh where you find yak

2. How is selective breading done? Explain taking sheep as an example. 3. Why do people working in wool industry suffer from health hazards? What are those hazards?

III. Long answer questions 1. Write a short notes on ‘Rearing of silkworms.’ 2. The process shearing is not done during winter. Then when is it done? Also shearing does not hurt the sheep. Justify by giving reasons.

21 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Fill in the blanks: (7 Marks) III. Answer the following: (4 Marks) The ____(a)___ silk moth lays ___(b)___, 1. Paheli went to the market to buy sarees from which hatch ____(c)___ called ___ for her mother. She took out a thread from (d)____ or ___(e)____. They grow in size and the edge of the two sarees shown by the when the caterpillar is ready to enter the shopkeeper and burnt them. One thread next stage of its life history called ___(f)____, burnt with a smell of burning hair and the it first weaves a covering to hold itself, which other burnt with the smell of burning paper. is known as a ___(g)____. Which thread is from a pure cotton saree and which one from a pure silk saree? Give reason for your answer.

II. Match the following: (4 Marks)

Column A Column B ANSWER a. Yak wool Sheared hair b. Angora goats Silkworm c. Mulberry Tibet and Ladakh leaves d. Scouring Jammu and Kashmir

22 4. Heat

Learning Outcome

By the end of this chapter, you will be: • Explain different modes of heat transfer. • Define temperature. • Cite examples for different modes of heat transfer. • Recognize three scales of temperature-Celcius, • Relate convection to formation of sea breeze and Fahrenheit and Kelvin scales. land breeze. • Read the thermometer-clinical and laboratory. • Analyze the clothing patterns with respect to season.

Concept Map

HEAT

Clothes we Transfer of Heat or cold wear Vs heat Seasons

Measuring Transfer of temperature Heat

Scales of Reading a Types of Convection Radiation temperature thermometer Thermometer Conduction

Clinical Laboratory

Keypoints

• Heat flows from a body at a higher temperature to • Through radiation, sunrays reach the earth and a body at a lower temperature. have made this planet warm and convenient for life • Celcius, Fahrenheit and Kelvin are the common forms to survive. temperature scales. • Heat transfer from one body to another can take Keywords: Celsius scale, conduction, conductor, place by the process of conduction, convection and convection, insulator, land breeze, radiation, sea radiation. breeze, temperature, thermometer. • In solids, heat is transferred by conduction. • In liquids and gases, heat is transferred by convection. • Conduction and convection require a medium for heat to flow, whereas radiation can take place even in vacuum. • Metals are usually good conductors of heat and are called conductors. Insulators are the substances that do not conduct heat. Plastic, paper, fur, cloth and wood are examples of insulators. • Sea breeze and land breeze are examples of convection currents in gases.

23 4. Heat

Work Plan

CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SHEET SIMULATION/ VIDEO

Measuring temperature Thermometers: PS-1 Scales of temperature Clinical lab. Heat or cold Reading a thermometer PS-2 Types of Thermometer

• Conduction Activity to Transfer of heat PS-3 • Convection demonstrate • Radiation transfer of heat in a metal strip Clothes we wear Vs PS-4 Seasons

Convection of heat Worksheet for “Heat” PS-5 in water and air Evaluation with self- Self-evaluation Sheet check or Peer check*

24 PRACTICE SHEET - 1 (PS-1)

I. Fill in the blanks selecting appropriate words from the box. kink 212°F 0°C to 110°C bad conduction radiation 1000F 37°C laboratory clinical good dark mercury copper light convection 1. Metal used in the thermometer is ______. 2. The ______in the thermometer prevents the backflow of mercury into the bulb. 3. The boiling point of water on Fahrenheit scale is ______. 4. The range of temperature in a laboratory thermometer is ______. 5. Water is a ______conductor of heat. 6. We receive sun’s light by ______. 7. Land breeze is formed due to ______. 8. In summer, we wear ______coloured clothes. 9. Temperature of a normal human body is ______. 10. When you have fever, your doctor uses a ______thermometer to find out your body temperature.

II. Say True or False: 1. Air is a good conductor of heat. 2. Actual movement of molecules takes place in convection. 3. When water at 50°C is poured at a pan heated to 80°C, heat flows from water to pan. 4. A clinical thermometer can measure the temperature of ice. 5. Conduction takes place only when two objects are not in contact with each other.

25 PRACTICE SHEET - 2 (PS-2)

I. Match the Following: COLUMN I COLUMN II 1. Convection current Actual movement of molecules 2. Conduction No medium required. 3. Insulators Instrument to measure body temperatures. 4. Clinical thermometer Two bodies in contact 5. Good absorbers of heat Rubber, cork, plastic, wood 6. Convection Gold, silver, copper, iron 7. Radiation Black colours and dark colours 8. Good conductors Land breeze and sea breeze

II. Select the appropriate word for the descriptions given below: Heat Insulator Radiation Conductor Thermometer Convection Conduction Clinical thermometer Temperature Laboratory thermometer 1. Degree of hotness of a body. 2. An instrument used to measure the temperature. 3. A thermometer used to measure the human body temperature. 4. A thermometer used in the laboratories to measure the temperature of chemicals. 5. Form of energy used to do work. 6. Heat transfer through a substance without actual movement of molecules. 7. A substance through which heat can flow easily. 8. Heat transfer by actual movement of molecules of the substance. 9. Transfer of heat without the need of any material medium. 10. A substance which blocks heat.

26 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option: 9. A marble tile would feel cold as compared to 1. Best conductor of heat is a wooden tile on a winter morning, because a. Gold the marble tile b. Silver a. Is a better conductor of heat than the c. Copper wooden tile. d. Mercury b. Is polished while wooden tile is not polished. 2. The thermometer used to measure body c. Reflects more heat than wooden tile. temperature is d. Is a poor conductor of heat than the a. Clinical thermometer wooden tile. b. Laboratory thermometer c. Kelvin thermometer 10. A beggar wrapped himself with a few layers d. Any of the above. of newspaper on a cold winter night. This helped him to keep himself warm because 3. In solids, transfer of heat takes place by a. Friction between the layers of newspaper a. Convection produces heat. b. Conduction b. Air trapped between the layers of c. Radiation newspaper is a bad conductor of heat. d. All of these. c. Newspaper is a conductor of heat. 4. Convection of heat takes place in d. Newspaper is at a higher temperature than a. Only solids the temperature of the surrounding. b. Only liquids c. Liquids and solids d. Liquids and gases 5. Which of the following is an insulator? a. Aluminum b. Bakelite c. Mercury d. Steel 6. Temperature is measured in a. Calories b. Celsius c. Joule d. All of these 7. Heat energy will flow from body “A” to body “B”, if a. B is at a higher temperature than A. b. A is at a higher temperature than B c. Both are at the same temperature. d. No heat flows. 8. Dark coloured clothes keep the body warm because they are a. Good absorbers of heat b. Bad absorbers of heat c. Neither good nor bad absorbers of heat d. None of these.

27 PRACTICE SHEET - 4 (PS-4)

I. Answer the following questions: 1. Shopkeepers selling ice blocks usually cover them with jute sacks. Explain why. 2. To keep her soup warm, Paheli wrapped the container in which it was kept, with a woollen cloth. Can she apply the same method to keep a glass of cold drink cool? Give reason for your answer. 3. In a mercury thermometer, the level of mercury rises when its bulb comes in contact with a hot object. What is the reason for this rise in the level of mercury? 4. For setting curd, a small amount of curd is added to warm milk. The microbes present in the curd help in setting if the temperature of the mixture remains approximately between 35°C to 40°C. At places, where room temperature remains much below the range, setting of curd becomes difficult. Suggest a way to set curd in such a situation. 5. You may have noticed that a few sharp jerks are given to clinical thermometer before using it. Why is it done so? 6. Why is it advised not to hold the thermometer by its bulb while reading it? 7. While constructing a house in a coastal area, in which direction should the windows preferably face and why?

28 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 7. Now a days, we see copper-bottomed stainless-steel vessels used in kitchen. 1. The process by which we get the sun’s heat is What could be the reason? called ______. a. To provide rich look a. Conduction b. Copper is better conductor of heat than b. Convection stainless steel c. Absorption c. The copper-bottomed vessels are cheaper d. Radiation d. Easy to clean 2. What coloured clothes are suggested to wear in summer? 8. We carry thermo flasks with us for later use of hot or cold substance. How does it prevent loss a. White or gain of heat? b. Light coloured a. By convection c. Black b. By conduction d. Either (A) or (B) c. By radiation 3. Land breeze means: d. All of these a. The cool air that moves from the land towards 9. To construct buildings, that are not affected the sea much by heat and cold outside: b. The air that moves from the sea towards the a. Outer walls of building should have trapped land layers of air c. The hot air that moves from the land towards b. Use hollowbricks the mountain c. Use wood to construct walls d. The air that is present in the atmosphere d. Both (A) and (B) 4. What is clinical thermometer? 10. Boojho wanted to buy ice. The shopkeeper a. The one used to measure the temperature of a wrapped ice in a gunny bag and gave him. What substance could be the reason? b. The one that measures our body temperature a. So that ice does not melt immediately c. The one that measures the weather b. For safety d. The one that measures the density c. To carry 5. The figure demonstrates: d. Not others to make it out a. Transfer of heat by II. Short answer questions convection in water b. Transfer of heat by 1. A metal chair and a wooden chair are kept in the conduction in water sun. Which chair will become hot faster? Why? c. Transfer of heat by 2. What do you observe in the image? Give reason. convection in air d. Transfer of heat by absorption in water 6. A clinical thermometer readstemperature from: a. 35°C to 42°C b. 37°C to 45°C c. 0°C to 100°C d. 40°C to 65°C 3. Why do you think the handles of pressure cooker and fry pans are made of thick plastic and why not the same material is used as that of pressure cooker?

29 PRACTICE SHEET - 5 (PS-5)

III. Long answer questions 1. Write an experiment to demonstrate transfer of heat by conduction. 2. Give reasons for the following: i) A wooden stirrer is better than a stainless-steel stirrer. ii) A cold drink bottle is wrapped with a jute bag while travelling. iii) Clinical thermometer is not hold at the bulb while noting the temperature. iv) China clay cups are used for serving hot tea. v) Hot tea left for a while becomes cold.

30 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Fill in the blanks: (3 Marks) 3. Which mode of heat transfer requires no 1. Hotness of an object is determined by its medium? ______.

2. Temperature is measured in degree ______. IV. Answer in two or three sentences: (6 Marks) 1. Why are clinical thermometers not used to 3. Land sea breeze blows during measure boiling point of water? ______.

II. Say true or false: (3 Marks) 1. Temperature of boiling water cannot be measured using a clinical thermometer. 2. At a camp site, there are tents of two shades – one made with black fabric and the other with white fabric. Which one will you prefer for resting on a hot summer afternoon? Give 2. While reading the temperature in a clinical reason for your choice. Would you like to thermometer, thermometer has to be kept prefer the same tent during winter? inside the smouth.

3. The flow of cool air from sea towards the land is called sea breeze.

III. Answer in a sentence: (3 Marks) 1. What is the scale used for measuring temperature for scientific purposes?

2. What is the function of kink in a clinical thermometer?

31 5. Acids, Bases and Salts

Learning Outcome

By the end of this chapter, you will be: • State the uses of bases. • Define acid. • Define salt. • Classify acids into organic and mineral acids. • Identify different types of indicators. • Cite examples for acids. • Define neutralization reaction. • State the uses of acids. • Explain the applications of neutralization reaction • Define a base. in our day to day life. • Cite examples for bases.

Concept Map

ACIDS, BASES AND SALTS

ACIDS BASES SALTS INDICATORS

Examples Examples Examples Natural

Neutralization Uses Uses Synthetic reaction

Keypoints • Acids are corrosive in nature and sour to taste. • Hydrogen gas is released when acids react with metals. • Bases react with acids and form salt and water. • Some bases are soluble in water are called alkalis. • Bases turn red litmus blue, whereas acids turn blue litmus red. • In a neutralisation reaction, an acid and a base react together to form salt and water. • Salt solutions can conduct electricity. • Hydrogen gas is liberated when metals react with acids.

Keywords: Acid, acidic, base, basic, indicator, neutral, neutralization, salt.

32 5. Acids, Bases and Salts

Work Plan

CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SHEET SIMULATION/ VIDEO

Acids • Examples Testing whether lemon • Uses PS-1 juice is acid or base by litmus paper Bases • Examples PS-2 • Uses Using China rose as indicator Salts • Examples PS-3 • Neutralization reaction Study process of neutralisation by using HCl Indicators • Natural PS-4 and NaOH with the help of • Synthetic phenolphthalein Worksheet for “Acids, Bases and Salts” PS-5

Evaluation with self- Self-evaluation check or Peer check* Sheet

33 PRACTICE SHEET - 1 (PS-1)

I. Fill in the blanks: 1. The presence of a/an ______makes a substance taste sour. 2. Acids react with bases to form ______and ______3. Sodium hydroxide + Hydrochloric acid → ______+ ______4. ______and ______are synthetic indicators. 5. Basic solution turns ______litmus to blue______. II. Where am i found in? ACID/BASE FOUND IN Acetic acid Formic acid Citric acid Lactic acid Oxalic acid Calcium hydroxide Ammonium hydroxide Sodium hydroxide Magnesium hydroxide

PRACTICE SHEET - 2 (PS-2)

I. Complete the following table: Sl. No Test solution Indicator that can Initial colour of Final colour of be used the test solution the test solution 1 Lemon juice Blue litmus 2 Milk of magnesia Phenolphthalein 3 Soda water Blue litmus 4 Baking soda Red litmus 5 Vinegar Blue litmus 6 Orange juice Blue litmus 7 Soap solution Phenolphthalein 8 Shampoo (dilute) Turmeric solution 9 ENO fruit salt Phenolphthalein

II. Complete the following table: Indicator Colour in Acidic medium Basic medium Neutral medium Blue litmus Red Red litmus Red Phenolphthalein Colourless Methyl orange Orange

34 PRACTICE SHEET - 3 (PS-3)

I. Choose the corrrect option: 8. A solution changes the colour of turmeric 1. The correct way of making a solution of acid indicator from yellow to red. The solution is in water is to a. Basic a. Add water to acid. b. Acidic b. Add acid to water. c. Neutral c. Mix acid and water simultaneously. d. Either neutral or acidic d. Add water to acid in a shallow container. 9. Which of the following set of substances 2. Products of a neutralization reaction are contain acids? always a. Grapes, lime water a. An acid and a base. b. Vinegar, soap b. An acid and a salt. c. Curd, milk of magnesia c. A salt and water. d. Curd, vinegar d. A salt and a base. 10. On adding phenolphthalein indicator to a 3. Turmeric is a natural indicator. On adding colourless solution, no change is observed. its paste to acid and base separately, which What is the nature of this solution? colours would be observed a. Basic a. Yellow in both acid and base. b. Either acidic or basic b. Yellow in acid and red in base. c. Either acidic or neutral c. Pink in acid and yellow in base. d. Either basic or neutral d. Red in acid and blue in base. 4. Phenolphthalein is a synthetic indicator and its colours in acidic and basic solutions, respectively are a. Red and blue. b. Blue and red. c. Pink and colourless. d. Colourless and pink 5. When the soil is too basic, plants do not grow well in it. To improve its quality, what must be added to the soil? a. Organic matter b. Quick lime c. Slaked lime d. Calamine solution 6. ‘Litmus’, a natural dye is an extract of which of the following? a. China rose (Gudhal) b. Beetroot c. Lichen d. Blue berries (Jamun) 7. Neutralization reaction is a a. Physical and reversible change. b. Physical change that cannot be reversed. c. Chemical and reversible change. d. Chemical change that cannot be reversed.

35 PRACTICE SHEET - 4 (PS-4)

I. Answer the following: 1. Look at the given reaction. Hydrochloric acid + Sodium hydroxide (base) → Sodium chloride (salt) + Water Sodium chloride formed in this reaction remains in solution form. Can we get solid sodium chloride from this solution? Suggest a method (if any). 2. While playing in a park, a child was stung by a wasp. Some elders suggested applying paste of baking soda and others lemon juice as remedy. Which remedy do you think is appropriate and why? 3. Form a sentence using the following words – baking soda, ant bite, moist, effect, neutralised, rubbing. 4. Boojho, Paheli and their friend Golu were provided with a test tube, each containing China rose solution which was pink in colour. Boojho added two drops of solution ‘A’ in his test tube and got dark pink colour. Paheli added 2 drops of solution ‘B’ to her test tube and got green colour. Golu added 2 drops of solution ‘C’ but could not get any change in colour. Suggest the possible cause for the variation in their results. 5. A farmer was unhappy because of his low crop yield. He discussed the problem with an agricultural scientist and realised that the soil of his field was either too acidic or too basic. What remedy would you suggest the farmer to neutralize the soil?

36 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 8. Which substance when tested with red and blue litmus paper doesn’t change its colour? 1. Special substances that are used to test whether the given substance is acidic or basic are called a. Milk ______. b. Mineral water a. Salts c. Lime water b. Soaps d. Butter milk c. Indicators 9. The acidic liquid injected by an ant bite is d. Lichens neutralised by rubbing the area with ______. 2. Milk of magnesia contains: a. Baking soda a. Magnesium hydroxide b. Calamine solution b. Hydrogen peroxide c. Phenolphthalein c. Nitrogen dioxide d. Either (A) or (B) d. Calcium chloride 10. Plants do not grow well when the soil is either too acidic or too basic. When the soil is too acid- 3. Natural indicator(s) among the following is/ are: ic, it is treated with bases like ______. a. Turmeric a. quick lime b. Litmus b. slakedlime c. China Rose petals c. Compost d. All of these d. Either (A) or (B) 4. In which of the following solutions does, phenolphthalein remains colourless? II. Short answer questions a. Salt solution 1. Why are the inner walls of vessels made up of b. Acidic solution brass and copper coated with another substance? c. Basic solution d. Neutral solution 2. Write some uses of acids in our daily life. 5. Which of the following is a basic in na- 3. Sugar is neutral, so Raju thought that it is a salt. ture? Do you agree with him? Write three reasons to support your answer. a. Soap solution b. Milk III. Long answer questions c. Lemon juice 1. What is an indicator? What are natural d. Tamarind indicators? Write a short note on them. 6. Which of the following indicators turn acidic 2. Why and how is acid rain caused? Identify the solutions to dark pink (magenta) and basic solu- effects of acid rain. tions to green. a. Turmeric b. China rose c. Litmus d. Phenolphthalein 7. While making lemon rice, when Paheli added lemon juice on to salt, she found the salt turned grey in colour. What could be the reason? a. Salt is impure b. Lemon is spoiled c. Lemon juice is acidic d. Salt is basic

37 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Say true or false: (4 Marks) IV. Answer the following: (4 Marks) a. All substances are either acidic or basic. 1. You are provided with three test tubes A, B and C as shown in Figure with different liquids. What will you observe when you put b. A compound if acidic will turn all indicators red.

c. Lime water turns red litmus blue.

d. Common salt dissolved in water turns blue litmus red. A B C Solution of Soap solution Pure water tartatic acid II. Match the following: (5 Marks) a. A piece of blue litmus paper in each test tube? COLUMN I COLUMN II b. A piece of red litmus paper in each test 1. Tartaric acid a. Soap tube? 2. Calcium hydroxide b. Curd c. A few drops of phenolphthalein solution to 3. Formic acid c. Unripe mangoes each test tube? 4. Sodium hydroxide d. Ant’s sting Solution Effect on Effect on Effect on 5. Lactic acid e. Lime water blue litmus red litmus phenol III. Give reasons: (2 Marks) phthalein Tartaric 1. Acids should be handled with care. acid

Soap

2. A farmer uses organic manure to the alkaline soil in the field. Pure water

2. Paheli observed that most of the fish in the pond of her village were gradually dying. She also observed that the waste of a factory in their village is flowing into the pond which probably caused the fish to die. a. Explain why the fish were dying.

b. If the factory waste is acidic in nature, how can it be neutralised?

38 6. Physical and Chemical Changes

Learning Outcome

By the end of this chapter, you will be able to: • Differentiate between a physical change and a • Define a physical change. chemical change. • State the characteristics of a physical change. • Represent a few chemical changes in the form of a • Cite examples for a physical change. word equation. • Define a chemical change. • Explain rusting of iron. • State the characteristics of a chemical change. • State methods to prevent rusting. • Cite examples for a chemical change. • Define galvanisation. • Define crystallisation. Concept Map

Key Points • A change in which a substance undergoes a change • Substances taking part in a chemical reaction in its physical properties is called a physical change. are called reactants, represented by LHS of the • A physical change is generally temporary and equation while products formed due to the reversible. reaction are written on RHS. • In a physical change there is no formation of new • Magnesium Oxide+ Water → Magnesium hydroxide substances, the properties of substances remain Reactants Product the same even when there is a change in its physical • When iron reacts with water and oxygen, it forms a state, some changes are reversible and a few may rust and the phenomenon is called rusting. be irreversible. • By alloying, greasing, painting and galvanization, • A change in which one or more new substances rusting can be prevented. are formed is called a chemical change. A chemical • Obtaining large crystals of pure substances from change is a chemical reaction. their solutions is called crystallization and it is a • In a chemical change, there is formation of one physical change. or more new substances, heat or light is given or absorbed, sound may be produced, a change in the smell can occur, colour change can take place, gas may be evolved or a precipitate may be formed. • A chemical equation represents the substances that react to form products.

39 6. Physical and Chemical Changes

Work Plan

CONCEPT CONCEPT DETAILS PRACTICE SHEET SIMULATION/VIDEO COVERAGE

• Properties of physical changes Demonstrating the Physical changes • Examples of physical changes PS – 1 change of state of ice from solid to liquid

• Properties of chemical changes Burning of magnesium Chemical changes PS – 2 • Examples of chemical changes ribbon

• Rusting of iron Rusting, galvanisation PS – 3 Reaction of co with lime • Galvanisation 2 and crystallisation PS – 4 water • Crystallisation

Worksheet for “Physical and Chemical Changes” PS – 5

Evaluation with self- Self-evaluation Sheet check or Peer check*

40 PRACTICE SHEET - 1 (PS-1)

I. Fill in the blanks with appropriate terms: 1. In a ______change, no new substances are formed. 2. Physical changes can be ______or ______. 3. ______react to form ______in a chemical change. 4. In a chemical change, ______may be absorbed or released. 5. Magnesium hydroxide turns ______litmus to ______. II. The characteristics of physical change and a chemical change are jumbled up. Separate them and place them under appropriate headings: 1. One or more new substances are formed that have totally different properties than the original reactants. 2. It does not alter the chemical composition of the substance. 3. Heat and light are absorbed/released in this type of change. 4. No new substance is formed. 5. Alters the chemical composition of the substance. 6. It is usually permanent and irreversible. 7. Heat or light is generally not evolved in this type of reaction. 8. It is usually temporary and mostly reversible.

41 PRACTICE SHEET - 2 (PS-2)

I. Classify the following as a physical change or a chemical change. 1. Burning of petrol. 2. Digestion of food. 3. Tearing paper into bits. 4. Burning of paper to ashes. 5. Formation of ice from water. 6. Burning of a magnesium ribbon. 7. Changing the shape of the clay dough. 8. Baking the wheat dough into a roti. 9. Boiling a cup of milk. 10. Forming curd from milk. 11. Cutting a log into smaller pieces. 12. Melting of ice cream. 13. Making ice cream from milk, cream and flavouring agent. 14. Reaction of hydrochloric acid with sodium hydroxide to form sodium chloride and water. 15. Inflating and deflating a rubber tube of the bicycle.

42 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option: 1. Which of the following is not a physical change? a. Crushing of paper b. Tearing paper c. Burning paper d. Making a paper boat 2. Which of the following is a physical but irreversible change? a. Burning of a match stick b. Melting of an ice cream c. Breaking a glass test tube d. Burning waste 3. Which of the following will result in a chemical change? a. Mixing salt and water b. Heating candle wax c. Adding curd to milk d. Adding water to milk 4. Rusting of iron can be prevented by a. Alloying b. Painting c. Galvanization d. All of the above 5. Which gas is evolved when vinegar reacts with baking soda? a. Oxygen b. Hydrogen c. Carbon dioxide d. Nitrogen 6. Which of the following is a physical change? a. Rusting of iron b. Combustion of magnesium ribbon c. Burning of candle d. Melting of wax 7. Which of the following is a chemical change? a. Twinkling of stars b. Cooking of vegetables c. Cutting of fruits d. Boiling of water 8. A chemical change may involve – a. Change in colour only b. Change in temperature only c. Evolution of gas only d. Any or all of the above

43 PRACTICE SHEET - 3 (PS-3)

9. Which of the following is/are true when milk changes into curd? i. Its state is changed from liquid to semi solid ii. It changes colour iii. It changes taste iv. The change cannot be reversed Choose the correct option from below: a. (i) and (ii) are correct b. (ii) and (iii) are correct c. (i), (iii) and (iv) are correct d. (i) to (iv) are correct 10. A man painted his main gate made up of iron, to i. Prevent it from rusting ii. Protect it from sun iii. Make it look beautiful iv. Make it dust free Which of the above statement(s) is/are correct? a. (i) and (ii) b. (ii) and (iii) c. only (ii) d. (i) and (iii) 11. Iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability? a. It is more than 7 metres high b. It weighs about 6000 kg c. It was built more than 1600 years ago d. It has not rusted after such a long period 12. Galvanisation is a process used to prevent the rusting of which of the following? a. Iron b. Zinc c. Aluminium d. Copper 13. Paheli’s mother made a concentrated sugar syrup by dissolving sugar in hot water. On cooling, crystals of sugar got separated. This indicates a – a. Physical change that can be reversed b. Chemical change that can be reversed c. Physical change that cannot be reversed d. Chemical change that cannot be reversed 14. Which of the following statement is incorrect for a chemical reaction? a. Heat may be given out but never absorbed b. Sound may be produced c. A colour change may take place d. A gas may be evolved 15. Two drops of dilute sulphuric acid were added to 1 g of copper sulphate powder and then small amount of hot water was added to dissolve it (step I). On cooling, beautiful blue coloured crystals got separated (step II). Step I and step II are: a. Physical and chemical changes respectively b. Chemical and physical changes respectively c. Both physical change d. Both chemical change

44 PRACTICE SHEET - 4 (PS-4)

Answer the following: 1. Melting of wax is a change where a solid changes to liquid state. Give one more such change which you observe in your surroundings. 2. What kind of change is shown by tearing of paper? 3. Write word equations for two chemical reactions with the help of materials given in the box. Air, copper sulphate, iron, vinegar, iron oxide, carbon dioxide, iron sulphate, copper, lime water, water 4. Explain the following: a. Lime water turns milky on passing carbon dioxide gas into it. b. Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate. 5. Give two examples for each of the following cases: a. Physical changes which are reversible. b. Physical changes which are not reversible. c. Chemical changes. 6. Give an example of a chemical reaction for each of the following situations: a A change in colour is observed. b. A gas is evolved. c. Sound is produced. 7. If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance called rust. a Do you think rust is different from iron? b. Can you change rust back into iron by some simple method? c. Do you think formation of rust from iron is a chemical change? d. Give two other examples of a similar type of change. 8. A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour. a. What changes do you expect? b. Are these changes chemical in nature? c. Write a word equation for the chemical change, if any.

45 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 8. When a pinch of baking soda is added to a teaspoonful of vinegar, the gas produced is 1. The ______water makes the process of rust ______. formation faster. a. Oxygen a. Distilled b. Hydrogen b. Sugar c. Nitrogen c. Salt d. Carbon dioxide d. River 9. What type of change is ‘burning of magnesium 2. The process of formation of salt crystals by the ribbon in air’? Is it reversible? evaporation of sea water is called: a. Physical change and reversible a. Radiation b. Chemical change and reversible b. Crystallisation c. Chemical change and not reversible c. Condensation d. Physical change and not reversible d. Galvanisation 10. Sun’s rays give out ultraviolet rays. Which of 3. The common name of acetic acid is: the following protects us as natural shield from a. Vinegar these radiations? b. Baking soda a. Atmosphere c. Lime water b. Ozone layer d. Washing soda c. Air 4. Identify the missing component in the equation. d. Water vapour in air a. CaO II. Short answer questions b. CaOH 1. What type of change is observed when baking c. Ca(OH)2 soda is added to acetic acid? Write the products d. CaO3 formed in an equation. 5. Which of these are essential for rusting? 2. How do you demonstrate that copper sulphate a. Oxygen and salt solution when reacts with iron gives iron sul- b. Oxygen and water vapour phate and copper? c. Hydrogen and water vapour 3. What type of change is ‘crushing a chalk piece d. Carbon dioxide and water into dust’? Can you get back the chalk piece? If yes, write the procedure. 6. Explosion of fireworks produces: a. Light III. Long answer questions b. Sound 1. Write about all the possible changes that may accompany a chemical change. c. Heat and unpleasant gases d. All of these 2. Compare and contrast between physical and chemical changes with examples. 7. Stainless-steel that we use in our kitchen does not rust. It is made by mixing iron with: a. Carbon and metals like chromium, nickel and manganese b. Copper and metals like chromium, nickel and manganese c. Sulphur and metals like chromium, nickel and manganese d. Magnesium and metals like chromium, nickel and manganese

46 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Say whether the following statements IV. Fill in the blanks: (3 Marks) are true or false: (2 Marks) 1. Making sugar solution is a _____ change. 1. When a candle burns, both physical and 2. A physical change is generally______. chemical changes take place. 3. Grinding of wheat grain changes its size. It is 2. Anaerobic bacteria digest animal waste and a ______change. produce biogas.

V. Complete the following equations: (3 Marks) II. Match the following: (3 Marks) 1. Magnesium + Oxygen → ______2. Copper sulphate + Iron → ______+ Column I Column II ______i. Large crystals a. Turns lime water milky 3. Carbon dioxide + Lime water → ______+ ii. Depositing a layer of b. Physical change ______zinc on iron iii. Souring of milk c. Rust iv. Carbon dioxide d. Sugar candy v. Iron oxide e. Chemical change vi. Dissolving common f. Galvanisation salt in water

III. Classify the following processses into physical change or a chemical change with a reason: (4 marks) 1. Beating of aluminium metal to make aluminium foil. 2. Digestion of food. 3. Cutting of a log of wood into pieces. 4. Burning of crackers.

47 7. Weather, Climate and Adaptations of Animals to Climate

Learning Outcome

By the end of this chapter, you will be: • Define adaptation. • Define weather. • Relate adaptation of animals to the climate of • Explain the factors that influence weather of a their dwelling. place. • Explain adaptations seen in polar bears and • Define climate. tropical rain forest animals. • Differentiate between weather and climate.

Concept Mapping

WEATHER,CLIMATE AND ADAPTATIONS

Weather Climate Adaptation

Polar Tropical Definition Elements Definition Zones regions rainforest

Temper- Wind Rainfall Humidity Torrid Frigid Temperate ature speed

Keypoints • Atmospheric conditions of an area on a daily basis • Animals living in polar regions are adapted to live is weather. in such conditions by having bigger bodies, thick • The average weather condition of a place over a fur and thick layer of fat. Some of them hibernate long period of time is climate. while some migrate to warmer places during winter • Saturated air is the air that has maximum amount season. of water vapour, it can hold at a particular • In tropical rainforests, animals live in different layers temperature, when it reaches this point, the air of the forest so that they do not have to compete cools suddenly and water vapour condenses to for food. Due to adequate food availability, large form clouds. numbers of organisms are found in tropical rain • Climate depends on the latitude, altitude, closeness forests. to sea, rainfall, humidity and other factors. • Torrid zone, frigid zone and temperate zone are the Keywords: Adaptation, climate, elements of three climatic zones of the earth. weather, humidity, maximum temperature, • Rainfall and wind at a place depends on the migration, minimum temperature, polar region, closeness to the sea and presence of mountains in tropical rainforest, tropical region, weather. the surroundings. • Equatorial belt has hot and wet climate and has abundant evergreen tropical rain forests.

48 7. Weather, Climate and Adaptations of Animals to Climate

Work Plan

CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SHEET

Weather • Rainfall • Temperature PS-1 • Humidity • Wind speed

Climate • Zones PS-2 – Torrid – Frigid – Temperate PS-3

Adaptation • Adaptation – Polar region PS-4 – Tropical rainforest

Worksheet for “Weather, Climate and Adaptations of Animals to Climate” PS-5

Evaluation with self- check or Self-evaluation Sheet Peer check*

49 PRACTICE SHEET - 1 (PS-1)

I Fill in the blanks choosing appropriate words from the box. Some can be used more than once: 1. The elements of weather are ______,______,______and ______2. The amount of water vapour present in air is called ______. 3. An instrument used to measure rainfall is ______. 4. ______of a place changes every day. 5. Relative humidity of a place is measured with an instrument called ______. 6. Winds bring ______with them. 7. ______forests are rich in flora and fauna. 8. Average weather over a long period forms the ______of the place.

II. Match the following: Column I Column II 1. Equator a. Flippers 2. North and South poles b. Trunk 3. Elephant c. Camel 4. Penguin d. Frigid zones 5. Long padded feet e. Divides earth into two equal halves

PRACTICE SHEET - 2 (PS-2)

I. Unscramble the following words: 1. MATLICE: Weather conditions in a region over a long period of time. 2. TREHMEOMRET: Used to measure temperature. 3. AROPL : Coolest region on the earth. 4. UHIDYTMI: One of the elements of the earth. 5. NOYAPC: Dense layers of tree crowns in tropical forests. II. Say True or False. If false, correct the statement. 1. Factors such as temperature, rainfall and humidity to determine the weather of a place. 2. The axis about which the earth rotates, is at a tilt with the plane of its orbit about the sun. 3. Penguins are adapted to live in temperate zones. 4. Instrument used to measure humidity is hydrometer. 5. Humidity of a place is usually lower in a rainy season than in summer and winter.

50 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option: 6. Which of the following statement is incorrect 1. The maximum and minimum temperature for penguins? displayed daily in the weather bulletin refer a. They huddle together. to the – b. They cannot swim. a. Highest day temperature and lowest night c. They have webbed feet. temperature of the day. d. They have streamlined body. b. Highest day temperature and highest night 7. Read the following environmental conditions temperature of the month. of tropical rain forests. c. Temperature recorded at 12 noon and at i. Hot and humid climate mid night (00.00 hrs). ii. Unequal lengths of day and night d. Average highest temperature of day and iii. Abundant rain fall average lowest temperature of night. iv. Abundant light and moisture 2. Out of the given definitions, which is the Identify the conditions from the above list most appropriate definition of climate? that are responsible for the presence of large a. Changes in weather conditions in a year. number of plants and animals in tropical rain b. Average weather pattern of many years. forests. c. Change in weather pattern in a few years. a. i and ii d. Weather conditions during summer. b. i and iii c. i,iii and iv 3. Which of the following briefly describes the d. ii and iv desert climate? a. Hot and humid 8. The coldest region on earth is the b. Dry and humid a. Polar region c. Hot and dry b. Tropical region d. Hot and wet c. Temperate region d. Coastal region 4. Paheli went to a wildlife sanctuary where she saw dense vegetation of trees, shrubs, herbs 9. Choose the odd one from the following and also a variety of animals like monkeys, options : birds, elephants, snakes, frogs, etc. The most a. Thick layer of fat under the skin likely location of this sanctuary is in the – b. White fur a. Temperate region c. Long grasping tail b. Tropical region d. Wide and large feet with sharp claws c. Polar region 10. Hump of a camel is a reservoir of d. Coastal region a. Fatty tissue 5. Given below are some adaptive features of b. Water animals: c. Milk i. Layer of fat under the skin d. All of these. ii. Long, curved and sharp claws iii. Slippery body iv. Thick white fur Which of them are the adaptive features of a polar bear? a. i only b. i and ii only c. i, ii and iii only d. i, ii and iv only

51 PRACTICE SHEET - 4 (PS-4)

I. Answer the following: 1. “A fish dies when taken out of water whereas a wall lizard will die if kept under water.” Mention the term used to describe such abilities that allow fish and lizard to survive in their respective habitats. 2. Give one example of an animal that can live both in water and on land. 3. Why is it difficult to predict the weather of a place while it is easy to predict its climate? 4. Name two animals each that live in Polar region and Tropical rain forests. 5. Write two common adaptive features of a polar bear which help in keeping it warm.

52 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 6. On which day is the maximum temperature noted as 26oC? 1. What all information does the daily weather report contain? a. Sunday a. Temperature b. Thursday b. Humidity c. Tuesday c. Rainfall d. Saturday d. All of these 7. When can you say that the climate of a place is wet? 2. Which instrument is used to measure rainfall? a. If the place receives rain for a major part of the a. Maximum and minimum thermometer year b. Rain gauge b. If the place receives very little rainfall c. Laboratory thermometer c. If the place receives no rainfall d. All of these d. All of these 3. ______of the elephant help it to keep cool in 8. Climate of a place has a profound effect on: the hot and humid climate of the rainforest. a. Only on plants a. Large ears b. Only on animals b. Big trunk c. All living organisms c. Heavy body d. All non-living organisms d. Two long tusks 9. The polar region got its name as it is situated at: 4. All changes in the weather are caused by: a. North pole a. The Earth b. South pole b. The atmosphere c. Both North and South pole c. The Sun d. Far away from the poles d. The wind 10. The days are shorter in the winter than summer. The given graph shows the variation of maximum What could be the reason? temperature in a week. Understand the graph and a. Earth revolves round the Sun. answer the questions that follow (Q5 and Q6): b. the Earth is tilted 23.4 degrees. c. the Earth rotates on its axis. d. of the atmosphere.

II. Short answer questions 1. What do you understand by the weather at a place and its elements? 2. How are the animals like polar bears adapted to the polar regions? Explain. 3. Why do we need to record weather conditions? What are its components? How is it going to benefit?

III. Long answer questions 1. Write a short note on how the animals are 5. On which day is the maximum temperature adapted to the climatic conditions they live in? recorded highest? 2. “Migratory birds travel as much as 15000 km”. a. Tuesday Why do they migrate? How are they able to b. Friday come back? Discuss. c. Monday d. Thursday

53 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

1. Match the following: (4 Marks) 4. Differentiate between the following: (2 Marks) COLUMN I COLUMN II a. Weather and climate i. Red eyed frog a. very sensitive hearing ii. Penguin b. stream lined body iii. Tiger c. silver white mane iv. Lion tailed macaque d. sticky powder on feet

2. Fill in the blanks: (3 Marks) b. Humidity and rainfall Weather of a place is the day-to-day condition of the _____(a)_____ with respect to ____(b)____, _____ (c)______, ____(d)______, _____(e)______at that place, while climate is the _____(f)______weather pattern taken over many years.

3. Given below is a list of climatic conditions and some examples of animals. Read them carefully and place the items in the relevant columns as shown. (6 Marks) Penguin, Gorilla, Monkey, Reindeer, Assam, Greenland, Sun does not rise for six months, Hot and humid climate, Days and nights are almost equal in length throughout the year, Winter temperature around –37°C, Western Ghats, covered with snow

TROPICAL RAIN FOREST POLAR REGIONS

54 8. Winds, Storms and Cyclones

Learning Outcome

By the end of this unit, a student will be able to: • Explain the formation of a cyclone. • Define wind. • List the destructive effects of cyclones. • Understand properties of air. • State safety measures to be taken by the people. • Identify factors that cause wind currents.WINDS, STORMS• Inf ANDer that CYCLONES technology can help in reducing the • Explain the factors that cause wind currents. destruction to life brought about by natural CONCEPT• Define thunder MAP: storms. disasters. • Define cyclones. Concept Map

WINDS, STORMS AND CYCLONES

Wind Thunderstorms Cyclones

Formation of Effective safety Properties Formation Destruction currents measures

By the end of this unit, a student will be able to

 Define wind

 Understand properties of air.

 Identify factors that cause wind currents.

 Explain the factors that cause wind currents

 Define thunderstorms

 Define cyclones

 Explain the formation of a cyclone.

 List the destructive effects of cyclones.

 State safety measures to be taken by the people. 55  Infer that technology can help in reducing the destruction to life brought about by natural disasters.

TIME FRAME: 08 Classes

UNIT PLAN: 8. Winds, Storms and Cyclones

Work Plan

CONCEPT SUB CONCEPT ACTIVITY SKILL TIME

Moving air is called Air exerts pressure. LESSON STARTER: Teacher shows a Observes 10 min wind. High speed winds video on cyclonic effects. From this Infers Properties of air are accompanied by video, teacher and students discuss reduced air pressure. about the topic. Air expands on warming. Teacher demonstrates Activity 8.1 (NCERT) and explains the concept Observes 15 min that air exerts pressure. Infers

Students work in small groups and complete Activity 8.2. From this Experiments 15 min activity, Observes they understand that when wind Infers speed increases, air pressure decreases.

HW: Bring necessary materials for Activities 8.3 and 8.4.

Students work in groups and Experiments 20 min complete Activities 8.3 and 8.4 (Refer Observes NCERT text). Teacher explains the Infers concept behind these two activities through a discussion. These activities reiterate the fact that increased wind speed is accompanied by a reduced air pressure.

Teacher demonstrates Activity 8.5 Observes 20 min (refer NCERT text). From this activity, Infers teacher explains the concept that air expand on heating.

Wind currents are Uneven heating Teacher demonstrates Activity 8.6 Observes 20 min generated due to between equator (Refer NCERT text). Then explain how Infers uneven heating on and poles. hot air moves up and cold air moves the earth. down. Uneven heating of land and water. Students watch the video on the formation of wind currents. Then Observes 20 min teacher explains the two situations that result in generation of wind currents.

56 8. Winds, Storms and Cyclones

Thunderstorms Precautions to Teacher explains thunderstorm Defines 20 min develop in hot, be taken during formation and precautions to be Recognizes humid tropical areas thunderstorm taken during a thunderstorm. like India very often. Students watch the video on cyclone Swift movement formation followed by explanation of of falling water the concept by the teacher. droplets along rising air creates lightning and sound called thunderstorm. A twisting funnel of Teacher explains about tornadoes. Recognizes 20 min wind with its narrow Tornadoes end towards the land is a tornado.

Effective safety Action on the part of Teacher and students discuss about Recognizes 20 min measures the people these aspects Recalls Usage of technology Students and teacher discuss chapter end exercise

HW: Complete chapter end exercise. 20 min

Students write WS 1,2 and 3 40 min

Students write WS 4 followed by peer 40 min or self check. Teacher shows the videos again to reiterate the concepts.

Students write a unit test 40 min

57 PRACTICE SHEET - 1 (PS-1)

I. Choose the appropriate term for the given description:

Natural calamity Wind Air current Air pressure Monsoon winds Thunder storm Lightning Cyclones Tornadoes 1. Huge electric discharge in the atmosphere occurring within a thunder cloud between clouds or between cloud and the ground. 2. Any physical phenomenon that may cause damage to the life and property. 3. A violent twisting funnel of wind on the earth. 4. Air moving from an area of high pressure to an area of low pressure. 5. A storm accompanied by the strong winds, rain, thunder and lightning. 6. Rain bearing winds from sea to land. 7. Pressure exerted by air. 8. A huge and very powerful storm where a low pressure region is surrounded by high speeding swirling winds. 9. Movement of air in atmosphere. II. Say true or false: 1. Wind is caused by uneven heating of the earth’s surface. 2. We hear thunder first and see lightning later. 3. A tornado is larger than a cyclone with high speed. 4. A cyclone has a low pressure area in the centre and high speed winds revolve around it. 5. A cyclone becomes weaker when it reaches

58 PRACTICE SHEET - 2 (PS-2)

land. I. Complete the organisers:

TWO IMPORTANT FEATURES OF WIND

What causes winds

Uneven ____ of ___ by ___- Measured by Measured by ______

Some places are ____ than others. FOUR SAFETY MEASURES DURING A CYCLONE

Hot air is ______air is heavier.

Warm air ___ up and ____ air flows in it to take its place

This sets up an air current called ______

59 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option: 10. A fire alarm usually detects smoke in case of fire. Where should such an alarm be placed in 1. Rain bearing winds that blow over the ocean a room? and to the land during a particular season are a. Near the door called ______. b. On the floor a. Sea breeze c. On any wall b. Storm d. On the ceiling c. Monsoon winds 11. Four schematic diagrams are shown in Figure d. All of these. to depict the direction of sea breeze. Which of 2. Air moves them gives the correct direction? a. From an area of high pressure to an area of low pressure b. An area of low pressure to an area of high pressure c. Between areas of same pressure d. None of these. 3. Cyclones develop over a. Oceans b. Lakes c. Land d. Mountains 12. Figure shows a child blowing air with a straw 4. The low pressure area at the centre of the near the opening of another straw which cyclone is called has its other end in a soft drink bottle. It a. Spout was observed that the level of the soft drink b. Typhoon in the straw rises up as soon as air is blown c. Eye over its open end. Which one of the following d. Storm surge explains the reason for rise in level of the 5. When strong winds moves towards the land drunk? accompanied by very high waves, it is called a. Tides b. Water spout c. Cyclone d. Storm surge 6. Moving air is called a. Air b. Wind c. Cyclone d. Tornado a. Blowing of air decreases pressure over the 7. Summer monsoon winds are winds that blow opening of the straw. from b. The straw of the soft drink bottle collapses a. Land to sea when air is blown over its open end. b. Sea to sea c. Blowing of air warms up the air inside the c. Sea to land straw. d. land to land d. Blowing of air increases the pressure on the 8. Moving air creates surface of soft drink in the bottle. a. High pressure area 13. Following are precautions one must take in b. Low pressure area case a storm is accompanied by lightning. c. Low temperature area i. Do not take shelter under a tree. d. High temperature area. ii. Do not take shelter under an umbrella with 9. Air pressure decreases with a metallic end. a. Decreasing altitude iii. Do not take shelter in open garages, storage b. Increasing altitude c. Both a and b d. Does not change at all. 60 PRACTICE SHEET - 3 (PS-3)

sheds, etc. iv. Do not take shelter in a bus in the open. Which one of these is not correct? a. i b. ii c. iii d. iv 14. Which of the following place is most likely to be affected by a cyclone? a. Mumbai b. Puri c. Goa d. Porbandar 15. A curtain is hanging at the entrance of a room. A long corridor runs at right angles to the door, that is parallel to the curtain. If a strong wind blows along the corridor, the curtain will a. Get pushed inside the room. b. Get pushed outside the room. c. Get collected towards one end/swirled.

61 PRACTICE SHEET - 4 (PS-4)

d. Remain unaffected I. Answer the following: 10. Suggest some precautions to be taken to prevent the roof of a tin sheet from flying 1. Why is Chandigarh unlikely to be affected by a cyclone?

2. Name the ocean which is mainly responsible to bring rain bearing monsoon winds to Kerala coast in June every year.

3. To expel hot air out of the kitchen, ‘A’ has an exhaust fan fitted on the window of her kitchen and ‘B’ has a similar exhaust fan fitted on the wall near the ceiling of her kitchen. Which of the exhaust fan will expel the hot air more effectively? Explain why.

4. Why is it advisable not to shut all the doors and windows during a storm?

5. A flat in Mumbai with a balcony facing the sea has some clothes hung on a clothes line in the balcony. Towards which direction the clothes will be blown in the afternoon? Explain.

6. Figure shows a diagrammatic representation of trees in the afternoon along a sea coast. State on which side is the sea; A or B? Give reasons for your choice.

7. A flag mounted on a flag post near the sea coast flutters in the direction of sea. At what time of the day does this happen – at midnight or in the afternoon?

8. Paheli kept an empty bottle made of plastic inside a refrigerator. After few hours, when she opened the refrigerator she found the bottle had collapsed. Explain the possible reason.

9. When strong/high speed wind blows, an umbrella held upright at times gets upturned. Explain the reason.

62 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option: 7. The difference of air pressure helps us to: 1. The winds from the ______carry water and a. eat food bring rain. b. drinking through straw a. oceans c. Inflating tires b. wells d. Both (B) and (C) c. lakes d. land 8. In winter, the direction of the wind flow gets reversed; it flows from the ______to the ______. 2. The wind speed of the cyclone that hit Orissa on 19th October 1999 is _____. a. ocean, land a. 150 km/h b. land, ocean b. 200 km/h c. land, land c. 220 km/h d. ocean, ocean d. 260 km/h 9. Which of following is not a property of air? 3. The word monsoon is derived from the a. Air exerts pressure ______word ______, which means ‘sea- b. Air expands on heating son’. c. Air occupies space a. Arabic, Mausam d. Air conducts electricity b. Greek, Mousam c. Latin, Mausom 10. High speed winds are accompanied by ______d. Italic, Mausam air pressure. a. Increased 4. Which of the following instruments is used to b. Reduced measure the speed of winds? c. 2 times the a. Thermometer d. None of the above b. Barometer c. Anemometer d. Speedometer II. Short answer questions 1. What are the after effects of a cyclone? 5. What happens when the wind is blowing? 2. How can you prove that air expands on heating? a. Leaves of trees flutter 3. What makes the wind blow? b. Banners flutter III. Long answer questions c. Flags flutter 1. What precautions should you take, if you ar- d. All of these estaying in a cyclone hit area? 2. Clouds bring rain and give ushappiness.Howev- 6. What do you call the wind blowing from sea to er, it is not always a happy Ending. Analyse the land? problems created by heavy rains? a. Sea breeze b. Land breeze c. Cyclone d. Storm

63 SELF EVALUATION SHEET Marks: 30 Time: 30 Mins

away during a fierce wind storm. I. Fill in the blanks: (4 Marks) 2. Explain why smoke rises up always? 1. Air around us exerts ______. 2. The moving air is called ______. 3. The main cause of wind movement is uneven ______on the earth. 4. High speed wind can cause cyclone in regions of ______pressure. 3. Why is it difficult ot force the paper ball into the bottle? II. State whether the following statements are True or False: (4 Marks) 1. If wind flows from land to the ocean, then it is daytime. 2. A very high pressure system, with very high speed wind surrounding it forms a cyclone. 4. List some effective safety measures for 3. The coast line of India is not vulnerable to cyclone. cyclones. 4. Warm air is lighter than cool air.

III. Match column I with column . There can be more than one match: (2 Marks) 5. What are monsoons?

COLUMN I COLUMN II a. On heating, air i. Descends b. On cooling, air ii. Expands iii. Contracts iv. Rises VI. Answer in detail: (5 Marks) IV. Answer in a word or a sentence: (5 Marks) 1. Describe an activity to demonstrate that warm air is lighter than cool air. 1. An instrument used to measure wind direction.

2. An instrument used to measure wind speed.

3. Another name for a cyclone.

4. What influences weather pattern of a region?

5. What happens to a cyclone as it approaches land?

V. Answer in two or three sentences: (10 Marks) 1. Is it difficult ot ride a bicycle against the direction of the wind? Why?

64 9. Soil

Learning Outcome

By the end of this chapter, you will be able to: • Explain properties of soil with respect to • State the importance of soil. percolation, moisture content and water • Explain soil profile. absorption capacity of soil. • Classify soils. • Reason the type of soil best suited for crops based • List the properties of different types of soils. on the needs of the plant and soil properties. Concept Map

Key Points • Continuous weathering of rock forms the soil. • Clayey soil is made up of fine particles with small • The formation of soil depends on several factors air spaces, retains moisture and becomes very such as climate, parent rock and land scape. sticky when wet. • A vertical section through different layers of the • Loamy soil is made up of sand and silt in equal soil is called the soil profile. proportions. It is rich in humus, has required • Horizons are the layers of the soil that differ in porosity and aeration for plants to grow. texture, colour, depth and chemical composition. • Soil has nitrates, sulphates and phosphates as • The layers of the soil are: nutrients. • Horizon A- Top soil, rich in humus • Sandy soil is suitable for fruits and vegetable • Horizon B-Sub soil, rich in minerals. cultivation. • Horizon C- Rich in weathered pieces of rock, • Clayey soil is suitable for paddy. characterized by cracks and crevices. • Loamy soil is suitable for cultivation of crops and • Bedrock-Lowers most layer, very hard with no gardening. water percolation. • Different types of soils are sandy, loamy and clayey soils. • Sandy soil has large particles with large air spaces, porous and prevents water retention.

65 9. Soil

Work Plan

CONCEPT COVERAGE CONCEPT DETAILS PRACTICE SHEET SIMULATION/ VIDEO

• Layers of soil Soil profile and its types PS – 01 • Types of soil

• Percolation rate of water Properties of soil • Moisture in soil PS – 02 • Absorption of water by soil

• Types of crops that can be Soil profile PS – 03 Soil and crops grown in different types of soil PS – 04 • Soil erosion

Worksheet for “Soil” PS – 05

Evaluation with self- check Self-evaluation or Peer check* Sheet

66 PRACTICE SHEET - 1 (PS-1)

I. State whether the following statements are true or false: 1. C horizon forms the top soil. 2. Water cannot penetrate the bed rock. 3. Particles of loamy soil are larger than the clayey soil. 4. Soil takes only few years to form. 5. Paddy requires sandy soil. II. Match the following and complete the box.

TERMS MEANINGS 1. Humus a. Top soil 2. Soil profile b. Greater proportion of fine particles. 3. A-horizon c. Loamy soils 4. B-horizon d. Rotten dead matter in soil 5. C-horizon e. Small lumps of rocks with cracks and crevices. 6. Bed rock f. (U-V) x 100 50 7. Sandy soil g. Mixture of big and small particles in almost equal proportions. 8. Clayey soil h. Greater proportion of big particles. 9. Loamy soil i. Vertical section through different layers. 10. Rate of percolation j. Mineral rich layer 11. Percentage of water absorbed k. ml/min 12. Lentils and pulses l. Water cannot penetrate through this layer.

67 PRACTICE SHEET - 2 (PS-2)

I. Unscramble the following words to meaningful words related to soil: 1. CORDEKB: 2. USHMU: 3. NADSY: 4. TCNPORLEOA: II. Write one word for the following: 1. Decayed plant and animal remains. 2. Disintegration of rocks on the earth’s surface caused by exposure to natural forces. 3. Removal of trees on a large scale. 4. The vertical section of a soil. 5. The amount of water that seeps through the soil.

68 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option: 1. Chemical weathering is fastest in a. Hot and wet climate b. Cold and moist climate c. Hot and dry climate d. Cold and dry climate. 2. Which one of the following layers is characterised by cracks and crevices? a. A horizon b. B-Horizon c. C-Horizon d. Bedrock. 3. Which type of soil dries out quickly after a rain? a. Loamy b. Sandy c. Clayey d. None 4. Soil pollution is caused by a. Excessive use of fertilizers and pesticides b. Leakage of chemicals into the soil c. Acid rain d. All of the above. 5. Soil contains a. Nitrates b. Phosphates c. Sulphates d. All of these. 6. Humus is made from dead and decaying ______matter. a. Inorganic b. Organic c. Metallic d. Non metallic 7. B-Horizon is also called a. Soil b. Sub soil c. Top soil d. Bed rock 8. Soil erosion is caused due to a. Vegetation b. Deforestation c. Overgrazing d. Both b and c 9. The microorganisms present in the soil require moisture (water) and nutrients for growth and survival. Choose from the options below the habitat (place) where the soil has plenty of water and nutrients. a. Desert b. Forest c. Open field d. Cricket ground

69 PRACTICE SHEET - 3 (PS-3)

10. Availability of water and minerals in the soil for maximum absorption by roots is in the ______. a. B-horizon b. C-horizon c. A-horizon d. Surface of soil 11. Soil conservation measures are mainly aimed at protecting which of the following? a. Plants b. Top soil c. Sub soil d. Soil organisms 12. Read the following statements with reference to soil. (i) Weathering is a very fast process of soil formation. (ii) Percolation of water is faster in sandy soils. (iii) Loamy soil contains only sand and clay. (iv) Top soil contains the maximum amount of humus. Choose the correct statements from the above. a. (ii) and (iv) b. (i) and (iii) c. (ii) and (iii) d. (i) and (ii) 13. Rate of percolation is given by the unit a. cm/min b. ml/min c. mm/sec d. ml/sec 14. Percentage of water absorption is calculated by using the formula a. (U-V)/50 x 100 b. (V-U)/50 x 100 c. (U-V)/100 x 50 d. U/V x 100 15. Wheat is best grown in a. Sandy soil b. Sandy and loamy soil c. Fine clayey soil d. Any of the above soils.

70 PRACTICE SHEET - 4 (PS-4)

I. Answer the following: 1. Soil has particles of different sizes. Arrange the words given below in increasing order of their particle size. rock, clay, sand, gravel, silt 2. Which of the following situations – ‘A’ or ‘B’ – is advantageous for absorption of water and minerals? Why? Situation ‘A’ : Growth and branching of roots in the C-horizon. Situation ‘B’ : Growth and branching of roots in A and B horizons. 3. How can a farmer convert acidic soil to neutral soil? 4. Locate the following zones given as boxed items in Fig. which shows a diagram of soil profile.

Top soil, Subsoil, C-horizon, Bedrock

5. Rajasthan is a desert state in India. Once while travelling to Rajasthan by train, Boojho observed several streams and rivulets of rain water during the journey but to his surprise he did not see streams of water in the desert region even during rains. Help Boojho find a suitable explanation for this. 6. Continuously water-logged soils are disadvantageous for plant growth. Why? 7. Why is soil erosion relatively less in dense forests as compared to barren, open fields?

71 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option. 8. The process of weathering takes place by the action of: 1. ______is made up of small lumps of rocks with cracks and crevices. a. Wind a. A-horizon b. Water b. B-horizon c. Climate c. C-horizon d. All of these d. Bed rock 9. Which of the following makes up soil profile? 2. Soil is affected by: a. Sand, clay, loam and silt a. Wind and rainfall b. A-horizon, B-horizon, C-horizon and Bed rock b. Temperature and light c. A-horizon, B-horizon, C-horizon and Sand c. Humidity particles d. All of these d. A-horizon, B-horizon, C-horizon and clay 3. Soil erosion is caused due to the removal of land 10. They are required for the growth of crops. What surface by: are they? a. Water a. Plastics b. Wind b. Pesticides c. Ice c. Nutrients and minerals d. All of these d. Fertilisers 4. ______occurs as a deposit in riverbeds. II. Short answer questions a. Loam 1. Write the formula to find percolation rate in a b. Silt soil. Calculate the rate of percolation of a soil if it takes 10 minutes for 50 ml to percolate. c. Sand d. Clay 2. What is the cause of soil erosion? How can you prevent soil erosion? 5. Which of the following is not a natural resource? 3. Soil is an inseparable part of our life. Justify. a. Sun light b. Soil III. Long answer questions c. Electricity 1. What is the soil? Write about the different types d. Water of soil. 6. Which of the soils is most aerated soil? 2. “Soil and crops that grow in it are inter-related”. Justify. a. Sandy soil b. Clayey soil c. Loamy soil d. All of these 7. Paheli has a field of fine clayey soil. Which crop do you suggest her to grow in it? a. Wheat b. Cotton c. Lentils d. Paddy

72 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Read the following statements and give the III. Answer the following: (6 Marks) appropriate terms for each of them. (4 Marks) 1. Calculate the percentage of absorption of a. The process of breakdown of rocks by the water in a soil sample of 50g, the initial action of wind, water, sunlight. volume of the water in the measuring cylinder was 5mL. The final volume of the water in the measuring cylinder was 2ml.

b. Removal of top soil during heavy rains or strong winds.

c. Accumulation of wastes in the soil generated 2. Gardeners gently dig up the soil around by human activity which alter the features of the roots of garden herbs frequently. Give soil. reasons. • For enabling easy root growth • For easier percolation of water • For aerating the soil/enabling air to get into deeper layers of soil • For removing the weeds. d. The process of movement of water into deeper layers of soil.

II. Match the animals in column I with their 3. Draw the diagram showing soil profile and natural place of dwelling (habitat) in column label the horizons. II. (5 Marks)

Column I Column II a. Earthworm i. Sand and beaches b. Garden lizard ii. Burrows in soil c. Crab iii. Deep narrow holes in dry soil d. Rodents iv. Surface of soil e. Scorpion v. Surface of shaded moist soil vi. Horizon of moist soils

73 10. Respiration in Organisms

Learning Outcome

By the end of this chapter, you will be: • Illustrate and label the parts of human respiratory • Define respiration. system. • State the significance of respiratory process. • Explain the process of respiration in human • Classify organisms as aerobes and anaerobes beings. based on mode of respiration. • Explain the process of respiration in cockroach. • Differentiate between aerobic and anaerobic • Explain the process of respiration in earthworm. respiration. • Explain the process of respiration in fish. • Explain the process of respiration in plants.

Concept Map

RESPIRATION IN ORGANISMS

Respiration Need for Kinds of in different respiration respiration organisms

Aerobic Anaerobic Man Cockroach Earthworm Plants

Respiratory Anaerobes Muscles Process organs

Keypoints • Respiration is a process in which food is oxidised to release energy in the body. • Inhalation refers to taking in oxygen rich air from the atmosphere. • Exhalation refers to giving out carbon dioxide rich air to the outside from the body of the organisms. • Nostrils, basal cavity, trachea and lungs are the respiratory organs in human beings. • Amoeba and earthworm breathe by diffusion of gases through their skin. • Insects have tracheal system for breathing. • Fishes have gills and birds have lungs. • Frogs respire through skin, lungs and through mouth. • Plants respire through root hairs, lenticels and stomata.

Keywords: Aerobic respiration, anaerobic respiration, breathing rate, cellular respiration, diaphragm, exhalation, gills, inhalation, spiracles, tracheae

74 10. Respiration in Organisms

Work Plan

CONCEPT COVERAGE COVERAGE DETAILS PRACTICE SHEET SIMULATION/ VIDEO

Why Respiration PS-1

Aerobic Human respiratory Kinds of Respiration Anaerobic PS-2 system Activity to check Organs and process the content of • Man PS-3 Respiration in different exhaled air during • Cockroach Organisms breathing • Earthworm • Plants PS-4

Worksheet for “Respiration in Organisms” PS-5

Evaluation with self- Self-evaluation check or Peer check* Sheet

75 PRACTICE SHEET - 1 (PS-1)

I. Fill in the blanks: 1. The ______is commonly called the windpipe. 2. The number of times, a person breathes is called ______. 3. Respiratory organs in fish are ______. 4. During exhalation, volume of the lungs ______. 5. In earthworm, ______serves as a respiratory organ. II. Say true or false: 1. When diaphragm contracts, carbon dioxide rich air is expelled out of the lungs. 2. Air enters larynx after passing through trachea. 3. Oxygen absorbed in the alveoli combines with red pigment of the blood. 4. Plants do not take in oxygen. 5. More energy is released during aerobic respiration. III. Label the parts of the human respiratory system:

76 PRACTICE SHEET - 2 (PS-2)

I. Differentiate between inhalation and exhalation by putting the following under appropriate headings: • Diaphragm relaxes and becomes dome shaped. • Lungs expand. • Volume of chest cavity decreases. • Air is forced out of lungs. • Diaphragm contracts and flattens. • Lungs contract. • Air flows into the lungs. • Volume of chest cavity increases.

INHALATION EXHALATION

II. Classify the following as animals with gills, animals with lungs and animals with spiracles: Bat Tree snake Prawn Butterfly Turtle Bee Crab Dragon fly Leopard Dog Sea snake Shell fish Ant Ladybird Beetle Lobsters Hermitcrab Crocodile Koala bear Rat snake Flying fish Shark

ANIMALS WITH GILLS ANIMALS WITH LUNGS ANIMALS WITH SPIRACLES

77 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option: 9. Gaseous exchange occurs in place through 1. Which of the following allows exchange of a. Roots gases? b. Stomata a. Respiration c. Stem b. Digestion d. All of the above. c. Excretion 10. Sometimes when we do heavy exercise, d. None of the above. anaerobic respiration takes place in our 2. The intake of oxygen rich air takes place in muscle cells. What is produced during this a. Inhalation process? b. Exhalation a. Alcohol and lactic acid c. Both a and b b. Alcohol and CO2 d. None of these. c. Lactic acid and CO2 d. Lactic acid only 3. Respiratory organ in honey bee is a. Nose 11. Yeast is used in wine and beer industries b. Gills because it respires c. Lungs a. Aerobically producing oxygen. d. Spiracles b. Aerobically producing alcohol. c. Anaerobically producing alcohol. 4. Which of these can absorb air dissolved in d. Anaerobically producing CO . water? 2 a. Gills 12. During the process of exhalation, the ribs b. Spiracles move c. Lungs a. Down and inwards. d. All of the above b. Up and inwards. c. Down and outwards. 5. Where does gaseous exchange takes place in d. Up and outward. earthworm? a. Moist skin b. Lungs c. Gills d. Body surface 6. ______is utilised during respiration. a. Protein b. Lactic acid c. Glucose d. Cellulose 7. Oxygen is carried to all parts of the cell by a. Blood b. Lungs c. Water d. Glucose 8. What is not required for anaerobic respiration? a. Energy b. Oxygen c. Glucose d. Carbon dioxide.

78 PRACTICE SHEET - 4 (PS-4)

I. Answer the following: 1. Pick the odd-one-out from each of the groups given below on the basis of respiratory organs. Give reason for your answer. a. cockroach, grasshopper, snail, ant b. lizard, cow, earthworm, snake c. crocodile, whale, dolphin, fish d. snake, tadpole, crow, goat 2. Which gas present in air is essential for aerobic respiration? What is the role of oxygen during respiration? 3. On an average, an adult human being at rest breathes 15–18 times per minute. The breathing rate, however, may differ under different conditions. Arrange the following activities given in the box in order of increasing breathing rates and give reason for your answer.

sleeping, cycling, brisk walk, watching T.V.

4. Whenever we feel drowsy or sleepy, we start yawning. Does yawning help us in anyway? 5. Insects and leaves of a plant have pores through which they exchange gases with the atmosphere. Can you write two points of differences between these pores with respect to their position, number and extension into the body? 6. Paheli participated in a 400 m race competition held at her school and won the race. When she came home, she had mixed feelings of joy and pain as she had cramps in her leg muscles. After a massage, she was relieved of the pain. Answer the following questions related to the situation. a. What can be the possible reasons for the pain in her legs? b. Why did she feel comfortable after a massage?

79 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 8. In the beginning of a movie you observe an advertisement that says to avoid smoking. Why 1. The number of times a person breathes in a a person is advised not to smoke? minute is termed as the _____. a. Smoking damages lungs a. Inhalation b. Smoking causes cancer b. Exhalation c. Smoking leads to lung infections c. Breathing rate d. All of these d. Breathing 9. What is the main difference of aerobic and 2. _____ helps fish to breathe under water. anaerobic respiration? a. Fins a. Energy is released only in aerobic respiration. b. Gills b. Only aerobic respiration requires oxygen. c. Tail c. Carbon dioxide is released in aerobic respiration d. Mouth whereas oxygen in anaerobic. 3. The percentage of oxygen in the inhaled air is d. Only anaerobic respiration releases water ______. along with carbon dioxide and energy. a. 16.4% 10. What happens to lime water, when we exhale air b. 21% into it? c. 0.04% a. remains same d. 4.4% b. turns blue 4. From where does the roots get air? c. turns milky a. Stem of the plant supply air to roots d. becomes colourless b. Water we pour will supply air to roots II. Short answer questions c. From air spaces present between the soil 1. Draw a neat labelled diagram of human particles respiratory system. d. From atmosphere roots take air 2. Explain the expansion of lungs while breathing 5. Earthworm and frog has moist skin because: experimentally. a. They breathe through their skin 3. What would happen if a potted plant is b. They live in water overwatered? c. They sweat a lot III. Long answer questions d. They consume more water 1. Write a short note on breathing. 6. Which of the following organism respire anaerobically? 2. Compare the two types of respiration with examples. a. Yeast b. Human being c. Plants d. All of these 7. During which of the following activities the breathing rate increases the most? a. Sleeping b. Heavy exercise c. Walking d. Writing

80 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Fill in the blanks: (3 Marks) IV. Answer the following: (6 Marks) 1. Diaphragm forms the ______of the chest 1. What is cellular respiration? cavity.

2. Exchange of gases in the leaves take place with the help of ______.

2. Differentiate between aerobic and anaerobic respiration. 3. Cockroaches breathe with the help of air tubes called ______Aerobic respiration Anaerobic respiration

II. Mark the following statements as True or False. Correct the false statements. (2 Marks) 1. Oxygen breaks down glucose outside the cells of organisms.

2. Insects have spiracles on the lower surface of the body.

3. Why do we get muscle cramps at times? III. Match the following: (4 Marks)

Column I Column II 1. Butterfly a. Lungs 2. Earthworms b. Gills 3. Sparrow c. Spiracles 4. Fish d. Skin

81 11. Transportation in Animals and Plants

Learning Outcome

By the end of this chapter, you will be able to: • Trace the path of blood flow in the human heart. • Explain the components of blood and their • Describe excretory system in human beings. structure. • State the functions of excretory system. • Describe the blood vessels-arteries, veins and • Explain the transport of water and minerals in capillaries. plants. • Describe the structure of human heart. • Recall transpiration as an important function. • Label the parts of the human heart. Concept Map

Key Points kidneys, ureters, urinary bladder and urethra. • Simple organisms like amoeba transport oxygen • Kidneys have nephrons to filter blood and produce and food through diffusion through the small urine. openings on the body surface. • Ureters collect urine from the kidneys and bring to • In higher and complex animals like human beings, urinary bladder. the substances are transported through a fluid • Urinary bladder is a muscular bag that stores urine called blood. temporarily. • The transport system of human beings consists of • Urethra is the opening through which urine is blood vessels, blood and a four chambered heart. excreted from the body. • Components of blood are RBC, WBC and platelets. • Plants also need a transport system. The • RBCs help in oxygen transport, WBCs help in transportation in plants is carried out by xylem and defending the body and platelets help in clotting phloem that form the vascular bundles. of blood. • Xylem helps in transport of water and minerals • In human beings, heart is the main organ of from the soil to different parts of the plant. circulatory system that circulates blood through • Phloem helps in transport of food materials from blood vessels. the leaves to different parts of the plant. • Wastes are produced during the process of • Transpiration is loss of water in the form of water respiration, digestion and metabolism. vapour from the aerial parts of the plant. • The excretory system of humans consists of • Transpiration helps in pushing water in the xylem

82 11. Transportation in Animals and Plants and it cools the plant.

83 PRACTICE SHEET - 1 (PS-1)

Work Plan

CONCEPT COVERAGE CONCEPT DETAILS PRACTICE SHEET SIMULATION/VIDEO

• Symbols of components of circuit Electric circuit and its • Function of each component in Human circulatory PS – 1 components the circuit system • Conductor and insulator

• Working of heating coil Heating effect of • Working of heating iron PS – 2 Working of human heart electric current • Working of fuse and its importance

• Magnetic effect of electric current Magnetic effects of Humans excretory • Electromagnet and its uses PS – 3 electric current system • Working of an electric bell

Worksheet for “Transportation in Animals and Plants” PS – 4

Evaluation with self- Self-evaluation check or Peer check* Sheet

84 PRACTICE SHEET - 1 (PS-1)

I. Give two examples for each of the following: a. Blood cells. b. Body wastes in humans. c. Parts of human heart. II. Write one word for the following: a. Straw coloured fluid that consists of suspended blood cells. b. Red pigment of the blood. c. Number of times blood flows in the arteries. III. Say whether the following statements are true or false: a. Blood transports urine from kidney to urethra. b. The circulatory fluid in human beings is water. c. Blood has two components- fluid component and blood cells. IV. Label the parts of the human heart.

V. Choose the correct option: 1. Which one of these substances need to be transported within a body? a. Food b. Oxygen and waste materials c. Water and minerals d. All of these. 2. Hydra and sponges get oxygen by a. Circulation b. Diffusion c. Transportation d. All of these. 3. Which of these is not a blood vessel? a. Artery b. Vein c. Capillary d. Xylem 4. Which of these cells are present in blood? a. RBC b. WBC c. Platelets d. All of these.

85 PRACTICE SHEET - 2 (PS-2)

5. The cells of the blood that help in defending the body a. RBC b. WBC c. Platelets d. Plasma 6. The absorption of nutrients and exchange of respiratory gases between blood and tissues takes place in – a. Veins b. Arteries c. Heart d. Capillaries 7. In which of the following parts of human body are sweat glands absent? a. Scalp b. Armpits c. Lips d. Palms VI. Answer the following: 1. Veins have valves which allow blood to flow only in one direction. Arteries do not have valves. Yet the blood flows in one direction only. Can you explain why? 2. What is the special feature present in a human heart which does not allow mixing of blood when oxygen-rich and carbon dioxide-rich blood reach the heart? 3. Name the organ which is located in the chest cavity with its lower tip slightly tilted towards the left. 4. (a) Name the only artery that carries carbon dioxide-rich blood. (b) Why is it called an artery if it does not carry oxygen-rich blood?

86 PRACTICE SHEET - 3 (PS-3)

I. Label the parts of human excretory system:

II. Choose the correct alternative: 1. The tubes that arise from kidneys are a. Ureters b. Urinary bladder c. Urethra d. Fallopian tube 2. The waste of human beings consists of a. Urea b. Uric acid c. Ammonia d. All of these. 3. The muscular tube through which stored urine is passed out of the body is called – a. Kidney b. Ureter c. Urethra d. Urinary bladder 4. Aquatic animals like fish excrete their wastes in gaseous form as a. Oxygen b. Hydrogen c. Ammonia d. Nitrogen III. Answer the following:

87 PRACTICE SHEET - 4 (PS-4)

I. Choose the correct option 8. When you run for some time and stop, you breathe restlessly because 1. Blood is composed of a. You need less oxygen a. Arteries b. You need more oxygen b. Plasma c. You sweet a lot c. Veins d. Your legs are painful d. Atrium 9. The walls of the chambers of the heart are made 2. Blood transports up of: a. Digested food a. Muscles b. Oxygen b. Blood c. Waste c. Capillaries d. All of these d. Veins 3. The largest excretory organ in human beings is 10. Imagine that you fell while playing and your a. Kidney knee is bleeding. Even after some time if it b. Lungs doesn’t clot, what you are supposed to do? c. Skin a. Put bandage d. Nose b. Leave it to clot on its own 4. Which of the following is responsible for blood c. Apply some ointment clot? d. Rush to doctor a. Platelets II. Short answer questions b. White blood cells 1. What are xylem and phloem? Write their func- c. Red blood cells tion. d. Haemoglobin 2. Write an activity to show that stem conducts 5. On reaching the tissues, arteries divide further water to all parts of the plant. into extremely thin tubes called 3. Blood is filtered by blood capillaries in the kid- a. Veins neys. Suppose the kidney’s stop working, what b. Capillaries could be the reasons for it? What happens to the c. Tissues waste collected at kidneys? By what process it d. Cells can be rectified? 6. Pulse rate is: III. Long answer questions a. Clotting of blood 1. Draw a neat labelled diagram of ‘Sections of b. Fighting against germs human heart’. c. Number of beats per minute 2. Voluntary blood donation is harmless. Justify. d. All of these How is it stored? Write its uses. 7. Which of the following organs work restlessly even when you are in sleep? a. Lungs b. Kidneys c. Heart d. All of these

88 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

1. Boojho’s uncle was hospitalised and put on specialised cells. They transport substances dialysis after a severe infection in both of his and form a two-way traffic in plants. Which kidneys. of the following terms qualify for the features a. What is dialysis? mentioned above? b. When does it become necessary to take a. Xylem tissue such a treatment? b. Vascular tissue c. Root hairs 2. Name the process and the organ which helps d. Phloem tissue in removing the following wastes from the body. 4. In a tall tree, which force is responsible for a. Carbon dioxide pulling water and minerals from the soil? b. Undigested food a. Gravitational force c. Urine b. Transportation force d. Sweat c. Suction force I. Name the following. d. Conduction force a. Products excreted by plants. IV. Answer the following. b. Process by which water is lost through 1. Paheli uprooted a rose plant from the soil. leaves. Most of the root tips, with root hairs got left c. The tissue that helps to conduct water in the behind in the soil. She planted it in a pot plant. with new soil and watered it regularly. Will II. True or false. the plant grow or die? Give reason for your answer. a. Phloem helps in transport of water. b. Transpiration helps in cooling the plant. III. Choose the correct alternative. 1. The vascular tissue in plants are a. Cambium and xylem b. Xylem and phloem c. Phloem and cambium d. None of these 2. Loss of water from the aerial parts of the plant is a. Diffusion b. Translocation c. Transpiration d. Respiration 3. They are pipe-like, consisting of a group of

89 12. Reproduction in Plants

Learning Outcome

By the end of this chapter, you will be able to: • Illustrate and label the structure of bisexual flower. • Define reproduction. • Define pollination. • Differentiate between sexual and asexual • Explain the process of sexual reproduction in reproduction. plants. • Describe different methods of vegetative • List the post fertilisation changes seen in a flower. propagation. • Explain different agents of seed dispersion. • Describe the structure of a bisexual flower. Concept Map

Key Points • In plants, asexual reproduction takes place by • Some natural pollinating agents are insects, birds, budding, fission, fragmentation, spore formation wind and water. and by stem and root cuttings. • The process of fusion of male and female gametes • Vegetative propagation takes place with the help to produce a zygote is called fertilization. of vegetative parts such as root, stem and leaves. • The ovary of the flower grows into a fruit and • Many methods of artificial propagation such as ovules becomes the seeds. cutting, grafting and layering are used by plant • Seeds have to be dispersed to prevent plants breeders to get new varieties of plants with from overcrowding and compete for air, minerals, improved characters. sunlight and soil. • Flowering plants reproduce with the help of • Agents for seed dispersal are air, water, animals flowers. The main reproductive part of a plant is and self explosion mechanisms. flower. Stamen and pistil are its male and female parts respectively. • Transfer of pollen grains from the anther to the stigma of a flower is called pollination. Pollination can be self pollination or cross pollination. 90 12. Reproduction in Plants

Work Plan

CONCEPT SUB CONCEPT PRACTICE SHEET SIMULATION/ VIDEO

• Vegetative propagation • Budding Vegetative Asexual reproduction PS – 1 • Fragmentation propagation • Spore formation

• Sexual reproduction in plants Structure of a Sexual reproduction PS – 2 • Seed dispersal flower

Worksheet for “Reproduction in Plants” PS – 3

Evaluation with self- Self-evaluation Sheet check or Peer check*

91 PRACTICE SHEET - 1 (PS-1)

I. Fill in the blanks with appropriate terms: 1. A flower is a ______part of a plant. 2. ______reproduces by budding. 3. Potato reproduces through the ______. 4. Roots, stem and leaves form ______parts. 5. The phenomenon where in the pollen falls on the stigma is called ______. II. Say whether the following statements are true or false. 1. Spirogyra reproduces by fragmentation. 2. In an asexual reproduction, seeds are formed. 3. Plants do not reproduce asexually. 4. Seeds of drumstick, maple and grasses are dispersed by wind. 5. Yeasts reproduce through formation of spores. III. Match the following:

COLUMN I COLUMN II 1. Unisexual flower a. Stem cuttings. 2. Fertilisation b. Bryophyllum 3. Spore formation c. Papaya 4. Leaf propagation d. Fungus 5. Rose e. Results in seed formation

IV. Choose the correct alternative. 1. Which of the following is not the vegetative part of the plant? a. Stem b. Roots c. Leaves d. Flowers 2. Spirogyra reproduces through: a. Spore formation b. Budding c. Fragmentation d. Cuttings 3. Which of these show asexual reproduction by budding? a. Yeast b. Hibiscus c. Apple d. All of these. 4. Which of these reproduce by spores? a. Spirogyra b. Algae c. Potato d. Fungus 5. Lila observed that a pond with clear water was covered up with a green algae within a week. By which method of reproduction did the algae spread so rapidly? a. Budding b. Sexual reproduction c. Fragmentation d. Pollination

92 PRACTICE SHEET - 1 (PS-1)

V. Match the terms with their definitions and complete the magic box:

DEFINITIONS TERMS 1. Plants that give rise to new plants forming seeds. a. Asexual reproduction 2. Male reproductive part b. Sexual reproduction 3. Fusion of male and female gamete. c. Bud 4. Transfer of pollen grains from stamen to stigma. d. Fragmentation 5. Plants give rise to new plants without formation of seeds. e. Stamens 6. Fertilization product of male and female gametes. f. Pistil 7. Flowers which contain both pistil and stamen. g. Unisexual flowers 8. Female reproductive part. h. Bisexual flowers 9. Transfer of pollen grains on to the stigma of the same i. Fertilization flower. 10. Small bulb like projection coming out of yeast cell. j. Pollination 11. A ripened ovary k. Self-pollination 12. Transfer of pollen onto the stigma of another flower of l. Cross pollination the same plant or another plant. 13. Flowers which contain only pistil or stamen. m. Zygote 14. Process where in an algae breaks down into 2 or more n. Fruit pieces and each piece develops into a new plant body.

VI. Answer the following: 1. Fungus, moss and fern reproduce by a common method of asexual reproduction. Name the method. 2. Pick the odd one out from the following on the basis of mode of reproduction and give reasons for it: sugarcane, potato, rice, rose

93 PRACTICE SHEET - 2 (PS-2)

I. Choose the correct option: 1. Young ones of their own kind are produced by a. Pollination b. Reproduction c. Fertilization d. Explosion 2. Which part of the flower converts to a fruit? a. Sepals b. Ovary c. Petals d. Ovules 3. Seeds with wings are dispersed by a. Water b. Air c. Self explosion d. Animals 4. Ovary wall becomes a ______after fertilisation. a. Fruit b. Embryo c. Seed d. Fruit wall 5. Which of the following parts of a plant take part in sexual reproduction? (i) Flower (ii) Seed (iii) Fruit (iv) Branch Choose the correct answer from below. a. (i) and (ii) b. (i), (ii) and (iii) c. (iii) and (iv) d. (ii), (iii) and (iv) 6. Seeds of drumstick and maple are carried to long distances by wind because they possess a. Winged seeds b. Large and hairy seeds c. Long and ridged fruits d. Spiny seeds 7. The ovaries of different flowers may contain a. Only one ovule b. Many ovules c. One to many ovules d. Only two ovules 8. Which of the following statements is/are true for sexual reproduction in plants? (i) Plants are obtained from seeds. (ii) Two plants are always essential. (iii) Fertilisation can occur only after pollination. (iv) Only insects are agents of pollination. Choose from the options given below. a. (i) and (iii) b. (i) only c. (ii) and (iii) d. (i) and (iv) 94 PRACTICE SHEET - 2 (PS-2)

9. Pollination refers to the a. Transfer of pollen from anther to ovary. b. Transfer of male gametes from anther to stigma. c. Transfer of pollen from anther to stigma. d. Transfer of pollen from anther to ovule. II. Answer each of these questions. 1. Which type of pollination does the Fig indicate?

2. In the diagram given in Fig, label the parts marked (a), (b) and (c).

3. Group the seeds given in Fig (i) to (iii) according to their means of dispersion.

a. Seed dispersed by wind b. Seed dispersed by water c. Seed dispersed by animal 4. Coconut is a large and heavy fruit. How is it adapted for dispersal by water?

95 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option 8. The slimy green patches in ponds, or in other stagnant water bodies called algae reproduce 1. Which of the following reproduce asexually? by ______. a. Mango a. spore formation b. Potato b. fragmentation c. Tomato c. budding d. Brinjal d. seeds 2. The method by which you get a new rose plant 9. Asexual reproduction takes place with the help is: of ______. a. Stem cutting a. vegetative parts b. Vegetation through eyes b. male part c. Vegetation through roots c. female part d. Vegetation through budding d. zygote 3. Transfer of pollen grains within the flower is 10. Which of the following is NOT a female repro- called ______. ductive part in a plant? a. cross pollination a. Stigma b. self-pollination b. Style c. seed dispersal c. Stamens d. crisscross pollination d. Ovary 4. ______is an example of a complete flower. II. Short answer questions a. Papaya 1. What do you understand by unisexual and bisex- b. Bottle gourd ual flowers? Give two examples for each. c. Cucumber 2. How do you get a new potato plant? Explain. d. Hibiscus 3. Find out the information about types of repro- 5. ______is a bisexual flower. duction in rose, sunflower, jasmine, and ashoka tree. Prepare a report on it. a. Petunia b. Bitter gourd III. Long answer questions c. Ridge gourd 1. What happens after fertilisation? d. Cucumber 2. “Butterfly acts as an agent of pollination”. 6. ______develop into seeds. Justify. a. Ovary b. Fruits c. Ovules d. Stamens 7. In which of the following reproduction through spores takes place? a. Fern b. Fungus c. Algae d. Both (A) and (B)

96 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Fill in the blanks: (5 Marks) The male and female gametes fuse to form a ______during the process of ______. This grows into an ______which is enclosed within a seed. After fertilization the ovules develop into ______and the ovary develops into a ______.

II. In the figure of a flower given in Fig, label the parts whose functions are given below and give their names. (5 Marks) a. The part which contains pollen grains. b. The part where the female gamete is formed. c. The female reproductive part where pollen grains germinate. d. The colourful part of flower which attracts insects.

III. Answer the following: 1. State any three different methods of asexual reproduction with an example. (3 marks)

2. Differentiate between self-pollination and cross pollination. (2 marks)

97 13. Motion and Time

Learning Outcome

By the end of this unit, a student will be able to: • Define time. • Define motion. • Explain the measurement of time. • Recall different types of motion. • Experimentally verify the time period of a simple • Cite examples for different types of motion. pendulum. • Define speed. • Interpret Distance-Time graphs. • Calculate speed using the formula. MOTION• ANDPlot Dist TIMEance -Time graphs. • State the units of speed. CONCEPT MAP: Concept Map

MOTION AND TIME

MOTION TIME

Types of Simple Speed Measurement motion pendulum

Definition of Calculation Linear Circular Periodic D-T graphs speed

Interpretation Construction

By the end of this unit, a student will be able to:

 Define motion.

 Recall different types of motion.

 Cit examples for different types of motion.

 Define speed.

 Calculate speed using the formula.

 State the units of speed.

 Define time.

 Explain the measurement of time.

 Experimentally verify the time period of a simple pendulum. 98

 Interpret Distance-Time graphs

 Plot Distance -Time graphs

TIME FRAME: 09 PERIODS 13. Motion and Time

Work Plan

CONCEPT SUB CONCEPT ACTIVITY SKILL TIME

Linear, circular and LESSON STARTER: Students brainstorm the Recalls 15 min periodic motions topic. Teacher asks students to complete Recognizes are the different Table 13.1 of the text individually and later types of motion. discusses the types of motion.

Students are asked to observe the pictures 15 min on page 144 of the text and determine the Observes vehicles that moved fastest, faster and fast. Reasons Speed is distance travelled by an From this, teacher and students discuss object in unit time. about speed and teacher defines speed. Defines 10 min

Calculation of Teacher takes the class outside. Teacher Records 25 min speed should also take 3 to 4 measuring tape and divide the class into three or four groups. A distance of 100 m is marked. Students run individually a distance of 100m upward and 100m downward. Time taken by each student is recorded. All the members of the group run and their time is noted. Student Distance Time Speed Derives 15 min Teacher and students get back to class and discuss how speed is calculated. From this discussion, students understand that Speed=Distance/Time taken

Units of speed Now teacher draws the attention to derive the units of speed by posing the following questions: What is the unit of distance? What is the unit of time? How can you express km/h in m/s or m/min? From this discussion, students understand that speed is expressed as m/s or Km/h. Conversion factor from Km/h to m/s is also discussed.

99 13. Motion and Time

Time Time –Units Time is measured using different units Recognizes 20 min Different like years, day, minute, seconds, micro or measurements of nanoseconds. Teacher explains about 12 time hour clock we normally use in clocks or 12 hour clock or 24 watches and usage of AM and PM to refer hour clock. time before 12 and after 12. Teacher also Evolution of clock explains about 24 hour clock commonly from the past to used in railways and airports. Teacher also the present. explains how clocks have evolved from the past to the present.

Simple pendulum Students work in groups and complete 20 min Activity 13.2 of NCERT. From this activity, Time period of a students realize that the time period of a simple pendulum pendulum remains the same. is a constant.

Measuring Speed Students work in small groups and complete 40 min Activity 13.3 of NCERT. Teacher again reiterates the conversion from km/h to m/s. Students complete Table 13.4.

Distance Time Teacher explains the construction of a D-T Constructs 40 min graph graph and the slope of the graph gives the Interprets speed. Computes D-T graphs are given. Students work in groups and interpret the graphs and compute problems based on the graph. (Refer Annexure 1)

Students work in groups and solve problems. Computes 40 min Teacher reiterates the concepts if needed. (Refer Annexure 2)

Students write WS-1,2 and 3 40 min

Students write WS 4 followed by peer check 40 min and discussion. Teacher and students discuss chapter end exercise. HW: Complete the chapter end exercise.

100 PRACTICE SHEET SHEET - 5 -(PS-5) 1 (PS-1)

I. Say True or False: 1. A sundial is more accurate than the quartz clock.

2. Speed is defined as the time taken by the object to move one kilometer.

3. Uniform motion is the motion in which an object travels equal distances in unequal intervals of time.

4. Unit of speed is m/s.

5. Slope of D-T graph gives the speed.

II. Select the correct term for the description below: Non uniform motion Oscillation Simple pendulum Speed Time period Uniform motion Speedometer Odometer

1. Distance covered by an object in unit time.

2. Consists of a small metallic ball or a piece of stone suspended from a rigid stand by a thread.

3. One to and fro motion of a bob.

4. Time taken to complete one oscillation.

5. Speed of an object along a straight line keeps on changing.

6. Speed of an object along a straight line remains constant.

7. An instrument that measures speed directly.

8. An instrument that measures distance.

101 PRACTICE SHEET SHEET - 5 -(PS-5) 2 (PS-2)

1. Plot a D-T graph for the following data: Time (min) Distance (km) 0 0 1 1 2 2 3 3 4 4 5 5

2. Plot a D-T graph for the following data: Time (min) Distance (km) 2 2 4 4 6 6 8 7 10 8 12 9 14 9 16 9 18 9 20 12

3. Plot a graph for the following data: Time (min) Distance (km) 2 2 4 4 6 6 8 7 10 10 12 12 14 14 16 16 18 18

102 PRACTICE SHEET SHEET - 5 -(PS-5) 3 (PS-3)

1. Which of the following cannot be used for The graph given in Figure is true for measurement of time? a. Both A and B. a. A leaking tap. b.. A only b. Simple pendulum. c.. B only c. Shadow of an object during the day. d. Neither A nor B. d. Blinking of eyes. 4. A bus travels 54 km in 90 minutes. The speed 2. Two clocks A and B are shown in Figure. of the bus is Clock A has an hour and a minute hand, a. 0.6 m/s whereas clock B has an hour hand, minute b. 10 m/s hand as well as a second hand. Which of c. m/s the following statement is correct for these d. 3.6 m/s clocks? 5. If we denote speed by S, distance by D and time by T, the relationship between these quantities is a. S=DX T b. T=S/D c. S=D/T d. S=T/D 6. Observe Figure.

a. A time interval of 30 seconds can be measured by clock A. b. A time interval of 30 seconds cannot be measured by clock B. c. Time interval of 5 minutes can be measured by both A and B. d. Time interval of 4 minutes 10 seconds can be measured by clock A. The time period of a simple pendulum is the 3. Two students were asked to plot a distance- time taken by it to travel from time graph for the motion described by Table a. A to B and back to A. A and Table B. b. O to A, A to B and B to A. c. B to A, A to B and B to O. d. A to B. 7. Fig. shows an oscillating pendulum. Time taken by the bob to move from A to C is t1 and from C to O is t2. The time period of this simple pendulum is

103 PRACTICE SHEET SHEET - 5 -(PS-5) 3 (PS-3)

a. (t1 + t2 ) b. 2 (t1 + t2 ) c. 3 (t1 + t2 ) d. 4 (t1 + t2 ) 8. The correct symbol to represent the speed of an object is a. 5 m/s b. 5 mp c. 5 m/s-1 d. 5 s/m 9. Boojho walks to his school which is at a distance of 3 km from his home in 30 minutes. On reaching he finds that the school is closed and comes back by a bicycle with his friend and reaches home in 20 minutes. His average speed in km/h is a. 8.3 b. 7.2 c. 5.0 d. 3.6 10. Which one of the following is not used for measuring of time? a. Pendulum b. Hour glass c. Metre scale d. Sun dial. 11. Which one of these is not a unit of time? a. m/s b. Week c. Month d. Year 12. Which one of these is a periodic motion? a. Rotation of earth about is axis. b. Revolution of moon about the earth c. To and fro motion of a vibrating spring d. All of these. 13. Conversion factor from km/h to m/s is a. 5/18 b. 18/5 c. 50/3 d. 5/3 14. In a distance time graph, uniform motion will be a a. Curved line b. Straight line c. A circle d. A bent line 15. If an object is travelling with uniform motion, its speed is equal to a. Total time taken b. Total distance covered. c. Total distance travelled /Time taken d. Total time taken in its first half of the motion.

104 PRACTICE SHEET SHEET - 5 -(PS-5) 4 (PS-4)

I. Answer the following questions: 1. A simple pendulum is oscillating between two points A and B as shown in Figure. Is the motion of the bob uniform or non-uniform?

2. Paheli and Boojho have to cover different distances to reach their school but they take a. What will be the position of the object at the same time to reach the school. What can 20s? you say about their speed? b. What will be the distance travelled by the 3. If Boojho covers a certain distance in one object in 12s? hour and Paheli covers the same distance in c. What is the average speed of the object? two hours, who travels in a higher speed? 4. The average age of children of Class VII is 12 years and 3 months. Express this age in seconds. 5. A spaceship travels 36,000 km in one hour. Express its speed in km/s. 6. Starting from A, Paheli moves along a rectangular path ABCD as shown in Figure. She takes 2 minutes to travel each side. Plot a distance-time graph and explain whether the motion is uniform or non-uniform.

7. Plot a distance-time graph of the tip of the second hand of a clock by selecting 4 points on x-axis and y-axis respectively. The circumference of the circle traced by the second hand is 64 cm. 8. Given below as Figure is the distance-time graph of the motion an object.

105 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 7. You might have observed the given image while coming to school on your father’s scooter. What 1. Which of the following is an example of periodic is the instrument called? motion? a. Odometer a. Car moving on a road b. Speedometer b. Earth moving around Sun c. Stopwatch c. Football kicked by a player d. Wristwatch d. Movement of a lift

8. An athlete runs 500 m in 1 m 40 sec. What is his 2. The bob of a simple pendulum is: speed in metres per second? a. The metallic ball a. 5 m/s b. The thread b. 8 m/s c. The hook c. m/s d. The support from which the thread d. 10 m/s is hung

9. I travel fastest of all. Who am I? 3. The motion of a simple pendulum is an example of: a. Sound a. Straight-line motion b. Light b. Periodic motion c. Wind c. Oscillatory motion d. Aero plane d. Both (B) and (C)

4. Which of the following statements is correct? a. Length of a room is measured in km 10. What do the points in the given graph represent? b. The age of a person is measured in years a. Distance c. Distance between two villages is measured in cm b. Time d. Your height is measured in mm c. Speed d. Type of motion

5. Rockets attain speed of ______, a. 8 cm/s b. 8 km/h c. 8 km/s d. 8 m/ s

6. Which of the following shows the straight-line motion? a. An arrow released from a bow b. Motion of a swing c. Motion of hands of a clock d. Motion of strings in Veena

106 PRACTICE SHEET - 5 (PS-5)

II. Short answer questions 1. Observe following motions of bodies and label them as Rotatory (R), Straight-line (S) Sl. No Image Motion (R) /(S) Motion of the 1. blades of a ceiling fan

2. Motion of a top

Motion of a rider on the bicycle 3. Motion of wheels of an object 2. A bus moves with a speed of 35 km/h for 30v minutes in the city and then with a speed of 70 km/h for the next 20 minutes on highway. Calculate the total distance covered by the bus: 3. “The to and fro motion of a simple pendulum is an example of a periodic or an oscillatory motion.” Thus, can you say that all objects in periodic motion are in oscillatory motion? Discuss.

III. Long answer questions 1. What are different types of motions. Explain. 2. i. Can an object be in two different types of motions? Explain with examples. ii. Motion of an object is always relative. Justify with examples.

107 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

3. Differentiate between uniform motion and non uniform motion. I. Answer in a sentence: (5X1=5) 1. Define an oscillation.

2. What are the two methods of writing time in a day?

4. How would you find out which vehicle is the fastest? 3. Name the SI unit of time.

4. List the types of motion.

5. Looking at the bar graph, write down the runs scored by a team in each over. 5. What does a speedometer measure?

II. Answer in brief: (5X2=10) 1. How is speed calculated? In what units are they generally expressed?

2. The average age of children of class 5 is 10 years, 3 months. Express this age in seconds.

108 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

III. Answer as directed: (2X5=10) 1. Distance between Bholu’s and Golu’s house is 9 km. Bholuhas to attend Golu’s birthday party at 7 o’clock. He started from his home at 6 o’clock on his bicycle and covered a distance of 6 km in 40 minutes. At that point he met Chintu and he spoke to him for 5 minutes and reached Golu’s birthday party at 7 o’clock. With what speed did he cover the second part of the journey? Calculate his average speed for the entire journey.

2. Boojho goes to the football ground to play football. The distance time graph of his journey from his home to the ground is given as Figure. a. What does the graph between point B and C indicate about the motion of Boojho? b. Is the motion between 0 to 4 minutes uniform or nonuniform? c. What is his speed between 8 and 12 minutes of his journey?

109 Annexure 1: Distance Time Graphs

I. The following table shows the motion of a student walking into a classroom (the distance is measured from the door): Distance (meters) 0 1 2 3 4 5 6 6 6 3 0 Time (seconds) 0 1 2 3 4 5 6 7 8 9 10

Draw a distance time graph (with time on the x-axis) to show the motion. II. Answer the questions below: 1. For the 6th to 8th second, what was the student’s movement? 2. How far into the classroom did the student move? 3. Where in the classroom was the student after 10 seconds? 4. Over which period of time did the student move the fastest? Can you explain how you know this? 5. How far in total did the student walk? 6. What was the average speed of the whole journey? 7. What was the velocity of the student at 9 seconds? (remember velocity has direction) 8. What was the velocity at 2 seconds? More difficult III. The following table represents a student riding a bicycle: Distance (meters) 0 4 12 24 40 60 84 84 84 84 72 60 48 36 24 12 0 Time (seconds) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Draw a distance time graph (with time on the x-axis) to show the motion. IV. Answer the questions below: 1. What is the bicycle doing for the first 6 seconds? 2. Describe the motion of the bicycle between 6 and 9 seconds. 3. What is the average speed of the bicycle? 4. What is the speed of the bicycle at 3 seconds? (hint: think tangents!) 5. How far away from the starting point is the bicycle after 8 seconds? 6. What is the bicycle doing between 9-16 seconds?

110 Annexure 1: Distance Time Graphs

1. The distance between two stations is 240 km. A train takes 4 hours to cover this distance. Calculate the speed of the train. 2. A simple pendulum takes 32 s to complete 20 oscillations. What is the time period of the pendulum? 3. Salma takes 15 minutes from her house to reach her school on a bicycle. If the bicycle has a speed of 2 m/s, calculate the distance between her house and the school. 4. The odometer of a car reads 57321.0 km when the clock shows the time 08:30 AM. What is the distance moved by the car, if at 08:50 AM, the odometer reading has changed to 57336.0 km? Calculate the speed of the car in km/min during this time. Express the speed in km/halso. 5. Nancy travelled a distance of 455 km by car in 10 hours. Find the speed of the car. 6. Find the speed and average speed of a train which leaves Chennai at 1 p.m. and reaches Vijayawada in the same day at 9 p.m. The distance between the two stations is 432 km and the total time for stoppage is 2 hours between these stations. 7. A car travels a distance of 595 km in 8 ½ hours. What is its speed? 8. If a person drives his car in the speed 50 miles per hour, how far can he cover in 2.5 hours? 9. If a person travels at a speed of 40 miles per hour. At the same rate, how long will he take to cover 160 miles distance? 10. A person travels at a speed of 60 kms per hour. Then how many meters can he travel in 5 minutes?

111 14. Electric Current and its Effects

Learning Outcome

By the end of this chapter, you will be able to: • Infers the importance of fuse in a circuit. • Recall the components of the circuit. • Explain the magnetic effect of current. • Build a simple circuit. • Explain the working of an electromagnet. • Assign the symbols to electric components. • Describe the construction of an electric bell. • Explain the heating effect of current. • Explain how an electric bell operates. Concept Map

Key Points • The flow of electrons through a conductor gives • An electro magnet loses its magnetism as soon as rise to electric current. the electric current is switched off. • An uninterrupted path through which electric • Electric bell, cranes, hard disks, speakers, motors, current flows is known as a circuit. generators have electromagnets and these are • The conditions necessary for electric flow are a some of the appliances that work on the magnetic source of current, a conducting material and an effects of current. unbroken path for the flow of current. • Cells can be arranged in series or in parallel Key words: electricity, fuse, electromagnet, depending on the requirement. conductor, wire, circuit, compass, current • An electric fuse is made up of alloy of tin and lead with a very low melting point. • A fuse acts as a safety device by breaking the circuit when more current flows suddenly. • Electric iron, electric geyser, heater, electric bulb and electric toaster are some of the appliances that work on the heating effect of current. • A current carrying conductor deflects the needle of a magnetic compass kept near it.

112 14. Electric Current and its Effects

Work Plan

CONCEPT SUB CONCEPT PRACTICE SHEET SIMULATION/VIDEO

• Symbols of components of Making simple electric circuit circuit by battery, safety Electric circuit and • Function of each component PS – 1 pin, wires and a bulb its components in the circuit • Conductor and insulator Effect of current on a compass needle • Working of heating coil Heating effect of • Working of heating iron PS – 2 electric current • Working of fuse and its Making an electromagnet importance Working of an electric bell • Magnetic effect of electric Magnetic effects of current PS – 3 electric current • Electromagnet and its uses • Working of an electric bell

Worksheet for “Electric Current and its Effects” PS – 4

Evaluation with self- Self-evaluation Sheet check or Peer check*

113 PRACTICE SHEET - 1 (PS-1)

I. Fill In the blanks with appropriate terms: 1. An uninterrupted path through which electric current flows is known as ______. 2. Bulb has a filament made up of ______. 3. To connect or disconnect a circuit, a ______is used. II. Draw the symbols of following components:

CELL ELECTRIC BULB

SWITCH IN ON POSITION SWITCH IN OFF POSITION

BATTERY WIRE

III. Choose the most appropriate answer for each of these statements: 1. Continuous flow of electric charge through a circuit requires a. Course of electric current b. Conducting material c. A closed circuit d. All of the above. 2. In a circuit diagram, the various components of the circuit are represented by a. Standard pictures b. Standard symbols c. Lines d. Circles 3. When a switch is in OFF position, i. Circuit starting from the positive terminal of the cell stops at the switch. ii. Circuit is open. iii. No current flows through it. iv. Current flows after some time. Choose the combination of correct answer from the following. a. All are correct b. (ii) and (iii) are correct c. Only (iv) is correct d. Only (i) and (ii) are correct

114 PRACTICE SHEET - 2 (PS-2)

I. Write a word/term for the following statements: 1. An unbroken path through which an electric current can flow. 2. A very thin wire made up of special material that glows in a bulb. 3. Tightly wound coils found in appliances that heat up. 4. A safety device used to prevent the excessive flow of electric current. 5. A device used to open or close an electric current. II. Write one example for each: 1. One necessary component of an electric circuit. 2. A material used to make the filament of an electric bulb. 3. An appliance that is based on the heating effect of electric current. III. Say whether the following statements are true or false: 1. A bulb glows due to the silver wire present in it. 2. The element of electric iron is made up of copper. 3. A current carrying wire deflects the needle of a magnetic compass kept near it. 4. The electric fuse works on the principle of heating effect of current. IV. Answer each of these questions: 1. Which property of a conducting wire is utilised in making an electric fuse? 2. Name the device used these days in place of electric fuses in electrical circuits. 3. Paheli does not have a night lamp in her room. She covered the bulb of her room with a towel in the night to get dim light. Has she taken the right step? Give one reason to justify your answer. 4. Why are compact fluorescent lamps (CFLs) preferred over electric bulbs? 5. Why is an electric fuse required in all electrical appliances? V. Choose the correct option for each of these statements: 1. Which of the following is not a safety device used in an electric circuit? a. MCB magnet b. Magnet c. Electric fuse d. Cartridge fuse 2. Which of the following appliance does not use the heating effect of current? a. Electric heater b. Electric bell c. Electric geyser d. Electric bulb 3. The heating effect of electric current is used in a. An electric bulb b. An electric toaster c. A room heater d. All of these. 4. An electric fuse is a. An electric circuit b. A heating device c. An element in a bulb d. A safety device

115 PRACTICE SHEET - 3 (PS-3)

I. Fill in the blanks: 1. An electric fuse has a______melting point. 2. Electric fuse works on the principle of ______of current. II. Match the following:

COLUMN A COLUMN B 1. Heating effect of current a. Fuse 2. A horse shoe magnet b. MCB 3. A wire of low melting point c. Electric bell 4. A safety device in which the switch trips d. Electric iron down 5. A wire of high resistance e. Tungsten 6. Heating effect of current f. Electric current

III. Answer in one/two words: 1. A magnet used in cranes. 2. A device that works on the magnetic effect of current. IV. Choose the correct alternative for each of these statements: 1. The strength of an electromagnet can be increased by a. Increasing number of coils b. Decreasing strength of current c. Decreasing number of coils d. All of the above methods. 2. What is the shape of the magnet in an electric bell? a. Cylindrical b. Bar c. Horse shoe d. Square 3. When an electric current flows through a wire, it a. Cools down b. Behaves like a magnet c. It boils d. Melts easily. 4. A hammer, a gong and a soft iron strip are all parts of a. An electromagnet b. An electric bell c. An electric fuse d. Electric circuit

116 PRACTICE SHEET - 3 (PS-3)

5. When an electric current flows through a copper wire AB as shown in Fig, the wire

a. Deflects a magnetic needle placed near it. b. Becomes red hot. c. Gives electric shock. d. Behaves like a fuse. 6. Choose the statement which is not correct in the case of an electric fuse. a. Fuses are inserted in electric circuits of all buildings. b. There is a maximum limit on the current which can safely flow through the electric circuits. c. There is a minimum limit on the current which can safely flow in the electric circuits. d. If a proper fuse is inserted in a circuit it will blow off if current exceeds the safe limit. 7. Three bulbs A, B, C are connected in a circuit as shown in Fig. When the switch is ‘ON’

a. Bulb C will glow first. b. Bulb B and C will glow simultaneously and bulb A will glow after some time. c. All the bulbs A, B and C will glow at the same time. d. The bulbs will glow in the order A, B and C. 8. Which of the following precautions need not be taken while using electric gadgets/ appliances / circuit? a. We should never touch a lighted electric bulb connected to the mains. b. We should never experiment with the electric supply from the mains or a generator or an inverter. c. We should never use just any wire or strip of metal in place of a fuse. d. We should never turn the switch in ON position.

117 PRACTICE SHEET - 4 (PS-4)

I. Choose the correct option 8. Damaged fluorescent tubes or CFLs need to be disposed off safely because they contain 1. On what factors is the amount of heat produced ______which is toxic in nature. in a wire depend? a. Filament a. Nature of the material with which wire is made b. Hydrogen gas b. Thickness of the wire c. Water vapour c. Length of wire d. Nitrogen gas d. All of these 2. The coil that behaves like a magnet when II. Short answer questions electric current flows through it is called 1. What is an electric fuse? What is its use? ______. 2. How do you make an electromagnet? Explain a. Electric wire with a neat diagram. b. Fuse 3. Why should an electrician use rubber gloves c. Electromagnet while repairing an electric switch. Explain. d. Magnet

3. Dry cell is a source of electric energy. It III. Long answer questions converts: a. Electrical energy into chemical energy 1. Explain the working of an electric bell. b. Chemical energy into electrical energy 2. Differentiate between a cell and a battery. How do you make a battery? Show diagrammatically c. Magnetic energy into electrical energy in two different ways. d. Electrical energy into magnetic energy 4. Which of the following components is used to close or open an electric circuit? a. Fuse b. Switch c. Cell d. Battery 5. What happens when two or more cells are joined? a. They form a circuit b. They form a switch c. They form a battery d. They form a fuse 6. Which of the following consume less electricity? a. Incandescent bulbs b. LED bulbs c. Fluorescent tubes d. CFLs 7. Which mark ensures the safety of the electrical appliance? a. CFL b. MCB c. Trademark d. ISI

118 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Fill in the blanks with appropriate terms: (4 Marks) 2. Draw the symbols of the following circuit 1. Our body is a ______of electricity. components. 2. An electric cell produces electricity from the a. Electric cell ______in it. b. Switch in off position 3. In an electric circuit a fuse is a ______c. Electric bulb to prevent possible fire. d. Battery 4. A combination of two or more cells is called a ______.

II. Say whether the following statements are true or false: (5 Marks) 1. Nichrome is used for making fuse wires.

2. Positive terminal of one cell is connected to the negative terminal of another cell in a torch.

3. An electromagnet is a permanent magnet.

4. The wires of a fuse melt when we draw more current from it. 3. Draw a simple circuit connecting a bulb through a wire in the switch on ‘ON’ position. 5. We should not touch an electric switch with wet hands.

III. Answer the following: (6 Marks) 1. Name two electric devices for each where (i) heating effect of current is used and (ii) magnetic effect of current is used.

119 15. Light

Learning Outcome

By the end of this chapter, you will be able to: • Recognize the nature of image formed in concave • Recall that light travels in a straight line. and convex lenses. • Explain reflection of light. • Infer that sunlight is a white light spectrum made • State the properties of image formed in a plane up of seven colours- VIBGYOR. mirror. • Recognize the nature of images formed in concave and convex mirrors.

Concept Map

Key Points • Light always travels in a straight line and is called rectilinear propagation of light. • When a beam of light falls on a surface it gets reflected. • A plane mirror always forms same-sized image but the image is laterally inverted. • In a concave mirror, the nature of the image varies with the distance of the object from the mirror. It can form real, inverted or virtual and an erect image, • The image formed in a convex mirror is always virtual, erect and diminished. • A convex lens is thick at the middle and thin at the edges. • A concave lens is thin at the middle and thick at the edges. • A convex lens can form virtual and magnified images or real and inverted images that can be of varied sizes. • White light splits into seven colours –VIBGYOR when it passes through a prism.

120 15. Light

Work Plan

CONCEPT SUBCONCEPT PRACTICE VIDEO/SIMULATION SHEETS

Spherical mirrors and • Reflection by mirror PS – 1 Demonstration of reflection of images formed by these light using torch and mirror. mirrors • Types of images formed Image of a candle in a plane by these mirrors PS – 2 mirror. • Properties of light Images formed by convex spoon/ mirror. Images formed by concave PS – 3 spoon/mirror. Images formed by convex lens Sunlight – White or Dispersion when an object is placed at PS – 4 coloured Newton’s disc different distances. Images formed by concave lens Worksheet for “Light” PS – 5 when object is placed at different distances. Evaluation with self- Self-evaluation check or Peer check* sheet

121 PRACTICE SHEET - 1 (PS-1)

I. Say whether the statements are true or false: 1. Concave and convex mirrors are plane reflecting surfaces. 2. An image which can be formed on a screen is called a real image. 3. Mirrors are found in spectacles. 4. A convex mirror forms only real images. 5. A convex lens always gives a virtual, erect and diminished image. II. Fill in the blanks with appropriate words:

1. We get diffused reflection from a ______surface. (rough/smooth) 2. A smooth polished surface that can return the rays of light incident on it to form a clear image is called a ______(lens/mirror) 3. Concave and convex mirrors can both form ______(real/virtual) images. 4. A lens is made of a ______(translucent/transparent) material. 5. ______(white/blue) light consists of many colours. III. Write an example for each of the following:

1. A surface that would give regular reflection. 2. A surface that would act as a mirror. 3. A mirror that always makes things look smaller.

PRACTICE SHEET - 2 (PS-2)

I. Fill in the blanks: 1. A plane mirror produces ______images. 2. A convex lens is also known as ______lens. 3. A concave lens is also known as ______lens. 4. An image that can be caught on the screen is a ______image. 5. ______is used as a shaving mirror. II. Complete the following table:

TYPES OF IMAGE FORMED PLANE MIRROR CONCAVE MIRROR CONVEX MIRROR Real or virtual

Erect or inverted

Size of the image

122 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option: 1. When light strikes on the plane mirror a. It reflects b. It scatters in all directions c. It is absorbed by the surface d. None of these. 2. The image formed by a plane mirror is a. Upright b. Virtual c. Same size as the object d. All of the above 3. Which one of the following is used by a dentist to examine the tooth of a patient? a. Concave mirror b. Convex mirror c. Concave lens d. Convex lens. 4. A rear view mirror in the vehicles is a a. Plane mirror b. Convex mirror c. Concave mirror d. Any of the above. 5. A real image can be obtained with a. A plane mirror b. Concave mirror c. Both a and b d. Convex mirror 6. A magnifying glass is a a. Concave mirror b. Convex mirror c. Concave lens d. Convex lens 7. Boojho and Paheli were given one mirror each by their teacher. Boojho found his image to be erect and of the same size whereas Paheli found her image erect and smaller in size. This means that the mirrors of Boojho and Paheli are, respectively a. Plane mirror and concave mirror. b. Concave mirror and convex mirror. c. Plane mirror and convex mirror. d. Convex mirror and plane mirror. 8. Which of the following can be used to form a real image? a. Concave mirror only. b. Plane mirror only. c. Convex mirror only. d. Both concave and convex mirrors. 9. You are provided with a concave mirror, a convex mirror, a concave lens and a convex lens. To obtain an enlarged image of an object you can use either a. Concave mirror or convex mirror. b. Concave mirror or convex lens. c. Concave mirror or concave lens. d. Concave lens or convex lens.

123 PRACTICE SHEET - 3 (PS-3)

10. An erect and enlarged image can be formed by a. Only a convex mirror. b. Only a concave mirror. c. Only a plane mirror. d. Both convex and concave mirrors. 11. You are provided with a convex mirror, a concave mirror, a convex lens and a concave lens. You can get an inverted image from a. Both concave lens and convex lens. b. Both concave mirror and convex mirror. c. Both concave mirror and convex lens. d. Both convex mirror and concave lens. 12. An image formed by a lens is erect. Such an image could be formed by a a. Convex lens provided the image is smaller than the object. b. Concave lens provided the image is smaller than object. c. Concave lens provided the image is larger than object. d. Concave lens provided the image is of the same size.

PRACTICE SHEET - 4 (PS-4) I. Choose the correct alternative: 1. State the correct sequence (1-7) of colours in the spectrum formed by the prisms A and B, shown in Fig

A B 1 RED 2 ORANGE 3 YELLOW 4 GREEN 5UE BL 6 INDIGO 7 VIOLET 2. A rainbow can be seen in the sky a. When the sun is in front of you. b. When the sun is behind you. c. When the sun is overhead. d. Only at the time of sun rise. II. Answer each of these questions: 1. An experiment is carried out by passing a narrow beam of white light through a glass prism. i. What would you observe and why? ii. Name a natural phenomenon that is based on this experiment. iii. What would you observe when a newton’s disc is rotated fast? Why? 2. What is a newton’s disc? 3. Which triangular substance is used for dispersing the white light?

124 PRACTICE SHEET - 5 (PS-5)

I. Choose the correct option 8. What type of image is formed when an object is too close to a concave mirror? 1. Which of the following are transparent? a. Erect, virtual and enlarged a. Plane mirror b. Erect, real and enlarged b. Concave mirror c. Inverted, virtual and diminished c. Lenses d. Inverted, real and enlarged d. Convex mirror 9. The inner surface of a spoon acts like a 2. The image formed by a plane mirror is at ______mirror, while its outer surface acts ______distance from the mirror as the object like a ______mirror. in front of it. a. convex, concave a. same b. concave, convex b. double the c. concave, concave c. half of the d. convex, convex d. three times the 10. What type of image is formed in a plane mirror? 3. Moon appears to be bright as: a. Sides appear to be interchanged a. It is the source of light b. Erect and virtual image b. It is a glowing object c. Same sized image c. Sun’s light reflects on it d. All of these d. Sun’s light passes through it 4. Which of the following colours can never be a II. Short answer questions colour in rainbow? 1. Show that light travels in a straight line. a. Violet 2. How do you show that the seven rainbow co- b. Black lours combine to give white colour. c. Yellow 3. Lenses are useful for us in many ways. Justify d. Orange the statement.

5. The reflectors of torches, headlights of cars and III. Long answer questions scooters are ______in shape a. concave 1. Two lenses are given to you. How can you identify them as convex and concave lens? What b. convex happens to the light that is projected on these c. plane lenses? d. All of these 2. Is the phenomenon called ‘reflection of light’ 6. Identify the surface that reflects the light among useful to us? Justify. the following. a. Water b. Polished stone c. Stainless steel plate d. All of these 7. Which of the following is used by dentists to get enlarged image of the teeth? a. Plane mirror b. Concave mirror c. Convex mirror d. Concave lens

125 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Say whether the following statements are true or false: (4 Marks) 1. Any polished or shining surface can act as a mirror. 2. In a plane mirror, images formed do not show any lateral inversion. 3. Only real images are formed in a convex lens. 4. A rainbow is formed due to dispersion of white light.

II. Answer in a sentence or a two: (8 Marks) 1. State any two properties of an image formed by a plane mirror. 2. State a use of a concave mirror and a convex mirror in our daily life. 3. Differentiate between a real image and a virtual image. 4. A shopkeeper wanted to fix a mirror which will give a maximum view of his shop. What type of mirror should he use? Give reason.

III. Answer in detail: (3 Marks) 1. You are given three mirrors of different types. How will you identify each one of them?

126 16. Water: A Precious Resource

Learning Outcome

By the end of this chapter, you will be able to: • Explain different ways to manage water. • Realize the amount of available water. • Analyze one’s role in conserving water. • Recall forms of water and water cycle. • State ways to conserve water. • Recognize the importance of ground water. • Discuss the effect of water scarcity on plants. • State reasons for depletion of water table. Concept Map

Key Points • Water exists in solid, liquid and gaseous states. • Water cycle involves evaporation, condensation and precipitation. • Water sources can be divided into two categories: surface water and underground water. • Seasonal monsoons maintain water levels in the Indian sub-continent. • India has a large network of rivers. A large number of dams have been constructed on these rivers to regulate the water flow in these rivers and distribute water more evenly throughout the year. • Water can be conserved by not wasting water in our house hold activities, by recycling water and through rain water harvesting.

127 16. Water: A Precious Resource

Work Plan

CONCEPT COVERAGE CONCEPT DETAILS PRACTICE SHEET

• Sources of water Sources and forms of water • Water cycle PS – 1 • Forms of water

Depletion of water and its • Reasons for depletion of water PS – 2 conservation • Methods to conserve water

Worksheet for “Water: A Precious Resource” PS – 3

Evaluation with self- check or Peer Self-evaluation Sheet check*

128 PRACTICE SHEET - 1 (PS-1)

I. Fill in the blanks with correct words: 1. All the three states of matter are ______. (reversible/irreversible) 2. Water freezes at ______. (100°C/0°C) 3. The continuous circulation of water in nature is called ______. (hydrogen cycle/hydrologic cycle) 4. ______. (Dams/Canals) are built on the rivers to store, regulate water flow and distribute water more evenly. 5. Water levels in rivers increase greatly during ______. (winter/monsoon) II. Match the definitions to their terms.

MEANINGS TERMS 1. Continuous circulation of water in nature. a. Aquifer 2. Water that is present on the surface of the earth. b. Water cycle/Hydrologic cycle 3. Water under the ground where soil is completely c. Water table filled or saturated with water. 4. The topmost level of underground water. d. Infiltration 5. Water reservoir formed above the impervious layers e. Surface water of rock or clay 6. Process of water seeping under the ground. f. Ground water

III. Match the following:

COLUMN A COLUMN B 1. Ground water a. Water conservation 2. Boiling temperature of water b. Growth in population 3. Economic use of water c. 100°C 4. Cause of water scarcity d. Drip irrigation 5. Method of watering plants e. Exhaustible renewable resource

IV. Say whether the following statements are true or false: 1. Water scarcity is caused when demand and usage of water is more than availability. 2. Rainfall occurs due to precipitation. 3. Surface water is called an aquifer. 4. Rain Water Harvesting involves chemicals to treat rain water. 5. Araveri, Ruparel and Sarsa have been revived by the efforts of social workers.

129 PRACTICE SHEET - 1 (PS-1)

V. Complete the following concept map:

130 PRACTICE SHEET - 2 (PS-2)

I. Choose the correct option: 1. Water in the industrial sector is used as a. Raw material b. Coolant c. A solvent d. All of the above. 2. In India, water scarcity is predominant in a. North Eastern states b. Tamil Nadu c. Himachal Pradesh d. Thar desert 3. Which one of the following is responsible for the depletion of water table? a. Deforestation b. Agricultural activities c. Increasing population d. All of these 4. Water is a ______resource. a. Renewable, exhaustible b. Non renewable, non exhaustible c. Non renewable, recyclable d. Non renewable, non recyclable. 5. The purest form of water is a. Sea water b. Rain water c. Ground water d. Rain water. 6. Which of the following does not show water shortage? a. Taps running dry. b. Long queues for getting water. c. Marches and protests for demand of water. d. A family gets three buckets of water per person per day. 7. Seas and oceans are full of water on earth. However, a very small percentage of water present on earth is available for us. This percentage is roughly a. 0.006%. b. 0.06%. c. 0.6%. d. 6%. 8. Which of the following are not the liquid forms of water? (i) Snow (ii) Lake water (iii) River water (iv) Water vapour (v) Ice Choose the correct combination from the options below. a. (i), (iv) and (v) b. (i) and (ii) c. (ii) and (iii) d. (iii) only

131 PRACTICE SHEET - 2 (PS-2)

9. A man digging the ground near a water body found that the soil was moist. As he kept digging deeper and deeper he reached a level where all the spaces between particles of soil and gaps between rocks were filled with water. The upper limit of this layer is called a. Water level. b. Water table. c. Ground water. d. Water limit. 10. Which of the following is a way to use water economically? a. Construction of bawris b. Rainwater harvesting c. Drip irrigation d. Infiltration 11. On which of the following days is World Water Day observed? a. 22 March b. 14 November c. 2 October d. 21 December 12. Water cycle does not involve which of the following? a. Evaporation b. Condensation c. Formation of clouds d. Rainwater harvesting 13. Which of the following inhibits the seepage of rainwater into ground? a. A pukka floor b. Playground c. Grass lawn d. Forest land II. Answer the following: 1. What is the source of water in each of the following? a. Wells b. Ground c. Atmosphere 2. Fill in the blanks in the given passage. The rainwater and ______a.______from other sources such as rivers and ponds seeps through the ______b.______and fills the empty spaces and cracks deep below the ground. The process of seeping of water into the ground is called ______c.______. 3. Fill in the blanks and complete the story selecting words from the box given here. cold, demand, leaders, dry, hot, scarcity, workers, wet, oceans, harvesting, rivers Rajasthan is a ___(a)____ and dry place. The challenge of natural ___ (b)____ of water was met by a successful experiment. A band of social ____ (c)____ had transformed a ____ (d)____ area into a green place. They have revived five dried-up ____ (e)____ by constructing water ______(f)_____ structures.

132 PRACTICE SHEET - 2 (PS-2)

4. Place the following statements in proper order to form a meaningful paragraph. a. Which in turn decreases the seepage of rain water into the ground. b. This decreases the open areas like park and playgrounds. c. Increasing population create demand for construction of houses, shops, offices, roads and pavements. d. This results in depletion of water table and creates scarcity of more water. 5. How can you observe the three forms of water in (i) nature and (ii) at home? 6. Complete the given table

FORM OF WATER PROCESS BY WHICH IT IS FORMED LOCATION FOUND a. Liquid Condensation and melting b. Solid Freezing c. Gaseous Evaporation

7. A list of jumbled words are given here. Write the correct form of each word. a. WASHFERRET b. CHARREGE c. QUIFERA d. WOSN 8. From where do the following usually get water? In which form is water present in them? (a) Clouds (b) Plants (c) Mountain tops (d) Aquifer (e) Animals

133 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option 8. Excessive rains cause______, whereas the absence of rains results in ______. 1. On which day is ‘world water day’ celebrated? a. floods, droughts a. 21st March b. droughts, floods b. 22nd March c. droughts, droughts c. 25th April d. floods, floods d. 30th April 9. Reasons for depletion of water table: 2. In which of the following seasons is the scarcity of water the most? a. Increase in population a. Rainy b. Increasing industrial and agricultural activities b. Winter c. Scanty rainfall c. Summer d. All of these d. Autumn 10. The consequences of water is not available to plants or a world without plants shall mean: 3. Water in which form is found in air around us? a. No food a. Water vapour b. No oxygen b. Liquid c. No rains c. Gaseous d. All of these d. Both (A) and (C) 4. What is the percentage of water in sea/ocean? II. Short answer questions a. 97% 1. What do you understand by drip irrigation? b. 91% 2. Write 3 slogans to convey people about saving c. 2% water. d. 95% 3. Water is a precious resource. Justify.

5. What is infiltration? III. Long answer questions a. Drawing underground water using hand pumps 1. Explain how the increase in population causes b. Seeping of water into the ground depletion of ground water? c. Filtering water 2. Water management should be strong enough to d. All of these recharge the ground water. Justify. 6. Deserts have ______rainfall. a. Abundant b. Less c. Scanty d. No 7. ______present in the soil indicates the presence of water underground. a. Moisture b. Animals c. Minerals d. Rocks

134 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. State whether the following statements are true or false and if false, write the correct statement: (4 Marks) a. Water vapour is the gaseous form of water.

b. Ice is solid whereas snow is the semi-solid form of water.

c. Ocean water cannot be used for domestic purposes.

d. Rapid growth of industries is one of the causes for water shortage.

II. Match the following: (3 Marks)

COLUMN A COLUMN B 1. Ground water a. Solid form of water 2. Bawri b. Wastage of water 3. Snow c. Water conservation 4. Drip irrigation d. Small water 5. Leaking taps e. Water table 6. Stopping a leaky f. Water management faucet

III. Answer the following: (8 Marks) 1. State any four ways to conserve water.

2. Explain water cycle briefly.

3. State any four uses of water.

4. What are the factors that deplete water table?

135 17. Forests : Our Lifeline

Learning Outcome

By the end of this chapter, you will be able to: • Cite examples for autotrophs, heterotrophs and • List the animals found in the forest. decomposers. • List the trees found in the forest. • State the products obtained from forest. • Define autotrophs, heterotrophs and decomposers. • Explain the significance of forest.

Concept Map

Key Points • Forests are natural resources. • Forests have three major important functions: productive, protective and regulatory • The animals and plants in a forest are linked together through food chain and food web. • Autotrophs are the organisms that prepare their own food. Example: Plants. • Heterotrophs are the organisms that depend on autotrophs directly or indirectly for their food. Example: Camel, lion • Decomposers are the organisms that act on dead and decaying matter, recycling nutrients back to the soil and atmosphere. • Paper, rubber, match, fibre industries are based on forest produce. • Deforestation is caused due to exploitation by human activities. • To conserve forests, preventive measures such as afforestation, planned cultivation, prevention of forest fires and prohibition of killing of animals, felling of trees should be adopted.

136 17. Forests : Our Lifeline

Work Plan

CONCEPT SUB CONCEPT PRACTICE SHEET

Some forest plants and • Importance of forest animals • Forest as habitat PS – 1 • Some common animals and plants of forest • Types of forest trees (crown, canopy and understory)

Interrelationship of plant, • Autotrophs, heterotrophs and saprophytes in forests soil and decomposers in • Importance of decomposers in forest PS – 2 a forest • Importance of forest

Worksheet for “Forests : Our Lifeline” PS – 3

Evaluation with self- Self-evaluation Sheet check or Peer check*

* Administering self-evaluation at the end of a chapter is a good practice • Teacher discusses the correct answer or displays it using an overhead projector and asks the students to exchange their sheets or books to check and correct each other’s work. • The teacher may only need to do a sample check of students’ work. • Typically takes 10 – 15 mins.

137 PRACTICE SHEET - 1 (PS-1)

I. Give two examples for each of the following: 1. Industries dependent on the forests. 2. Trees. 3. Animals. 4. Heterotrophs. 5. Decomposers. II. State whether the following statements are true or false: 1. Xerophytic scrubs are found in tropical forests. 2. Producers feed on animals. III. Select the appropriate term from the box for the following descriptions: Canopy Crown Deforestation Topography Heterotrophs

1. Organisms that depend on producers directly or indirectly. 2. Physical feature of a place. 3. Upper most layer of a forest. 4. Layer from which trees branch off from the tree trunk. 5. Act of destroying the forests by cutting down the trees. II. Answer the following Questions: 1. Why did the monkeys disturb the birds on seeing human beings? 2. Name the products obtained from the forest. 3. What are the different layers of the forest. 4. Form a food chain: frog, eagle, plant, insect, snake

138 PRACTICE SHEET - 2 (PS-2)

I. Choose the correct option: 1. The types of trees and animals thriving in the forest depends on a. Climate of a place b. Topography of a place c. Soil type of a place d. All of these. 2. Forests have been cleared for a. Agriculture b. Industry and housing c. Construction of roads d. All of these. 3. Plants that give us medicines are a. Vanilla and mango b. Teak and sal c. Neem and Eucalyptus d. Both b and c 4. Green plants are a. Producers b. Herbivores c. Decomposers d. Scavengers 5. Which of the following is not a forest product? a. Medicines b. Spices c. Gums d. Plastics. 6. Which of the following serve as green lungs? a. Green pigment of the plants b. Forests c. Kitchen gardens d. Green house gases 7. Boojho visited a forest near his town with his classmates and his teacher. As they were entering the forest, their class teacher told them not to make noise in the forest as noise could disturb the a. Birds b. Animals c. Both birds and animals d. Plants 8. Which among the following forest animals is the smallest? a. Fox b. Boar c. Bison d. Porcupine 9. Which of the following has the strongest stem? a. A tree b. A creeper c. A climber d. A bush

139 PRACTICE SHEET - 2 (PS-2)

10. Which of the following is not prepared from the wood obtained from forest? a. Paper b. Thermocol c. Matchsticks d. Plywood 11. Which of the following is not the name of a tree? a. Teak b. Sal c. Porcupine d. Kachnar 12. Pick the option which gives the names of a tree and an animal, respectively from the following. a. Small, hornbill b. Sal, khair c. Chinkara, blue bull d. Neem, palash 13. Which of the products is not obtained from a forest? a. Honey b. Catechu c. Gum d. Ginger 14. The branchy part of a tree above the stem is known as a. Crown b. Canopy c. Sapling d. Humus 15. Forests are not responsible for a. Providing medicinal plants. b. Maintaining the flow of water into the streams. c. Creating flood conditions. d. Absorbing rainwater and maintaining water table. II. Answer the following: 1. While moving in a forest, Paheli observed that there was no noise pollution, though lots of heavy vehicles were passing from the nearby highway. Why? 2. How do microbes help in recycling? 3. Two friends shared their experiences of their vacation to two different forests. Do you think they would have seen the same type of plants and animals during their respective trips? Give reason. 4. “A bunch of seedlings were seen sprouting on a heap of animal dung in a forest.” How do you think is the seedling benefited from the animal dung?

140 PRACTICE SHEET - 2 (PS-2)

5. Deforestation may lead to floods. Why? 6. Name any four useful things you would lose if forests are destroyed? 7. Fig shows a part of a forest. Write any three activities going on in the forest on the basis of this figure.

III. State whether the following statements are true or false. If false, give the correct statement. a. Forests influence climate, water cycle and air quality. b. In a forest, trees form the uppermost layer, followed by herbs. The shrubs form the lowest layer of vegetation. c. The forest keeps on growing and changing and can regenerate. d. Forests protect the soil from erosion. e. Interconnected food chains form a food web. f. Most of the food chains begin with producers. g. Fungi and bacteria help in recycling of nutrients.

141 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option 8. Which of these are found on the forest floor? 1. The reason for decrease in the area of forests: a. Dead and decaying leaves a. Construction of roads and buildings b. Fruits and seeds b. Industrial development c. Twigs and small herbs c. Increase demand of wood d. All of these d. All of these 9. Which of the following is not a product from forest? 2. Which of the following feed on dead animals? a. Oils a. Vultures b. Gum b. Jackals c. Rice c. Insects d. Spices d. All of these 10. Which of the following trees form lowest layer of 3. In the presence of ______the nutrients of the understoreys in the forest? dead plants and animals are released into the soil. a. Giant and tall trees a. Humus b. Shrubs and tall grasses b. Insects c. Herbs c. Snakes d. Both (B) and (C) d. Ants II. Short answer questions 4. Identify the missing component in the given 1. List few trees that grow in forest. diagram. 2. Write three different food chains. a. Micro-organisms b. Plants 3. Forest is a dynamic living entity. Justify. c. Decomposers III. Long answer questions d. Humus 1. How important are forests? Explain. 5. Micro-organisms which convert the dead plants 2. There is interrelationship between plants, ani- and animals to humus are known as: mals, soil and decomposers in a forest. Justify. a. Insects b. Animals c. Decomposers d. Birds 6. Branchy part of a tree above the stem is known as the ______of the tree. a. Crown b. Leaves c. Head d. Trunk 7. Which of the following statements is NOT true? a. Climatic conditions differ from forest to forest. b. Types of trees and plants vary from forest to forest. c. Same kind of animals are found in different forests. d. Along with giant trees we find shrubs and herbs in forests.

142 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Fill in the blanks: (6 Marks) 1. Many interconnected food chains form a ______.

2. ______and ______are decomposers.

3. The lowermost layer of the forest is ______.

4. Most of the food chains begin with ______.

5. Tigers, lions, cow and goat are ______.

6. The branchy part of a tree above the stem is known as the _____.

II. Answer each of these questions: (9 Marks) 1. People say that nothing goes waste in a forest. Can you explain how? 2. Give any three factors which are responsible for the destruction of forests. 3. All the needs of animals living in a forest are fulfilled. Justify this statement in a forest.

143 18. Wastewater Story

Learning Outcome

By the end of this chapter, you will be able to: • Describe how water reaches from homes to waste • Explain sewage. water treatment plants. • List the contaminants of water. • Describe the steps involved in Waste Water • Classify the contaminants as organic impurities Treatment. and inorganic impurities. • State ways to become an active citizen to reduce waste water generation and conserve water.

Concept Map

Key Points • Household, industry, mining and agricultural • Low cost, on site sewage disposal system like activities are the sources of waste water. septic tanks, chemical toilets and composting pits • Sewage is carried out of our homes through improve sanitation. sewers and drains. • Adopting good sanitation practices should be our • A channel system of pipelines known as sewage way of life. system carries sewage out of our homes to treatment plants. • Human faeces, animal wastes, oil, urea are organic impurities of sewage. • Nitrates, phosphates and metals are inorganic impurities of sewage. • In the treatment plants mechanical, biological and chemical treatments cleanse the water. • Treated water is released into water bodies. • People consuming contaminated water suffer from gastroenteritis, dysentery, typhoid and hepatitis.

144 18. Wastewater Story

Work Plan

CONCEPT COVERAGE CONCEPT DETAILS PRACTICE SHEET

Water pollution and generation of • Sources of water pollution waste water • Generation of wastewater PS – 1 • Sewage • Wastewater treatment

Water conservation • Tips for water conservation • Better housekeeping techniques PS – 2 • Sanitation • Public hygiene

Worksheet for “Wastewater Story” PS – 3

Evaluation with self- check or Peer Self-evaluation Sheet check*

145 PRACTICE SHEET - 1 (PS-1)

I. Write the term that describes each of these statements: 1. Network of big and small pipes. 2. Nitrates, metals and phosphates in water. 3. Solids like faeces that settle down at the bottom of the waste water treatment plant. 4. Settling of suspended microbes at the bottom of the lake. 5. An onsite sewage disposal system. II. Match the following: COLUMN I COLUMN II 1. Chlorine and ozone a. Chemical treatment 2. Ground water b. Suspended impurities 3. Secondary treatment of sewage c. Water disinfectants 4. Phosphorus, nitrogen d. Sources of water for wells, tube wells and springs. 5. Contaminants e. Nutrients

III. Answer the following: 1. What are the reasons for water scarcity? 2. What is sewage treatment? 3. Define sewage. 4. Name the organic and inorganic impurities of sewage. 5. What is the composition of activated sludge and use of dried sludge?

IV. Match the meanings with their terms MEANING TERM 1. Blowing of air into aeration tank. a. Anaerobic bacteria 2. Bacteria that needs oxygen for its respiration b. Sewage 3. Gas produced from the waste of living things. c. Aeration 4. Suspended impurities of water d. Biogas 5. Bacteria that does not need oxygen for its respiration e. Activated sludge 6. Waste water f. Contaminants 7. Network of big and small pipes g. Aerobic bacteria 8. Settling of suspended microbes at the bottom of the h. Sewers tank.

V. Say whether the following statements are true or false: 1. Water from sinks and bath tubs do not generate waste water. 2. Primary treatment of water is a physical process. 3. Open drains are perfect places for breeding of mosquitoes. 4. Chemicals like paints and solvents clog the drains. 5. Cholera, typhoid, polio, meningitis, hepatitis and dysentery are water borne diseases.

146 PRACTICE SHEET - 2 (PS-2)

I. Choose the correct option. 1. Which one of the these is a mechanical process of treating waste water? a. Screening of wastes b. Digestion of wastes c. Disinfecting water d. None of these. 2. Improper management of sewage results in a. Diseases b. Contamination of water supply c. Water pollution d. All of these. 3. Which one of these is not a water borne disease? a. Cholera b. Typhoid c. Dysentery d. Polio 4. The light materials that float during waste water treatment a. Scum b. Sewer c. Sludge d. Sewage 5. Treated water has a a. Very high level of organic material and suspended matter. b. Very low level of inorganic material and suspended matter. c. A very low level of organic material and suspended matter. d. None of these. 6. Which of the following is waste water? a. Water trickling from a damaged tap. b. Water coming out of a shower. c. Water flowing in a river. d. Water coming out of a laundry. 7. Sewage is mainly a a. Liquid waste. b. Solid waste. c. Gaseous waste. d. Mixture of solid and gas. 8. Which of the following is/are products of wastewater treatment? a. Biogas b. Sludge c. Both biogas and sludge d. Aerator 9. Open drain system is a breeding place for which of the following? a. Flies b. Mosquitoes c. Organisms which cause diseases d. All of these

147 PRACTICE SHEET - 2 (PS-2)

10. Water polluted by various human activities causes a number of water borne diseases. Which of the following is not a water borne disease? a. Cholera b. Typhoid c. Asthma d. Dysentry 11. Pick one chemical from the following which is used to disinfect water a. Chlorine b. Washing soda c. Silica d. Coal 12. The system of a network of pipes used for taking away wastewater from homes or public buildings to the treatment plant is known as a. Sewers. b. Sewerage. c. Transport system. d. Treatment plant. 13. Which of the following is a part of inorganic impurities of the sewage? a. Pesticides b. Urea c. Phosphates d. Vegetable waste 14. In a filtration plant, water is filtered using layers of a. Sand and clay. b. Clay and fine gravel. c. Sand and fine gravel. d. Sand, fine gravel and medium gravel. 15. Which of the following is not a source of waste water? a. Sewers b. Homes c. Industries d. Hospitals II. Answer the following: 1. Why are open drains a concern? 2. How are open drains harmful for human health? 3. Name two inorganic impurities present in sewage. 4. Animal waste, oil and urea are some of the organic impurities present in sewage. Name two more organic impurities present in sewage. 5. Given below is a jumbled sequence of the processes involved in a wastewater treatment plant. Arrange them in their correct sequence. a. Sludge is scraped out and skimmer removes the floating grease. b. Water is made to settle in a large tank with a slope in the middle. c. Large objects like plastic bags are removed by passing wastewater through bar screens. d. Sand, grit and pebbles are made to settle by decreasing the speed of incoming wastewater. e. Wastewater enters a grit and sand removal tank.

148 PRACTICE SHEET - 2 (PS-2)

6. Three statements are provided here which define the terms – (a) sludge (b) sewage and (c) wastewater. Pick out the correct definition for each of these terms. a. The settled solids that are removed in wastewater treatment with a scraper. b. Water from kitchen used for washing dishes. c. Wastewater released from homes, industries, hospitals and other public buildings. 7. A mixture (x) in water contains suspended solids, organic impurities, inorganic impurities (a), nutrients (b), disease causing bacteria and other microbes. Give names for (x), (a) and (b)? 8. The terms sewage, sewers and sewerage are interlinked with each other. Can you explain how?

149 PRACTICE SHEET - 3 (PS-3)

I. Choose the correct option 8. What is the sludge in the wastewater treatment? 1. General Assembly of the United Nations a. Solid waste that settles at the bottom of the proclaimed the period 2005–2015 as the tank International Decade for action on: b. Water that goes to the grit and sand removal a. Water for life tank b. Cleaning of water c. Large rags, sticks that are removed in step 1 c. Water that is wasted d. Floating solids like oil and grease d. Wastewater 9. The biogas produced during wastewater 2. Wastewater treatment is commonly known as: treatment is used: a. Purifying water a. As fuel b. Sewage Treatment b. To produce electricity c. Saltwater treatment c. As Air purifier d. Used water treatment d. Both (A) and (B) 3. In which of the following states do we find 10. We should plant eucalyptus trees all along sewage? sewage ponds. Why? a. Solid a. To absorb the bad smell b. Gaseous b. To absorb all surplus wastewater rapidly c. Liquid c. To release pure water vapour into the atmosphere d. Mixture of solid and gas d. Both (B) and (C) 4. Which of the following breed rapidly in open drainage system? II. Short answer questions a. Mosquitoes 1. List out the factors for increasing scarcity of b. Flies fresh water? c. Disease causing germs 2. What are the consequences of having open d. All of these drainage system? 5. The treated water from wastewater treat- 3. What do you do, if there is an open drainage ment plant is disinfected with chemicals like system in your locality? ______and ______before releasing it into the III. Long answer questions distribution system. a. Chlorine 1. Write a short note on advantage of onsite sewage. b. Ozone c. Both (A) and (B) 2. What precautions are to be taken while releasing the waste that is produced at houses into d. Nitrogen the drain? Explain. 6. Aerobic bacteria in clarified water feeds on: a. Human waste b. Food waste c. Soaps d. All of these 7. When wastewater is passed through ______, large objects like rags, sticks, cans, plastic pack- ets, napkins are removed. a. Filter paper b. Bar screens c. Pipes d. Road

150 SELF EVALUATION SHEET Marks: 15 Time: 30 Mins

I. Match the following: (4 Marks) 2. A man travelling in a train threw an empty packet of food on the platform. Do you think COLUMN I COLUMN II this is a proper waste disposal method? a. Inorganic impurities i. Phosphorus and Elaborate. nitrogen b. Organic impurities ii. Nitrates and phosphates c. Nutrients iii. Cholera and typhoid d. Bacteria iv. Pesticides and herbicides

II. Fill in the blanks: (5 Marks) 1. Waste water is generated from farms containing ______(crops/pesticides) 3. Why should we not throw 2. All waste water released from various (a) used tea leaves into sink? sources forms the ______(sewage/ (b) cooking oil and fats down the drain? impurities) 3. Sewer system is a channel of ______(pipelines/tanks) that carries out sewage from our houses. 4. Solids like feces settle at the bottom, removed with a scraper form the ______(sludge/activated sludge) 5. ______is used to disinfect water before releasing it into distribution system. (Nitrogen/Chlorine)

III. Answer the following: (6 Marks) 1. Name two alternative arrangements for sewage disposal where there is no sewerage system.

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