TERM 2 - CLASS 4 - PRIME YEARS

Mass: 1 gram = 1000 mg 1 mg = g = 0.001 gm 250 mg = 0.250g 550 mg = 0.550g 1000g = 1 kg 1g = kg 250g = 0.250 kg 750g = 0.750 kg 500g = 0.5 kg Capacity: 1000 ml = 1 litre 1 ml = 0.001 litre 20 . 250 ml = 20.250 litre l 7 . 55 ml = 7.055 litre l 8 . 5 ml = 8.005 litre l 1 1000 1 1000 Addition and subtraction of decimals Example: Add 1.25 + 7.183 + 12.254 + 4.5 = _______ Steps: 1. Write the decimals in the Place value Chart 2. Add them as you add whole numbers Note: Add zero to represent missing places. It is very important that you write decimals in the correct places. 101

Thousands Hundreds Tens Units Tenth Hundredth Thousandth 1 10 1 100 1 1000 1. 2. 3. 4. 1 . . . . . 7 8 1 3 5 2 0 2 1 5 2 4 4 0 5 0 Example: 123.8 + 3.005 + 9.07 1 1 2 5 1 8 7 . Hundreds Tens Units Tenth Hundredth Thousandth 0.1 0.01 0.001 3 . . . . 3 0 0 5 0 8 0 9 7 0 0 1 3 5 8 7 5 . 1 2 1 Guided 1. Add: Rs. 1.25 + Rs. 128.05 + Rs. 1250.75 + Rs. 50.01 = 2. Add: 14.08 kg + 154.250 kg + 18.005 kg + 26.5 kg = 102 1

1. Add Rs. 120.85 + Rs. 250.15 + Rs. 10.80 + Rs. 1.75 = 2. Add 24.5l + 250.25l + 85.008l + 12.05l = 3. Add 25.86 km + 150.03 km + 8.005 km + 4.085 km = Independent 1. Write in the Place Value Chart and add. a. 10.125 + 130.5 + 41.008 + 1.205 = b. 112.008 + 11.208 + 1.128 + 2.201 = 2. Subtract the second from the first. a. 205.005 – 103.296 = b. 113.00 – 54.209 = c. 41.020 – 24.899 = 3. Convert the following into decimals and add. a. 150 , 200 ml, 8 . 5ml, 20l. 75ml l l b. 22 kg 256g, 10 kg 5g, 45 kg 75 g c. 30 m 15 cm, 4m 2 cm, 8m 75 cm, 5m 8 cm d. 100 rupees 25 paise, 45 rupees 10 paise, 8 rupees 5 paise, 1194 rupees 50 paise, 5 rupees 5 paise. 4. From a ribbon of 8 m 25 cm length, a piece is cut off. The length of the remaining piece is 3.92 cm. What is the length that is cut off? Express in decimals. 5. From a barrel containing 120 kg rice, 55 kg 305g rice was removed. What is the weight of rice remaining? 103

1. Arun bought a pen for Rs. 15.84, a notebook for Rs. 20.07 and chart papers worth Rs. 20.04. Find the total amount that Arun spent. He gave the shopkeeper Rs. 100. What is the balance that he got? 2. In a tank, there is 15.560 litres of water. 8.125 litres more water is added to it. What is the quantity of water in the tank now? 3. km of a 20 km stretch of road is to be repaired. What is the length that does not require repair? Express it in decimals. Observe a ruler. Each centimeter is divided into 10 equal parts. Express the value of each division as a decimal. Using the ruler, measure the length of your pencil and maths notebook. Express the length as a decimal. Measure these objects and write as decimal. 1 5 8 104

Roman Numbers Roman Numerals upto 10 are commonly used by us. 1 2 3 4 5 6 7 8 9 10 I II III IV V VI VII VIII IX X Roman numerals beyond 10 are not very common. Let’s see roman numerals upto 20 X XI XII XIII XIV XV XVI XVII XVIII XIX XX 10 11 12 13 14 15 16 17 18 19 20 Hindu Arabic Numerals: Roman Numerals: XI = 10 + 1 = 11 XII = 10 + 2 = 12 XIII = 10 + 3 = 13 XIV = 10 + (5-1) = 14 XV = 10 + 5 = 15 XVI = 10 + 5 + 1 = 16 XVII = 10 + 5 + 2 = 17 XVIII = 10 + 5 + 3 = 18 XIX = 10 + (10-1) = 19 XX = 10 + 10 = 20 XXI = 21 XXII = 22 XXIII = 23 XXIV = 20 + (5-1) = 24 XXV = 25 XXVI = 20 + 5 + 1 = 26 XXVII = 27 XXVIII = 28 XXIX = 20 + (10-1) = 29 XXX = 30 105

Let’s see how numbers such as 50, 100, 500 and 1000 are written in Roman form. 50 = L 60 = L X (50 + 10) 100 = C 61 = L X I 500 = D 62 = L X II 1000 = M 63 = L X III 64 = L X + (5-1) = L X IV 40 = X L (50 -10) 41 = XLI 42 = XLII 43 = XLIII C = 100 CL = 100 + 50 = 150 CC = 200 XC = 100 – 10 = 90 CX = 100 +10 = 110 DL = 500 + 50 = 550 LD = 500 – 50 = 450 DLX = 500 + 50 + 10 = 560 M = 1000 MC = 1000 + 100 = 1100 CM = 1000 – 100 = 900 106

1. Give the Hindu Arabic Numerals for the following: a. XCIX : _____________ b. XLIV : _____________ c. CXIX : _____________ d. LXIII : _____________ e. CML : _____________ f. LDIV : _____________ 2. Give the Roman Numerals for the following: a. 49 : _____________ b. 53 : _____________ c. 99 : _____________ d. 64 : _____________ e. 75 : _____________ f. 42 : _____________ g. 61 : _____________ h. 405 : _____________ Guided 107

2. Add or subtract the following: a. XIX + XXX = _____________ b. XL – XIX = _____________ c. DL + XL = _____________ 1. Write the Hindu Arabic Numerals for the following: a. XCL b. XC c. LXXIV d. XLV e. XCIV f. CXV g. LXXXI h. DCL i. CDL j. XCV k. XCVIII Rearrange two lines in the following in order to make the statements true. 1) VI I = IV + 2) XI I = IX + 3) XL V = XXXVI + 108

Using matchsticks make roman numerals for the following: 1. 25 : __________________ eg: 2. 43 : __________________ 3. 99 : __________________ 4. 140 : __________________ 5. 160 : __________________ 6. 940 : __________________ 7. 460 : __________________ 8. 250 : __________________ 109

Operations on Money Profit and loss involves money. Therefore we need to learn multiplication and division involving money. Example: One pen costs Rs. 8.25. What is the cost of 15 pens? Cost of 15 pens = 8.25 x 15. Multiply as a whole number and then put a point 2 places to the left of the product. Ans : Rs. 123.75 Example: Cost of 12 Books is Rs. 97.25. What is the cost of 1 book? Cost of 1 book = 97.25 12. Do the division just as in the case of whole numbers but put decimal point when you bring down decimal digit. 12 x 8 = 96. Write 8 in the quotient. And subtract 96. Bring down 2 and put a point after 8. 12 x 1 = 12. Bring down 5 and add a 0. Ans: Rs. 8.14. (Stop the division with 2 decimal places) 4 1 2 5 8 2 5 x 1 5 8 2 5 x 123.75 8.14 12 97.25 - 96 12 12 0.50 48 2 1. Cost of one calculator is Rs. 415.50. Find the cost of 4 calculators. 2. The cost of 4 shirts is Rs. 960.40. What is the cost of 1 shirt? 110

Profit and Loss We buy various things from our neighbourhood shop. Where does the shopkeeper get the things? The shopkeeper buys the things from a wholesale dealer. He sells the items at a higher price to the customers. Thus, he makes a profit in the transaction. The price the shopkeeper pays to the wholesale dealer is called the Cost Price. The price at which he sells them to the customers is called the Selling Price. Profit = Selling Price – Cost Price If the selling price is less than the cost price, he incurs a loss. Loss = Cost Price – Selling Price Activity: 1. Conduct a team quiz. One team asks questions while the other team answers. Team A gives the selling price and cost price of items. Team B has to tell whether there is a profit or a loss in the transaction and how much. There can be about 5-6 rounds of this quiz. 2. Conduct a mini-shop in the class. Each student can bring an item from his home with a price tag. The price can be a little more than the price at which they bought the item from the shop. Someone else in the class can “buy” that item. Teacher gives tokens worth Rs. 20, Rs 10, Rs 5, Rs 2 and Re 1. Students can use these tokens instead of money to buy things. Teacher writes the actual price of the item on the board and the price at which it was sold in the class. At the end, students calculate the profit in each case. 3. A shirt costs Rs. 200.75 more than a T-Shirt. What is the cost of the shirt if T-Shirt costs Rs. 140.28. What is the total cost of the shirt and T-Shirt? 4. Cost of 32 tickets is Rs. 540.75. What is the cost of 1 ticket? 111

1. Cost Price = Rs. 125.75; Profit = Rs. 15.25. What is the selling price? 2. CP = Rs. 18.50; S.P. = Rs. 16.75; Loss = ? 3. SP = Rs. 180.75; Profit = Rs. 10.25; CP = ? 4. SP = Rs. 75.20; Loss = Rs. 7.85; CP = ? 5. CP = Rs. 125.15; Loss = Rs. 25.75; SP = ? Guided Independent 1. CP = Rs. 125.75; Loss = Rs. 20; SP = ? 2. SP = Rs. 256.12; CP = Rs. 250.75; Profit = ? 3. SP = Rs. 156.75; Profit = Rs. 25.18; CP = ? 4. A water filter costs Rs. 1530. After 3 months, it is sold at a price of Rs. 1105. What is the loss incurred? 1. CP = Rs. 150; SP = Rs. 170.81. Profit or Loss = ? 2. SP = Rs. 115.75; Loss = Rs. 12.50; CP = ? 3. CP = Rs. 90.75; Loss = Rs. 15; SP = ? 112

Rapid Fire: 1) CP – SP = ____________ (Loss/Profit) 2) SP – CP = ______________ (Loss/Profit) 3) SP – Profit = _____________ (CP / Loss) 4) SP + Loss = _________________ (CP/Gain) 5) CP = SP + Loss (true / false) 6) SP = CP + Profit (True / False) 7) CP = SP – Profit (True / False) 8) SP = CP – Loss (True / False) 9) SP = Rs. 170, CP = Rs. 130. Profit / Loss = _________ ? 10) CP = Rs. 180, Loss = Rs. 20, SP = _________ ? 11) CP = Rs. 120, Profit = Rs. 15, SP = _________ ? 113 A shopkeeper bought an almirah for Rs. 15,780. Arun bought it from him for Rs. 17,500. He sold it to his neighbour after 6 months for Rs. 15,250. 1. What is shopkeeper’s profit? 2. What is Arun’s loss?

114 Discuss in groups and find an answer to the following problems: 1. Cost price of 11 oranges is equal to the selling price of 10. What is the profit or loss? (Hint: find the SP & CP of one orange) 2. How do shopkeepers make a profit after selling their items at a discount? 3. Do you think products are cheaper if we directly buy them from company showrooms? 1. When you buy things from a supermarket, mall etc., note down the MRP and the price mentioned in the bill. Verify whether they are sold at MRP. What is the full form of MRP? What will you do if the items are sold at a price higher than the MRP? 2. Buy the same brand of a product from 3 different shops and find out the difference in selling price of the items.

Contents 1. Plant Life________________116 2. Food production in plants __ 128 3. Adaptation______________ 136 4. Reproduction in Animals ___ 145 5. Clothes we wear_________ 153 6. Health and Disease_______ 161 Class 4 Term 2

Plant Life PLANTS Roots Functions of the roots: 1. A root fixes the plant in the soil 2. Roots absorb water from the soil and pass it to the other parts of the plant, especially leaves. 3. Some roots store the excess food. Example: radish, carrot, beetroot etc. 116 ROOTS STEM Special functions pollination fruits seeds supports the plants photosynthesis LEAVES fix the plant in soil stores food special functions FLOWERS

Special functions of the root: 1. In swamps, roots come up to the top of the soil to take in air. Such roots are called breathing roots. E.g. trees in tidal forests . 2. Sometimes, roots grow from branches 117 Banyan Tree Stem Stems support the branches of plants. Functions of stem: 1. It gives support to the plant and helps it grow. 2. It passes water and minerals absorbed by the roots to other parts of the plant. 3. Some stems grow underground. They store food. Example: potato, ginger, yam, turmeric etc. They are termed as stem modifications. 4. Some stems function as reproducing agents. New Potato Ginger Screw pine tree Breathing roots and they reach the ground and fix themselves in the ground. They are called branch roots. E.g. Banyan tree, Screw pine. plants grow from such stems. Example: hibiscus, rose. 5. In desert plants, stems are fleshy and green. In these plants, stems perform the task of photosynthesis and they store water. Tip of root with poreo Water Soil Branch root

Leaf Leaf is called the food factory of the plant. Leaves are green in colour due to the presence of a green pigment called chlorophyll. Leaves also absorb carbon dioxide from the air. In presence of sunlight, carbon dioxide and water are used by leaves to prepare starch. Leaves Banana leaf Compound leaves 118 contain small pores called stomata. They are used for breathing. Leaves are of different types. They can be small or large, single or compound. Functions of leaves: 1. They prepare food. 2. Plants breathe through leaves. 3. Excess water is given out through leaves of plants. This process is called transpiration. 4. Some plants reproduce through leaves. Example: Bryophyllum, Brahmakamalam. Bryophyllum leaf

Flowers Plants produce flowers. Flowers of different plants are of different size, shape and colour. Some of them have fragrance too. Flowers are the most attractive part of a plant. Functions of flowers: 1. Flowers contain nectar. Insects come to flowers in search of nectar. In doing so, they transfer nectar from other flowers. This is called pollination. 2. Flower produce fruits after pollination 3. Fruits contain seeds. Seeds grow into new plants. 119 Hibiscus Rose Sunflower 1. Collect different types of flowers. Observe their parts, paste them in your note book, and press them. 2. Collect different types of leaves. Paste them in your note book and write the names of the plants.

Parts of a flower Fruits Fruits are of different types. Some fruits have a single seed. Example: mango, neem, plum etc. Other fruits have many seeds. Example: apple, guava, pomegranate, etc. 120 Apple seed Mango seed Pomegranate seeds

Some fruits are like pods with seeds arranged in rows within them. Example: tamarind, beans, peas etc. They are called legumes. Guava tree Mango tree Papaya tree 121 Functions of fruits: 1. Most fruits are edible. They are food for animals. However, not all fruits are edible. 2. Fruits contain seeds which grow into new plants. Tamarind seed Beans seed Green Peas seed Reproduction in plants Most of the plants reproduce from seeds. Seeds when sown in the soil sprout and grow into new plants.

Take a few gram or beans seeds. Sow them in an icecream cup. Sprinkle water daily. Observe the changes and note them down date wise till the seeds grow into a baby plant. Seed dispersal If all the seeds sprout under the mother tree, they will not get enough sunlight and nutrients to grow. Therefore, nature has different ways to carry the seeds far away from the mother plant so that they can sprout and grow properly. This is called seed dispersal. Seeds are carried away from the mother plant by wind, water, animals, and also by an explosive mechanism. Let us see how it is done. 1. Dispersal by wind : Seeds dispersed by wind are light. They have hairs all over the body which help them to move fast in the wind. Example: Aak seed, dandelion, cotton seed etc. Some seeds have wing like structures which help them to fly in the air Example: Maple seeds, drum stick seeds. Dandelion Maple seed cotton 122

2. Dispersal by animals: a. Some seeds get dispersed by animals. Animals, after eating fruits, throw away the seeds. Birds, after swallowing berries, secrete the seeds in remote places, where they grow into new plants. Example: mango, guava, neem fruits, tomato, orange, sappota, pomegranate etc. 123 b. Some seeds have a hook like structure. These hooks stick to the hairy body of cattle and cattle carry them far away and drop them. Example: cockleburs. Orange Mango Pomegranate Guava Tomato Dispersal through water: The seeds dispersed by water have a fibrous coating which enable them to float in water. They reach the river banks or lakeshores where they sprout and grow into new plants. Example: coconut c. Some fruits or berries have thorn like outgrowth. This outgrowth sticks to the cloth of human beings or to the hairy body of animals and are dispersed. Example: Datura. Explosive mechanism: When pods or legumes such as beans, peas, gulmohar, drooping plant etc. dry up, they explode, throwing their seeds around. Thus, the seeds get dispersed. Ladyfinger behaves in a similar fashion. Datura Coconut

Vegetative reproduction All plants do not reproduce through seeds. Some plants reproduce through stems and roots. A few plants even reproduce through the leaves. Reproduction through body parts other than flowers is called vegetative reproduction. Plants like rose, hibiscus, Bougainvillea etc. reproduce through their stems. Stem cuttings of such plants are planted in the soil. A few days later, they sprout and grow into new plants. Plants such as Bryophyllum reproduce through leaves. Lady's finger 1. Visit your school campus or a nearby garden. Observe how each plant reproduces. Collect fruit/ seeds of these plants. Discuss in the class how they are dispersed. 2. Look for dandelion or aak seed in your school campus or a park nearby. Look for cotton seeds too. Bring them to the class and observe how the seeds are surrounded by hairy growth. 124 Experiment: Take a one foot long ruler or stick. Tie 3 seeds at the top of the one each at the ends and one in the middle by means of a rubber band. Put it in water in a glass. See that the seed in the middle just touches the water surface. One seed is above water and one is immersed in water. Observe every day. Which one of the three seeds germinates? Why don’t the other two seeds germinate? Discuss in the class.

All plants do not produce flowers. Non flowering plants have other means of reproduction. Pine, oak, Eucalyptus etc. produce cones instead of seeds which grow into new plants. Hydroponics It is the technique of growing plants without soil. Minerals and other nutrients in the form of chemicals are added to water in bowls or bottles and stem cuttings or baby plants are put in this water. Eg. money plant, onion, lily, rose, bamboo etc. Water must be periodically replaced when growing plants through this method. Plants such as ferns reproduce through spores. On the back of a fern leaf, you can see a row of spores. 125 Money Plant Bamboo Experiment: From the web, obtain the names of chemicals required for hydroponics. Prepare the water base for growing plants through this method. Try different plants in the water medium. Display them in the class.

1. Tidal forests - trees that grow in marshy places. 2. Swamps - stagnant muddy water, several feet deep. 3. Compound leaf - many small leaflets attached to a common stalk. 4. Seed dispersal - Seeds being carried away from the parent plant. 5. Legumes - long fleshy coat inside which seeds are arranged in a row. 6. Hydroponics - growing plants in water without soil. 1. Name the parts of a plant. 2. What are the functions of the root of a plant? 3. What are the functions of leaves in a plant? 4. What is pollination? 5. What are the different modes of seed dispersal? 6. What is the need for dispersal of seeds? Write a speech on ‘Plants are our Friends’ in about 100-150 words. 126

Complete the analogy 1. Leaf: food preparation; Stem: ____________ 2. Potato: stem, Carrot: ______________ 3. Banyan tree: branching root; _____________ : breathing roots 4. Rose : stem : Oak: ____________________ 5. Cotton seed: air; Neem seed: _________________ Do the activities mentioned in the text Do the experiment on germination. Circle the odd one out in each of the following groups: 1. POTATO, RADISH, CARROT, BEETROOT. 2. ONION, GINGER, TURMERIC, POTATO 3. MANGO, NEEM, GULMOHAR, BANYAN 4. COCONUT, NEEM, MANGO, GUAVA 5. MANGO, GUAVA, HIBISCUS, APPLE 127

Food Production in Plants You have already learned that plants are food producers. Animals depend on plants for food. Leaves are the organs that prepare food in a plant. Leaves absorb carbon dioxide and water. In presence of sunlight and a pigment called chlorophyll, they combine carbon dioxide and water to produce glucose. Let’s see how the structure of a leaf is suited for its function as food factory of plants. Parts of leaf Petiole Axil Stipule Vein Blade Tip 128

A leaf is attached to the stem of a plant through a stalk. A main vein runs through the entire length of the leaf. From the main vein, other veins originate. The flat surface of the leaf is called leaf blade. On a leaf, there are fine pores called stomata. Stomata have the following functions: 1. Absorbs gases from the air, including carbon dioxide. 2. Gives out excess water. The process is called transpiration. Stomata in a leaf can be seen only through a microscope. Photosynthesis: The following are the steps involved in photosynthesis. 1. Water absorbed by the roots reaches the leaves. 2. Leaves absorb carbon dioxide from air through stomata. 129

3. Carbon dioxide and water combine in presence of chlorophyll and sunlight to form glucose. 4. Oxygen is given out in this process. 5. The glucose is used by plants to produce energy. 6. The excess of glucose is converted to starch and stored in leaves, stems, and roots of the plant. Carbon dioxide + Water __________ Glucose + Oxygen. Sunlight Chlorophyll Chlorophyll and sunlight are essential for photosynthesis. In the absence of sunlight and chlorophyll, photosynthesis does not occur. Testing for starch Experiment: 1 How do we know that plants store the food in their leaves and other parts as starch? We can show that through an experiment. Iodine solution turns starch into bluish black colour. This is the test for starch. Take any cooked food – rice, potato or radish. Add one or two drops of iodine solution to the food. You will observe that the food item turns blue black. 130

Experiment 2: To show that sunlight is necessary for photosynthesis. 1) Keep a potted plant in a dark room for 3-4 days. Stick a black paper on a portion of a leaf in the plant and keep the plant in the sunlight for about 2 hours. 1. Why didn’t the portion earlier covered by black paper become black? __________________________________________________________ __________________________________________________________ 2. Why was the leaf covered with black paper? __________________________________________________________ __________________________________________________________ 3. Why was the plant kept in a dark room for 3-4 days? __________________________________________________________ __________________________________________________________ 4. What did you learn from this experiment? __________________________________________________________ __________________________________________________________ 2) Pluck the leaf covered with black paper. Remove the paper and boil the leaf in alcohol. (It should be done very carefully. Alcohol catches fire very fast) using a spirit lamp. When the colour of the leaf changes to light brown, take it out and pour iodine solution on it. The portion covered by black paper does not become black. Now, try and answer the following: 131

Experiment 3: To show that chlorophyll is required for photosynthesis. Take two identical croton leaves. Note the non- green parts in both. Boil one leaf in alcohol till its colour fades. Test it with an iodine solution. Compare the two leaves. The non green parts in the boiled leaf do not turn black. Answer the following: 1. Why didn’t the non- green part turn black? ___________________________________________________________ ___________________________________________________________ 2. Why did you take two leaves while you used only one? ___________________________________________________________ ___________________________________________________________ 3. Why was there no trace of starch in the non- green part of the leaf? ___________________________________________________________ ___________________________________________________________ Do this activity at home: Take hot fuming rice in a plate. Sprinkle a pinch of salt on it. You will see blue black colour where salt comes in contact with the rice. Why does it happen? Think and write. __________________________________________________________________ __________________________________________________________________ 132

Food chain Plants produce food. Animals depend on plants for food. These plant eating animals are eaten by other animals. This is known as the food chain. Thus, there is flow of energy and nutrients from plants to various levels of animals. Plant eating animals are called herbivores, while flesh eating animals are called carnivores. If the animals at the intermediate level animals. If the population of animals in each level is maintained, there will be ecological balance. In other words, large scale killing of animals will affect the ecosystem. 133 in a food chain are reduced in number, it will affect the population of the highest level of

1. What is photosynthesis? 2. What are the functions of stomata in leaves? 3. What is the gas given out during photosynthesis in plants? 4. Outline the steps involved in photosynthesis in plants. 5. How do you test for starch? 1. Transpiration - Plants give out excess water through their leaves. This is called transpiration. 2. Photosynthesis - The term “Photo” refers to light, and ‘Synthesis’ means to produce something. 3. Glucose - a type of sugar. 4. Starch - several glucose units combine to form a large chain. This is starch. 5. Ecosystem - boundary of plants, animals, water and air. • Make as many food chains as possible • With the species given below (5 minimum) • Grass, frog, grass hopper, plants, lion, elephant, deer, tiger, snake, eagle, grains, rat, goat. The 10% law: Biologists say that only 10% of energy is transferred from one level of a food chain to the next level. Example:Plants 100% Herbivores 10% Carnivores 1 % When it reaches the final level, just 1% of the total energy produced is available. That is why some people say vegetarian food is better than non- vegetarian food for energy. 134

1. Why saplings planted in thick shade of other trees do not grow properly? 2. An area inhabited by large number of birds, snakes and frogs was cleared of bushes and trees. It was found that the frog population increased rapidly and a large number of snails came to sight in the area. What may be the reason for this occurrence? 3. Clearing of forests leads to large scale extinction of animals. Why? Find out what they are or what they do ? 1. The gas used by plants for preparing food. 2. Plants breathe through _______________ 3. Iodine solution is used for _______________ 4. What is missing for preparation of food by plants: carbon dioxide, chlorophyll, sunlight, __________ 5. Food prepared by plants ____________ 6. Food stored in the parts of the plant ___________ 1. Write a report of the experiments done by the teacher to prove: a. Sunlight is necessary for photosynthesis b. Chlorophyll is necessary for photosynthesis. 2. Prepare a write up on importance of forests in about 100- 150 words. 135

Adaptation in Animals and Plants Adaptation means evolutionary changes that occur in living organisms to suit their climate, environment, feeding habits, and habitat. Adaptation in plants Plants growing in different climatic regions are different in physical features and growth pattern. For example, the plants you see in forests cannot be seen in a desert. Plants in the plains are different from plants on snowy mountains. Similarly, aquatic plants are different from terrestrial plants. Plants in rainforests They grow very tall. They have large leaves which are flat to allow rainwater to drain out. They form a thick canopy above to reduce the force of rain and prevent top soil from being washed away. Plants in the desert region Plants here are thorny bushes with very tiny leaves. Leaves are small so that water loss through transpiration can be reduced. Roots of these plants grow deep into the soil in search of water. 136

Plants in high mountains These plants are conical in shape and have long, needle like leaves. The conical shape helps to let the snow slip down. The needle shaped leaves prevent the snow accumulating on them. Plants in marshy places In the marshy areas, roots cannot fix the plants firmly, as the soil is loose and slimy. The plants thus have thin winding stems and spongy roots. They are also called breathing roots. Plants in semi arid regions Plants, especially trees in these regions, shed their leaves in summer. They do so to reduce water loss by transpiration, as rainfall is very less in these regions. Cacti Plant Cacti are plants in which leaves are reduced to spines and the stem is fleshy and green. They can store water in the stem and therefore, can survive for many days without water. Cacti 137

Aquatic plants Aquatic plants are of two types: floating plants and underwater plants. 138 Floating plants: Water hyacinth, pista, and duck weed are some examples of floating plants. Their leaves have a wax like coating. They have spongy roots to absorb air dissolved in water, and also from the atmosphere. Water Lilly Lotus Vellisneria Underwater plants: There are two kinds of underwater plants: 1. Plants fixed in the water bed. 2. Plants growing fully underwater. Water lily and lotus are examples of plants fixed in the waterbed. Their leaves have wax like coating and their stem is spongy and floating. Their roots are fixed in the water bed. However, their stem and leaves can be seen floating in water. Vallisneria and Hydrilla are examples of plants that grow fully underwater. Aquatic plants do not have stomata in the leaves.

Insectivorous Plants: These plants can digest insects. Thus, they don’t prepare their own food. Their body is adapted to their mode of nutrition. Example: Venus flytrap has an attractive colour and spikes all over the flower. When insects sit on the flower, it closes its mouth and traps the insect. Adaptations in animals Animals have adaptations to suit their climate, habitat, and feeding habits. Adaptations to suit habitat 1. Aquatic animals: They have a boat shaped body and fins that help them to swim. E.g. fish, whale. 2. Amphibians: These are animals that can live in water as well as land. E.g. Frog, turtle, salamanders etc. They breathe through their gills in water Venus flytrap Whale Fish Similarly, the pitcher plant has a pitcher like outgrowth from its leaves. These pitchers have a slippery edge. As the insects land on the pitcher, they slip and fall inside. Pitcher plant 139

and through their lungs on land. They have webbed feet and moist skin. 3. Birds: They spend most of their time flying in the sky. They have a light body, hollow bones and wings that help them to fly. 4. Animals in polar regions Example: Polar bear, Seal, walrus etc. They have a thick fur or a thick, leathery coat to protect them from extremely cold weather. Polar bears have a fur coat, while seals and walrus have a thick, leathery coat. 140 Snake Lizard Seal Polar bear Walrus Adaptations for climatic change Some animals hibernate during extremely cold weather. Example: frogs and polar bear. A few varieties of snakes and lizards too hibernate during extremely cold weather. They do so to preserve their energy and protect themselves from cold.

Other kinds of adaptations Many animals have adaptations in order to catch their prey easily or protect themselves from other animals. Camel For example: The Chameleon changes colour according to its surrounding. A Zebra has stripes on its body, which act as a camouflage. Other animals have difficulty spotting the zebra in thick bushes. A tiger too has stripes on its body, which help it to hide and catch its prey. A Porcupine has spikes all over its body to protect itself from other animals. Tortoise, snail, crab etc have shells on their back. They can hide in their shells when they are in danger. Honeybee and wasps have stings to protect themselves from enemies. Chameleon Camel: Camel is the animal used for journey in desert. It has broad hoofs. It has a hump to store fat. It has long eye lashes to protect from sand storms. 141

Adaptation according to feeding habits Vulture Ostrich Eagle Kangaroo Cow Carnivores have long and sharp canines to tear flesh. Vulture and eagle have hooked claws called talons to hold their prey while flying. They have a very strong and hooked beak. A kangaroo has a pouch to hold its baby till it is fully grown. An ostrich has very long neck and legs. Cattle have 4 chambers in their stomach to enable them to chew the cud. They have sharp front teeth to cut grass and herbs. 142

1. Adaptation - Changes or modification in physical features to suit the environment, climate or habitat. 2. Canopy - roof 3. Semi arid - A region that receives moderate rainfall. 4. Hybernation - Sleeping underground during unfavorable climatic conditions. 5. Insectivorous plants - Plants that consume insects. 6. Camouflage - External features that make an animal indistinguishable from its surrounding. 1. What is adaptation? 2. What is the adaptation in cacti? 3. How is the camel’s body adapted to desert climate? 4. Why do trees in high mountains have conical shape? 5. Why do trees in forests of semi arid regions shed their leaves in summer? 6. What are the adaptations in aquatic plants? Explain the following a. Bird migration b. Camouflage c. Insectivorous plants 143

Do human beings adapt themselves to suit the climate of their place, or their food habits? Analyze the food habits, dresses and houses of people living in different climatic zones- desert, tropical zone, polar regions, and subtropical regions. Divide the class into groups. Each group has to give a presentation on the life of the people in (1) Himalayan regions (2) Southern India (3) Arab countries (4) Greenland (5) Northern states of America. Focus on the food habits of people and how they dress? Browse the web and collect 5 plants and 5 animals known for their adaptations, other than those given in the text book. What are the adaptations in the following: a. Polar bear b. Frog c. Honeybee d. Porcupine e. Zebra f. Fish g. Birds h. Tortoise 144

Reproduction in Animals All living beings reproduce. Plants reproduce from seeds or body parts, while animals either lay eggs or give birth to young ones. Some classes of animals that lay eggs are fish, amphibians, reptiles, birds and insects. The eggs hatch to bring out the babies. Terrestrial animals including human beings reproduce by giving birth to babies. They are called mammals. Mammals are animals that feed the young ones with their own milk. Do all birds lay eggs? Do all fish lay eggs? Well, there are exceptions. Whales and dolphins do not lay eggs. They give birth to young ones. The bat, although it is a bird, gives birth to babies. In Snakes swallow most of the eggs they lay. It is nature’s way of keeping snake population under control. A tortoise hatches its eggs by standing at a distance from the eggs and just by looking at them. fact, the bat has teeth, unlike other birds. A kangaroo keeps its baby in a pouch on the exterior of its body till it is old enough to go out and walk. Such animals are called marsupials. Insects do not directly hatch their eggs into adults. The eggs undergo various stages of development before they become an adult. 145

Animals that give birth to young ones Mammals carry their young ones in their womb for several weeks and then deliver them. The time for which the young remains in the womb varies from animal to animal. For human beings, it is 9 months and 2 weeks. For dogs, it is 5 months. Mammals feed their babies with their own milk till they are able to digest other food. Larger mammals like elephant, monkey horse, cows, buffaloes and other herbivores give birth to only one baby. Other animals, especially carnivores, give birth to many babies at a time. However, goats give birth to 2- 3 kids at a time. Horse Monkey Elephant Dog 146

Birds Birds build nests and lay eggs. The mother bird sits on the eggs to give them warmth. After hatching the eggs, mother bird brings food and feeds the chicks till they are able to fly and procure their own food. You might have observed that a hen takes its chicks with her and teaches them to peck worms, grains and insects. The crow on the other hand goes on feeding its babies for months. Who is a better mother? Decide yourself. Parts of an Egg Egg is a common food. Have you ever seen what is inside an egg? Inside the shell, there is a thick fluid. Inside fluid, there is a yellow solid mass. The centre of the yellow mass is a small, dark, spherical matter. The fluid is called white of the egg, or albumen. The yellow solid mass is called yolk and the dark round spot at the centre is the embryo. 147 Birds

It is the embryo that grows into a chick. When the baby is fully grown, it breaks the shell and comes out. The yolk and albumen provide nutrition for the embryo till it grows into a baby. Egg Adult Tadpole Young Frog Frog 148 Life cycle of a frog Study the sketch and describe how a frog’s egg changes to an adult frog. 1. Adult frog lays eggs in water. It looks like a huge bubble with many tiny round eggs within. The bubble protects the egg from being swallowed by other water animals. 2. The eggs hatch and small fish like creatures come out. These are called tadpoles.

3. Tadpoles in due course develop limbs and the tail gets shortened. 4. Finally, the baby frog grows into an adult. This whole process is called metamorphosis. Life cycle of an insect Silk is a fibre obtained from the cocoon of the silk moth. The cocoons left after the moth comes out and put into boiling water and the fibres stretch out from the cocoon. 149 Insects Insects also undergo metamorphosis. Observe the sketch given below. Observe the stages of development of a butterfly as it grows into an adult from an egg. 1. The eggs hatch and caterpillars come out. 2. They feed on leaves. 3. After a few days, they start forming a cover called cocoons and remain inside the cocoon. At this stage, the young ones are called pupa. 4. After the stipulated time, an adult butterfly comes out of the cocoon. Butterfly Egg Caterpillar Cocoon Pupa

1. Reproduction - Produce young ones to carry on life. 2. Terrestrial - Belonging to land. 3. Mammals - Animals that feed young ones with their own milk. 4. Marsupials - Animals that have exterior pouch for keeping premature babies till they are fully grown. 5. Embryo - A cell that grows into a baby. 6. Metamorphosis - The changes an egg undergoes till it becomes an adult. There are many stages in metamorphosis. 7. Reptiles - Animals that crawl on their belly and have scales on their body. 1. What are the two modes of reproduction in animals? 2. What is the difference in reproduction process of birds and insects, although both of them lay eggs? 3. What do you mean by hatching? 4. How are whales and dolphins different from other fish? 5. What is the difference between a bat and other birds? Reptiles Reptiles like snakes, turtles and crocodiles lay their eggs in sand. They do not sit on the eggs to give warmth. Instead, they hatch eggs by the warmth of the Sun. Most of the eggs of these creatures are eaten by other animals. Only a few are hatched into babies. 150