TERM 2 - CLASS 5 - PRIME YEARS

Profit and loss Trade and business involves profit. Sometimes, they incur loss too. Traders get things from producers at a lower price and they sell them to consumers at a higher price. In such a transaction, they make a profit. However, at times, they have to dispose off their old goods at a price lower than the cost price. In such cases, they incur a loss. Profit = Selling Price – Cost Price Loss = Cost price – selling price SP = CP + profit SP = CP – loss CP = SP - profit CP = SP + loss profit % = x 100 loss % = x 100 profit CP loss CP 101

1. Find profit percent when SP = Rs 105, CP = Rs 98 Profit = SP – CP = 105 – 98 = 7 Profit % = x 100 = x 100 = 7.14% 2. CP =50, profit% = 5% SP = 5% = x CP = x 50 = 2.5 SP = CP + Profit = 50+2.5 = 52.5 3. SP = 35, profit = Rs.5 CP = 35 – 5 = Rs.30 Guided 5 100 profit CP 7 98 5 100 Independent A. 1. Find SP when CP = Rs.104; profit is Rs.34 2. Find SP when CP = Rs.216; profit is Rs.21 3. Find SP when CP = Rs.500; Loss is Rs.49 B. Find CP: 1. When SP = Rs.120; profit = Rs.50 2. When SP = Rs.1250; profit = Rs.75 3. When SP = Rs.480; loss = Rs, 105 C. Find profit/loss %: 1. SP = Rs.210, CP = Rs.180 2. SP = Rs.1500, CP = Rs.1650 3. SP = Rs.525, CP = Rs.600 4. SP = Rs.1800, CP = Rs.1625 102

1. A shopkeeper offers 10% discount on the marked price of a grinder which is Rs.5000. He gets a profit of Rs.250 on the sale. Find the cost price of the grinder. 2. A saree was sold at Rs.1380. Its cost price was Rs.1100. Find the profit percent. 3. A toy costs Rs.3200, It is sold at a discount of 20% if the marked price is Rs.4200, find the profit percent. 4. Fill in the table. S.No CP SP Profit Loss Profit/Loss% 1 125 150 - - 2 240 - 50 - - 3 - 1500 - 250 - 4 480 520 - - - 5 325 - 100 - - 6 500 - - 70 - 103

1. SP = Rs.50, CP = Rs.48. profit = ____________ 2. SP + Profit = ____________ 3. CP – loss = ____________ 4. Profit % = x 100 5. Profit% = 5%. CP = Rs.80. Profit = x 6. Profit% = 8%. CP = Rs.25. SP = ____________ 7. SP = Rs.60, CP = 54, profit% = ____________ 8. CP = 100, loss = 50%. SP = ____________ 9. CP = 500, profit = 25% SP = ____________ 5 100 Time: 10 minutes 104

Simple interest Interest is the money we pay as an additional amount when we take loan from a bank or money lender. Suppose you borrow Rs.1000 from a bank. After two or three years, when you return the money to the bank, you will have to pay an extra amount other than the Rs 1000, as per the rate of interest that was fixed at the time of borrowing. Terms in simple interest Principal (P) – the amount borrowed Simple interest (SI) – additional amount paid. Rate (R) – interest rate as % T or N – No of years (Time) There is a formula for calculating simple interest. Rate of interest is always calculated for Rs.100. Activity 1: Steps to find the formula for calculating simple interest. Let for Rs 100 borrowed, interest be 5 rupees for 1 year. At the end of 1 year, the amount payable is P+I = 100 + 5=105 Interest = 5%= 5/100 105

Thus, for 500 rupees at the end of 1 year, the interest is 500 x For 500 rupees at the end of 2 years, the interest is 500 x x 2 At the end of 3 years, the interest is 500 x x 3 At the end of T years, the interest is 500 x x T For P rupees, interest at the end of T years = P x x T For P rupees at R% interest for T years, I = Thus, Simple interest = This is the formula for calculating simple interest. Example 1: Calculate the simple interest for Rs.700 at 5% rate of interest for 7 years. SI = = = Rs.245 Formula for Principal P I = Cross-multiply P T R = 100 I P = Formula for R R = 5 100 5 100 5 100 5 100 5 100 P x R x T 100 P R T 100 P R T 100 700 x 7 X 5 100 100 I RT 100 I PT P T R 100 106 Formula for T T= 100 I PR

100 I PR 100 x 500 2500 x 6 20 5 20 6 1 3 1. Find the amount borrowed if simple interest is Rs.25 for 3 years at 5% rate of interest. Formula for P, P = = = = Rs.166.66 Guided 100 I PT 100 x 225 3 x 1500 15 5 3. Find out after how many years a sum of Rs.2500 will fetch an interest of Rs.500 at 6% rate of interest. [ P = 2500, R = 6%, I = Rs.500, T = ? ] T = = = = 3 years 107 2. Find the rate of interest if simple interest for Rs.1500 for 3 years is Rs.225. R = I=Rs.225, T=3years, P=Rs.1500 R = = 5% 5 100 I RT 100 x 25 5 x 3 500 3

Activity 1: 1. Prepare a set of cards containing the data for simple interest, and cards with actual simple interest written on them. Prepare 10 such matching cards. 500 x 2 x 5 100 Rs. 50 Data S.I. 100 x 75 5% x 4yr. Rs. 375 3. Data card for R 4. Data card for T Prepare 5 sets for each data (P,T, I, R) Students sit in groups. Each group is given one set of data cards and the answer cards are shuffled. Students match the data cards with answer cards. When one set is over, exchange the sets. Each group now starts with a different set of cards. In this manner, all the 4 sets are played. 100 x 500 2500 x 4yr 6 % 100 x 500 2500 x 5% 4 yr. 2 3 Example: 2. Data card for P Specimen: 108

1. What is the simple interest for Rs.25000 for a period of 3 years at 6% SI? 2. Mr. X borrowed some money from the bank at 8% interest for 2 years. He had to pay Rs.1700 as interest. What was the amount that he borrowed? 3. In how many years will Rs.7500 earn an interest of Rs.1350 at 9% rate of interest? 4. In how many years will a sum of Rs.50000 become Rs.65000 at 10% interest? 5. A sum of Rs.6500 earns an interest of Rs.1200 in 6 years. Find the rate of interest. 1. Formula for SI = _________________ 2. Formula for P = _________________ 3. Formula for R = _________________ 4. Formula for T = _________________ 5. P = 100, R = 5%, T = 1Year. I = _________________ 6. I = 5, T = 1, P = 100 R = _________________ 7. R = 10, P = 1000, T = 2, I = _________________ 8. P = 500, R = 10%, I = 50, T = _________________ Time: 10 minutes 109

1. Mr. A borrowed a certain amount from a bank for 2 years. At the end of 2 years, he had to pay back Rs.1650. However, he didn’t pay back the money. At the end of the 3 year, rd he was asked to pay Rs.1720. What was the rate of interest? What was the amount borrowed? [Hint: difference between the two amounts is the simple interest for 1 year for a principal of Rs. 1650] To find P, T, R, or I One team puts the questions. The other team answers them. The questions can be prepared before hand by the teams. A money lender adds the interest to the principal every year and charges interest for the added amount. Thus, previous principal + interest becomes the new principal for the next year. Calculate stepwise the interest for the 3 year. rd 110

Unitary method When cost of ‘one’ is given, we can find the cost of ‘many’ by multiplication. If the cost of ‘many’ is given, we can find the cost of ‘one’ by division. It is called the unitary method. Example: Cost of 5 pencils is Rs.21. What is the cost of 15 pencils? Step I: Find the cost of 1 pencil by division: = Rs.4.20 Step II: Find the cost of 15 pencils by multiplication: 4.20 x 15 = Rs.63.00 21 5 Simplifying operation by cancellation Instead of computing the value of items in two steps in the unitary method, computation can be done in a single step to save time. 1. 24 notebooks cost Rs.600. Find the cost of 45 notebooks. Cost of 1 note book = 600 24 Cost of 45 notebooks x 45 = 75 x15 = Rs.1125 600 24 75 8 15 111

2. 5 kg of mangoes cost Rs.200. What is the cost of 15 kg of mangoes? Cost of 1kg of mangoes = Cost of 15kg of mangoes = x 15 = Rs.600 200 5 200 5 3 1. A person earns Rs.500 per week. What is his monthly earning? 2. 5 buses can carry 150 children. How many buses are required to carry 450 children? 3. 18 bogies of a train can carry 1260 people. How many people can 21 bogies carry? 4. Mrs. A purchased 5 kg onions for Rs.305. Mrs. B purchased 7 kg onions for Rs.416.5. Who has got a better deal? 5. One dog covers a distance of 2.5 kilometers in 15 minutes. Another dog covers 4.5 kilometers in 2 hours. Which dog can run faster? 6. The wages of 12 workers combined is Rs.60000. How much is the wage of one worker? What amount is needed to pay 21 workers ? 7. If a dozen oranges cost Rs.60, find the cost of 15 oranges. 8. Cost of 180 books is Rs.2791. What is the cost of 240 books? 9. 1 Quintal of rice costs Rs.4500. What is the cost of 65 kg of rice? 112

Contents 1. Diseases and their prevention ............................... 114 2. Housing and clothing...............122 3. Animal world ............................134 4. Reproduction in plants ............142 Class 5 Term 2

Diseases and their Prevention Diseases Disease is a condition that effects the normal functioning of the body. There are several causes for diseases. There are different kinds of diseases, such as deficiency diseases, infectious or communicable diseases, and non communicable diseases. In addition to these, there are hereditary or genetic diseases as well. Deficiency diseases have been dealt with in the previous chapter. In this chapter, we shall deal with other kinds of diseases. Communicable diseases These diseases spread through air, water, food, personal contact, insects, and animals. 1. Water borne diseases: These spread through contaminated water. Disease Symptoms Caused by Remedy Cholera Acute diarrhoea, Bacteria vomiting and dehydration Saline solution given intravenously. It can be prevented by leaving the place where the disease breaks out till the situation comes back to normal 114

Air-borne diseases Common cold, flu, tuberculosis, and pneumonia are some common examples of air borne diseases. Common cold and flu are caused by virus, while the other two are caused by bacteria. Tuberculosis: It affects the lungs. There is continuous cough, along with discharge of blood with sputum. The patient should be isolated to prevent outbreak. The bacteria spread through the sputum. One should avoid personal contact with the patient and should not use clothes worn by the patient. Fresh air and a warm, pleasant climate are favorable. Disease Symptoms Caused by Remedy Typhoid High, prolonged fever; temperature rising and falling at intervals Bacteria Isolating the patient; boil the water for drinking and cooking; maintain cleanliness. Proper medication. Dysentery Acute diarrhoea; watery discharge; sometimes mucus along with discharge Bacteria, Drink boiled and amoeba filtered water; Proper medication. Hepatitis Yellow pigmentation of eyes, loss of appetite, giddiness Virus Use filtered and boiled water; under go medication and strict diet 115

Pneumonia: This is indicated by breathing trouble due to inflammation of lungs, and high fever. Regular medication, fresh air, and a well-ventilated room are a must for curing this disease. Diseases spread by insects and animals Malaria, dengue, chikun gunya, swine flu, and rabies are diseases caused by either insects or animals. Swine flu and rabies are caused by animals, while the others are caused by insects. Malaria: It is caused by female anopheles mosquitos. It spreads the disease causing protozoa through blood. The protozoa that causes Malaria is called plasmodium. It can be cured by quinine tablets. Sir Ronald Ross, who was awarded the Nobel Prize for medicine, discovered the cause of Malaria and the carrier of malaria causing protozoa. Dengue: This fever is also spread by mosquito bites. High temperature, followed by muscle and joint pain are common symptoms of dengue. Chikungunya: Headache, high fever, body pain and lack of sleep are the symptoms of this disease. It is caused by a virus carried by mosquitoes. Swine Flu: It is caused by a virus, the carrier of which is pigs. Rabies: It is caused by a virus from dog bite. When an affected dog bites a person, the virus enters his body. It is also called hydrophobia, as the main symptom of the disease is fear of water. The symptoms of rabies 116

show only after 90 days. However, once the symptoms show themselves, there is no cure for the disease. The patient suffers from brain disorder, fear, and anxiety. After showing such symptoms, the patient dies within 48 hours. . Louis Pasteur invented the vaccine for rabies. As soon a person is bitten by a dog, he should be given the vaccine. Diseases spread by direct contact Chicken pox, whooping cough, skin diseases and ring worm are some contagious diseases that spread through direct contact. They spread through an affected person’s clothing, touch etc. Prevention of diseases Some disease can be prevented by vaccination and inoculation. Vaccinations help the body become immune to certain diseases. Vaccination: Measles, mump, whooping cough, cholera, typhoid, tetanus, polio etc. can be prevented by vaccination. 1. BCG – it is given to prevent tuberculosis. 2. DPT – It is a triple antigen to prevent Diphtheria, whooping cough (Pertussis) and Tetanus. It is given to children aged between 6 weeks and 9 months. Polio vaccine is given orally, while DPT is given as an injection. 117 1. Obtain your health record from your parents. Note down the vaccines given to you from the very first day, any diseases you had, and the treatment given.

Inoculation: It is the process of injecting live microbes in the body to produce antibodies which help fight the disease. Of late, instead of triple antigen, pentavalent vaceine (PPT) is administered to children. It prevents the occurrence of 5 diseases, viz. diphtheria, whooping cough tetanus, hepatitis B, and influenza. Sanitation vs. diseases Sanitation means keeping public places free of garbage, and keeping public toilets clean. Most of the diseases occur because of unclean surroundings. Unclean toilets and stinking garbage are the breeding grounds for germs. Maintenance of sanitation in public places is a very difficult task. In cities, there is a problem of slums to add to the woes. However, we can always make an effort. For example, biodegradable wastes can be used to make compost. Moreover, such waste should be dumped in a place remote from the city and buried or burnt. The non biodegradable waste should be segregated and sent for recycling. These are matters easier said than done though. Pollution It is another cause of diseases. Air, water and soil are being polluted by thoughtless actions of people. This leads to several diseases. 118

Activity 1: Air pollution Discuss in groups. List the ways in which air gets polluted and what preventive measures can be taken. Teacher consolidates points given by groups and gives the final points to note down. Activity 2: Water pollution A similar activity to list the causes of water pollution and preventive measures that can be taken. Soil Pollution: Soil is polluted by excessive use of pesticides, insecticides and fertilizers. Vegetables and fruits that we buy from the market have traces of harmful chemicals in them. Very often, the milk we get from dairy farms is adulterated. Food grains that are used to make flour are often sprayed with fungicide and insecticides to prevent them from rotting. All of this in due course of time can lead to diseases like cancer, as well as kidney, liver and lung problems. Water Pollution 119

1. Immunization - make the body immune to diseases. 2. Inoculation - injecting live active microbes to produce antibodies in the body. 3. Vaccination - injecting or oral administration of the suspension of weakened microbes. 4. Biodegradable - Things that decompose into simpler particles and become nutrients for soil. 1. What are communicable diseases? 2. What are the symptoms of Rabies? 3. What is the difference between vaccination and inoculation? 4. What is DPT? 5. What are the causes of air pollution? 6. How does water get contaminated? 120

7. Circle the one which is different ? 1. Typhoid, pneumonia, cholera, desentery 2. Tuberculosis, whooping cough, cancer, typhoid. 3. Grapes, leaf, vegetable, plastic flowers. 4. Swine flu, rabies, dengue. Prepare a speech on “Let’s keep the country pollution free”. 121

Houses Visit an old building in your city/town/village. Observe the walls, floor, roof, doors, windows and the plaster on the walls of the building. Compare it with the house you live in. Make a table of comparison. Houses provide shelter. Early man built houses to protect himself from rain, cold and wild animals. Over the years, the need for houses changed. As man progressed, kingdoms came up. Houses were no longer a shelter, but a status symbol. While kings and rich people lived in palatial buildings, the poor still had to be satisfied with mud houses. Types of houses 1. Mud houses with thatched roof: These are easy to make and easy to pull down. In villages, people still live in mud houses with tiled roof or thatched roof. Mud Houses 122

2. Tents: In the cities, tents are a common sight. People have makeshift tents in clusters. They use discarded polythene sheets and bamboos for construction of these tents. City slums are known for such tents. 3. Wooden houses: These are common in mountainous regions where timber is easily available. The roofs of such houses are made of tin or asbestos, while floors and walls are made of wood. Japan is known for its wooden houses. This is so because Japan experiences frequent earthquakes, and wooden houses cause lesser damage. 4. Houses with stone and lime mortar: Old houses are built of stones and lime. Lime was later replaced by cement. Earlier, houses had sloping roofs. At present though, flat concrete roofs are preferred. Constructing a house 123

Advantages of sloping roofs In mountains and hill slopes, sloping roofs are a must. It helps to drain off the rain water. If rain water stagnates on the roof, it can weaken the walls of the building and lead to collapse. In Kerala, people face problem of water stagnation and discoloration of distempered walls due to heavy rainfall. Thus, people in Kerala are going back to old style of houses, with sloping roofs, because Kerala is a place that experiences heavy rainfall. Same is the case in north- eastern states of India. 5. Houses built with stone, granite and cement: This is the latest style of houses. These houses are stronger than the houses built by people in the olden days. 6. Apartments: Apartments are clusters of houses under the same roof. This form of construction helps save space and is the best way to tackle problem of housing in cities with growing population. However, it has its own disadvantages. Apartment 124

House on wheels: Nomadic people stay in caravans or houses on wheels. They can go from place to place in these moving houses. Of late, it has become a fashion of sorts in developed countries to live this way. Many House boats: In places surrounded by water, houseboats are a common sight. In places like Kashmir and Kerala, houseboats are used as tourist resorts and mobile restaurants. Some people use it as their permanent home too. The science of housing materials used for building of houses Earlier, houses were built of mud and stones. Later, people learned to use lime and mortar for fixing the stones in order to make strong walls. If you observe buildings which are older than 100 years, you will see that they are built of lime mortar and stones. Cement became popular only in the 1930s. people in developed countries live in makeshift houses. They use trucks, cars and vans for this purpose. They call it house on wheels. House Boat House on wheels 125

How is lime mortar made? What are its advantages? Lime mortar Lime is obtained from sea shells by heating them. The lime so obtained is mixed with water and sand to make mortar. This mortar is used to fix stones to build walls. The mixture of lime, sand and water absorbs carbon dioxide from air and changes into a hard mass. This makes the walls strong. Ancient buildings in India and the Mughal buildings are built with lime mortar. Back then, they used to mix powdered wheat and green gram with lime mortar to plaster the walls. This helped to keep the interiors cool. The tiled roof also helped to keep the house cool. Tiles Asbestos Sheets Cement Stone Mud Mesh Bricks Iron Nail Timber Iron Rod Palm Leaves Rope 126

Modern architects use cement in place of lime. Cement is harder than lime. Cement is obtained when lime stone, sand and a chemical called gypsum are heated in cylindrical kilns. Cement is gray in colour. When mixed with water and sand, it sets to a hard mass. However, cement has certain disadvantages too. For example, cement makes the interiors Wooden house of a building hot, unlike lime. In summers, it can be very uncomfortable to stay inside houses built of cement. People in metro cities now prefer wooden walls instead of cemented walls. However, this can turn out to be disastrous for forests. Green houses or eco-friendly houses People are now looking for ways to build houses that are in harmony with the ecosystem. Animals, plants, air, water, and earth together form the ecosystem. Wooden houses in Ladakh 127

Architects are coming out with novel ways of constructing houses which are eco-friendly. Mud-walls with in-built windows, roofs with lawns, mud tiles instead of ceramics, solar heaters and solar lights instead of electricity, lots of greenery around are some of the features of modern, eco-friendly houses. Instead of walls, such houses have bamboo corridors to let in fresh air. However, these houses are not as strong as cement houses. On the plus side though, the cost of building such houses is less. Wood v/s Iron Wood is now being replaced by iron in houses. In a way, it is advantageous since the use of wood in houses will be restricted. Use of distemper Earlier, lime was used to paint the walls of buildings white. Now, we have washable distempers and paints to beautify the houses. However, these synthetic distempers pollute the air as they disintegrate. Internal Heating In olden days, in cold regions, there was a fire place in the main room to warm up the room in cold weather. Now, fire places have been replaced by internal room heating arrangements. They use either hot water or hot air. From newspapers or magazines, collect photographs of eco-friendly houses. Analyse the various techniques used to make them eco- friendly. 128

Clothing Like housing, clothing too has undergone drastic changes. Protection of body is no longer the only purpose of clothing. Instead, it has evolved into style and fashion. Before sewing machine was invented, people wore long prices of cloth around their body. Later, they learned to stitch cloth to suit their body size. It was done by hand. Invention of sewing machine was a milestone in man’s development. Woven cloth Hand stitching Sewing Tailor and Tailoring shops Readymade garments fashion designers boutiques The sequence given above shows the long journey from unstitched clothes to fashionable dresses. Refer to books or websites. Get photographs of dresses worn by people in the BCs, in 400-600 AD, in the 17 century, and now. Collect th photographs of both Indian and western dresses. Make a booklet. Materials used for making dresses Animal skin and tree barks were used by early man to make clothing for himself. However, the first processed material for making cloth was cotton, followed by linen, silk and wool. 129

Synthetic fibres came to the market only in the 19 century. The first th synthetic fibre known was Nylon. The fibre gets its name from the fact that it was invented at the same time by scientists in New York and London. As the fibre hit the market in these cities at the same time, it came to be known as Nylon. Nylon took various forms later on. Towards the middle of the 20 th century, polyester and other synthetic fibres appeared in the textile world. 1. Cotton, silk and wool: They still retain their identity. Pure cotton, silk and woollen clothes are still preferred. There are other blended materials also. 2. Rayons: Rayons are modified cellulose fibers. Natural cellulose is chemically treated to make it strong and lustrous. Bed sheets, dress materials, sofa covers etc. are made with this. people wearing different dresses 130

3. Tericot: Pure terylene clothes do not allow air circulation and cause skin problems. Therefore, it is mixed with cotton to reduce its harmful effects. It is preferred for shirtings and salwar suits. 4. Teriwool: It is a blend of terylene and wool. The mixture of terylene and wool makes the cloth durable, while retaining the properties of wool at the same time. 5. Terisilk: It is a blend of terylene and silk. It is preferred for sarees and shawls. 6. Polycot and Polysilk: They are blends of polyester with cotton and silk respectively. Blends are of two types 1. Mixing the yarns while weaving. 2. Mixing the fibres before spinning them into a yarn. Dying Earlier, chemical dyes were used to dye cloth. Today however, herbal and vegetable dyes are gaining popularity. With the help of an elder, grind a piece of beet root and extract its juice. Don’t add water to it. Make a block print by carving out any design on the cross section of a potato or radish. Pour a little bit of the extract on a piece of sponge or cotton. Press the carved block in the sponge and press it on a piece of cloth. You get a vegetable print. 131

1. Architect - A person who plans the structure and layout of a building. 2. Boutiques - A show room for latest fashion dresses made to order. 3. Distemper - Chemical substance used for colouring walls and ceilings of houses. 4. Disintegrate - Break up into simpler compounds. 1. Mention the different types of houses. 2. Make a list of the materials needed for building a house. 3. What are the advantages of sloping roofs? 4. What are houses on wheels? 5. List the different kinds of fabrics used for making dresses. 6. What are rayons? 7. What are blended fabrics? 1. Collect samples of different kinds of cloth materials. Find out their names and what they are best suited for. 2. From newspapers or magazines, collect pictures of dresses of different fashions and materials. Make a booklet or collage out of it. 132

1. With the help of a flow chart, illustrate the changes that housing has undergone from prehistoric times to date. [continue what is given] Caves Mud houses • Collect bits of different types of clothes from a tailor or from a boutique. • Paste them in your notebook and write the name of each. 1. Organise a fashion show in the class. Each participant should explain the material of which the dress is made and the merits of the fabric. 2. Make a group presentation on different types of houses and the recent trends in construction. 3. Make a group presentation on history of clothing and the present trend. 2. Do all the activities mentioned in the lesson. Write a report of each. 133

Animal world Fish Fish are of different kinds. There are fresh water fish and salt water fish; tiny fish and giant fish. Fish have boat like body and fins, which help them to swim under water. There are several species of fish. However, there are some sea animals that look like fish, but do not belong to the family of fish. For example: Whales and dolphins: Whales and dolphins are sea mammals. They breathe through lungs and give birth to babies. Seal: A seal looks like a fish, but it is not really a fish. Life first originated in water. Aquatic plants were first formed, followed by aquatic animals. They were microscopic organisms. After millions of years, the first vertebrates were formed in water. Vertebrates are animals having a backbone. Fish were the first vertebrate animals to be formed under water. Slowly, other animals evolved in a sequence like the following: Fish amphibians reptiles mammals birds 134

Walruses: They have canine teeth like that of mammals, though their body resembles that of fish. Walruses are called sea elephants because of their enormous size. Seals and Walruses are found in polar regions. Other sea animals: Sea is home to a variety of animals and plants. In fact, more species of animals can be found in sea, than on land. Some examples of sea animals are sea horse, sea anemone, octopus, star fish, jelly fish, corals, molluscs like oyster, crab etc. Mollusca are invertebrates with a hard shell over their body. Sea horse Star Fish Jelly fish Sea anemone Molluse Octopus Crab Shell 135

Amphibians: These are animals that can live both in water and on land. They have gills as well as lungs for breathing. In water, they breathe through gills, just like fish do. On land, they breathe through their lungs. Examples: frog, turtle, tortoise and salamander. Turtle is mostly found in sea. It has flaps instead of legs. A tortoise, unlike a turtle, has 2 pairs of lungs. However, both the turtle and the tortoise have a hard shell on their back as a protective cover. Tortoise is the animal with the longest life span. It can live for nearly 200 years. Reptiles: They have scales on their body. Usually, these creatures crawl on their belly. Even though they have legs, they move around supported by their belly. Snakes, crocodiles and alligators are some examples of reptiles. The giant dinosaurs which are believed to have existed millions Frog Tortoise Alligator Snake Crocodile 136

of years ago were reptiles too, according to biologists. Alligators can walk supported by their belly and they have a long snout. Crocodiles resemble alligators, but they do not have a snout. Lizards, chameleon and garden lizards also come under reptites. Birds Birds spend most of their life time flying in the air. Hence, they are called aerial animals. Their body is designed to fly in the air. They have hollow bones and feathers all over their body. They are provided with wings, which enable them to fly. Mammals They are also called terrestrial animals, because they move about on land. Monkeys, pandas and other similar mammals which spend most of their time on trees are called arboreal. Mammals give birth to young ones. Some mammals are herbivores, while some are carnivores. There are some animals which eat both plant products and meat. Such animals are called omnivores. Bear, cat, dog, rats, and some birds like crow, and human beings are omnivores. Rats Cow Dog Bear Cat 137

Mammals’ bodies are adapted to their habitat and climate. For example, a camel’s body features are adapted to life in the desert. The polar bear has adaptations to suit the extreme cold weather of the region. Some animals come out to catch their prey only at night. They are called nocturnal animals. They have sharp eyesight, which enables them to see even in the dark. Some examples of nocturnal animals are owl, cat, tigers, bat etc. Of all the mammals, the bat is perhaps the most interesting. It has wings like birds; it has teeth like mammals; and it gives birth to babies. It sleeps hanging upside down from tree branches or celings of abandoned buildings throughout the day, and comes out for food only at night. It cannot see in the dark, but can hear sounds of low frequency, which other animals cannot hear. Penguins are flightless birds. Ostrich is also a flightless bird, but it can run fast. It is the largest bird in the world. The largest terrestrial animal is elephant. It is a herbivore. The largest aquatic animal is the whale. It is also a herbivore. Bat Owl Tiger Ostrich Elephant 138

Insects Insects are tiny animals which have segmented bodies and 3 pairs of legs. Their body is divided into head, thorax and abdomen. Legs are used for movement and catching prey. They have wings to fly. Grasshopper, mosquito, housefly, butterfly, honeybee, wasp, dragonfly, fire fly, cockroach etc. are some examples of insects. Ant is also an insect, although it has no wings. Spider is an insect too, although it has 4 pairs of legs. 1. Vertebrates - animals with a backbone. 2. Mollusca - invertebrates with shell on their body. 3. Gills - breathing organ for aquatic animals. 4. Aerials - animals that spend most of their time flying in air. 5. Arboreal - animals that live on trees 6. Terrestrial - animals that live on land. Cockroach Spider Honeybee Dragonfly Firefly Grasshopper Housefly Mosquito Ant 139

1. Explain the body features of fish. 2. Mention 5 sea animals other than the fish. 3. What are amphibians? Give 2 examples. 4. What are the characteristics of reptiles? 5. What are arboreal animals? 6. How is a bat different from other animals? 7. What are the characteristics of insects? To which class of animals do the following belong: 1. Otters 2. Scorpion 3. Earth worm 4. Centipede Discuss in groups, analyse the features of all animals, and come to a conclusion. Refer to the features of each class given below: 1. Mammals give birth to young ones. 2. Insects usually have six legs and a sucker 3. Insects have a segmented body. 4. Reptiles crawl. 5. Reptiles have scales on their body. Do the above animals belong to any of these classes? 140

Give the most striking features of the following: 1. Polar bear 2. Bat 3. Tortoise 4. Snake 5. Monkey 6. Dolphin 7. Snail Identify the animal 1. It is a bird but it cannot fly. 2. It is neither a bird nor a mammal, though it has characteristics of both. 3. It breathes through gills and lungs. 4. It is an aquatic animal, but it is a mammal. 5. It is the animal with the longest life span. 1. Why ant and spider are called insects though they don't have wings? 2. Is bat a bird or mammal? Justify your view with relevant facts. 141

Reproduction in plants Flowering plants reproduce through seeds. Flowers change into fruits and fruits have seeds in them. Parts of a flower Experiment 1: Open up a hibiscus flower and study its parts. Do you find the parts shown in the picture? Identify the parts. While visiting flowers for nectar, insects transfer pollen of one flower to the stigma of another flower of the same kind. This is called pollination. After pollination, ovary starts growing and petals fall down. The ovary becomes the fruit. Cut open the ovary of a hibiscus flower. You will see many tiny, bead- like structures packed inside. These will become seeds when the ovary grows into a fruit. They are called ovum. 142

When fruits ripen, animals eat them and throw away the seeds. Thus, the seeds are dispersed. However, fruits which are not edible have other ways of seed dispersal. They are taken to remote places by wind, water, and animals, where they sprout and grow into new plants. Structure of a seed Experiment 2: Soak some Bengal gram seeds overnight. Next morning, drain off the water and keep the seeds on a wet cloth and fold it. After about 6 seed coat hypocotyl cotyledon hours, you will see that the seeds have sprouted. You will notice a white thread like structure coming out of each seed. This process is called germination. Experiment 3: Take one sprouted seed. Split it carefully without breaking it. You will see a baby plant inside. The leafy part inside the split seed is called plumule. It grows into a shoot and puts on leaves. The white bottom part is called radical. It grows into a root. The split parts of the seed are called cotyledons. The baby plant uses the food stored in the cotyledons to grow, until it puts on leaves and is able to prepare its own food by photosynthesis. You will notice that the root grows down in the soil, while the shoot grows vertically upwards. radicle Structure of a seed 143 hypocotyl Shoot Root Leaves Cotyledons

Experiment 4: Keep some soaked seeds in a strainer. Suspend the strainer with a string. Cover the seeds with a wet tissue paper or cloth. Sprinkle some water on the cloth frequently. Observe the strainer after two days. What do you see? You will see roots penetrating down through the holes in the strainer. Note: The strainer should have big round holes. Experiment 5: Take a potted plant with a single stem. The plant should be small. Put the pot on its side, as shown. Observe it after a few days. What do you observe? You will notice that the shoot has bent and grown vertically upwards. This is called phototropism. The shoot always grows vertically upwards to face the Sun. On the other hand, roots always grow vertically downwards. This movement is called geotropism. 144

Mono cotyledonous and dicoledonous seeds Pulses and almost all other seeds have two cotyledons. Such plants are called dicots. However, cereals and millets like rice, wheat, maize, ragi etc have only one cotyledon. Such plants are called monocots. Coconut is another example of a monocot. 1. Reproduction from roots: Example: Carrot, radish, beetroot, and sweet potato. Experiment 6: Cut the top part of a few carrots. Put them in water in a bowl. You see the carrot pieces floating. After a few days, scale leaves appear on the carrots and tiny roots start growing out of the cut portion. You can try this experiment with a small sweet potato and a beetroot too. You do not need to cut them. You may put the whole root in water, as long as you make sure that the sprouting part is above the water. • Monocots have a fibrous root system. They have parallel venation on their leaves. We can predict the root system and the seed type from the venation. • Some plants, though they produce flowers, do not produce seeds. Example: Rose, hibiscus, bougainvillea, crotons, cacti etc. Such plants reproduce either through root, stems, or leaf. This type of reproduction is called vegetative reproduction. Rose Cactus Croton Bougainvillea Hibiscus 145

Reproduction through stems: New plants can be grown from underground stems like potato, ginger, turmeric, yam etc. Experiment 7: Cut a potato into half. Put it in water, with the cut part down. Observe it after a few days. You will see that the potato has sprouted. Repeat the experiment with ginger. Plant a piece in an ice cream cup and see the shoot coming out. Note: The eye of the potato is actually a bud which sprouts into a new plant. The potato can be grown in soil instead of water. Soil can be taken in a plastic bowl. Half immerse the potato in the soil and water it regularly. You will see a potato sprouting up after a few days. Stem cutting: Rose, hibiscus etc. can be grown from a piece of stem cut from the plant. The stem needs to kept fixed in the soil. After a few days, it starts sprouting. Reproduction through leaf: Plants like Bryophyllum and Brahma Kamalam reproduce through leaves. Bryophyllum 146

Activity 1 : Visit a nursery and look for these two plants. Bring them and grow them in your house. Observe how they grow new plants from leaves. Non flowering plants Pine tree Oak tree Fern tree Mushroom 147 Non flowering plants like pine, oak, eucalyptus etc. produce cones that sprout into new plants. Plants like Fern, mushroom and moss produce spores. New plants grow from these spores.

1. Ovum - eggs that grow into seeds. 2. Ovary - the part of the living organism that produce eggs. 3. Sprouting - germination; the baby plant coming out of the seed. 4. Bengal gram - Channa 5. Phototropism - movement of a shoot towards sunlight. 6. Geotropism - movement of a root towards the gravity of the Earth. 7. Cotyledon - the fleshy part of a seed. Food for a baby plant is stored in the cotyledons. 8. Vegetative reproduction - reproducing from plant parts other than the seeds. 9. Spores - tiny particles produced by non-flowering plants. They remain dormant till conditions are favourable for growing into plants. 1. What is pollination? 2. What happens after pollination? 3. What is seed dispersal? 4. What are cotyledons? How are they useful? 5. What is vegetative reproduction? 6. How do non flowering plants reproduce? Do all the experiments and activities mentioned in the lesson and make a record of your findings. 148

How do the following reproduce? What are these? 1. This part of the flower grows into a fruit. 2. Baby plant coming out of soaked seeds. 3. Shoot growing towards sunlight. 4. Part of the baby plant that grows into a shoot. 5. These provide food for the baby plant. 6. Pine reproduces through this. 1. Paddy 2. Sugarcane 3. Coconut 4. Rose 5. Potato 6. Papaya 7. Neem 8. Lotus 9. Guava 10. Bogainvillea 11. Crotons 149

150 1. Explain the parts of a flower with the help of a diagram. 2. Draw the diagram of a baby plant and label its parts.