II. Shade the figure according to the fraction 1 3 4 2 5 10 3 1 8 4 2 6 To Compare Natural Fraction and identifies greater and Smaller. Introduction Mother : Muthamizh and Sentamizh come here Muthamizh & Sentamizh: Yes, Amma (Mother had four equal parts of a watermelon. She gave them each one piece of the watermelon) Sentamizh : Amma, I need one more piece? (She gave another piece to him) Muthamizh : Amma you gave more than one piece to brother, that’s 1/4 for me and 2/4 for brother. Mother : Muthamizh! Sentamizh is your younger brother know? So only I gave him ok, eat it and then play (After returned from the play) Sentamizh : Amma, I am hungry (Mother gave last piece of the watermelon to him) Muthamizh : Amma you gave me 1/4 part of the watermelon. For brother you gave 2/4 it’s 47 4th_Unit_06_Fraction_Term 2.indd 47 8/5/2019 6:32:52 PM
more than 1/4. Now you gave the last piece (1/4) part to brother so you gave more (3/4) parts of the watermelon. Mother : you Know, your brother never tolerate his hungry? I have milk for you, go and drink it. The four equal pieces of the watermelon A piece given to Muthamizh = 1/4 First a piece given to Sentamizh = 1/4 Again a piece given to Sentamizh= 2/4 Muthamizh Compares her piece of fruit with his brother and realizes that her mother gives more pieces to him than her. 2/4 is greater than 1/4 or 1/4 < 2/4 Sentamizh after finished his playing he ate one more piece = 1/4 So totally he ate = 3 4 (three fourth) Muthamizh now realize that 3 4 is greater than 2/4, Muthamizh Compares all the three: 3 4 is greater than 1/4 3 4 is greater than 2 4 Thus: 1 < 2 < 3 4 4 4 1 < 2 < 3 4 4 4 48 4th_Unit_06_Fraction_Term 2.indd 48 8/5/2019 6:32:53 PM
Simple fraction (or like fraction) 1 < 2 < 3 4 4 4 The shaded portion of the circle’s fraction 1 , 2 , 3 4 4 4 respectively Here 1, 2, 3 = Numerator 4, 4, 4 = Denominator Thus the fractions have same denominator, such fractions are called similar or like fraction. Similar (like) fraction are fraction with same denominators. EXAMPLE 1 Identify which one is greater or smaller • If you observe the pictures you can notice that they are equally divided. • In the 1st picture one part is shaded so its fraction = 1/4 • In the 2nd picture two parts are shaded. So its fraction = 2/4 In picture 2 the shaded portion is greater than picture 1. Picture 2 is greater than picture 1 ∴ 2/4>1/4 49 4th_Unit_06_Fraction_Term 2.indd 49 8/5/2019 6:32:53 PM
EXAMPLE 2 1st picture's fraction = 2 5 2nd picture's fraction = 3 5 Here the shaded portion of the 2nd picture is high, so the 2nd picture is greater than the first. In other words we can say picture 1 is smaller than picture 2 2 5 < 3 5 ( 2 5 is smaller than 3/5) Exercise 6.6 I. Circle the greater fractions 1. 1 3 , 2 3 2. 3 4 , 1 4 3. 2 5 , 4 5 4. 6 8 , 3 8 5. 4 10 , 3 10 6. 2 9 , 7 9 II. Tick the smaller fractions 1. 2. 3. 50 4th_Unit_06_Fraction_Term 2.indd 50 8/5/2019 6:32:53 PM
I N F O R M A T I O N PROCESSING 1. Route Map • Able to locate short and long paths. • Able to fi nd out and check for connectivity between places. Shortest path : School house. School play ground house Longest path School library computer centre + house 7.1 Modelling UNIT-7 Library SCHOOL 51 4th_Unit_07_Information_Term 2.indd 51 31/07/19 8:43 PM
Activity 1 ) In how many ways you can go from your home to the hospital ? ) Draw a path and then Identify shortest path and longest path. Activity 2 Write the shortest and longest path of addition of 16 Exercise 7.1 MARKET SCHOOL BANK TEXTILE LIBRARY -7 -4 16 -1 -6 -5 -11 52 4th_Unit_07_Information_Term 2.indd 52 31/07/19 8:43 PM
(i) How many paths are there to reach temple from bus stop? (ii) Which is the longest path and shortest path? (iii) Specify the two places on the route from market to school? (iv) __________ is the places found between temple and mosque (a) Bank (b) textile (c) Library EXAMPLE Creating a plan to set – up a garden in the school. Step 1 : Levelling the land of 6m length and 5m Breadth. Step 2 : 5kg seed preparation Step 3 : Seeding 30cm intervals Step4 : Setting up fence with a 22 metre Circumference. Step5 : Watering once in five days Activity 1 List out the steps for the cleanliness programme in your school. 53 4th_Unit_07_Information_Term 2.indd 53 31/07/19 8:43 PM
Activity 2 One of the teams frame the rules. One team prepares to play and one of the team monitor the game. Water filling Competition EXAMPLE Group I : Making the students to stand in line. Group II : Measuring the height of the students. Group III : Taking notes. Name Height in cm Guru Selvi Kumar Ammu 120 124 110 108 Group IV : Transfer of students based on height. Group V : Ask the students to sit down in their places. Exercise 7.2 1. Prepare a plan to buy the necessary books for the school library. Arranging the books in order. 2. To prepare a project on the school annual day function. 54 4th_Unit_07_Information_Term 2.indd 54 31/07/19 8:43 PM
S C I E N C E TERM - II 4 4rd STD -Science_Term_II EM-WRAPPER.indd 55 06/08/19 2:58 PM
Unit Topic Index Page no 1 Food 57 2. Water 69 3. Plants 77 E-Book Evaluation Digi Link 4rd STD -Science_Term_II EM-WRAPPER.indd 56 06/08/19 2:59 PM
57 Food Unit 1 Learning Objectives After learning this lesson, students will be able to differentiate between raw and cooked food items understands the different methods of cooking describe the different types of cooking utensils identify hygienic food and food to be consumed during illness explain the importance of not wasting food Introduction Food is one of the basic needs of life. We get energy for all our activities from food. Food obtained from the nature provides all the nutrients to our body. But seeing the advertisement, we are attracted towards junk food. In this lesson, we will study about food items that are good for our health, cooking methods and the importance of not wasting food. I. Food Classify the following food items. (Carrot, Egg, Coconut oil, Milk, Radish, Meat, Potato, Curd, Brinjal, Lady‛sfi nger, Fish, Drumstick, Butter, Onion, Buttermilk, Cucumber, Ghee) Food items from plants Food items from animals Let us do 4th Science Unit 1 My food.indd 57 08/08/19 1:05 PM
58 Food that we eat directly without cooking is called raw food. We eat fruits, some vegetables, tubers and nuts in the raw form. Some pulses and cereals are also eaten as raw food. All raw food must be washed with clean water before eating. Some of the raw food items are given below. In our daily life, we depend on plants and animals for our food. Some can be eaten raw but most of them need to be cooked. Let‛s see what food can be eaten raw and which one needs cooking. 1. Raw Food (Uncooked Food) Which food do you eat without cooking? Think and answer Arrange some fruits, vegetables, nuts and tubers on the table and ask each student to pick one food item. Based on what food item they choose, divide them into four groups. Let us Do Shall we make some salad? Collect some raw food items available in your locality. Clean them with fresh water, cut them into small pieces (keep the nuts whole), put them in a bowl then add salt, spices and mix it well. Enjoy your tasty salad! Let us Make Fruits Vegetables Tubers Nuts 4th Science Unit 1 My food.indd 58 08/08/19 1:06 PM
59 Why should we cook food? • Cooked food is digested easily. • Cooking softens the food materials. • Cooking kills germs. • Cooking adds taste and fl avour to food. 2. Cooked Food We cannot eat all the food items in raw form. Food that needs to be processed using heat before it can be eaten is called cooked food. Try to Answer Write any fi ve raw and cooked food. a. Raw food: ---------, ---------,---------,--------- and ---------. b. Cooked food: ---------,---------,---------, --------- and ---------. II. Cooking methods and Habits Children, look at the menu card given here. Do you see food items on this menu? Do you think all these items are cooked the same way? Think and answer HOTEL KANNAMMA TODAY‛S SPECIAL Idly Dosa Meduvadai Poori Masala Idiyappam Pongal Coffee Badam Milk Honey is the only food that does not spoil. 4th Science Unit 1 My food.indd 59 08/08/19 1:07 PM
60 Some of the commonly used cooking methods are given below. Boiling: It is a method of cooking food by immersing it in boiling water. So that the food becomes soft. Example: Rice, Egg. Steaming: It is a method of cooking food in steam by immersing the vessel in a container with boiling water. Example: Idli, Idiyappam. Pressure cooking: It is a method of cooking food in a pressure cooker. Example: Rice, Dhal. Roasting: It is a method of cooking food by heating on a tawa or frying pan without covering it. Example: Groundnuts, Cashewnut. Frying: It is a method of cooking food in hot oil. Example: Chips, Poori. Cooking methods 1. Boiling 2. Steaming 3. Pressure cooking 1. Roasting 2. Baking 3. Frying Moist heat Dry heat Other methods 1. Microwave cooking 2. Solar cooking 4th Science Unit 1 My food.indd 60 08/08/19 1:07 PM
61 Cooking Habits • Wash your hands with soap before cooking. • Wash vegetables and fruits before cutting. • Wash cooking vessels and knives. • Don‛t cook food for a long time because it destroys the nutrients present in the food. • Don‛t use the same oil for cooking food many times. • Using the food items after their expiry date is not good for health. Tabulate the given food items according to the cooking methods. (Rice, Poori, Murukku, Pop-corn, Idli, Milk, Fish, Puttu, Dhal, Idiyappam, Groundnut) Boiling Steaming Roasting Frying Let us do Try to Answer 1. Write any two cooking methods that your mother follows: ---------------, -------------------. 2. Say True or False. a. You should wash your hands before cooking. ---------- b. Vegetables and fruits should be washed after cutting. ------------ III. Cooking Utensils Utensils are in different shapes and sizes. We use specifi c utensils for each cooking method. Clay pots were used earlier. Stainless steel and aluminum vessels are now generally used for cooking. 4th Science Unit 1 My food.indd 61 08/08/19 1:08 PM
62 Solar cooker It is an appliance which is used to cook food using sunlight. It saves fuel and reduces air pollution. Write the cooking utensils used for preparing given food items. (Pan, Pot, Rice cooker, Tawa, Idli cooker) S No. Food items Name of the cooking utensils 1. Rice 2. Idiyappam, Puttu 3. Vada 4. Sambar 5. Dosa Let us do Try to Answer Write True or False. 1. Earlier people cooked their food in pressure cooker. __________ 2. Solar cooker reduces the use of fuel. ______________ 3. Pressure cooker is not a cooking utensil. ______________ Cooking in clay pot Clay pots are well-suited for all types of cooking. Cooking in clay pots improves the quality and taste of food and also retains the nutrients. The natural insulation properties of clay cause heat and moisture to balance and circulate throughout the pot and keep the nutrients unharmed and prevent the dish from burning. Benefi ts of claypot cooking are, • Easy to digest. • Preserves the nutrients. • Needs less oil for cooking. • Adds fl avour to the dish. • Keeps the food warm for a long time. • Keeps the food from becoming stale soon. • Alkaline property in the pot neutralizes the acidic property in the food. 4th Science Unit 1 My food.indd 62 08/08/19 1:08 PM
63 Meal-time hygiene includes ways to make sure that we do not get sick because of the way we eat or make food. Some of the hygienic ways of taking food are given below: • Always cover food to protect them from dust and insects. • Eat fresh food always. • Avoid taking food that is too cold or too hot. • Avoid fast food and fried food. • Always wash your hands with soap before and after eating. Healthy foods Unhealthy foods IV. Meal-time Hygiene Look at the pictures given below. Which one is good for health? Why? Think and answer 4th Science Unit 1 My food.indd 63 08/08/19 1:10 PM
64 Try to Answer Write Yes or No. 1. Junk food is good for health. ___________________ 2. You should wash your hands before and after eating. ________________ V. Food During Illness When you are sick, what kind of food your mother serves you? Think and answer When we are sick, we should avoid food items that are fried in oil. We should take energy-giving, easily digestible food. Some of them are given below: • Porridge of rice or cereals. • Fruit juice, tender coconut. • Steamed foods like idly. Here is Nandini‘s lunch box. a. Are all the items healthy? b. Suggest her to remove one food which is not healthy and add one food which is healthy. Give reasons for change. Let us discuss Tick () the appropriate one. Food Hygienic food Junk Food Fresh fruits Samosa Nuts Panipoori Vegetable salad Let us do 4th Science Unit 1 My food.indd 64 08/08/19 1:11 PM
65 VI. Food Wastage Do you usually eat your lunch without wasting anything? If you say no, why do you waste? Can you suggest few ways to reduce food waste in your school and house? Think and answer We should not waste food. Food that is not eaten is called leftover food. That is discarded as waste. Following are the simple ways to avoid food wastage. • Take what you‛ll eat and eat what you take. • Share the excess food. • Give the excess food to hungry animals. Note to teacher Make small paper rolls, each having a food item‛s name. Put all of them on a table. Make two big circles on the fl oor. Name one circle ‘MUST AVOID DURING ILLNESS‛ and another circle ‘MUST TAKE DURING ILLNESS‛. Ask children to take one roll each and stand in the correct circle after reading the name on the roll. Let us do Try to Answer Fill in the blanks. 1. ___________ is an easily digested food. (Idly / Biriyani) 2. We should avoid eating ___________food. (junk/ fresh) 4th Science Unit 1 My food.indd 65 08/08/19 1:11 PM
66 We can preserve the food for long time by using the following methods. Food Preservation Refrigerating - Keeping food in the refrigerators (fridge) to preserve them for a short time. Example-Fruits,Vegetables Drying - Removing the water content of the food. Example- Fish, Red chillies Canning - Storing food in air tight containers. Example-Jam World Hunger Day-May 28 Pickling - Mixing fruits and vegetables with oil and salt. Example- Pickle One third of the food produced in the world is wasted. It is a total of 1.2 lakh crores tonnes per year. (1 ton = 1000kg) 4th Science Unit 1 My food.indd 66 08/08/19 1:12 PM
67 Try to Answer Fill in the blanks. 1. World Hunger Day is observed on ___________________. 2. We can preserve pickle by_____________________. I. Choose the best answer. 1. Which one can be eaten as raw food? a) Meat b) Carrot c) Fish d) Potato 2. Uncooked food is called a) junk food b) hygienic food c) raw food d) cooked food 3. Solar cooker reduces___________ . a) air pollution b) water pollution c) land pollution d) noise pollution 4. Which one cannot be preserved by drying method? a) Rice b) Cereals c) Fish d) Fruits 5. We can avoid food wastage by a) giving to the needy b) eating more than we need c) buying extra food d) throwing in a dust bin II. Fill in the blanks. 1. __________ gives us energy to work and play. (Raw food / Junk food) 2. Cooked food is easily_________. (digested / undigested) 3. Pressure cooker is one of the _________ utensils. (modern / olden) 4. We need pure air, protected water and ___________food for our healthy life. (junk / hygienic) 5. We make Idiyappam by ____________ method. (boiling / steaming) Make students to list out all the food wasted in their home (thrown away) for one week. Make them discuss what they saw and what changes they can make to reduce waste. Let us do Evaluation 4th Science Unit 1 My food.indd 67 08/08/19 1:13 PM
68 III. Match the following. 1. Grapes - Modern utensil 2. Mixture of vegetables - Food during illness 3. Electric rice cooker - Olden utensil 4. Earthen pot - Raw food 5. Less fatty food - Salad IV. Write Yes or No. 1. Biriyani is a raw food. 2. Frying is a method of cooking. 3. We can cook rice on a tawa. 4. Cooking in a solar oven needs sunlight. 5. Consuming too much oily food is bad for our health. V. Answer briefl y. 1. Name any three cooking methods. 2. Write any two food items you should eat when you are sick? 3. Draw one of your favourite raw food and colour it. 4. Write about any two preservation methods. 5. How can you reduce wastage of food in your home? VI. Answer in detail. 1. Explain any four food preservation methods. 2. Explain any four cooking methods. 3. What are the hygenic ways of cooking food? VII. Project. Make a cardboard plate. Make your favourite fruits and vegetables from clay and fi x them on the plate. 4th Science Unit 1 My food.indd 68 08/08/19 1:13 PM
69 Water Unit 2 Learning Objectives After learning this lesson, students will be able to understand the change of states in water describe the water cycle explain the importance of water cycle summarise rainwater harvesting and its uses Introduction Water is the most abundant and precious resource on the Earth. It is found in oceans, seas, rivers, streams, lakes, ponds and even under the ground. All living things need water to live and to do many other activities. We have already learnt about this in the previous classes. Let us learn more about water in this lesson. I. Change of States in Water See the given pictures and write down the state of each objects.(Solid, Liquid, Gas) Let us do 4th Science Unit 2 Water.indd 69 06/08/19 12:23 PM
70 Water occurs naturally in three forms: ice, water and water vapour. These forms are also called states of water. Ice is in solid form, water is in liquid form and watervapour is in gaseous form. These states occur naturally because of temperature changes. Water becomes ice in cold regions, remains as water in oceans/rivers and becomes water vapour due to the heat of the Sun. More to know Human body consists of 75% of water. Water Solid (Ice, Snow) Liquid (Drinking water) Gas (Water vapour) Ice Water Water vapour Fill in the boxes given below with correct answers. (Liquid, Solid, Melting, Freezing, Cooling, Heating, Gas) Let us do Change of States in water 4th Science Unit 2 Water.indd 70 06/08/19 12:24 PM
71 LIQUID STATE (Water) Water in liquid state is available in water bodies such as oceans, river, waterfalls etc. GASEOUS STATE (Water vapour) Water becomes water vapour as the temperature increases due to heat. Heating forms a white mist of extremely small water droplets in the air known as water vapour. Heating Water Water vapour 1000C Try to Answer 1. Why water is a good example for all states of matter? 2. Which of the following is in liquid state? Rain/Ice/Snow Fill water in an ice tray and keep it in the freezer. After few hours, take it out. What happened to the water? ___________________________________________________________. Now keep this ice tray on a table for some time. What happens to the ice? ___________________________________________________________. Pour water from the ice tray into a kettle. Ask an elder at your home to heat the kettle and observe the mouth of the kettle when the water starts boiling. What do you see? ___________________________________________________________. Let us do SOLID STATE (Ice) Ice is a solid form of water. At temperature below 00 C water becomes ice. This process is called freezing. Cooling Water Ice below 00C Write any two water bodies in your area. ___________, ___________. 4th Science Unit 2 Water.indd 71 06/08/19 12:25 PM
72 More to know Each day, we lose a little more than a cup of water when we exhale. What happens to the water in a wet cloth? Think and answer In nature, water keeps changing its state. Let us see how this happens. Due to the Sun‛s heat, water in oceans and rivers changes into water vapour and rises up. Water becoming water vapour on heating is called evaporation. The water vapour, when comes into contact with cool air, becomes water droplets. This is called condensation. The water droplets combine to form clouds. The water droplets continue to combine, and they become big and heavy. These water droplets then fall down as rain. This is called precipitation. In colder places, combined water droplets come down as snow, sleet or hail. This continuous change of water from one state to another in nature is called water cycle. Water Storage (Lake, Ocean) Water Cycle Try to Answer Choose the correct answer. In the water cycle ________ a. only evaporation is involved b. only condensation is involved c. evaporation and condensation are involved II. Water Cycle The continuous cycle through which water is circulated by different processes like evaporation, condensation and precipitation is called water cycle. 4th Science Unit 2 Water.indd 72 06/08/19 12:27 PM
73 Importance of water cycle • To improve the availability of ground water. • To control the Earth‛s temperature. • To provide water to plants and animals especially humans. • To recycle the Earth‛s supply of water constantly. Try to Answer 1. Unscramble the words and fi ll in the blanks. ondencsaonti, vaeionorpat, ecippitatrino ______________, ______________, ______________. 2. Is water cycle important for farming? ___________ 3. Why is water cycle important to human? ___________ 4. Name the process which is responsible for the formation of droplets on the surface of a glass of cold drink. ___________ 73% of our brain‛s mass consists of water. The Antartic region has about 70% of the worlds fresh water. ‘Rainwater harvesting‛ is the process of collecting and storing rainwater for future use. Rainwater can be collected in natural reservoirs or artifi cial tanks. Roof top harvesting is also a type of rainwater harvesting. The rainwater on the top of the building is collected and passed into the ground through pipes. Water passing through the pipes enters the pit which consist of gravels and Coarse sand. As it passes impurities are fi ltered and stored as ground water. More to know H2O is the chemical formula of water. III. Rain Water Harvesting Borewell Pit Drainage tube 4th Science Unit 2 Water.indd 73 06/08/19 12:28 PM
74 Benefi ts of rainwater harvesting • It increases the ground water level • It can be used for agriculture • It increases the availability of water for living things More to know • The rain water harvesting was launched in the year 2001 by the Tamil Nadu government. • Tamil Nadu is the fi rst Indian state which made rainwater harvesting as mandatory. 1. List out some other benefi ts of rain water harvesting. 2. Suggest some ideas to save rainwater in your school. Let us do Discuss with your friends. Rain water harvesting has an important role to protect our environment. Let us do Try to Answer Construct a pit of any shape or size. It may be generally constructed, 1-2 metre wide and 2-3 metre depth. The pits can be fi lled with boulders, gravels and Coarse sand. Put the boulders in the bottom, sand in the top and gravels in the middle. Tips to construct a rainwater harvesting pit at school/home. Sand Gravels Boulders 1 inch of rainfall on a 2,000 sq.ft. roof is equal to 4,800 litres of water. Rain water harvesting is the only way to conserve rain water 4th Science Unit 2 Water.indd 74 06/08/19 12:28 PM
75 I. Choose the correct answer. 1. Water is the most __________ resource on the Earth. (a) precious (b) solid (c) gas 2. Water exists in _________ states. (a) two (b) three (c) four 3. At temperature below _______ water freezes to form ice. (a) 10º C (b) 100º C (c) 0º C 4. ______ is the process by which water becomes water vapour. (a) Condensation (b) Evaporation (c) Freezing 5. Which controls the ecological functions of life? (a) Bicycle (b) Water cycle (c) Recycle water II. Fill in the blanks with suitable answer. 1. Water is converted into __________ when it is heated (ice cube / water vapour). 2. Water becomes ice on _________ (heating / freezing). 3. Water droplets Combines to forms ___________ (rain /clouds). 4. Water cycle increases the availability of ________ (water tank / ground water). 5. _____________ is a type of rainwater harvesting (Roof top harvesting / Watercycle). III. Write True or False. 1. Water is a good example for all states of matter. 2. Water cycle controls Earth‛s temperature. 3. Water becoming water vapour on heating is called evaporation. 4. 37% of our brain‛s mass consists of water. 5. Roof top harvesting method is used in agriculture fi eld. Evaluation 4th Science Unit 2 Water.indd 75 06/08/19 12:29 PM
76 IV. Answer briefl y. 1. Write the states of water. 2. What is freezing? 3. Name the processes involved in water cycle. 4. Which state government made rain water harvesting as mandatory in the year 2001? 5. What is needed to construct a rain water harvesting pit? V. Answer in detail. 1. What is water cycle? Write any three importances of water cycle. 2. What is rain water harvesting? List out the advantages of rain water harvesting. VI. Colour the given picture and write the correct name in the given blanks. (Precipitation, Evaporation, Condensation, Water storage) VII. Project. Make a model of house with roof top rain water harvesting system. 4th Science Unit 2 Water.indd 76 06/08/19 12:29 PM
77 Plants Unit 3 Learning Objectives After learning this lesson, students will be able to list out the parts of leaf and their functions explain the process of photosynthesis describe the role of plants as a primary producer know about green and non green plants describe the features of fl ower list out the exotic plants and their role identify the edible part of different plants Introduction All living things eat food. Food helps them grow and perform daily activities. We have seen animals eating their food. But, have you ever wondered how plants get their food? Plants produce their own food with the help of chlorophyll, a pigment present in leaves. Humans and animals depend on plants for their food either directly or indirectly. Let us learn more about plants in this lesson. I. Parts of a Leaf Leaves are of different shapes and sizes and have different parts. However, there are some basic parts that are common in most of the leaves. Blade : The broad fl at part of the leaf (Lamina). Apex : The tip of the leaf. Midrib : The midrib runs along the centre of the leaf. Veins : Veins are branch out from the midrib. They are the framework of hollow tubes that carry water and minerals. Petiole: This part joins the leaf to the main stem. apex veins midrib blade petiole 4th_Science_Unit 3 Plants.indd 77 06/08/19 1:19 PM
78 Plants need food but they never depend on people or animals to provide them. Most of the plants are able to make their own food through a process called photosynthesis. Photosynthesis = Photo (light) + synthesis (make) Photosynthesis is a process by which plants make their food using chlorophyll water, carbon dioxide in the presence of sunlight. Let us see how this process is organized with in the plants. 1. Leaf as food factory Sunlight Chlorophyll Oxygen Carbon dioxide Water Stomata : Stomata are tiny openings or pores mostly found at the base of the leaves. Air enters and leaves the plant through these openings. Stomata helps the plants to breathe. Stomata are used to exchange gases. Opened Stomata Closed Stomata Water: Water is absorbed by the roots and is passed to the leaves through the tubes. Carbon dioxide: Carbon dioxide in the air passes through small pores in the leaves. Sunlight: A green pigment in the leaves help them to trap sunlight. This pigment is called chlorophyll. Most leaves are green in colour because of this green pigment. Through photosynthesis plants produce the food and release oxygen into the air. Sun light Water + Carbon dioxide Food + Oxygen chlorophyll As plants prepare food for themselves and also for other living things, they are called primary producers. Which part of the leaf collects carbon dioxide? Think and answer Which part of the leaf transports water? 4th_Science_Unit 3 Plants.indd 78 06/08/19 1:19 PM
79 Try to Answer Fill in the blanks by rearranging the letters in the bracket. 1. During photosynthesis plants releases _________ (egxyno). 2. _________ is a primary producer (tanpl). 3. Stomata are seen in the _______ (owler) surface of the leaf. 4. Pigment involved in the food synthesis is _________ (phllylochor). Why would living things not be able to live without plants? Think and answer Take two potted plants. Keep one in sunlight and other in a fully covered box. Water them regularly. After a week observe the plants. Before a week After a week What did you observe? Plant in sunlight Plant in box Let us do More to know Plants like cactus do not have leaves. Their food is made in their green stems. Without primary producers, living things that are not capable of producing their own food and will not be able to live. 4th_Science_Unit 3 Plants.indd 79 06/08/19 1:19 PM
80 II. Classifi cation of Plants Plants are classifi ed in many ways based on stems, life span, seeds, fl ower and colour. In this session we will study about the classifi cation of plants based on the fl ower and colour (pigment). Plants Flowering plants Neem, Mango Non-flowering plants Algae, Fungi, Ferns Colour Green plants Grass, Algae, Paddy Non- green plants Fungi Flower 1. Flowering and Non-fl owering plants Flower is the most important part of many plants, because it is involved in reproduction. But some of the plants are not having fl ower. These plants are also reproduce in different modes. Based on this plants, can be classifi ed into two types. Flowering plants Non-fl owering plants. Flowering plants Plants bearing fl owers are called fl owering plants. It reproduce by sex cells or gametes and produce seeds. Seeds produce new plants. Eg – Mango, Neem, groundnut, paddy. Neem Paddy Mango 4th_Science_Unit 3 Plants.indd 80 06/08/19 1:19 PM
81 Non-fl owering plants Plants without fl ower that can reproduce are called non-fl owering plants. These plants do not produce seeds. They reproduce by a special structure called spores. E.g. Algae, Fungi, ferns. Algae Fungi Fern List out the fl owering and Non-fl owering plants in your surrounding. Flowering plants Non-fl owering plants Let us do 2. Green and Non-green plants The most important pigment present in plants are called chlorophyll. Based on the colour present in the plant, they are divided into two groups such as Green and Nongreen plants. Green plants Plants containing green pigments are called green plants. It looks green in colour. They prepare their own food with the help of them. It depends atmosphere, light and pigment for food preparation. Green plants are commonly called autotrophs. E.g. Grass, Paddy, Algae. Grass Paddy Algae 4th_Science_Unit 3 Plants.indd 81 06/08/19 1:19 PM
82 Non-green plants Plant that lacks chlorophyll pigment and looks not green are called non-green plants. They cannot prepare their food. These plants depend on other organism for their food and living place. These are commonly called heterotrophs. Mushroom Bread moulds Bracket Fungi List out the places where you see the non-green plants ______________________ ______________________ ______________________ ______________________ Let us do Try to Answer Fill in the blanks. 1. ___________ is an example for non fl owering plant. 2. Plants are classifi ed based on pigment and _________ of the plant. 3. _________ depend on other organism to live and get their food. 4. Autotrophs use ____________ , _____________ and chlorophyll to prepare their own food. III. Parts of Flower Have you seen fl owers? Try to answer the questions given below a) Which is your favourite fl ower? __________________ b) What is the colour of the fl ower? __________________ c) How does it smell? __________________ The four visible parts of a fl ower are explained below. Sepal: Sepals are leaves that protect the fl ower while it is still a bud. Sepals are usually green in colour. 4th_Science_Unit 3 Plants.indd 82 06/08/19 1:19 PM
83 Petal: Petals are often bright coloured. Their main job is to attract insects such as bees or butterfl ies, to the fl ower. The insects help the fl owers in the transfer of pollen grains. Stamen: Stamen can be seen at the centre of a fl ower. They contain pollen grains that help the plants to multiply. It is the male part of a fl ower. Pistil: Pistil is also seen at the centre of the fl ower. The pistil uses the pollen to help the fl ower become the fruit. It is the female part of a fl ower. Try to Answer Fill in the blanks. 1. Sepals __________ the fl ower while it is still a bud. 2. Stamen contains _________ grains. 3. Pistil is ___________ part of a fl ower. Bring few hibiscus fl owers to the classroom. Distribute the fl owers to children. Introduce the parts of the fl ower to them. Then, ask them to observe and feel the different parts of the fl ower and tell them to record their observation. Parts of fl ower What is its colour? Petal Sepal Pistil Stamen Let us do More to know The largest fl ower in the world is Raffl esia. This rare fl ower is found in the rainforests of Indonesia. Pistil Stamen Sepal Petal Stalk 4th_Science_Unit 3 Plants.indd 83 06/08/19 1:20 PM
84 The change in climate that occurs periodically is called seasons. There are four general seasons - Spring, Summer, Autumn and Winter. Most fl owers bloom in a specifi c season. Hence, they are called seasonal fl owers. Flowers that bloom in winter December Winter Jasmine Tuberose Flowers that bloom in summer Jasmine Sunfl ower Rose Flowers that bloom in autumn and spring Dahlia (Autumn) Saffron (Autumn) Tulip (Spring) Seasonal Flowers Can you name the four seasons? Think and answer 4th_Science_Unit 3 Plants.indd 84 06/08/19 1:20 PM
85 More to know IV. Exotic Plants The plants that are growing outside its native area either purposefully or accidentally are called exotic plants. Most of these plants are brought to new areas for decoration purposes. Some of them are given below. Sago palm (Cycas) Fern Crotons Travelers palm Boat lily Aloevera Firecracker fl owers bloom in all seasons Kurinji fl ower blooms once in 12 years 4th_Science_Unit 3 Plants.indd 85 06/08/19 1:20 PM
86 Humans and other animals often use plants as food. Plants we eat are edible. Edible parts of some plants include leaves, stems and roots. We also eat fruits produced by plants. Edible parts of plants All the parts of different plants are edible, that is, we can eat them as food. Roots as food Many plants store excess food in their roots. They have thick and swollen roots. These roots are used as food. Some of them are given below. More to know Parthenium plant accidentally grow in a new native. This plant expands its range and disturbs the cultivation areas. The pollen of this plant is allergic in nature. So, don‛t touch this plant wherever you see. Try to Answer 1. Find the odd one. i. December, Tuberose, Tulip. ii. Saffron, Dahlia, Rose. iii. Rose, Boat lily, Crotons. Collect various ornamental plants and plant in your school garden or at home. Let us do V. Plants as Food Carrot Beetroot Tapioca 4th_Science_Unit 3 Plants.indd 86 06/08/19 1:20 PM
87 Stems as food In some plants the stem stores the excess food in it. Potato, onion, ginger are underground stems that we eat. Some of them are given below. Onion Turmeric Sugarcane Leaves as food Leaves of some plants are used as food. In some plants extra food is stored in leaves. We eat the leaves of plants like cabbage. Some of the leaves used as food are given below. Coriander Cabbage Moringa Flowers as food Flowers are the most attractive part of the plant. Many fl owers are used as food. Some of them are given below. Banana fl ower Caulifl ower Clove 4th_Science_Unit 3 Plants.indd 87 06/08/19 1:20 PM
88 Try to Answer Fill in the blanks. 1. _______ fl ower is used as food. 2. _______ part of the potato plant is used as food. 3. Stem of the ________ stores food in it. 4. Seeds are rich in________ and ______. Fruits as food Many fruits are used as food. Fruits are rich in vitamins and minerals. They keep us healthy. All fruits can be eaten raw. Banana Mango Jack fruit Grains as food Grains of pulses, cereals and pods are the commonly eaten seeds. They are rich sources of carbohydrates and proteins. Rice Pulses Fenugreek More to know Trees are the longest living organism on earth. Bamboo plants can grow upto 90cm in one day. 4th_Science_Unit 3 Plants.indd 88 06/08/19 1:20 PM
89 Complete the table to show which parts of the plant we eat. Food items Parts of the plant eaten Carrot Banana fl ower Mango Caulifl ower Rice Dhal Moringo Turmeric Onion Cabbage Jackfruit Beetroot Let us do Evaluation I. Choose the correct answer. 1. The tip of the leaf is a. blade b. apex c. midrib d. veins 2. Which one of the following is a primary producer? a. Plant b. Animal c. Human d. None of the above 3. Which fl ower blooms during winter? a. Jasmine b. Tulip c. December d. Fire cracker 4. Choose the ornamental plant from the list. a. Parthenium b. Mango c. Travellars palm d. Groundnut 5. Which plant fl ower is edible? a. Caulifl ower b. Potato c. Mint d. Cabbage II. Fill in the blanks. 1. During photosynthesis ________ is produced and stored in the leaf. 2. Green plants have __________ pigment. 4th_Science_Unit 3 Plants.indd 89 06/08/19 1:20 PM
90 3. Onion is a __________ part of a Plant. 4. The male part of the fl ower is ________. 5. An example for edible seed is __________. III. Answer the following in one or two words. 1. Which is the female part of the plant? 2. Write the name of any one of the leaf that is used as a food. 3. Which fl ower bud is used as spices in food? 4. What are the nutrients present in the seeds? 5. Write any one of the fl ower that blooms in summer. IV. Answer briefl y. 1. Write the parts of the leaf. 2. Defi ne – Photosynthesis. 3. Write the names of the exotic plants. 4. Write the names of any two underground stem plant. 5. Why should we not touch parthenium plant? V. Answer in detail. 1. Mark any four parts and describe the parts of a leaf. 2. Draw a diagram of a fl ower and explain the parts of a fl ower . VI. Project. 1. Collect the edible parts of different plants used in your home and display them in your class room. 2. Collect some fl owers and discuss with your friends about the parts of fl ower. 4th_Science_Unit 3 Plants.indd 90 06/08/19 1:20 PM
91 Philanthropists of Sangam Age Social Science Term-II 4 4th_Social Science_Philanthropists of Sangam Age.indd 91 08/08/19 4:28 PM
Philanthropists of Sangam Age 92 Ebook Assessment Digi Links Contents Unit Topic 1. Philanthropists of Sangam Age 93 2. Physical Features of Tamil Nadu 106 3. Transport 115 Page no 4th_Social Science_Philanthropists of Sangam Age.indd 92 08/08/19 4:28 PM
93 Learning Objectives Philanthropists of Sangam Age 1 Children will be able to: name the philanthropists name the regions ruled by the philanthropists. understand the significance of kindness. explain how the philanthropists ruled their region. Unit 4th_Social Science_Philanthropists of Sangam Age.indd 93 08/08/19 4:28 PM
Philanthropists of Sangam Age 94 Who ruled these regions? Why only seven were famous? Who were they? They would have used horses and donkeys to climb up the hill. In the Sangam Age, many philanthropists ruled the hilly regions. But, seven of them were very famous. Grandpa, how did people come to these hills before buses and cars were used? Geetha and her Grandpa are on a trip during summer holidays. They are on their way to Kodaikanal the hill station in Tamil Nadu.This is the first time that Geetha is travelling up a steep hill in a bus. Do You Know? Sangam literature, consisting of several classical poetry is the main sources of the Sangam Age. 4th_Social Science_Philanthropists of Sangam Age.indd 94 08/08/19 4:28 PM
95 Philanthropists of Sangam Age I would love that! Those seven philanthropists were Pegan, Pari, Nedumudi kari, Aay, Adhiyaman, Nalli and Valvil Ori. They ruled different hilly regions at different periods during the Sangam Age. They were all powerful, kind and cared for nature and the people. Hills usually have lot of trees. It is important for people to take care of them. Shall I tell you a few stories about how those philanthropists and the people protected nature and how in turn nature protected them? Is that! why there are more trees in the hills than in Chennai? Try to Answer 1. Name any three philanthropists. 2. During which age did the seven famous philanthropists rule the hilly regions? 4th_Social Science_Philanthropists of Sangam Age.indd 95 08/08/19 4:28 PM
Philanthropists of Sangam Age 96 Pegan Okay. This story is about Pegan. Pegan ruled Palani hills (Dindigul district) – the very same hill range that we are visiting today. Isn't it cold here? Correct. One day, while Pegan was on his walk, he saw a peacock shivering. He assumed that the peacock was shivering due to cold and he covered the peacock with shawl. May be not.The point is that Pegan treated the peacock just like his own child. How many people now a days show such kindness towards animals? Yes, grandpa. That‛s why Amma has packed sweaters for us. Can a peacock use a shawl? Yes! Are you ready for the first story? 4th_Social Science_Philanthropists of Sangam Age.indd 96 08/08/19 4:28 PM