4 Author Sunita Thakur M.Sc (Physics), B.Ed Printed by Ultimate Printing Press © All rights reserved. All rights reserved with the Publishers. No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means: electronic, mechanical, photocopying, recording or otherwise without the prior written permission of publisher. Please note the QR Code consists of the weblinks of different websites. These web links are given for the learner’s extra knowledge and reference purposes only. The publisher is not liable for any misinformation on websites. Thanks The publisher expresses gratitude to all the authors whose works have been included in the book. Permission for publication could not be obtained from the creators/copyright holders of some works compiled in this book due to unavoidable reasons. Those creators/copyright holders are expected to contact the publisher for permission to publish.
Key terms introduced in the chapter are listed along with their meanings. It gives the crux of the chapter for summarizing the concepts and topics presented in the chapter. Some interesting topics have been taken out for children for their reading which increases knowledge. To help students know what they are going to learn about the chapter. An interactive, fun way to step into the lesson. Helping young minds to get an overview of the chapter. Provides extra proficiency, amazing & interesting information related to the topic(s) discussed. ffis section gives important and convenient tips for a greener and safer ecosystem. Reading Fun A set of difflerent types of questions is given to assess the knowledge and understanding of the students about the topics covered. ( stands for Science, Technology Engineering, and Mathematics. But it’s more than that. STEM has grown to represent a unique approach to teaching and learning, one that centres around individual students’ learning styles and interests. STEM moves beyond simple test performance and focuses on developing higher-level thinking skills by connecting classroom learning to the real world.) Apart from chapters -based activity pages are given in this series for students for their practical knowledge. It Includes interesting, skillful STEM-based activities and projects which develop creativity, team spirit and the scientific temperament in students. DIY ACTIVITY To indulge students’ brains to an advanced level of thinking (HOTS).
An observational questionnaire along with pictures to check the understanding. Significant activities have been designed primarily to make learning a joyful experience for both students and teachers. ffe blend of STEM, NEP 2020, NCF 2023 guidelines & 21st Century Skills (5C’s) is incorporated in this portion. Steps to use QR Code 1. Open Mobile and click on the Google Lens icon. 2. Scan the QR code in the chapter from it then click on the search option. 3. ffen web-page/video related to the chapter will open for reference. 4. Affier clicking on the search option, if this error comes then click on skip advertisement. ffen Your Web-page/video will open. Group discussion-based topics/ questions for students. Appropriate instructions are given to the teacher for interesting and efflective teaching of the chapter. To help Inquisitive learners get an extra edge of amazing and fascinating information related to chapters just by scanning the QR codes. Just scan you will be redirected to the weblinks related to the topic. Concepts related to real life are covered in this portion to help students to become responsible citizens and develop life values. NEP 2020 Skills, NCF Guidelines and 21st Century Skills (5C) • Experiential learning • Behavioural skills • Self-direction • Holistic Learning • Leadership skills • Life skills • Art integration • Application of knowledge • Project work • Critical thinking • Curiosity • Communication skills • Creativity WEBLINK
SCIENCE-4 Wonder of Science : Reading Fun 5 Unit I: Plants as Living Beings 1. Adaptations in Plants 6 2. Plants: Making and Storing Food 14 Activity Time-1 23 Unit II: Animals as Living Beings 3. Adaptations in Animals 24 4. Reproduction in Animals 33 Activity Time-2 42 Unit III: fie Human Body and Our Needs 5. Food and Health 43 6. Teeth, Digestion and Microbes 51 7. Safety and First Aid 61 8. Clothes We Wear 69 Activity Time-3 76 Unit IV: fie Universe 9. Our Universe: ffe Solar System 77 More About Moon : Reading Fun 86 Activity Time-4 87 Unit V: Our Earth and Natural Resources 10. Environment and Pollution 88 11. Weather and Water 98 Activity Time-5 106 Unit VI: Matter and Force 12. States of Matter 107 13. Force, Work and Energy 116 Activity Time-6 126 Model Test Paper–1 127 Model Test Paper–2 128
5 Science–4 Wonder of Science Some lesser-known and intriguing science facts Octopuses Have Three Hearts: Octopuses, those clever underwater creatures, have not one but three hearts. Two pump blood to the gills, while the third pumps it to the rest of their body. Honey Never Spoils: Archaeologists have found pots of honey in ancient Egyptian tombs that are over 3,000 years old and still perfectly edible. Honey’s natural composition makes it resistant to bacteria and spoilage. The Smell of Rain: That pleasant earthy smell you sometimes notice after it rains is called “petrichor.” It’s caused by a combination of rainwater, soil, and certain oils released by plants. A Group of Flamingos is Called a “Flamboyance”: When a group of flamingos gathers, it’s referred to as a flamboyance, which is a fitting name for these colourful birds. Bees Can Recognize Human Faces: Researchers have discovered that bees can recognize and remember human faces, which is quite an impressive cognitive ability for such small insects. The Slowest Moving Plant: The plant known as the “sensitive plant” or “touchme-not” moves when touched. Its leaves fold inward when stimulated and then reopen slowly. Electric Eels Can Generate Electricity: Electric eels can generate electric shocks of up to 600 volts to stun prey or deter predators. They use specialized cells called electrocytes. The Eiffel Tower Gets Shorter in Cold Weather: When the weather is very cold, the iron structure of the Eiffel Tower can contract, making the tower slightly shorter than on a warm day. A Rainbow is a Full Circle: While we typically see rainbows as semi-circles, they are actually full circles. However, the ground usually obstructs the bottom half. Water Cycle in a Bag: Create a mini water cycle in a sealed plastic bag. Fill it with water, tape it to a window to catch sunlight, and observe condensation, precipitation, and evaporation occurring within the bag. Reading Fun
6 Science–4 LEARNING GOALS Afier completing this chapter, you will be able to know about: Terrestrial plants Aquatic plants Adaptation for protection Insectivorous plants Plants of the grass family Adaptations in Plants Plants are found all over the world. They live and grow in many different conditions. Some plants grow in places which are very cold, other plants grow in hot, dry deserts. Some plants grow in water and some even grow under water. Plants develop special features to help them survive in their surroundings. This process is known as adaptation. LET’S WARM UP Write L for plants that grow on land and W for plants that grow in water. 1 Adaptations in Plants Word Help Adaptation: To adjust in a new living condition. Unit-I : Plants as Living Beings Self Direction
7 Science–4 There are two main habitats of plants-land and water. Plants which grow and live on land are called terrestrial plants. Plants which grow and live in water are called aquatic plants. Let’s know about classification of plants according to their habitats. TERRESTRIAL PLANTS Plants that grow on land are called terrestrial plants. Such types of plants include grasses, shrubs, herbs and trees. Plants show special features that help them to adapt with their environment. On the basis of the type of soil and climate, the terrestrial plants can be categorized as follows: Plants in Hilly Areas Trees such as pine, fir, deodar and spruce grow in cold hilly areas or on mountains. These trees have adapted themselves to live in cold conditions. Trees in hilly areas have thick barks. They are tall, straight and cone-shaped. This shape helps snow to easily slide off the branches. The waxy needle-like leaves do not allow the trees to lose their water. So that is the reason the trees remain green even in the extreme cold. Plants Growing in Plains In the plains, trees have many branches and leaves. These trees can bear heat as the climate in plains neither too hot nor too cold. They shed their leaves in winter to protect themselves against less of water and grew new leaves in the spring season. Ashoka, neem, teak, mango, peepal and banyan are such trees. Plants Terrestrial (On land) Aquatic (In water) Coastal areas Hills and mountains Plains Marshes Deserts Under Floating Fixed water Deodar tree Ashoka Tree Pocket Fact An adaptation can be physical or behavioural. Both animals and plants adapt. Living organisms that cannot adapt to changes in their environment become extinct.
8 Science–4 TEST YOUR UNDERSTANDING Give one example of a plant growing in each of the following regions. Hills ________________ Marshes ________________ Deserts ________________ Plains ________________ Coastal regions ________________ Plants in Coastal Areas The area near the sea having high rainfall is called coastal area. In this area, water is salty and the climate is usually humid. Some plants like coconut and teak trees grow in this area. They are known as evergreen trees as they do not shed their leaves. Coconut, rubber and pepper are some plants that grow in these regions. Plants in Deserts Plants that grow in the deserts are called xerophytes. Cactus and palm date tree are desert plants. Some desert plants do not have leaves. Cactus and prickly pear are such plants in which leaves are reduced to spines. This helps the plant to conserve water and keep away animals. The stem is green and fleshy. The green stem contains chlorophyll and makes food instead of the leaves. They have long roots that go deep into the ground to absorb water. Plants Growing in Marshy Areas Areas with lot of water and sticky, clayey soil are called marshy areas. You see them near the seashore where the rivers meet the sea. The plants that grow here are called mangroves. Their roots do not get air as the soil is covered with water. So the roots grow out of the soil and water to breathe. Such roots are called breathing roots. Coconut Tree Mangroves Catcus Rubber Tree Critical ffinking
9 Science–4 Underwater Plants Underwater plants are special kinds of plants that grow completely submerged in water. So these are also called submerged plants. AQUATIC PLANTS Plants which grow in water are called aquatic plants. There are three kinds of aquatic plants: floating plants, fixed plants and underwater plants. Floating Plants These light, spongy plants float freely on the surface of the water. Two examples are water hyacinth and duckweed. Their stems are reduced and roots are poorly developed. The leaves have a thin waxy coating so that water may not wet the surface and block the stomata. Fixed Plants The word fixed means these plants are fixed to the bottom of the pond with their roots. They have long hollow stems that help the broad leaves to float on the surface of water. Stomata are found on the upper surface of these leaves. Can you tell why? The common examples of fixed plants are water lily and lotus. The leaves also have a waxy coating. So that water does not stick on them. They breathe through pores on the upper surface of the leaves. Water lettuce Lotus Water lily Pocket Fact Bamboo is the fastest growing plant. It has been found that it grows upto 91 cm (35 inches) per day. Hydrilla Tape-grass DIY ACTIVITY Dip your fingers in a bowl of water for 10 minutes. You will notice that the skin of your fingers gets wrinkled. Why do not the leaves of aquatic plants get wrinkled? This is because the aquatic plants have a waxy coating on the surface of leaves, which prevents them from absorbing excessive water and getting wrinkled.
10 Science–4 TEST YOUR UNDERSTANDING Fill in the blanks. 1. Aquatic plants are special because they grow entirely ____________. 2. Underwater plants are also called ______________ plants. 3. Aquatic plants play an important role in the ecosystem by providing ____________ for underwater animals. 4. ______________ on the leaves of underwater plants prevent them from ______________. 5. Just like land plants, aquatic plants also need ____________ and sunlight to grow. Unlike most plants that grow on land, these plants have adapted to living and thriving in aquatic environments. They can be found in lakes, rivers, ponds, and oceans, where they play an important role in providing oxygen for underwater animals and helping to maintain the health of aquatic ecosystems. Some common examples of underwater plants include water lilies, seagrasses, and algae. INSECTIVOROUS PLANTS Insectivorous plants are special kinds of plants that have adapted to catch and eat insects and other small creatures as a source of nutrients. They have unique structures, such as sticky leaves or traps, which help them capture and digest their prey. Insectivorous plants live in places where the soil may lack essential nutrients, so they rely on insects to supplement their diet. Some common examples of insectivorous plants include the Venus flytrap and the pitcher plant. PLANTS OF THE GRASS FAMILY Cereals like maize, wheat and rice belong to the grass family. These plants are useful to us in many ways: They provide food to human beings and animals. We get fodder for animals from such plants. Bamboo, a giant grass, is used to make brooms, baskets, mats, etc. Venus fflytrap Rice Plant (Paddy) Pocket Fact Insectivorous plants are green and carry out photosynthesis. Application of Knowledge
11 Science–4 Various grasses are used to make paper. Paper was first made by the people of Egypt from a grass called papyrus. Paper got its name from this grass. Dried grasses are used as packing material. Grasses conserve the soil as they hold the soil with their roots and prevent soil erosion. Word Help Soil erosion: Wasting or blowing away of the top layer of the soil KEY WORDS Adapt : To adjust in a new living condition is called to adapt. Terrestrial plants : Plants that grow on land are called terrestrial plants. Aquatic plants : Plants that grow in water are called aquatic plants. Insectivorous plants : Plants that trap insects are called insectivorous plants. SUMMARY Plants are found all over the earth- on mountains, in deserts, in coastal areas. In plains and in water. Plants that grow on land are called terrestrial plants. Trees that grow in plains have many branches full of leaves. These help them to use the sunlight to make food. Plants in hilly areas have waxy needle-like leaves. Plants in deserts have spines. Some plants develop different adaptations to protect themselves from being eaten up by animals. Some plants eat insects to get enough nutrition. We can benefit from plants in the grass family in a variety of ways. EXERCISE TIME A. Choose the correct option. 1. Plants growing in hilly area have (a) no leaves (b) needle-like leaves (c) broad leaves (d) cactus Pocket Fact Do you know about Chipko Movement in 1970’s a nonviolent social & ecological movement run by rural villages of Chamoli district in Uttarakhand, aimed at protecting trees and forest slated for government backed logging. ffe villagers put their arms around the trees, telling the loggers that they would not be able to cut the trees before killing them.
12 Science–4 2. Which of the following is not an aquatic plant? (a) Duckweed (b) Lotus (c) Venus fflytrap (d) Water Lilly 3. Which of the following has needle like leaves? (a) Fir (b) Palm (c) Babul (d) Apple 4. Which is the faster growing plant on land? (a) Maize (b) Wheat (c) Jawar (d) Potato B. Write T for true statement and F for false statement. 1. All plants have the same structures and features. 2. Plants can adapt to diffierent environments to survive. 3. Plants that grow on land are called terrestrial plants. 4. Cacti have leaves that help them collect more water. 5. Some plants have thorns or spines to protect themselves from animals. C. Give one word or a few words answer. 1. What part of a cactus stores water? 2. Plants that eat insects and other small creatures. 3. Can plants move to flnd better soil? 4. An aquatic plant that does not have stomata. D. Write short answer. 1. What is the role of roots in plants? 2. What is adaptation? 3. What are marshy areas? 4. Name any three plants that grow on hilly areas. E. Answer these questions. 1. Diffierentiate between terrestrial and aquatic plants. 2. What are mangroves? How are they adapted to live in marshy areas? 3. How does the pitcher plant trap insects? 4. How are underwater plants useful? TIME TO THINK (HOTS) Tea plants grow on hill slopes and valleys where there is heavy rainfall. Can they be grown in the plains? If not, flnd out the reasons.
13 Science–4 Observe the picture and answer the following questions. 1. Name the type of plants. ____________________________ 2. Where do they grow? ____________________________ 3. What are the roots growing out of the soil and water called? ____________________________ TIME TO OBSERVE (Observational Skills) Take a picture of your favourite plant and paste it on a chart paper. Describe where it grows and what it looks like? Also describe its special features that help it to adapt to its environment. TIME TO CREATE (Project Work/Creative Skills) Look at the objects inside your classroom. Is there anything that has been made from plant products? Discuss. TIME TO DISCUSS (Collaborative Skills) Some portion of the tree is cut down somewhere for every sheet of paper we use. Do you adhere to these procedures to reduce paper use? 1. I make use of the entire sheet of paper. 2. Even if my old notebooks have a few blank pages, I still buy new ones. 3. I create origami activities using blank sheets of paper. 4. I use a slate to practise drawing or do arithmetic problems. 5. I make use of unused blank notebook pages from the previous year. LIFE SKILLS Take the children to a garden and show them diffierent kinds of plants. Show them videos of aquatic and insectivorous plants to explain their features. FOR THE TEACHER (Go Green, Life Skills) To know more about diffierent types of plant, please scan this QR code. WEBLINK
14 Science–4 LEARNING GOALS Afier completing this chapter, you will be able to know about: Parts of a leaf Food preparation in plants How do plants use their food? Function of a leaf Non-Green plants Interdependence between plants and animals Balance in nature LET’S WARM UP Colour the leaves and answer the questions that followed: (i) Do all the leaves have the same size? ____________________________ (ii) Do all leaves have a pointed tip? ____________________________ (iii) Do all leaves have a smooth edge? ____________________________ 2 Plants: Making and Storing Food Every living thing needs food. It helps us to grow and carry out daily life activities such as studying, playing and working. Some living things make their own food and others obtain their food from different sources. In plants, the leaves helps to make food so they are called food factory or kitchen of the plants. Leaves are green because they have a green substance known as chlorophyll. Only green leaves which contain chlorophyll, can make food for the plant. (Creativity)
15 Science–4 Different plants have different shapes and sizes of leaves. Let us learn more about leaves. PARTS OF A LEAF Observe a peepal leaf. The flat part of the leaf is called leaf blade or lamina. There is a double pipeline of cells that runs in the centre of the leaf. This is called main vein or midrib. The thin lines that run parallel to one another from the main vein are called veins. The veins carry water and minerals to the leaf. Food prepared in the leaves is carried by the veins to different parts of the plant. The leaf is attached to the stem with a stalk. The leaf has tiny openings between the cells called stomata. The leaf takes in carbon dioxide and gives out oxygen through stomata. Sometimes the leaf has extra water. This goes out through the stomata as water vapour. This is called transpiration. FOOd PREPARATiOn in PLAnTS Plants make food by the process of photosynthesis. 'Photo’ means light and 'synthesis' means putting together 'photosynthesis' is a process by which green leaves prepare their own food by using water and carbon dioxide in the presence of sunlight and chlorophyll. To make food the leaves need the following: Chlorophyll (pigment) from the green leaves. Water and minerals from the soil. Carbon dioxide gas from the air through stomata. Leaf tip Part of Leaf Photosynthesis Main vein Side vein Blade Stalk Stomata
16 Science–4 DIY ACTIVITY-1 TEST YOUR UNDERSTANDING Complete the sentences. 1. Plants prepare their own food in the _______________ . 2. Leaves are green because they have a green substance called ___________ . 3. ffe fflat part of the leaf is called _______________ . 4. ffe leaf is attached to the stem with a _______________ . Sunlight falling on the leaves is absorbed by chlorophyll. All the animals and plants use the Oxygen given out by the plants to breathe. Pocket Fact Plants, like animals, take in oxygen and give out carbon dioxide during respiration. Only during photosynthesis, plants take in carbon dioxide and release oxygen. HOW dO PLAnTS USE THEiR FOOd? The food prepared by plants is in the form of simple sugar, i.e. glucose. It is used in a number of ways. It is used for the growth of the plant. It is used to get energy to do various activities. The extra food is changed into a substance called starch. It is stored in leaves, roots, stems, fruits or seeds. Lettuce (leaves), sugar cane (stem), carrot (root), banana (fruit) and pea (seeds) are examples of parts of plants that we eat. Let us perform an activity that demonstrates the presence of starch in green leaves. Application of Knowledge
17 Science–4 DIY ACTIVITY-3 DIY ACTIVITY-2 Chlorophyll is needed for photosynthesis. Take a coloured leaf like coleus. Make a sketch of the leaf on a paper, clearly, marking the green parts of the leaf. Test for starch as done in previous activity. Compare the blue-black part of the leaf with your sketch. Result : Only the part that was somewhat green turns blue-black showing the presence of starch in it. ffus, it is conffirmed that photosynthesis has taken place only in those green parts. ffis shows that chlorophyll is needed for photosynthesis Sunlight is essential for photosynthesis. Keep a plant in a dark place for a day. ffe leaves will not be able to make food during this time due to the absence of sunlight. Cover a part of one leaf with black paper. Now, keep the plant in sunlight for about 6-8 hours Remove the paper and test the leaf for starch. Result : ffe leaf, except the covered part, shows the presence of starch and turns blue-black. Only the part which gets sunlight is able to make and store food. Result : When iodine is added to starch, the leaf turns blue. This shows that starch is present in the leaf.
18 Science–4 FUncTiOnS OF A LEAF A leaf performs the following functions: Green leaf of a plant makes food for the plant. Leaves are, therefore, known as the food factories of a plant. It helps a plant to breathe through the holes on its surface. Some plants such as mint, spinach, and cabbage have leaves that can be eaten as food. Some leaves have medicinal value too. For example, tulsi and neem. nOn-GREEn PLAnTS Non-green plants cannot make their food due to the lack of chlorophyll . They get their food from dead and decaying plants and animals. For example: Mushroom and Mould are not- green plants. inTERdEPEndEncE BETWEEn PLAnTS And AniMALS Plants and animals depend on each other for survival. Human beings and animals need food and oxygen which they get from plants. Plants need carbon dioxide to prepare their food. They get it from human beings and animals when they release carbon dioxide through breathing. So, plants and animals are interdependent. Pocket Fact Loss of water from the plant takes place through the stomata in the leaves. ffis also helps in the water cycle. Mushroom Interdependence of plants and animals Mould Animals depend on plants for food Animals breathe out carbon dioxide Carbon dioxide is used by plants Oxygen is used by animals Plants give out oxygen
19 Science–4 KEY WORDS Chlorophyll : the green substance present in leaves Glucose : a kind of simple sugar Insectivorous plants : carnivorous plants that trap and kill insects for food Leaf apex : the tip of a leaf Leaf blade : fflat part of the leaf Midrib : a thin tube running through the middle of a leaf Photosynthesis : the process by which leaves prepare food, using carbon dioxide and water in the presence of sunlight and chlorophyll Side veins : smaller tubes that are attached to the midrib of a leaf Stomata : tiny pores on the lower surface of a leaf, where exchange of gases takes place SUMMARY Most plants have green leaves. They prepare their food with the help of leaves. Plants are the basic source of food for all living things. Chlorophyll is a green pigment present in leaves. BALAncE in nATURE What will happen if there is a sudden rise in the number of animals? Plants may not be able to supply enough food and oxygen to all the animals. Or, if there is a sudden increase in the number of plants, the carbon dioxide breathed out by animals may not be sufficient for the plants. Similarly, if there is a sudden decrease in the numbers of either plants or animals it will disturb the balance in nature. To maintain this balance in nature, we must protect both plant and animal life. Various wildlife protection programmes have been started to give protection to wild animals, forest reserves and sanctuaries. Programmes like Vanamahotsava promote planting of trees and make people aware of the harmful consequences of cutting trees. To maintain the existence of life on the earth, a balance in nature is must. Pocket Fact ffe Amazon rainforest is so huge and are called the lungs of earth because it is estimated to produce 20% of the total oxygen in the earth's atmosphere through photosynthesis. Composting leaves is one of the smartest things you can do to make fertilizers. It's a great way to mulch, fertilize and improve your soil. Green Tip
20 Science–4 A. Choose the correct option. 1. ffe main vein of leaf carries. (a) Oxygen (b) Food (c) Chlorophyll (d) All of these 2. Which of the following is a non-green plant? (a) Cactus (b) Mould (c) Neem (d) Tulsi 3. ffe word 'Photo' means (a) Soil (b) Water (c) Light (d) Fruit 4. Which of the following is not necessary for photosynthesis? (a) Sunlight (b) Leaves (c) Oxygen (d) Carbon dioxide 5. Which plant leaves are used as medicine? (a) Mango (b) Banana (c) Rose (d) Tulsi B. Write T for true statement and F for false statement. 1. Plants make their own food through a process called photosynthesis. 2. ffe veins carry water and minerals to the food. 3. ffe leaf takes in carbon dioxide and gives out oxygen through stomata. 4. ffe leaves of croton plant do not have chlorophyll. 5. Plants can only make food during the daytime when the sun is shining. 6. Animals and plants depend on one another. Space between the cells from small openings called stomata. Photosynthesis is a process of food making in plants. A fine network of lines on the under surface of leaves are called veins. There must be a balance between plants and animals in nature. Stalk, leaf blade, main vein and side veins are the parts of leaf. A balance between plant and animal must be maintained in nature. EXERCISE TIME
21 Science–4 C. Match the following columns. Column A Column B 1. Iodine solution a. Green pigment 2. Chlorophyll b. Cactus 3. Sugarcane c. Tiny pores 4. Stomata d. Stem 5. Non-green plants e. Turns starch blue D. Write short answer. 1. Deffine photosynthesis. 2. What are food factories? 3. What are the substances formed afier photosynthesis? 4. What is transpiration? 5. How is food produced by cactus plants? E. Answer these questions. 1. Draw a leaf and label its various parts. 2. Explain with the help of an activity that sunlight is required for photosynthesis. 3. How do plants use their food? 4. Red leaves cover croton. Is it capable of producing food on its own? 5. How are plants and animals dependent on each other? 6. Explain the fflow of energy in living things. TIME TO THINK (HOTS) Imagine you have a plant at home that isn't growing well. What might you do to ensure it has enough food and sunlight for healthy growth? Collect pictures of any 5 unusual plants and paste them on a sheet of chart paper. Write 2-3 lines about each. Show it to your teacher. Also give an oral presentation on your chart. TIME TO CREATE (Project Work/Creative Skills) What would happen if there were no plants on the earth? TIME TO DISCUSS (Collaborative Skills)
22 Science–4 Look at the picture and answer the questions: 1. In what form does the potato plant stores its extra food? (Vitamins/Starch) 2. If you put a few drops of iodine on a cutted potato, what would you observe? You have a small garden plot in your backyard. What responsibilities do you have in terms of taking care of the plants, including making sure they have the right food and conditions for growth? LIFE SKILLS Take students to the school garden and show them the diflerent kinds of leaves. Ask each student to collect fallen leaf and point out the various parts of a leaf. FOR THE TEACHER TIME TO OBSERVE (Observational Skills) (Go Green, Life Skills)
Activity Project: Plants Are Living Beings: Investigating the Life of Plants Aim: To explore and demonstrate that plants are living organisms with specific needs and characteristics. Materials Needed: 1. Potted plants (one for each student or group) 2. Small pots or containers 3. Potting soil 4. Seeds (e.g., bean seeds) 5. Watering cans or spray bottles 6. Drawing materials (paper, coloured pencils, markers) 7. Access to books or online resources for research Create Plant Profiles: Make separate plant profiles for each selected plant. Include the following information: Plant name Environment where it's found Adaptations it has developed Any interesting facts about the plant Planting Seeds: Provide small pots, potting soil, and seeds (e.g., bean seeds). Instruct students to plant a seed in their pots and explain that they will observe and care for their plant throughout the project. Recording Observations: Ask students to keep a plant journal where they record daily or weekly observations about their plant's growth, changes in leaves, stems, and any flowers that appear. Discussion: Facilitate a class discussion about the importance of plants in our lives and the ways in which they are similar to and different from other living beings. Activity Time–1 APPROACH 23 Science–4
24 Science–4 LEARNING GOALS Afier completing this chapter, you will be able to know about: Adaptation to habitat Adaptation for food Adaptation for protection Endangered animals Protecting wildlife Adaptations in Animals 3 LET’S WARM UP Write the names of three animals that live in each of these places. Like plants, animals are found everywhere on the earth. Some animals live on land, some live in water, some in deserts and some in cold regions. The place where an animal lives is known as its habitat. The living conditions in these habitats are very different from each other. The conditions which decide the habitat of the animals are soil, moisture range of temperature, light intensity and availability of food. Land ____________________ ____________________ ____________________ On trees ____________________ ____________________ ____________________ Mostly in the air ____________________ ____________________ ____________________ Land and water ____________________ ____________________ ____________________ In water ____________________ ____________________ ____________________ Unit-II : Animals as Living Beings (Experiential Learning)
25 Science–4 ADAPTATIONS TO HABITAT Adaptations to habitat are the unique traits and behaviours that plants and animals develop to live successfully in their specific homes or environments. These adaptations help them find food, stay safe from danger, and have babies, ensuring their survival in their particular habitat. Animals That Live on Land Terrestrial Animals Terrestrial animals are animals that live and primarily dwell on land. They are adapted to living on solid ground rather than in water or the air. These animals include a wide variety of species that can be found in different types of habitats all over the world. They have well-developed sense organs such as eyes, ears or nose to sense their surroundings. They have different body coverings such as fur, hair or scales suited to the habitat that they live in. Tigers, elephants, horses, cows, pigs, dogs and bears are some examples of terrestrial animals. Let us learn about some terrestrial animals that survive in extremely harsh climates such as in deserts or in polar regions. Desert Deserts are very hot during the daytime. So, desert animals have special features to prevent water loss from their bodies. For example, camels which live in deserts have a very thick skin and less body hair. They do not sweat. This prevents water loss from their bodies. The thick skin helps camels to bear the heat and cold in a desert. Tiger Animal Adaptation of Habitat Camel Pocket Fact Camels have long, thick eyelashes to protect their eyes from blowing sand and harsh sunlight in the desert. Pocket Fact Some terrestrial animals such as snakes do not have legs. ffey use their skin to crawl along the ground.
26 Science–4 Polar Regions The North and South poles are covered with ice throughout the year. These are the coldest places on the Earth. There is very little food available in these regions. Polar bear, artic fox and penguin are some animals that live in polar regions. They have a thick layer of fat called blubber under their skin to keep their body warm. Polar bears live in the cold polar regions. Yaks, snow leopards, llamas and mountain goats live in mountains. They have a thick layer of hair which protects them from cold. Animals That Live in Water Animals that live in water are called aquatic animals. The body of some aquatic animals is covered with a hard covering to protect them from other animals. For example, fishes have scales, while crabs have a hard shell to cover their body. Aquatic animals have fins or modified limbs to help them swim in water. Fish and many other aquatic animals have gills to breathe in water. Animals That Live Both on Land and in Water Animals such as frogs and toads live both on land and in water. They are called amphibians. They can breathe in water and outside the water. When they are in water they breathe through their skin and when they are on land they breathe through their lungs. Frogs and toads have long hind legs which help them to move on land by jumping. They have webbed feet and tails which help them to swim in water. Fishes have scales Polar bears have a thick layer of fat and fur to help them to live in very cold places. Frog is an amphibian
27 Science–4 Animals That Live on Trees Animals that spend most of their time on trees are called arboreal animals. Spider monkeys, orangutans and tree lizards are arboreal animals. They have strong claws and muscular limbs to climb trees. They use their strong claws to hold on to the branches of trees. Squirrels have highly flexible ankle joints that help them to move up and down quickly on trees. Spider monkey, opossum and chameleon have very long tails. They use their tail as a fifth limb to hold on to branches while swinging from tree to tree. Animals That Fly Animals that can fly in the air are called aerial animals. Most birds and insects have wings that help them to fly. Birds have feathers to keep their body warm. Their bones are hollow and have air spaces. This allows birds to take in a lot of air for producing more energy. Their boat-shaped body which is narrow in the front and back and broad in the middle helps them to fly through the air easily. ffe hands, feet and tail of monkeys become adapted for grasping ad holding branches. Pocket Fact Chameleons, are famous for their ability to change colour. ffey use this skill for communication, temperature regulation, and to blend in with their surroundings. Birds travel long distances towards warmer places for food and warmth. TEST YOUR UNDERSTANDING State True or False 1. Animals in deserts are adapted to conserve water in their body. __________ 2. ffe surrounding in which an animal lives is called its habitat. __________ 3. Spider monkey is a desert animal. __________ 4. Fish can live both on land and in water. __________ 5. Birds have hollow bones that help them to ffly. __________ Application of Knowledge
28 Science–4 ADAPTATIONS FOR FOOD Different animals eat different kinds of food. To help them eat their kind of food, they have special kinds of body parts such as mouth, teeth and claws. Herbivores Plant-eating animals like cow, goat, deer, giraffe and elephant are herbivores. They have sharp front teeth to cut tough plants and the grasses. They have flat and strong grinding teeth to grind leaves, seeds and twigs. Giraffe has a long neck to reach the leaves of tall trees. Herbivores possess long and strong legs to travel long distances in search of food. This also helps them to run away from predators. Carnivores Carnivorous animals or carnivores eat the flesh of other animals. They have sharp teeth and claws for tearing out the flesh of their prey. Birds such as eagles and hawks also eat flesh. They use their sharp claws to catch and hold on to their prey. They have a hooked beak to tear the flesh. Wolves, tigers, lions, eagles and falcons are carnivores. Many snakes are poisonous and their bite can kill a prey. They can open their mouth very wide to swallow their food whole. Omnivores Animals that eat both the plants and animals are called omnivorous animals. Animals like crow, cockroaches, ants, cat and bear eat both plant and animals. Human beings are also omnivorous because they eat flesh of some animals and plants both. Parasites Some animals live either on or inside the bodies of other animals for their food. They are called parasites. The animals on which parasites depend for their food are called hosts. Mosquitoes,
29 Science–4 hookworms, leeches and fleas are parasites. They have suckers or sucking tubes to suck blood from their host. The body of most parasites is flat from both the surfaces as they need to hook on the host. Scavengers Animals that eat dead animals are known as scavengers. For example vulture and hyens. Animals like hyena have broad and strong teeth, while birds like vulture have strong hooked and curved beak. They also have strong sense of smell and excellent eyesight. They help to keep the forests clean. ADAPTATIONS FOR PROTECTION Animals adapt to protect themselves from being harmed or hunted by other animals. • Deer and zebra run very fast to save themselves from lions and tigers. • Rhinoceros and buffalo have horns to keep away their enemies. • The huge size of an elephant and a hippopotamus scares away their enemies. • Porcupine and hedgehog have sharp spines that save them from their enemies. • Tortoise and snail have hard shells on their bodies. They hide in their shells when faced with danger. • Some snakes, lizards, the Arctic ground squirrel and frogs cannot survive in the cold winter months. So, they eat a lot during summer and store the extra food in their body as fat. When winter comes, they sleep in caves or underground holes for many months. This is called hibernation. These animals are able to survive on the extra fat stored in their body. • Some animals have features by which they blend into their environment. A chameleon can change its colour to match its surroundings and outwit its predators. Animals such as zebras, tigers and leopards that live in the jungles have stripes or spots on the body. This helps in blending with their surroundings so that it is hard for their enemies to spot them. • Some animals such as crocodiles and lungfish go to sleep for a long time during hot and dry period to avoid extreme heat. This is known as aestivation. Pocket Fact Female mosquitoes have a tubelike mouth to suck blood.
30 Science–4 ENDANGERED ANIMALS Some species of animals are now extremely rare. They are leaving the planet quickly. It’s because people are hunting them for their body parts or ruining their habitats. These creatures are known as endangered species. Animals under danger of extinction include the tiger, rhinoceros, elephant, panda, crocodile, polar bear, and sea turtle. PROTECTING WILDLIFE Without habitat protection, endangered species of animals risk extinction. The Indian government has passed legislation to regulate animal killing and the sale of body parts in an effort to safeguard these species. Many national parks and wildlife sanctuaries have been set up by our government to protect these animals. Some of them are Jim Corbett National Park (Uttarakhand), Kaziranga National Park (Assam), Kanha National Park (Madhya Pradesh), Bharatpur Bird Sanctuary (Rajasthan) and Gir National Park (Gujarat). KEY WORDS Habitat : the place where a plant or an animal lives. Adaptation : alterations or changes made by living organisms to suit their environment. Omnivores : animals that eat both plants and fflesh. Parasite : animals living on or inside the bodies of other animals. Endangered : in danger of disappearing from the earth. SUMMARY Animals have unique adaptations to the environments they live in, which allows them to survive in various parts of the world. According to their habitat, animals can be classified as terrestrial, aquatic, amphibian, aerial, or arboreal. Animals may be parasites, herbivores, carnivores, or omnivores. Animals change to defend themselves against predators. Do not purchase endangered bird and animals species, as they are being sold at high prices by the poachers. If we don’t purchase them, it will decrease or stop the sale of those birds and animals. Green Tip Wild sancturies and national parks of India Word Help National park: A location where animals are housed and provided with a natural environment. Wildlife sanctuary: A protected area for natural plants and animals.
31 Science–4 EXERCISE TIME A. Tick () the correct answer. 1. ffe natural home of an animal is called its: (a) Habitat (b) Respiration (c) Extinction (d) Building 2. Terrestrial animals breathe through: (a) Air holes (b) Gills (c) Lungs (d) All of these 3. Which is the world’s biggest bird? (a) Penguin (b) Ostrich (c) Eagle (d) Sparrow 4. Which animal get their food by sucking the blood? (a) Ant (b) Leeches (c) Whale (d) All of these 5. Flesh eating animals are also called: (a) Scavengers (b) Herbivores (c) Omnivores (d) Endangered 6. Which of the following is not an arboreal animal? (a) Monkey (b) Rabbit (c) Chameleon (d) Whale B. Write T for true statement and F for false statement. 1. Animals can change their physical characteristics to adapt to new environments. 2. Arctic animals, like polar bears, have thick fur and layers of blubber to stay warm in cold environments. 3. Animals that live in the desert, such as camels, have adapted to store water in their humps. 4. Animals in the ocean have gills, which allow them to breathe underwater. If we keep killing endangered creatures and destroying their habitats, they may go extinct. The Indian government has established national parks and wildlife sanctuaries in order to safeguard and conserve animals.
32 Science–4 C. Write short answers. 1. How would you deffine habitat? 2. What is blubber? 3. What is the advantage of muscular limbs in arboreal animals? 4. Why is the ability to change color an important adaptation for some animals, like chameleons? D. Answer these questions. 1. Why do elephants live in large communities? 2. What is blubber? How is it helpful for the animals? 3. How have herbivores adapted themselves to eat their food? 4. How can we prevent animals from becoming extinct? TIME TO THINK (HOTS) 1. What changes will a polar bear need to make in its body to be able to live in a desert? 2. Fish are unable to live on land. Why? 1. Visit a zoo and study the different animals found there. Make a note of animals for which special surroundings have been created. 2. Collect pictures of different types of animals living in cold and hot regions. TIME TO CREATE (Project Work/Creative Skills) Have a discussion on extinct animals. Discuss how animals are endangered and how they will become extinct, if steps are not taken to protect them. TIME TO DISCUSS (Collaborative Skills) ffe tiger is an endangered animal. Make a list of any ffive endangered animals. Make a poster on saving any of these. Write a suitable slogan. LIFE SKILLS Teacher can show a cactus plant to the students to show the features developed by them to save water. FOR THE TEACHER (Go Green, Life Skills) To know more about adaptation in animals, please scan this QR code. WEBLINK
33 Science–4 LEARNING GOALS Afier completing this chapter, you will be able to know about: Animals that produce babies Animals that lay eggs Eggs of frogs and insects Eggs of ffsh and reptiles Care of the young ones 4 Reproduction in Animals LET’S WARM UP Match the animals with their babies. Also write their names. All living things do not live forever. They gradually grow with time and then die. The process by which living beings produce young ones of their own kind structure of an egg is called reproduction. If the young ones are not produced, the species will be get extinct from the world. (Experiential Learning)
34 Science–4 Pocket Fact Ostrich lays the largest egg. It weighs around 1.5 kg while the hummingbird lays the smallest bird egg which weighs around half a gram. Kitten with cat Calf with cow Dog mother with puppies All animals do not have the same way of reproduction. Some animals lay eggs, but some of them give birth to their young ones. Animals reproduce in different ways: ANIMALS THAT PRODUCE BABIES Mammals are creatures that give birth to young and provide them with milk. Mammals include the tiger, dog, horse, cat, and human being. Mother animals give their young their own milk to drink. ANIMALS THAT LAY EGGS Eggs are laid by animals like birds, fish, frogs, turtles, crocodiles, and snakes. Their offspring emerge from the eggs. These creatures are referred to as oviparous or egg-laying animals. Birds The eggs are laid by female birds, who then rest on the nests to stay warm. Incubation refers to this stage of keeping warm. The eggs open, releasing the young birds. The newborns spend several weeks, months, or even years growing inside the mother’s womb. Some mammals, including the cow, the human, and the monkey, typically give birth to one child at a time. They occasionally give birth to two or more children. Other mammals like the dog, cat, and rat give birth to several young at once. Word Help Womb: A female animal’s organ where the baby is developed.
35 Science–4 Structure of an Egg The structure of eggs of all birds is broadly the same. An egg has a hard protective shell. It contains a yellow yolk which provides food to the chick growing inside it. The growing chick is also called an embryo. The yolk is surrounded by a white albumen which protects the growing chick. The mother bird sits on the egg to keep it warm. The embryo develops into a chick only when the egg is kept warm. The chick breaks the shell and comes out when it has grown. This is called hatching. Frog A female frog lays hundreds of eggs at a time in a lake or a pond. When the eggs hatch, tiny baby frogs called tadpoles come out of them. A tadpole has a tail and Structure of an egg DIY ACTIVITY-1 Grab a bowl and an egg. Gently crack the egg shell using a knife or the handle of a spoon. Carefully pour the mixture into the bowl. The albumen and yolk are visible. You’ve broken open the egg shell. TEST YOUR UNDERSTANDING Answer in one word. 1. An animal that lays eggs ____________________ 2. ffle process of producing young ones ____________________ 3. ffle part of the egg that protects embryo from shocks and jerks ____________________ Life cycle of a hen ffle hen warms the eggs ffle chick hatches 4–5 week young chick adult Application of Knowledge
36 Science–4 Insects Insects like grasshopper and cockroach also lay eggs. They complete their life cycle during three stages. The young insect that comes out of the egg is called nymph. It looks like an adult insect. As the nymph grows, it sheds its skin. This is called moulting. After moulting many times, a nymph becomes an adult. Insects like butterflies have four stages in their life cycle. The female butterfly lays eggs in clusters on the upper part of a leaf. First the egg hatches into a larva. It is different from an adult. The larva of a butterfly is called a caterpillar. While the larva of a butterfly is called maggot. The larva eats and grows rapidly. After sometime, it stops eating and covers itself in cocoon. This stage is called the pupa. The caterpillar under goes mounting several times inside pupa. Finally, pupa burst and the adult insects comes out. looks like a fish. It swims in water and eats water plants. After about two months, lungs and legs appear. They have gills for breathing under water. They are fast eaters. The leg grows longer and the tail becomes shorter. Now, the young frog looks more like its parents. The process in which tadpole undergoes several changes to become an adult is known as metamorphosis. The feeding jabots change into an adult frog. Life cycle of a cockroach Life cycle of a frog Life cycle of a butterffiy Eggs Caterpillar Pupa Word Help Larva: ffle immature insect, which is distinct from the adult bug. Nymph Egg Adult Frog Young Frog Eggs Tadpole with legs
37 Science–4 There are four stages in the life cycle of a housefly. The eggs of a housefly are long and white. It lays its eggs in the garbage and in rotten food. A few hours after an egg has been laid, it changes into a larva. The larva of a housefly is called maggot. These maggots feed on the food where they are laid. A few days later, they drop their body covering and develop a new one. Each larva grows into a pupa. The pupa finally changes into an adult housefly. Fish A fish lays thousands of eggs at one time in water. Eggs of fish are called spawn. The eggs of fish do not have shells. A fish lays a large number of eggs at a time but a few of them develop into small fish. Many eggs and young fish are eaten by big fish. A baby fish is called fry. Reptiles Turtles, snakes, and lizards, among other reptiles, deposit their eggs in the ground. They do not warm their eggs while seated. The heat of their surroundings warms them, causing them to hatch and give birth to young. They lay eggs with soft shells. Leathery describes them. In the earth, crocodiles lay their eggs. The young are placed in the water as soon as they hatch. They are fed and cared for until they can support themselves. Life cycle of a Houseffiy Life cycle of a ffsh DIY ACTIVITY-2 Collect some caterpillars in rainy seasons and put them in a shoe box with some fresh leaves. Make small holes in the box for some light and air. Do not disturb it for few days. After one week the caterpillar transforms into pupa. After one or two weeks a beautiful butterfly comes out from the pupa. The silk-moth also reproduces in the same way as butterfly. The thread from the cocoon of silk moth is used to make silk. Houseffiy Eggs Larva Pupa Eggs Young ffsh Life cycle of ffsh Young Fish Adult Fish
38 Science–4 KEY WORDS Reproduction : ffle process through which animals produce young ones of their own kind. Mammals : Animals that give birth to young babies. Hatching : Coming out of a young one from an egg. Spawns : Clusters of eggs. Moulting : Shedding old skin. Nymph : Young one of an insect resembling the adult. Womb : A hollow muscular organ in the pelvic cavity of females. CARE OF THE YOUNG ONES Mammals take care of their babies for a long period of time. Usually the mother cares for the young ones. She feeds the babies, clean them and keeps them warm. The father bring food for them. Parents protect the young ones from enemies. As they grow, their parents teach them to find food and live on their own. Birds lay their eggs in the nest. The parent birds take turns in protecting the eggs and sit on the eggs to help them for hatching. When the baby birds come out, the parent birds feed them and care for them till they are able to fly off and take care of themselves. Reptiles like crocodiles lay their eggs in holes in the ground and cover them till they are hatched. After that the mother picks the babies in its mouth and carries them to water. She guards them for several months. These types of care are not seen in lower animals like fish, frogs, lizards and most of the insects. They take care in laying the eggs in a safe place. After that, they pay no attention to the eggs. As a result many eggs and young ones are eaten up by other animals. TEST YOUR UNDERSTANDING Write ‘T’ for true and write ‘F’ for false statement. 1. Reptiles are creatures that give birth to young and nurse them with their milk. 2. ffle growing embryo receives nutrition from the albumen. 3. A nymph is the name for the young cockroach that hatches from the egg. 4. Pupa refers to a houseffiy’s larva. Self Direction
39 Science–4 SUMMARY All creatures that are alive have offspring that resemble them. Reproduction is what we term this process. While some animals give birth to their young, others lay eggs from which their young develop. Mammals are creatures that give birth to young and provide them with milk. Birds produce eggs. The egg has a golden yolk, white albumen, and an outer shell. A cockroach has three phases in its life cycle: the egg, the nymph, and the adult. There are four stages in both the butterfly and housefly life cycles. Thousands of eggs are laid by fish in water. Snakes, turtles, and lizards are reptiles that deposit their eggs in the ground without warming them up. EXERCISE TIME A. Tick () the correct answer. 1. ffle process of producing young ones is called (a) Digestion (b) Reproduction (c) Photosynthesis (d) Egg 2. ffle red spot in the center of an egg is called the (a) Shell (b) Embryo (c) Yolk (d) All of these 3. A baby frog is called a (a) Nymph (b) Tadpole (c) Fry (d) Chick 4. A baby ffsh is called a (a) Larvae (b) Fry (c) Nymph (d) None of these 5. ffle yellow portion inside an egg is the (a) Yolk (b) Albumen (c) Lemon (d) None of these
40 Science–4 6. What is called the process of shedding the old skin? (a) Maggot (b) Nymph (c) Pupa (d) Yolk 7. ffle eggs of a ffsh are collectively called (a) Nymph (b) Spawn (c) Tad pole (d) Group 8. Which of the following reptile make a nest in ground (a) Lizard (b) Dinosaur (c) Crocodile (d) Tortoise B. Match the following. 1. Yolk (a) incubation 2. Cockroach (b) tadpole 3. Birds (c) egg 4. Frog (d) Larva 5. Caterpillar (e) nymph C. Fill in the blanks. 1. ffle clusters of eggs laid by female frogs are called _______________. 2. A caterpillar feeds on _________________ . 3. __________________ produce milk and feed their young ones. 4. ffle yolk in the egg provides_______________ to the growing chick. 5. Birds sit on their eggs to _______________ them. D. Write short answers. 1. Why do animals reproduce? 2. What kind of care do mammals give to their young? 3. Deffne life cycle and moulting. 4. Explain the structure of a bird’s egg with the help of a labelled diagram. 5. What is metamorphosis? E. Answer these questions. 1. Describe the life cycle of a butterffiy. 2. What is the diflerence between the life cycle of a frog and a houseffiy? 3. Explain the life cycle of a frog. 4. Explain the structure of a bird’s egg with the help of a labelled diagram. 5. How do mammals take care of their young ones afier they are born?
41 Science–4 TIME TO THINK (HOTS) What would happen if there is no reproduction in animals? 1. Visit a poultry farm and watch the parental care of hens. 2. Visit a nearby pond and look for the frog’s eggs and tadpoles. What do tadpoles look like? TIME TO CREATE (Project Work/Creative Skills) Why do birds need to make their nests? TIME TO DISCUSS (Collaborative Skills) What are your plans if you come across a bird’s nest? For each statement, type “Yes” or “No.” 1. I am not going to disrupt the nest. ____________ 2. I will approach the nest closely. ____________ 3. I will try to give the chicks food. ____________ 4. I will move the chicks to a secure area. ____________ 5. I will keep a distance from the chicks and watch them. ____________ LIFE SKILLS Talk to your kids about animal reproduction. Describe how animals procreate and raise their young. Discuss the many egg-laying animals’ life cycles. FOR THE TEACHER (Life Skills) To know more about lifecycle of animals, please scan this QR code. WEBLINK
Activity Project: Animals as Living Beings: Investigating the Life of Animals Aim: To help students understand that animals are living beings with characteristics like breathing, eating, moving, growing, having feelings and reproduction. Materials Needed: 1. Pictures or images of various animals 2. Drawing or colouring materials 3. Books or online resources about animal adaptations 4. Poster board or large paper 5. Glue, scissors, and markers Animal Pictures Discuss the habitats of these animals (e.g. desert, rainforest, polar regions) and ask the students what they think helps these animals survive in those places. Research Provide books or online resources about animal adaptations. In pairs or small groups, assign each group a specific animal and its habitat. Have them research and take notes about how their assigned animal has adapted to its environment. Reproduction Activity Organize a simple hands-on activity to demonstrate how animals reproduce. For example, you can use playdough to model the process of a bird building a nest and laying eggs. This can help students visualize the concept. Discussion: Ask questions like, “What are the different methods of animal reproduction?” and “Why do you think some animals lay eggs while others give live birth?” Activity Time–2 APPROACH 42 Science–4
43 Science–4 LEARNING GOALS Afier completing this chapter, you will be able to know about: We need food Nutrients A balanced diet Awareness concerning food Food and Health 5 LET’S WARM UP Write some examples of following types of food : WE NEED FOOD We need food for several important reasons. First and foremost, food provides us with the energy our bodies need to function. Just like a car needs fuel to run, our bodies require food to give us the energy to play, learn, and do all the things we enjoy. Secondly, food helps us grow and stay healthy. It contains special things called nutrients, like vitamins and minerals, which are like the building blocks that make our bones stronger and help our muscles grow. These nutrients also help our bodies repair when we get small injuries. Body-building Food ____________________ ____________________ ____________________ ____________________ Energy-giving Food ____________________ ____________________ ____________________ ____________________ Protective Food ____________________ ____________________ ____________________ ____________________ Unit-III : The Human Body and Our Needs Self Direction
44 Science–4 NUTRIENTS Nutrients are like tiny superheroes that help us to keep our bodies healthy and strong. They are special substances found in the food we eat, and they have important jobs to do inside our bodies. Proteins, fats, carbohydrates, vitamins and minerals are the five nutrients that our food contains. Our food also contains water and roughage. So, these superheroes called nutrients are essential for our bodies to grow, stay healthy, and have the energy to do all the fun things we love to do. Eating a variety of foods helps us get all these nutrients and keeps our bodies happy and strong. Proteins Proteins are nutrients that help our bodies grow and repair themselves. They help our body to build muscles. That is why food which contain proteins are called bodybuilding food. Children need more proteins in comparison to adults as they are in the growing stage. Milk, cheese, pulses, nuts, meat, fish and eggs are rich in proteins. Carbohydrates Carbohydrates are the main source of energy in our food. They are called fuel foods. They give us heat and energy. Sugar and starch are rich in carbohydrates. Sugar is present in fruits and sugarcane. Starch is present in almost all the foods we eat, such as, wheat, rice, potatoes, jam and cakes. These food items are called energy giving foods. Fats Fats are an essential part of our diet, and they play a vital role in keeping our bodies healthy. They are like the cozy blankets that provide warmth and give us extra energy. There are different types of fats, and Sources of proteins Sources of carbohydrates Sources of fats We should not waste food. Only take much food which is required. Excess food which is left after marriages and parties should be distributed to the needy people. Green Tip
45 Science–4 TEST YOUR UNDERSTANDING Complete the sentences. 1. _______________ makes our bones and teeth strong. 2. Proteins are called ________________ nutrients. 3. ________________ helps in making blood. 4. Oil and butter are good sources of ________________. 5. People who do lot of physical work need more ________________. some are healthier than others.Oil, butter, ghee, nuts and fish contain fats. Excess amount of fat is stored in the body to be used later. Fats also help to protect the important organs inside our body. Food items rich in carbohydrates and fats are called energy-giving foods. Vitamins and Minerals Vitamins and minerals are needed in less quantity by our body. They keep our body healthy. So they are called protective foods. We must have them every day. Vitamins: Vitamins help our body to fight diseases. Some of the vitamins are vitamin A, vitamin B, vitamin C, vitamin D, vitamin E and vitamin K. Minerals: There are many different minerals such as calcium and iron which are needed by our body. We need calcium for strong bones and teeth. Iron helps in the formation of blood. Meat, fish, milk, vegetables and fresh fruits are rich in vitamins and minerals. So, when we eat a variety of foods like colourful fruits, dairy, leafy greens, and lean proteins, we make sure that our bodies get all the vitamins and minerals they need. These nutrients help us to grow, stay healthy, and have the energy to do all the fun things we enjoy! Sources of vitamins and minerals Application of Knowledge Find out the nutritional worth of five of your favourite fruits and vegetables by conducting an online search. ACTIVITY Application of Knowledge
46 Science–4 Roughage Roughage, also known as dietary fiber. It cannot be digested. Roughage does not contain nutrients. It helps keep our stomachs and intestines healthy and helps in the digestion of the food. Fruits and vegetables have a lot of roughage. Roughage is also found in the bran of whole grains. Water Although it contains no nutrients, water is nonetheless vital to life. Our body weight is roughly 70% water. Water aids in appropriate food digestion in the body. It facilitates the body’s elimination of waste. Additionally, it keeps the body’s temperature stable. Water is a component of food. But it is not enough. More water is required by the body. Every day, we should consume eight to ten glasses of water. A BALANCED DIET A balanced diet is like a special mix of different types of foods that our bodies need to grow, stay healthy, and have plenty of energy. It’s like a jigsaw puzzle, where each type of food has its own important role. We need foods like fruits, vegetables, grains, proteins, and dairy in just the right amounts to keep our bodies working properly, stay strong and happy! ALERTNESS CONCERNING FOOD Cleaning the Raw Food In fields, produce such as fruits and vegetables grows. They are frequently caked in mud and grit. These transport pathogenic microbes. In order to protect them DIY ACTIVITY Examine the nutrition labels of five items you consume frequently, such as milk, bread, cereals, etc. Paste them to your notebook and indicate in the table if the food is mostly made up of protein, carbohydrates, or fat.
47 Science–4 Wash fruits and vegetables before cutting. from infections, fruits and vegetables are also treated with chemicals. But these substances are bad for humans. Therefore, food should be carefully cleansed before consumption. After being chopped, fruits and vegetables lose some of their nutrients if they are washed. Therefore, they should always be washed before cutting. Precautions While Cooking Eaten raw, the majority of fruits and several vegetables, including carrot, cucumber, and radish. However, some foods must be prepared before consumption. Food that has been cooked is softer, tastier, and easier to digest. It also eradicates bacteria. Cooking techniques include boiling, steaming, frying, roasting, baking, and more. We should not cook food for a long time. Overcooking destroys nutrients. Food should be cooked in just enough water. Extra water in cooked food also contains nutrients. If the extra water is thrown away, the nutrients in it are also lost. Preserving Food Sometimes, when food is not stored properly it may get spoiled. To prevent food from spoiling, it needs to be preserved. Different kinds of foods are preserved in different ways. Raw food Cooked food Methods for preserving food Refrigerating Canning Preserving pickles We should grow some vegetables in our kitchen garden. We should use waste food for making compost manure. Green Tip
48 Science–4 EXERCISE TIME A. Tick () the correct answer. 1. What is the primary purpose of food for our bodies? a. To taste delicious b. To provide energy c. To make us grow taller d. To quench our thirst 2. ffis helps in the digestion of food. a. Carbohydrates b. Roughage c. Vitamins d. Minerals KEY WORDS SUMMARY Food gives us energy. It also provides us with materials required for the growth, repair and general health of our body. Proteins, fats, carbohydrates, vitamins and minerals are the five nutrients that our food contains. Besides, nutrients, we also need water and roughage to make our body function properly. A balanced diet contains all the nutrients in the right amount. We should wash fruits and vegetables thoroughly before eating. Boiling, steaming, frying, roasting and baking are the different methods of cooking. Food can be preserved in different ways like drying, refrigeration, canning and bottling, etc. Nutrients : components of the food that are needed for growth, to stay healthy and to fflght diseases Proteins : nutrients which help us to grow Fats : nutrients which give us more energy than carbohydrates Carbohydrates : nutrients which give us energy to perform our daily work Vitamins : protective nutrients that help our body to fflght diseases Roughage : the fflbre present in food that helps in removal of waste from our body Balanced diet : a diet that contains all the nutrients in the right amount Food preservation : the method used to preserve food for a long time
49 Science–4 3. Which food group provides us with energy to stay active and play? a. Fruits and vegetables b. Dairy products c. Protein-rich foods d. Carbohydrates 4. Which nutrient is essential for building strong bones and teeth? a. Vitamins b. Protein c. Calcium d. Fiber 5. Food is not preserved by a. Melting b. Cooking c. Drying d. Refrigeration B. Fill in the blanks with correct words from the brackets. 1. Food can be eaten in __________________ or __________________ form. 2. __________________ and __________________ are energy giving nutrients. 3. Water makes up __________________ of our body. 4. __________________ is important for proper digestion of food. 5. __________________ helps the body to fflght diseases. 6. We must not eat __________________ food. C. Write ‘T’ for true and ‘F’ for false statements. 1. Water is not necessary for our body. 2. Red chillies can be preserved by keeping them in water. 3. Vitamin B is called the sunshine vitamin. 4. Roughage helps the body to get rid of undigested food. 5. Canning requires removal of moisture. D. Write short answers. 1. What do you mean by nutrients? 2. What is the function of vitamins in our body? 3. How is roughage useful for our body? 4. Why should we not overcook food? 5. List some methods of preserving food. E. Answer these questions. 1. Why do we need food? 2. How are carbohydrates and fats useful for our body? 3. Why are proteins especially important for children? 4. Why is water essential for our body? 5. Why should we clean raw food?
50 Science–4 Ajay works in a big office. He either orders a large pizza or a burger and cola for his lunch daily. Lately, he has developed some health problems. Discuss what kind of health problems is Ajay prone to developing and suggest what he should do to cure these problems? LIFE SKILLS Explain the students why we need to eat food? Why junk food is not good for health? Encourage students by telling them what are benefflts of eating good nutritious food. FOR THE TEACHER TIME TO THINK (HOTS) Somesh eats rice, chapattis, bread, fruits and vegetables on a regular basis. On the other hand, Ritesh eats nuts, fried chicken and toast with butter. Who has greater chances of gaining weight and why? Do you notice any colourful fruits in the picture? Why are colourful foods important in our diet? _____________________________________________ _____________________________________________ _____________________________________________ TIME TO OBSERVE (Observational Skills) In groups of four, make a chart on the different ways in which we preserve food. Collect pictures of different foods that are preserved. TIME TO CREATE (Project Work/Creative Skills) Discuss the importance of variety in our diet and the potential consequences of not eating a variety of foods. TIME TO DISCUSS (Collaborative Skills) To know more about importance of nutrients intake, please scan this QR code. WEBLINK