Science and Elementary Technology

UNIT 1: AGRICULTURAL TOOLS

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  Introduction 

  • People do different types of jobs for their living. 
  • Many jobs can be done using hands.
  • But some jobs are not easy to do with hands alone.
  • To make such jobs easier, we use tools. 
    

  1.1 Identification of Agricultural Tools

  Activity-1: Identifying and naming Agricultural Tools Below;

  

  These are some agricultural tools. Farmers use these tools in farming.

  Please answer these questions below:

               1. What are these?

               2. Who use these tools and what for?

               3. Identify these tools and write their names in your science notebook.

  1.2 Uses of Agricultural Tools

  Activity-2: Grouping Agricultural Tools Based on their Uses

  

  Identify the tools the farm workers use.

  Group these tools according to their uses. Fill in the table below.

  
  

  Table 1.1: Grouping Agricultural Tools Based on their Uses

  a) Cleaning Tools

  
  

  b) Digging Tools

  

  c) Watering Tools

  
  

  d) Transplanting Tools

  
  

  e) Sharpening Tools

  
  

  f) Cutting Tools

  
  

  g) Transporting Tools

  
  

  h) Milking Tools

  
  

  i) Spraying Tools

  
  

  j) Cleaning Tools

  
  

  Can you name some other agricultural tools?

  1.3 Maintenance of Agricultural Tools
  

  Activity-3: Practicing the Maintenance of Agricultural Tools

  • Visit a nearby agricultural farm.
  • Observe and practice the ways people maintain all agricultural tools.
  • Make a report on it and present to the class.
    

  The following are useful methods to maintain agricultural tools in good condition:

  1. Tools must be cleaned properly after use.
  2. After cleaning, tools must be stored in a safe, dry and termite-free place.
  3.  Digging and cutting tools should be kept sharp.
  4. Plastic sprayers must be kept away from the fire.  Pipes and nozzles must be cleaned regularly to prevent blockages.
  5. Damaged tools must be repaired properly.
  6. Metallic tools like wheelbarrows must be painted regularly to avoid rusting.
  7. On transporting tools and their parts, oiling and greasing have to be done regularly.
  8. Tools must be handled with care.
  9. Tools must be used for the purpose they are designed for.
  10. Records of the movement of tools must be kept.

  1.4 Storage of Agricultural Tools

  Activity-4: Storing Agricultural Tools

  • Visit a nearby agricultural farm.
  • Observe the techniques the farm workers use to store their agricultural tools.
  • Make a report on it and present to the class.
    

  After using the tools, they must be stored in a safe place. The following points should be kept in mind while storing tools:

  • Store all tools in a damp-proof or a dry room.
  • The storeroom should be well lit.
  • Tools should be kept dry.
  • Tools may be hung on hooks on the wall or from the ceiling.
  • Tools must be stored in fixed places.
  • Damaged tools must be repaired and greased before storing.
  • Tools we use often should be kept near the door.
  • Storeroom should be locked to protect the tools from theft.
    

  

  1.5 Dangers of Misuse of Agricultural Tools

  Activity-5: Discussion on Dangers of Misuse of Agricultural tools

  • Discuss the prevention against possible dangers of misusing agricultural tools.
  • Make a report on it and present to your science teacher
  • Misuse of agricultural tools could lead to injuries to people and their co-workers. 
    
  • Incorrect storage of tools could also lead to injuries. We may get cut with the sharp edges of the tools.   
  • Therefore, tools must be handled with care. 
  • If an agrochemical is inhaled as a mist, it may cause a headache, nausea, and diseases of the lungs. 
    
  • So it is necessary to wear a mask while spraying pesticides.
  • Ensure that nobody is around there while spraying.
    

  1.6 Precaution while Using Agricultural Tools

  Activity-6: Discussion on Precautions while Using Agricultural Tools

  • Go to a nearby agricultural farm.
  • Observe the ways the farm workers handle the tools.
  •  Also, list the precautions to be taken while using the tools., 
    

  The following precautions should be taken while using agricultural tools:

  

  • Debris should be removed so that the fields become safer places to work.
  • Worn out tools in poor condition can lead to accidents. Therefore, these must not be used.
  • If we get cut with any tools, first aid should be applied properly.
  • Agrochemicals are poisonous.
  • These should be used by wearing gloves and mask.
  • Agrochemicals must not be checked by inhaling.
  • Handgloves, boots and a mask should be worn while sprinkling pesticides.
  • After working with pesticides, wash your hands with soap properly.

  
  

    Figure 3. Things that must be worn while using agricultural tools

  1.7 Keywords

  •  Agricultural tools: Tools we use in farm work.  
  •  Agrochemicals: Chemicals used in agriculture. 
  • Container: Anything that can hold some other material. 
  •  Fertilizer: Chemicals that add nutrients to the soil. 
  •  Herbicides: Chemicals that can kill herbs. 
  • Insecticides: Chemicals that can kill insects. 
  • Pesticides: Chemicals that can kill pests. 
  • Tool: A hand-held instrument. 
  • Weedicides: Chemicals that can kill weeds. 
    

  1.8 Summary

  • The tools we use in farming are called agricultural tools. Examples: hoe, spade, rake, axe, wheelbarrow, machete, trowel, milking can, sprayer and file.  
  • Tools like hoe, spade, and trowels are used for digging the soil.
  • Tools like watering cans, pipes and watering wheels are the common watering tools.

  • Transplanting of seedling can be done with the help of spades and trowels.

  • Sharpening of tools can be done with the help of a file.

  • Axes and machetes are the common cutting tools.
  • Wheelbarrows and tractors are common transporting tools.
  • Maintenance of tools increases the life of the tools.
  • After using the tools, they must be stored in a safe, dry and termite-free place.
  • Misuse of agricultural tools could lead to injuries to people and their co-workers.
  • If agrochemicals are inhaled as a mist, it may cause a headache, nausea, and diseases of  the lungs.
  • Handgloves, boots and a mask should be worn while using agricultural tools.

  1.9 Unit Review Exercises

  Do these review exercises below in your exercise book;

  I. Fill in the blanks with the correct options:

  1. Axes and machetes are .........................tools.

  a) cutting                             b) watering

  c) transporting                    d)clearing

  2. .................................has toothed bars fixed diagonally to a handle.

  a) Rake               b) Spade

  c) File                  d) Trowel

  3. A trowel is a ............................tool.

  a) sharpening           b) none of these

  c) cutting                   d) transplanting

  4. A wheelbarrow is a ................... tool.

  a) transporting                  b) sharpening

  c) transplanting                d) digging

  5. ............... is a sharpening tool.

  a) Machete                       b) Trowel

  c) Spade                          d) File

  II. State whether the following statements are true or false:

  1. Tools make our job easier.

  2. Digging and cutting tools should be kept sharp regularly.

  3. Tools must be handled with care.

  4. Agricultural tools must be stored in a damped room.

  5. One must wear a mask while spraying insecticides.

  III. Match the following:

  Column A                                                    Column B

  1. Hoe                                            (a) Watering tool

  2. Rake                                          (b) Transporting tool

  3. Axe                                             (c) Digging tool

  4. Tractor                                        (d) Levelling soil

  5. Watering can                              (e) Cutting tool

  IV. Answer the following questions briefly:

  1. What are agricultural tools?

  2. List some common agricultural tools.

  3. Write the uses of the following tools:

  (a) Hoe                        (b) Rake                        (c) Spraying pumps

  (d) Trowel                    (e) Machete

  4. Write some methods of maintenance of agricultural tools.

  5. Explain the dangers of the misuse of agricultural tools.

  V. Complete the crossword puzzle using the clues below:

  

  Clues:

  Across

  2. It is a plastic container with backpacks and spray guns.

  4. The boat-shaped tool which is used for transplanting of seedlings.

  5. It is a single wheel, small hand pushed cart.

  Down

  1. We use this tool for storing and transporting milk.

  3. It is a big knife-like tool used for clearing bushes.

  Mark as done
• We can make many things for playing with from things found in our environment.

  We can make toys from clay, wires, leaves, stick, etc. We can also make different utility objects using sticks and plant fibers. 

  Similarly, we can make difference learning materials using papers.

  2.1 Making Toys in Clay and Wires

  We can make toys using clay and wires.

  Activity-1: Making a Toy Bicycle from Wire

  You will need 

   A soft aluminium wire and a wire cutter.

  Note: Do this activity under the guidance of your teacher or an elder. 

  Procedure

              Step 1:  Fold the wire as shown.                                                Step 2: Add a seat.

          

  Step 3: Make the total frame and the back wheel.                             Step 4: Make pedals.

         

                             Step 5: Fix a Chain  and a Carrier

    

  Now your toy bicycle is ready. 

  Activity-2: Making a Clay Doll

  You will need

  • Natural clay
  • Water
  • Stones

  Procedure                                                            

  Step 1: Take some clay. Pour water on it. 

  Knead it until it stops sticking on to your fingers.

  Step 2: Remove stones and sticks from the clay.

  Step 3: Roll some of the kneaded clay into a cylinder.

   Cut it into four equal parts. These will be used as legs and arms.

  
  

  Step 4: Model your baby doll with no legs and hands.
  

  
  

  Step 5: Model the legs and arms. Fix them on the shape you have made.
  

  

  Step 6: Put stones as eyes.

  

  Step 7: Dry your clay doll under the shade.

  Step 8: Display your clay doll in the classroom.

  Activity-3: Marking a Wire Doll

  You will need
  

  A soft aluminium wire (about 30 cm), a wire cutter and a pair of pliers.

  Note: Do this activity under the guidance of your teacher or an elder.

  Procedure

  Step 1: Cut the wire into three pieces. The first one is about 6 cm, the second one is about 10 cm and the third one is about 14 cm. 

  

  Step 2: Now fold the two larger wires into ‘U’ to make the legs and arms of the doll.

  

  Step 3: Join the three wires to make the body of the doll as shown.

  

  Step 4: Using a pair of pliers fold the small wire to make the head.

  

  Step 5: Take another small wire and criss-cross it to make the eyes.

  

  Step 6: Using the pliers fold the legs from the bottom to make feet.

  
  

  Display your wire doll in the class. 

  Activity-4: Making a Cat from Clay

  You will need

  • Natural clay                           
  • Water                     
  • Stones
    

  Procedure                                                             

  Step 1: Take some clay. Pour water on it. Knead it until

  it stops sticking onto your fingers.

  step 2: Remove stones and sticks from the clay.

  Step 3: Roll some of the kneaded clay into a cylinder.
  Cut it into five equal parts. These will be used as legs
  and tail.

      

  Step 4: Model the cat with no legs and tail.

       

  Step 5: Model the legs and tail and fix them on the shape you have made.

                       

                                      Step 6: Put two small stones as eyes.

                     

  Step 7: Dry your toy cat in a safe place under the shade.

  Step 8: Display your toy cat in the classroom Similarly, you can make many other animals.

  Activity-5: Making a Motorcycle from Clay

  • You will need
  • Natural clay 
  • Knife

  Procedure

  Step 1: Take some clay and roll into a ball. Flatten it with your palm. It will be used as a wheel.

  

  Step 2: Do the same for another wheel.

  Step 3: Roll some clay into a cylinder. It will be used as a frame and handles.

  

  Step 4: Cut four cylinders from it. Make frame as shown below.

  

  Step 5: Roll some clay into a cylinder. Use it to make the handles as shown.

  

  Step 6: Roll some clay to a ball. Make it a triangular shape. Now insert it to the seat post.

  

  Step 7: Cut a small cylinder. Flatten it as the shape of a chain cover. Fix it with the frame and the back wheel.

  

  Step 8: Roll some clay into a small ball. Mold it as the shape of a headlight. Then fix it with the frame.

  
  

  Your motorcycle is ready.

  Step 9: Dry your motorcycle in shade.

  Step 10: Colour it and display in your classroom.

  2.2 Making Utility Objects in the Sticks

  Children are fond of playing with the sticks. It will be fun for them if they learn how to make some utility objects like a basket with the sticks.

  You will need

  • Soft sticks which can be bent 
  • String

  Procedure

  Step 1: Take some soft sticks which can be bent. You can choose mid-ribs of palm leaves.

  Step 2: Put the sticks as shown.

  

  Step 3: Take another stick. Make a ring round the sticks using string.

  

  Step 4: Continue this process until you get the size of the base.

  

  Step 5: When you get the size of the base, bend the sticks upwards and continue making rings.

  

  Step 6: At the top, bend the end on one another.

  Step 7: Fix a string to make the handle.

  Step 8: Display your basket in the classroom.

  2.3 Making Utility Objects with Banana Fibres

  • Banana fibers are obtained from the banana plant. It is eco-friendly. 
  • We can use it to make objects like ropes, mats, bags, and dustbins.
    

  

  Fig. 1. Typical African banana plantations and their fibers

  Activity -7: Making a Mat from Banana Fibre

  You will need

  • Straight banana fiber 
  • A pair of scissors
  • String 
    

  Procedure

  Step 1: Arrange about 6–8 banana fibers as shown.

  

  Step 2: Weave other fibers across the fibers above.

  

  Step 3: When it becomes the size of a mat, stitch all its borders with a string.

  

  Step 4: Cut the extra length of the fibers with the help of a pair of scissors. 

  Your doormat is ready to use.

  Step 5: Display your mat in the classroom.

  Activity-8: Making a Dustbin from Banana Fibre

  You will need

  • Straight banana fibre 
  • A pair of scissors 
  • String

  Procedure

  Step 1: Arrange about 4 to 6 banana fibres as shown.

  

  Step 2: Weave other fibres across the fibres above.

  

  Step 3: When it becomes the size of a dustbin’s base, bend the fibres upward and continue weaving. 

  

  Step 4: At the top, cut the extra length of the fibres with the help of a pairof scissors. Bind the edge with a string. 

  

  Your dustbin is ready.

  Step 5: Display your dustbin in the classroom.

  2.4 Making Learning Materials in Paper

  Making shapes from a sheet of paper is an art. Children can make different shapes like triangle, rectangle, and square with paper.

  Activity -9: Making a Triangle from a Sheet of Paper

  You will need

  • A rectangular sheet of paper
  • A pair of scissors

  Procedure

  Step 1: Fold and unfold the rectangular sheet of paper in half lengthwise.

  

  Step 2: Fold the top-right corner of the paper down. So that the corner meets the crease made in step 1 (join the dots). The crease made should intersect with the bottom-right corner.

  

  Step 3: Fold left side of the paper over the flap made in step 2. Use the raw edge of the flap as a guide to position this fold.

  

  Step 4: Unfold and cut along the creases to get an equilateral triangle.

  

  You will get an equilateral triangle as a result.

  

  Activity -10: Making a Rectangle from a Sheet of Paper

  You will need 

  A square-shaped sheet of paper 

   A pair of scissors

  Procedure

  Step 1: Fold and unfold the square shaped paper in half lengthwise.

  

  Step 2: Unfold and cut along the creases to get a rectangle.

  

  Step 3: The rectangle made is as shown below.

  

  Activity -11: Making a Square from a Sheet of Paper

  You will need 

  • A rectangular sheet of paper 
  • A pair of scissors

  Procedure

  Step 1: Take the rectangular sheet of paper. Hold its bottom left corner and fold it towards the upper right side. It makes a triangle.

  

  Step 2: Cut the excess paper using a pair of scissors.

  

  Step 3: Unfold the triangle. You will get the square.

  

  2.5 Maintenance of Utilities and Learning Objects

  The prepared utilities and learning tools are soft. We must take extra care to keep them safe

  They should be;

  • kept at dry and clean place.
  • handled with care.
  • cleaned with dry soft brush.

  PRACTICAL ACTIVITY

  1. Collect the following things:

  • Clay and wires to make toys.
  • Fibres, knife/razor-blade, needle or lancelet, wood, sisal, sticks to make utility objects.
  • Paper, manila paper and a pair of scissors to make learning objects.

  2. Prepare toys, utilities and learning objects individually.

  3. Discuss the maintenance of objects produced.

  2.6 Keywords

  Cylinder: A solid object with two circular bases and a curved surface.

  Equilateral triangle: A triangle in which all three sides are equal.

  Fibre: A plant material from which a textile is formed.

  Flap: A flat piece of paper that is hinged on one side only.

  Knead: Work (moisten flour or clay) into dough or paste with hands.

  Object: A material that can be seen or touched.

  Rectangle: A plane figure with four straight sides and four right angles.

  Square: A plane figure with four equal straight sides and four right angles.

  Triangle: A plane figure with three straight sides and three angles.

  2.7 Summary

  • Banana fibre is eco-friendly. We can use it to make items like ropes, mats, bags, dustbins, and some other materials.
  • Making shapes from a sheet of paper is an art. Children can make different shapes like triangle, rectangle, and square with paper.
  • The prepared utilities and learning tools are soft. These should be kept at dry and clean place. These should be handled with care.

  2.8 Unit Review Exercises

  Do these review exercises in your exercise book.

  Answer the following questions briefly:

  1. What type of soil is used for modeling?

  2. Name at least three objects made of clay.

  3. Which material is used to make the toy below?

  

  (a) Cement 

  (b) Clay 

  (c) Plaster of Paris

  4. List at least three objects made up of fibres.

  5. Name the following shapes.

  

  

  II. Complete the crossword puzzle using the clues below:

  

  Clues:

  Across

  2. A material that can be seen or touched.

  4. A plane figure with four equal straight sides and four right angles.

  5. A plane figure with four straight sides and four right angles.

  Down

  1. A plant material from which a textile is formed.

  3. A plane figure with three straight sides and three angles.

  Project Work

  1. Choose:

  • a play object like a clay doll or a clay motorcycle.
  • a utility object like a mat or a dustbin.
  • a learning object like a triangle or a square or a rectangle.

  2. Using the techniques you have learned; make it over a week or two.

  3. Bring it to display in the class.

  Mark as done
• The computer is a basic need in every field. Life becomes easier with the introduction of different information and communication technology (ICT) tools.

  3.1 Common ICT Terms Used in ICT Field

  Activity -1: Observing and Listing Different ICT Tools

  1. Visit the school computer lab. Observe the equipment and make a brief description of all ICT tools found.
  2. List the other ICT tools which are not found in the school computer lab.
  3. Share the information on ICT tools with your classmates and discuss the role of each tool.
  4. Write the role of ICT tools in your notebook.

  Computers, mobile phones, calculators, radios, thermometers, and fax machines are common ICT tools. These tools help us to use information and share it digitally.

  (a) Computer

  

                       Fig. 1. An XO Laptop

  A computer is a machine. It accepts data and processes it. Finally, it produces output results. It is used to do difficult calculations.

  Role of a Computer

  A computer plays various roles in our daily life.

  1. It can be used for personal computing.
  2. It can be used for educational references.
  3. It can be used in the field of health and medicine.
  4. It can be used for scientific research.
  5. It can be used for communication and entertainment.

  (b) Data and Information

  • Data: Whatever you type from the keyboard is data. It may be numbers, alphabets, and/or symbols. 
  • Information: Computer processes data. The processed data is called information. In a computer, we can get information through output devices, for example, monitor and printer.
    

  
  

  (c) Communication

  Activity -2: Discussion on the Role of Tools of Communication

  • Discuss with parents or guardians the role of tools of communication (the telephone, the computer, the radio, television) and how the communication was done before the invention of these tools.
  • Take note about the responses received in your notebook.
  • Share the information with your classmates.

  Communication is the process of sending or receiving information. We can communicate by speaking, writing, through art and music, and books. 

  With a mobile phone, we can communicate with any part of the world. We can make calls, send and receive text messages. 

        

        Fig. 3. Communicating with mobile phones                       Fig. 4. Sending or receiving text messages

  Activity -3: Calling and Sending Messages Using Mobile Phones

  Calling Using Mobile Phone

  Write the receiver’s telephone number.

                                    

                                          2. Push on the call key.

                                   

  Sending Message Using Mobile Phones

  Open writing option on the mobile phone.

                                               

  2. Write a greetings message.

                                

  3. Write the receiver’s telephone number.

                    

  4. Push on send key.

  Activity -4: Typing and Sending Text Messages Using Mobile Phone 

  • Type a text message from a mobile phone keypad.
  • Send this message to one of your friends and a family member.

  Role of Communication:

  Communication plays an important role in our day-to-day life.

  1. It is a source of information.
  2. We know what is happening around the world.
  3. Without communication, we cannot convey our thoughts and feelings.

  (d) Technology

  Technology is the collection of techniques, skills, methods, and processes used to complete a work. Communication technology helps us to send and receive information. With the help of communication technology, messages can be sent within a moment around the globe. 

  Examples of technology used for communication are Internet, emails, fax, phones, chat groups and social networking sites.

  Internet, Website, and WWW 

  Internet: It is a large group of computers connected to each other. It is used to send information quickly. It is widely used at hospitals, railway stations, airports, schools, and offices.

  Website: It is a collection of web pages. A website gives information about any subject. Each website has its own web address. It can be reached through an Internet connection by typing the domain name in the address bar. The first opening page of a website is called homepage.
  

  Activity -5: Typing Domain Name in the Address Bar of the Browse Activity 

  Type a domain name of Rwanda Education Board (REB) in the address bar in the browse activity. 

  World Wide Web (WWW): 

  It is a collection of millions of electronic pages. These pages are interlinked just like a spider’s web. These pages display a variety of information.

  (e) Activity

  Sugar is a collection of Activities. Activities are Applications that involve active engagement from the learner. They automatically save results to a journal, where reflections are recorded. Activities can be shared between learners.

  (f) Projects

  A project is a planned set of interrelated tasks. It should be completed over a fixed period within certain cost and other limitations. 

  On websites, we get the necessary information regarding a project. Online projects can be done with the help of related websites. 

  (g) Digital and Analogue Data                                   

  • Any signal or data which is expressed in digits (0–9) is called digital. For example,digital watch displays the time by means ofdisplayed digits.    

    

                                                                                                                                     Fig. 5. Digital clock

                                                                                   

  • A system that represents changing values ascontinuously variable physical quantities is called analogue.  

                                                                                                                                    

                                                                                                                                   Fig. 6. Analogue clock  

    Hardware and Software

  Computer Hardware refers to computer physical parts that can be touched. For example, system unit, monitor, printer, keyboard, and mouse. 

  
  

  The software is a set of instructions for a computer to perform specific operations that cannot be touched. For example, Windows Media Player for music and word processing.

  
  

  (i) Switch ON a Computer
  

  Activity-6: Switching on a Computer

  Desktop Computer

  To switch ON a desktop computer, follow the steps:

  Switch ON the main power supply.

  Activity -7: Switching OFF a Computer

  Desktop Computer: To switch a computer OFF, follow these steps: 

  1. Switch ON the main power supply.
  

  

  2. Switch ON the UPS.

  
  

  3. Switch ON the power button of the System unit.
  

  
  

  4. Switch ON the monitor.
  

  
  

  XO Laptop

  1. Push the power button to turn on the laptop.

  

  (j) Switch OFF a Computer

  Activity -7: Switching OFF a Computer
  

  Desktop Computer                                                 

  To switch a computer OFF, follow these

  steps:                                                            

  
  

  • Click on the Start button. 
  • A menu appears on the screen. 
    
  • In the right pane of the Start menu, click on the Shutdown button. Wait till the computer shuts up. 
    

  3. Switch OFF the UPS.

                                    

  4. Switch OFF the main power supply.

                                         

  5. Switch OFF the main power supply button.

  XO Laptop

  1. Hover over the XO icon in the center of the Home view.

  2. A menu appears.

  3. Choose the Shutdown option.

                                  

  3.2 Sugar Interface

  Activity -8: Switching ON an XO Laptop

  Switch ON an XO laptop and describe how the icons are arranged on Home screen.

  Sugar interface is both a desktop and a collection of activities. Activities automatically save results to a journal, where reflections are recorded. 

  You can write documents, share books and pictures or make music together with ease. Power-on XO laptop or any computer with sugar installed, you should see the Sugar Home view. 

  Activity -9: Starting up Sugar Interface

  Any Computer with Sugar Installed

  1. Switch on your computer with Sugar installed.
  2. At the log-in screen, click the “Options” button:

                             

  3. Choose Select Session as shown. Then the pop-up menu appears:

                             

  4. Choose Sugar and click Change Session and log-in normally.

  XO Laptop 

  Switch on an XO laptop. The first screen you see is a Sugar Home View.

                      

  Elements of Sugar Interface

  Different elements of Sugar Interface are given in the following figure.

  

  

  (a) Home View

  To get to the Home view, click the Home icon on the frame or press F3 key.

  

  Modes of Home View

  • Ring view
  • List view
  • Freeform view

  Ring mode: The favorite activities are placed in a ring.

  

  List view: The installed activities are arranged in a list.

  
  

  Free form mode: All the icons are not arranged in a ring or a list, you can arrange icons in a way that makes sense to you. 

  
  

  (b) Neighbourhood View

  This view helps to see your friends or classmates’ activities, and you can join them in order to collaborate. 

  
  

  XO Menu

  Activity -10: Observing Different XO Menu

  1. Switch on your XO laptop.
  2. Hover over the XO icon in the middle of the ring of activities.
  3. Write in your notebook the options which appear on the menu.

  The XO menu appears when you point on the XO icon.

  

  3.3 Gnome Interface

  The XO laptop allows switching from sugar interface to GNOME interface.

  Activity -11: Switching to GNOME Interface from Sugar Interface

  To switch to GNOME interface from Sugar Interface:

  1. Hover over XO icon in the middle of ring of activities.
     

  
  

  2. Choose the option “My Settings”.

  
  

  3. Select the Switch Desktop option under My Settings and follow steps until you click on switch to GNOME. 

  
  

  GNOME is a graphical user interface.

  3.4 Major Components of GNOME Desktop

  Figure 16 shows some major components of the GNOME desktop.

  
  

  1. Desktop Basics

  The desktop lies behind all other components on your screen. You can place files and folders on the desktop that you want to have easy access to.

  The desktop also has several special objects on it:

  • The Computer icon gives you access to Compact Discs, removable media such as pen drive, and also the entire file system. 
    
  • All of your personal files are kept in your Home Folder, labeled username’s Home. 
  • You can also open this folder from the Places menu.
  • The Trash is a special folder where you can place files and folders you no longer need.

  2. Desktop Panels

  The bars across the top and bottom of the desktop are called panels.

  By default the top panel appears as follows:

  
  

  The Application menu provides access to the applications installed in the system.

  The Places menu provides a list of locations. On selection, these are opened in file browser windows. 

  The System menu provides options for:

  • configuring the system, and 
  • the desktop environment such as desktop theme and screen resolution. 

  In the above picture of the desktop, the icons next to the system menu provide quick access to common applications and tools. 

  The right-hand side of the panel includes the current time, volume control and a network status indicator.

  The left desktop panel contains three items appearing as follows:

                               

  The area containing squares controls the currently displayed virtual workspace.

  The GNOME desktop allows multiple workspaces to be active at any one time. We can move from one application to another by clicking on one of the squares in the bottom toolbar.

  Creating a Folder
  

  Activity -12: Creating and Renaming a Folder in GNOME

  1. Switch to GNOME from Sugar.
  2. Right click on blank area of Desktop and the menu appears.

  
  

  3. Click on option “New Folder” and the folder will be created on the Desktop.

                   

  4. Rename the new folder appeared on desktop as your choice.

                      

  3. Windows

  Windows is a rectangular area of an opened application.

   

                                                                                                                               

  
  

  
  

  Workspaces allow managing windows on the screen. By default four workspaces are available.

                                                                                                                                                                                                                                                                        Fig. 20. Workspaces

  A window is a rectangular area of the screen. It has a border all around and a title bar at the top. Each window displays an application. It allows you to have more than one application visible, and work on more than one task at a time.

                 

  Buttons on title bar allow you to minimize, maximize, and close the windows. You can control a window’s position of the screen, as well as its size. You can control those windows which overlap other windows, so the one you want to work with is completely visible.
  

  Giving Focus to a Window

  To work with an application, you need to give the focus to its window. Only one window can have focus at a time. The window that has focus will appear on top of other windows, so nothing covers any part of it.

  4. Workspaces

  Workspaces allow you to manage which windows are on your screen. Every workspace contains the same desktop, the same panels, and the same menus.  By default, four workspaces are available. You can switch between them with the Workspace Switcher applet at the right of the bottom edge panel. This shows a representation of your workspaces, by default a row of four rectangles. 

                                  

                                  Fig. 22. Workspaces displayed in workspace switcher

  Switching between Workspaces

  To switch between workspaces, follow these steps:

  Using the mouse:

  1. Open the Launcher and click the workspace switcher button near the bottom.
     
  2. Double-click on any window or workspace to switch to it, or press the workspace switcher button again to return to your previous workspace.

  Using the keyboard:

  1. Press Ctrl+Alt+→ to move to a workspace which is to the right of the current workspace.
     
  2. Press Ctrl+Alt+← to move to a workspace which is to the left of the current workspace.
     
  3. Press Ctrl+Alt+↓  to move to a workspace which is below the current workspace.
     
  4. Press Ctrl+Alt+↑  to move to a workspace which is above the current workspace.

  5. Applications

  An application is a type of computer program that allows you to perform a particular task. You might use applications:

  •  to create text documents such as letters or reports;
    
  •  to work with spreadsheets;
    
  •  to listen to your favourite music;
    
  •  to navigate the Internet;
    
  •  to create, edit, or view images and videos.
    

  For each of these tasks, you would use a different application.
  

  To launch an application, open the Applications menu and choose the application you want from the submenus.

  
  

  The applications that are part of GNOME include the following:

  
  

   GEDIT is an application of GNOME that can be used to create, edit, format and save a document.

   

      

                                              Fig. 23. Various applications of GNOME

  
  

  There are other applications in GNOME like, Dictionary, Image viewer and calculator.

  
  

         

                                                Fig. 24. The GNOME gedit text editor

  
  

  3.5 Switching to Sugar from GNOME

  
  Switching back to Sugar from GNOME can be done by clicking on icon “Switch to Sugar’’ of GNOME desktop.

  
  

      

                                  Fig. 25. Switching from Sugar to GNOME desktop

  
  

  3.6 The Journal

  
  The Sugar Journal records everything you do using Sugar interface. 

  You can use a Journal as a place:

  ♦ to revisit old work,

  ♦ to resume incomplete work,
  

  ♦ to organize completed work, and
  

  ♦ to reflect upon your progress as a learner.

  Opening the Journal

  To show the Journal, click the Journal icon on the Frame.

       

                                                            Fig. 26. Opening the Journal

  On an XO laptop, you can press the magnifying glass key in the top row of the keyboard to immediately open the Journal and search.

  Journal Features

  

  The Journal view contains a menu and a list of journal entries:

  1. Star: You can mark important entries to help them stand out in the list by clicking the star icon for that entry. When you click the star icon, the star is coloured in.

  2. Icon: Each Journal entry has an icon. The colour of the icon shows who created the entry. For example, if you copy a photo from a friend, the photo’s icon has your friend’s colours.

  You can launch the Activity for the entry by clicking the icon. A hover menu may reveal additional options. In particular, “Erase” deletes that entry from your Journal.

  “Erase” deletes any data associated with the entry shown. For example,if you delete an entry       that shows that you installed an Activity, youdelete the Activity as well.

  3. Entry name: Each entry has a name. You can edit the name by clicking it.

  4. Buddy icons: If other participants join you in this Activity, icons in their colours will appear here.

  5. Elapsed time: The Journal displays the time since the most recent change to the entry.

  6. Detail view button: Click this button to see detailed information about the entry. See “Journal detail view”, on next page.

  7. Scroll bar: When there are more entries in the Journal than can fit on the screen, you can use the scroll bar to scroll through them.

  8. Search box: Type words in the box to search for entries that match those words. Entries are displayed when they contain all of the typed words. Comparison will be against all of:

  •  the entry name field
    
  •  the description field (see “Journal detail view”)
    
  •  the tag field (see “Journal detail view”)

  9. Select by type (Anything): Choose an entry type to display only entries of that type. Types include the Activity that created an entry, or the object type, such as, picture, sound, text, and so on.

  10. Filter by date (Anytime): You can limit the Journal View to entries made within the past day, week, or month.

  Journal Detail View

  

                                              Fig. 28. Components of Journal Detail view

  The Detail view appears when you click the Detail view button for an entry. This view lets you examine and annotate the entry. The detail view has the following components.

  1. Back icon line: You can click anywhere in this line to return to the main Journal View.

  2. Star and icon: These items duplicate their functions on the main Journal view—a star represents a special, never-deleted Journal entry and the icon colour indicates who created it originally.

  3. Thumbnail image: Each entry has a thumbnail image that is created automatically. The image shows the Activity screen when the last change to the Journal entry was saved.

  4. Entry name: You can change the name of the entry by clicking it and typing in a new name.

  5. Elapsed time: Displays the time since the most recent change to the entry.

  6. Description field: You can type a description of the entry in this field. Use a description to remind you of what you did.

  7. Tag field: You can enter search tags. Use keywords to describe a journal entry so that you can find it later using the Search box in the main Journal view.

  8. Participants: Displays the XO icons of each person who participated in a shared Activity.

  9. Resume button: You can click the Resume button to resume an Activity. A hover menu may show additional options. For example, you can resume working with an image using either the Browser or the Paint Activity.

  10. Copy button: You can copy a Journal entry to the clipboard (or to one of the removable storage devices shown on the bottom edge of the Journal screen) by clicking the Copy button.

  11. Erase button: You can erase an entry by clicking the Erase button.

  Using Removable Media

  Activity-13Using Removable Media

  1. Plug a flash dish into the XO laptop.

  2. Push on magnifying glass key to open Journal.
  

  3. Write on the notebook two icons found on the button of Journal.
  

  4. Open the Universal Serial Bus (USB) device by clicking on the icon representing flash disk on the bottom of the Journal.
  

  5. Click on Journal icon besides the USB device icon to see the activities saved in Journal.

  The Journal also supports external storage media such as USB device or Secure Digital (SD) card.

          

                                          Fig. 29. Use of removable media in Journal

  Activity -14 Saving Entries from Journal to USB Device

  1. Plug USB device into XO laptop.

  2. Open Journal.
  

  3. Point on the entry you want to move and hold the touchpad key.
  

  4. Drag down to the USB device icon.

  

  Activity -15 Saving Entries from USB Device to Journal

  1. Plug USB device into XO laptop.

  2. Open Journal.
  

  3. Click on USB icon to view its content.
  

  4. Point on the entry you want to move and hold the touchpad key.
  

  5. Drag down to the Journal icon.

  

  To Remove USB Device

  Hover over the icon of USB device and on the appeared menu, click Unmount or Remove option.

                                       

                                              Fig. 30. Removing USB device

  Activity-16Sending Documents to Each Other

  Find your friend’s XO Friend in the Neighbourhood view. In your friend’s pop-up palette menu select Make friend.
  Use the search text box in the Neighbourhood view tool bar to find a known XO Friend name.

                                                                                 

  (+) Make friend                                                          

  Click on the Journal icon in the
  

  Sugar Frame.

  Click on the item you want to send:
  ReadMeFirst.txt

  Wait for the pop-up palette menu;

  click on send to, and select the friend
  

  you established in the previous step.

  • (The drop down does not take a screen shot while it is activated - so it is not shown here.)

  Note: A Red Arrow will appear on the left side of the receiving system’s Sugar Frame. Then it appears in               the upper Sugar Frame when the Activity is running. Here the user has to accept the transfer, before           it is transmitted into the Journal in Sugar.

  • Point the mouse at a corner of the screen/window and wait for the Frame to extend.
    

  The Red arrow icon drop-down palette indicates a file was received also.

  •        Here in the Home view, the Red Arrow icon drop-down palette 
    

  shows that a file
  

  was received into the
  

  Journal.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
      
  
  3.7 Keywords
  
  Computer: Computer is an electronic device that accepts data, processes, organizes and produces results.
  
  Data: Whatever you have typed from the keyboard is the data.
  
  GNOME Interface: A graphical user interface which has many applications designed to help you in your daily work.
  
  Information: The processed data.
  
  Internet: A large group of computers connected to each other.
  
  Journal: An automated diary of everything you do within Sugar.
  
  Website: A collection of web pages related to each other by a certain topic.
  
  

  3.8 Summary

  Communication is the process of sending or receiving information. We can communicate by speaking, writing, through art and music and books.

  Technology is the collection of techniques, skills, methods and processes used to complete a work. Communication technology helps us to send and receive information.

  Project is a planned set of interrelated tasks. It should be completed over a fixed period within certain cost and other limitations.

  Computer hardware refers to physical parts that can be touched. For example, system unit, monitor, printer, keyboard and mouse.

  Software is a set of instructions for a computer to perform specific operations that cannot be touched. For example, Windows Media Player and Word Processing.

  3.9 Unit Review Exercises

  Do these review exercises in your exercise book.

  I. Fill in the blanks with the correct options:

  1. ....................... tools help us use information and share it digitally.

  (a) ICT                    (b) UPS
  (c) DATA                 (d) Website

  2. .................... is a collection of web pages.

  (a) Data                    (b) Website
  (c) Digital                  (d) Analogue

  3. The ................. lies behind all other components on your screen.

  (a) mouse                  (b) keyboard
  (c) desktop                (d) none of these

  4. The ............ is a special folder where you can place files and folders you no longer need.

  (a) window                     (b) home
  (c) icon                           (d) trash

  5. ............... is a type of computer program that allows you to perform a particular task.

  (a) Application                           (b) Text Editor
  (c) Calculator                             (d) Character map

  II. State whether the following statements are true or false:

  1. Computer hardware refers to physical parts that can be touched.

  2. Gedit Text Editor can read, create, or modify any kind of simple text without any formatting.

  3. Buttons on status bar allow you to minimize, maximize, and close the windows.

  4. Sugar is a graphic user interface.

  5. The Sugar Journal records everything we do using Sugar Interface.

  III. Match the following:

  Column A                                                                                     Column B

  1. Project                                                                               (a) processed data

  2. Communication                                                                 (b) an electronic device

  3. Information                                                                        (c) collection of electronic pages

  4. www                                                                                   (d) exchanging information

  5. Computer                                                                           (e) a planned set of interrelated tasks

  IV. Answer the following questions briefly:

  1. What are the roles of a computer?

  2. Differentiate between data and information.

  3. Explain the features of website.

  4. List some uses of the following:

  (a) Scroll bar                     (b) Gedit Text Editor                  (c) GNOME interface

  (d) System menu                (e) Workspaces

  5. Write the steps to switch on and switch off a computer.

  6. What is Journal Activity?

  Computer My Friend 71

  V. Complete the following crossword puzzle using the clues below:

  

  Clues:

  Across

  2. A device or program that enables a user to communicate with a computer.

  6. This is the processed data.

  7. It is a large group of computers connected to each other.

  Down

  1. The collection of techniques, skills, methods and processes used to complete a work.

  3. This is a set of instructions for a computer to perform specific operations.

  4. Something on which operations are performed by a computer.

  5. An electronic device that accepts data, processes, organizes and produces results.

  Group Activity

  Students in group practise switching from Sugar to Gnome interface and vice versa.

  Project Work

  Send a document to your classmates through sugar interface.
  Discuss it with each other.

  Mark as done
• Writing Skills
  We like to write and decorate words and sentences in our notebooks. In the same way, word processing applications help us write, edit, and format a document in a computer. 
  Word processing programs like Microsoft Word, Word Perfect, WordPad, and WordPro give us options for text formatting. Observe the various tools of MS Word in the following picture. These tools help us in writing, editing, and formatting a document.
  
  
  4.1 Text Selection
  Selection of text highlights the text. After selecting the text, we use formatting or editing tools to make changes in the text. You can select text either using the keyboard or using the mouse.
  
  Selecting Text Using Keyboard
  
                        
  5. Select the last character of your name by placing cursor at the end of your name, press SHIFT key, hold it and then press LEFT ARROW key at the same time
                     
  6. Select your second name from its beginning to its end by placing cursor at the beginning of your second name, press and hold CTRL+ SHIFT + RIGHT ARROW keys at the same time.
                   
  7. Select your second name from its end to its beginning by placing cursor at the end of your second name, press and hold CTRL+ SHIFT + LEFT ARROW keys at the same time.
                  
  8. Select your full name from its beginning to its end by placing cursor at the beginning of your full name, press and hold HOME key and then SHIFT + END keys.
                 
  9. Select your full name from its end to its beginning by placing cursor at the end of your full name, press and hold END key and then SHIFT + HOME keys.
  
  
  
  1. Open a new document and write a home life story.
  
  
  2. Select a sentence down by placing a cursor at the beginning of the sentence, press and hold END key and then SHIFT + DOWN ARROW keys.
            
  
  3. Select a sentence up by placing a cursor at the end of the sentence, press and hold HOME key and then SHIFT + UP ARROW keys.
  
            
  
  4. Select a paragraph from its end to its beginning by placing the cursor at the end of the paragraph, press and hold CTRL key and then press SHIFT + DOWN ARROW keys.
  
           
  
  5. Select a paragraph from its beginning to its end by placing the cursor at the beginning of the paragraph, press and hold CTRL key and then press SHIFT + UP ARROW keys.
  
          
  
  6. Select a whole document by pressing CTRL + A keys at the same time.
  
           
  
  7. Select a whole document from its beginning by placing the cursor at the beginning of the document, press and hold CTRL key and then press SHIFT + END keys.
  
          
  
  8. Select a whole document from its end by placing the cursor at the end of the document, press and hold CTRL key and then press SHIFT + HOME keys
  
          
  
  Selection can be done using keyboard or using mouse, before formatting a text you need to select it.
  
  Selecting Text with Mouse
  
  We can use mouse to select characters, words, sentences, paragraphs, or a whole document.
  
  
  
  1. Open the existing document that you have typed in the previous activity.
  2. To select a word, double click on it.
  3. To select a sentence:
  (i) Place the cursor anywhere on the sentence.
  (ii) Holding the CTRL key, click anywhere on the sentence.
  4. To select a paragraph, triple click anywhere on the paragraph.
  5. To select entire document:
  (i) Place the cursor at the beginning of the document.
  (ii) Holding the SHIFT key, click at the end of the document.
  Note: Click means clicking the left mouse button.
  
  4.2 Formatting Text
  
  1. Formatting a text by making it Bold, Italic, Underlined, Changing colour and size.
  2. Type the text as shown below.
  
  
  
  3. Observe the font options on the word document Ribbon.
  4. Select the first two sentences and make them bold by clicking on B by pressing the CTR+B keys.
  
  
  
  5. Select the word “software”, make it Italic and Underline it by clicking on I and U or by pressing Ctrl + I for italic and Ctrl + U for underlining.
  
  
  
  6. Change the size of whole text from 11 to 16, change the style from Arial to Times New Roman and put the first sentence in red color.
  
  
  
  Formatting a text means changing the style, color, and size of the desired text. Font size indicates the size (both height and width) of the text. Using the font size tool, you can increase or decrease the text size.
  
  Changing the Character Case of the Text
  
  Character Case indicates the case of the text. It is used to change the text from lower case to upper case or vice-versa.
  To change the character case of the text:
  1. Select the text whose character case is to be changed using the keyboard or mouse.
  2. Click on change case box  on the Home tab of the Ribbon.
  3. Select the desired case style from the drop down list.
  
  Spelling and Grammar Checking
  
  1. Type the following sentence exactly as shown. Include all the errors.
  On frrday, I went to the shoip to buyi tomatoies.
  2. Using the right button of your mouse , click on the first word that has the red mavy line under it.
  3. Several choices will appear. Click on the correct one.
  
  
  4. Do the same thing with each of the words with wavy lines under them. Spelling errors are displayed with a red wavy line under the text. A red wavy line means the word is wrongly spelt or it is not an English word.
  
  Saving a Word Document
  
  When your work finished ,you need to save it for further use. you should save the document at proper place with a suitable name.
  
  To save a word document:
  1. Press Ctrl + S or Click on the  button on the Home tab of the Ribbon. The Save As window will appear.
  2. Select the location in the computer where you wish to save the document.
  3. Write a file name in the File name box. For example, “Computer”.
  4. Click on the Save button. The file will be saved by the name “Computer”.
  
  
  Opening a Word Document
  
  You can open the same file, if you have to see or work again on the same document.
  To open a word document:
  1. Press Ctrl + O or Click on Office  button and select option. The Open dialog box appears.
  
  2. Select the location where you saved the document.
  3. Choose the document to be opened and click on Open button. The document you selected appears on the screen.
  
  Sharing and Collaboration
  
  The Write Activity in Sugar Interface helps multiple users to work together or collaborate on a single document. You can show edits made to a document so that others can review the edits. You can also merge edits from multiple users. To do this, sharing is required.
  
  
  
  1. Open the Activity on which the document is prepared.
  
  
  

  2. Send an invitation. To send an invitation:
  

  ♦ Go to the Neighbourhood view.
  ♦ Click a friend’s XO icon to send an Invite request.
  
           Science and Elementary Technology—Primary 4
  
  3. Receive/Accept an invitation:
  After you have invited your friend, he/she has to click the Write icon in the Frame and choose Join.
  

  
  

  4. Once you and your friends have shared the Write Activity, everyone sees the same document.Then both of you can type on the same document.Group Work
  1. Go to you Computer Lab.
  

  2. Search or connect to friends in the Neighbourhood view.

  
  

  
  

  Go to your computer laboratory. Type the following document. Then format
  this document as instructed below.
  
  Information and Communication Technology (ICT)
  
  ICT stands for Information and Communication Technology. Computer is the basic need in every field. Life becomes easier with the introduction of different ICT tools.
  Computers, mobile phones, calculators, radios, thermometers and fax machines are the common ICT tools. These tools help us use information and share it digitally.
  1. Select the heading “Information and Communication Technology (ICT)”.
  2. Make it bold.
  3. Change its colour into red.
  4. Make it underlined.
  5. Change its style into Arial.
  6. Select the first paragraph and change its case to uppercase.
  7. Select the second paragraph and make it italic.
  

  8. Save this document with the name ‘ICT’.

  4.3 The Keyboard and Touchpad
  Keyboard is an input device of a computer system. Data are entered into the computer with the help of keyboard. It plays a very crucial role while working on a computer.
  
  
  

                             Fig. 6. Keyboard

  Touchpad is a pointing device on laptops and some
  keyboards. It is operated using fingers. It allows the user
  to touch an area on the screen in order to enter data. Like
  computer mouse, it also has two buttons. These two buttons
  

  allow the user to left-click or right-click.

  Frame Keys
  Frame keys are the keys which are available on the multimedia keyboard. These keys are used for special functions or as short-cut keys.
  
  Volume Control
  

  The following keys of multimedia keyboard are used for Volume control.

  
  
  Brightness Control
  

  The following keys of multimedia keyboard are used for brightness control.

  

  Special Keys on the Keyboard
  
  The keys which are marked with red are special keys. All special keys have some special functions.
  
  

  

  Application of Special Keys in the MS Word Document
  
  

  
  

  
  
  

  

  4.4 Keywords
  
  ‹Collaboration: The action of working with someone to produce something.
  ‹Font size: The size (both height and width) of the text.
  ‹Formatting text: Changing the style, colour, and size of the text.
  ‹Frame keys: The keys available on the multimedia keyboard.
  ‹Keyboard: An input device of a computer system.
  ‹Touchpad: A device for controlling the pointer on a display screen by sliding the finger along a touch-sensitive surface.
  
  4.5 Summary
  
  ‹Word processing applications help us write, edit, and format a document in an effective manner.
  ‹Text formatting buttons are used to make the text bold, italic, and underlined.
  ‹When our work is finished, we need to save a document for further use.
  ‹Selection of text highlights the text. After selecting the text, we use a
  formatting or editing tool to make changes in the text.
  
  4.6 Unit Review Exercises
  
  Do these review exercises in your exercise book.
  
  I. Fill in the blanks with the correct options:
  
  1. The buttons which are used for formatting are called ............ buttons.
  (a) formatting                              (b) editing
  (c) calculating                             (d) none of these
  
  2. Ctrl + I command is used to make the text…………. .
  (a) bold                              (b) italic
  (c) underlined                    (d) none of these
  
  3. A word can be selected with mouse by ………….. clicking on it.
  (a) single                           (b) double
  (c) triple                             (d) none of these
  
  4. ………... keys are used to select a sentence from its beginning to its end.
  (a) Home + Shift + End                     (b) End + Shift + Home
  (c) Home + Shift + Up Arrow             (d) Home + Shift + Down Arrow
  
  5. ............... key erases the characters from left side of the cursor.
  (a) Esc                      (b) End
  

  (c) Delete                 (d) Backspace

  II. State whether the following statements are true or false:
  
  1. Right arrow key moves the cursor in right direction.
  2. To select a sentence with mouse, hold down the Ctrl key then click the sentence.
  3. Font size box on the formatting toolbar is used to change the font style of the character.
  4. button is used to change the text from lower case to upper case.
  5. Sharing and collaboration feature helps multiple users to work together on a single document.
  
  III. Match the following shortcut keys with their functions:
  Shortcut keys Function
  
  1. Ctrl + Z                                   (a) Pastes the most recent addition
  2. Ctrl + A                                   (b) Applies or removes underline
  3. Ctrl + V                                   (c) Selects the whole document
  4. Ctrl + U                                   (d) Applies or removes italic formatting
  5. Ctrl + I                                     (e) Used to undo an action.
  
  IV. Answer the following questions briefly:
  
  1. Define formatting.
  
  2. State the steps to select a paragraph with mouse.
  
  3. How will you select whole document with keyboard?
  
  4. Differentiate between Keyboard and Touchpad.
  
  5. Give uses of the following special keys:
  
  (a) Enter key             (b) Esc key             (c) End key
  (d) Home key            (e) Delete key
  
  6. Write steps to:
  
  (a) change the colour of text
  (b) change the style of text
  

  (c) save a word document

  V. Complete the crossword puzzle using the clues below:
  

  
  

  Clues:
  
  Across
  
  3. The action of working with someone to produce something.
  4. An online backup and data storage software.
  5. An input device of a computer system which has 104 keys.
  
  Down
  
  1. The keys available on the multimedia keyboard.
  2. A device for controlling the pointer on a display screen by sliding the finger along a touch-sensitive        surface.

  Mark as done
• Computer graphics is one of the most effective way to communicate the processed information to the user. It displays the information in the form of graphics objects such as pictures, graphs and diagrams. Let us learn about Paint Application.

  5.1 Paint Application

  Definition and Role

  Paint is an activity in Sugar Interface. It is used to draw, colour and edit pictures. The program mainly saves file as .JPEG.

  Paint Activity

  5.2 Toolbar

  Primary Toolbar

  The Primary toolbar is located at the top of the screen.

  

  1. Brush tool: It is used to paint.
  2. Brush properties tool: It shows the properties of brush tool.
  3. Shape tool: Draw different types of shape.
  4. Shape properties tool: It is used to edit shape size and colour.
     
  5. Text tool: It is used to type text in your activity and change the format of text, i.e., bold, italic and font face.
     
  6.  Image tool: It is used to insert image, colour formatting (Grayscale and colour), and editing.
  7.  Stop: It quits the Activity and exits the program.

  

                   1. Take an image of market place from the Internet.
                   2. Reduce its size with the help of crop tool.
                   3. Delete some of unwanted images from it.
                   4. Change colour of image.

  

  Secondary Toolbar

  Each tool bar contains a logically grouped set of buttons and controls, as the name on its corresponding tab suggests. Each of these sets represents a distinct editingor control context, called Secondary toolbar.

            1. Display or change the name of the image that is saved in the Journal.

  

            2. Edit tool:

  

  

  

  3. Brush tool: Brush tool is used               

  for painting and editing image

  colour. It works like traditional

  drawing tools for applying

  colour.

  

         4. Brush properties: Changes the properties of the brush tool or the stamp tool. When the brush tool              is selected, it changes the colour, size and shape of the brush tool. It also affects the shape and text            tools.

  

  5. Shapes: Draw different types shapes in your clip art.

  

                                         Table 3: Shape Tools and their Functions

  6. Shapes properties: This tool changes the properties of the shape tool. When the shape tool is selected, it changes the colour, size and shape of the brush tool.

  
  

                          Fig. 6. Properties of shape tools

  7. Text tool: This tool is used to change the font, the size of the font and formatting.

                         

  

  8. Image Editing: Image Editing tool is used to edit image colour, rotation and importing image in a                 document.

                             
  

  
  

  5.3 Drawing with Free Hands
  

  
  

  
  

   

  
  

  
  

  
  

  
  

     5.4 Drawing Using Shapes
  

  
  

  
  

  
  

  

  

  

   

  

  

    5.5 Comments on a Picture

  

  

  

    5.6 Saving and Closing an Activity

  
  

  
  

  
  

     5.7 Opening a Saved Activity

  
  

  
  

  
  

  5.8 Keywords

  Bucket tool: It is used to fill colour in an enclosed shape.

  •  Font face tool: It is used to change the face of the font.
  •  Paint: It is an Activity on Sugar Interface.
  • Undo command: This command is used to revert last step.

  5.9 Summary

  •  Primary tool bar is used to follow initial steps for drawing in paint activity.
  •  Secondary tool bar consists of logically grouped set of buttons and controls. Each set represents distinct editing tools.
  • Picker tool picks colour from other objects.
  •  Shape properties tool changes the properties of the shape tool.
  •  Comment is used to inform about the topic or theme of the subject or image.

  5.10 Unit Review Exercises

  Do these review exercises in your exercise book.

  I. Fill in the blanks with the correct options:

     1. ......................... is a simple graphics program.

               (a) Clip Art        (b) Paint       (c) Font Face    (d) None of these
  

     2. To undo command you have to press ......................... keys together.

               (a) Ctrl + Z         (b) Ctrl + Y    (c) Ctrl + S         (d) Ctrl + X

      3. To increase or decrease font size of a text, .......................... tool is used.

               (a) Font Size                    (b) Font Face                  (c) Bucket                        (d) None of these

      4. .......................... key is used to close a Paint Activity.

               (a) Ctrl + Z        (b) Ctrl + Q          (c) Ctrl + C          (d) Ctrl + Y

  II. State whether the following statements are true or false:

       1. In an XO laptop paint icon is found at Home view.

       2. The paint program saves file as .JPEG.

       3. Image tool is used to format colour.

       4. Invert colour is used to rotate image left.

       5. To go for the Home view, we have to press F4.

  III. Match the following:

  Column A                                                                                  Column B

  

  IV. Answer the following questions briefly:

  1. What is the use of Paint Activity?

  2. Differentiate between primary and secondary tool bar.

  3. Write the use of following tools.

  (a) Brush                               (b) Eraser                        (c) Bucket                          (d) Picker

  4. Write the command for following actions.

  (a) Undo                                                            (b) Redo

  (c) To go for the Home view                              (d) To close a Paint Activity
  

  Mark as done
•  Computer program is a set of instructions. A computer requires programs to function. A program is usually written in a programming language. Scratch and Turtle Art are two popular programming languages for kids.

  

  Turtle Art is a part of LOGO. It allows children to draw colourful and complex images. In Turtle Art, a turtle needs commands to draw pictures and designs.

  

  

  The Start up screen of Turtle Art looks like this.

  

                                              Fig. 1. Start up screen of Turtle Art

  

  The Turtle Art window has the following elements.

  Main Toolbar

  The Main toolbar consists of the following tools:

  

                            Fig. 2. Main toolbar and its components

  1. Activity toolbar (includes sharing; saving/loading options);

  2. Edit toolbar (includes copy and paste);

  3. View toolbar (includes full-screen, coordinate overlays and turtle status);

  4. Palette toolbar (includes all programming blocks);

  5. Erase canvas;

  6. Run project fast (rabbit);

  7. Run project slow (snail);

  8. Hide blocks (This button is replaced by the stop button when the project is running);

  9. Help;

  10. Load examples;

  11. Stop activity.

  

  To get the Palettes toolbar, click on the Block icon on the Main toolbar.

  

                                                                               Fig. 3. Palettes toolbar and its components

  The palettes toolbar consists of the following palettes:

                        

  Each palette consists of blocks. A block is a command for the turtle, e.g., there is a block to tell the turtle to go forward.

  

        1. Practise how to add a block by dragging it from the palette to the mainarea.
         2. Practise how to delete a block by dragging it back onto the palette.
  

  You can add blocks to your program by clicking on or dragging them from the palette to the main area. You can also delete a block by dragging it back onto the palette.

  Some of the palettes are discussed below.

  
  

  Blocks available in Turtle palette are used to control the movements of the turtle.

  

                     Fig. 4. Turtle palette

  

  Blocks available in Pen palette are used to control the attributes of the Turtle’s pen.

  

                                                      Fig. 5. Pen palette

  

  Blocks available in Colour palette can be used with the set-pen-colour block in place of a number block.

  

                               Fig. 6. Colour palette

  

  The blocks available in Numbers palette are used to perform arithmetic operations.

  For example: Addition, subtraction, multiplication, division, identity, modulo, square root, random number, etc.

  

                                                               Fig. 7. Numbers palette

  

  Blocks available in Flow palette control the program flow.

  

                                            Fig. 8. Flow palette

  

  The blocks available in Blocks palette can be used to define variables andsubroutines, and store a number, string, or media object in a named box.

  

                                                                                                        Fig. 9. Blocks palette

  

  Blocks available in Sensors palette are used to check keyboard input, current valueof keyboard input, check picture value and pixels, set volume loudness and pitch.

  

                                                                                  Fig. 10. Sensors palette

  

  Blocks available in Media palette can be used to control your media like scaling,fonts, play, stop and duration.

  
  

                                                          Fig. 11. Media palette

  
  

  Using the blocks, we can access advanced features. For example, push value ontoFILO (first-in last-out) heap, show FILO in status block, empty the FILO, printvalue in status block, program comment (displayed in “walk” mode).

  
  

                                                        Fig. 12. Extras palette

  
  

  Using the blocks, we can see and run our activity in full screen. We can also adjust our presentation position, for example, left, right, top and bottom.

  
  

                                            Fig. 13. Portfolio palette or presentation palette

  
  

  Using the blocks, we can easily delete or restore all holds block. We can also clear our trash.

  
  

                                                                                  Fig. 14. Trash palette

  
  

  Here are some instructions you can use in Turtle Art.

  (a) Forward: Using this command, you can move the turtle forward with the number of pixels entered.

  
  

                                           Fig. 15. Forward command
  

  (b) Back: Using this command, you can move the turtle backward with the number of pixels entered.

                               

                                              Fig. 16. Back command

  (c) Left: Using this command, you can change the turtle’s direction to the left by a specified angle.

      

                   Fig. 17. Left command      

  (d) Right: Using this command, you can change the turtle’s direction to the right by a specified angle.

     

                  Fig. 18. Right command

  (e) Arc: Using this command, you can draw a part of the circle. The angle is the part of the circle that the turtle draws.

  

                                     Fig. 19. Arc command

  (f) Clean: Using this command, you can clean or clear the screen of all drawings.

                                                 

                                                        Fig. 20. Clean command

  

  Using multiple blocks from the Turtle palette, we can draw lines (horizontal and vertical), square, rectangle and circle.

  
  

  To draw a vertical line:

  1. Move the turtle forward 100 spaces

  2. To make the line longer, repeat this step.

                 

  To draw a horizontal line:

  1. Turn the turtle right 90 degrees.

  2. Then move the turtle forward 100 spaces.

                  

  To draw a oblique line:

  1. Turn the turtle right 60 degrees.

  2. Then move the turtle forward 100 spaces.

                 

     To draw a square:

  1. Move the turtle forward 100 spaces.

  2. Then turn the turtle right 90 degrees.

  3. Move the turtle forward 100 spaces.

  4. Then turn the turtle right 90 degrees.

  5. Move the turtle forward 100 spaces.

  6. Then turn the turtle right 90 degrees.

  7. Move the turtle forward 100 spaces.

  8. Now the turtle comes to its original position and forms a square.

           

  To draw a rectangle:

  1. Move the turtle forward 250 spaces.

  2. Then turn the turtle right 90 degrees.

  3. Move the turtle forward 500 spaces.

  4. Then turn the turtle right 90 degrees.

  5. Move the turtle forward 250 spaces.

  6. Then turn the turtle right 90 degrees.

  7. Move the turtle forward 500 spaces.

  8. Now the turtle comes to its original position and forms a rectangle.

  

  To draw a circle:

  u Arc the turtle right 360 degrees with radius 100 spaces.

  

  

  To save a document:Once you have completed your work, it is time to save the document.

  1. Click on Project toolbar.

  2. Click on Save menu. It will offer four options.

  3. Click on option in which you wish to save.

  The Save As dialogue box appears.

  4. Choose the location where you want to save your document.

  5. Click on Save.

  To close a document: When your document is saved, it is time to close it.

  To close:

  1. Click on Stop Activity on Main toolbar.

  2. Turtle art window will be closed.

  

  

  

  Scratch is a fun programming language. It provides a learning environment for kids. It allows us to create games, stories and animation. It can be used to write and run a program. Scratch is developed by the Lifelong Kindergarten Research group at the MIT Media Lab, USA.

  
  

         1. Go to the folder where you copied the Scratch.

        2. Double click the Scratch icon.

  You will see the Scratch window as shown.

  

                                          Fig. 23. Scratch window

  The Scratch window has the following components:

  

                                  Fig. 24. Components of Scratch window

  (a) Command Palette

  Command Palette is an area in the top-right corner of the Scratch window. These blocks consist of the following categories:

  Motion: Moves sprites and changes angles.

  Looks: Controls the visuals of the sprite; attaches speech or thought bubble, changes background, makes the sprite bigger or smaller.

  Sound: Plays audio files and programmable sequenced audio.

  Pen: To draw on portrait by controlling pen width, color, and shade.

  Control: Conditional if-else statement, “forever”, “repeat”, and “stop”.

  Sensing: Sprites can interact with the surroundings the user has created.

   Operators: Mathematical operators, random number generator, and and-or statement that compare sprite positions.

   Variables: Defines variable and makes list for sprites.

  Toolbar contains all the eight commands of Command Palette as shown below.

  

                                                                                                                                                         (Continued...)

  

                                                       Table 1: Commands of a Command Palette

  (b) Script Pane

  The middle pane of scratch is called the Scripting pane. Here all program codes are constructed and stored. You can create and view the scripts pertaining to the current sprite.

  

  (c) Stage Pane

  The stage is where all the actions take place. The stage is 480 steps wide by 360 steps tall.

                               

                                     Fig. 26. Stage pane of Scratch

  (d) Thumbnails Pane

  On the left, you can see a thumbnail for the stage. Clicking on Thumbnails Pane, it changes ‘Current Sprite Information’ area to reflect properties of the stage. To change the appearance of the stage, you would select a different ‘Background’ as opposed to ‘Costume’.

  On the right, you can see thumbnails of all of the sprites used in the project together with sprite’s name. You can easily change current sprite by clicking on a different one.

  
  

  

  You can change costumes or position of an object by animation. Animation involves sprites to talk and interact. The following are different steps to animate an object.

  (a) Choosing New Sprite from File

  1. Choose File menu from menu bar.

  2. Click on New option from drop-down list box. You will get sprite to work on new project.

  (b) Changing the Background

  To change the background of an object:

  1. Select the Stage thumbnail from the Sprite List.

  2. Now choose Backgrounds from the Tabs area. You can print a background yourself. import a                     background from a file. You can also edit an existing background or copy a background (useful to do         before editing).

  3. Select Import and find a background you like in one of existing files (such as‘Outdoors’ > ‘brick-wall1’).         Click ‘OK’ when ready.

  4. Since you no longer need ‘background1’ you can delete it. You should now have an interesting background!

  
  

  
  

  
  

  1. Go to the folder where you copied the Scratch. Then double click the Scratch icon to open the Scratch         window.

  2. Delete the Cat sprite named ‘Sprite1’.

  To delete the sprite, right click on ‘Sprite1’ and select Delete.

  3. Click ( ) to open Paint Editor. The Paint Editor window appears

  

  

  4. Click Ellipse Tool ( ) and click hollow mode ( ). Draw five circles.

  
  

  
  

  
  

  
  

  
  

  
  

  
  

  View in full-screen mode or presentation mode by clicking 
  

  
  

  
  

  A project is a creation made in the Scratch program. It can be about anything from music to animation, art and games.

  

  1. Click on File menu. A Drop-down List Box appears.

  

  

               Fig. 28. File menu

  2. Choose Save option. The Save Project dialog box appears

  .

                Fig. 29. The Save Project dialog box

  3. Choose the location where you want to save the project. Type your file name in the New Filename box. Write the name of the Project Author. Write About this project.

  4. Click on OK button.

  

  To close your scratch activity:

  1. Click on File menu. A Drop-down List Box will appear.

  2. Choose Quit option. Your scratch activity will be closed.

  

  If you want to show your saved project to your friends:

  1. Open the Scratch window.

  2. Click on File menu. A Drop-down List Box appears.

  3. Choose Open option. The Open Project dialog box appears.

  4. Select the location. Double click on the saved project. Your project will be opened.

  

        1. In Scratch window, create a sprite.

        2. Animate it by arranging the instructions required.

  

  Program: A collection of instructions.

  Scratch: Scratch can be used to write and run programs.

  Scripting pane: All program code is constructed and stored in this pane.

  Thumbnails Pane: It changes ‘Current Sprite Information’ area to reflect properties of the stage.

  Turtle Art: It is a part of LOGO.

  

  A computer program is usually written by a computer programmer in a programming language.

  Blocks can be added to program by clicking on or dragging them from the palette to canvas.

  You can add blocks to your program by clicking on or dragging them from the palette to canvas. You can also delete a block by dragging it back onto the palette.

  Using arc command you can draw a part of the circle. The angle is the part of the circle the turtle draws.

  With Scratch, you can program your own interactive stories, games, and animations. You can share your creations with others in the online community..

  
  

  Do these review exercises in your exercise book.

  I. Fill in the blanks with the correct options:

  1. Turtle Art is a part of ................ .

  (a) LOGO          (b) PASCAL          (c) BASIC            (d) ASCII

  2. Using ………… command you can move the turtle forward with the number of pixels entered.

  (a) Back            (b) Forward           (c) Left                  (d) Right

  3. Using …………. command you can move the turtle backward with the number of pixels entered.

  (a) Back            (b) Forward            (c) Left                  (d) Right

  4. Scratch can be used to write and run ……………. .

  (a) application     (b) hardware        (c) software           (d) programs

  5. All program codes are constructed and stored in ……….. .

  (a) Command Palette                      (b) Script Pane

  (c) Stage Pane                                (d) Thumbnails Pane

  II. State whether the following statements are true or false:

  1. A computer requires programs to function.

  2. Scratch and Turtle Art are two popular programming languages for kids.

  3. Using clean command you can clear the screen of all drawings.

  4. Using left command you can change the turtle’s direction to right by the angle specified.

  5. Pen Palettes are used to control the movements of the turtle.

  III. Match the following:

  Palette                                                  Function

  1. Flow Palette                                    (a) controls the attributes of the Turtle’s pen

  2. Colour Palette                                   (b) controls the movements of the turtle

  3. Pen Palette                                         (c) all the actions take place

  4. Turtle Palette                                        (d) is used with the set-pen-colour block

  5. Stage Pane (e) controls program flow

  IV. Answer the following questions briefly:

  1. List any two popular programming languages for kids.

  2. What is the use of Arc command?

  3. List categories of Command Palette.

  4. List uses of the following commands:

  (a) Forward         (b) Back        (c) Left       (d) Right

  5. Write commands to draw a:

  (a) horizontal line           (b) rectangle

  6. Write the steps to open a scratch activity.

  V. Complete the following crossword puzzle using the clues below:
  

  
  

  Clues:

  Across

  3. It is a part of LOGO.

  4. This command is used to clear the screen of all drawings.

  Down

  1. This is a fun programming language for kids.

  2. It is a collection of instructions.

  Mark as done
• Air is what everybody breathes. It is a mixture of gases. A moving air is called wind. Air is the gaseous  medium through which sound propagates.

  

  You will feel air. Air is every where. We cannot see it. We can only feel it.

  7.1 Main Properties of Air

  

  Air makes the balloon inflate. This is because the air blown into the balloon occupies space. In the same way, air causes football and cycle tubes to inflate. This shows that air occupies space.

  

  The inflated balloon goes down as it is heavy. The inflated balloon is heavy because it has air in it. This shows that the air has weight.

  

  Air inside the syringe gets compressed to a certain extent. This shows that air can be compressed.

  Thus, the air has the following properties:

  (a) Air occupies space

  (b) Air has weight

  (c) Air can be compressed

  7.2 Composition of Air

  

  The candle stops burning when it is covered by the jar. It is because the burning candle has used up the oxygen present inside the jar. Water rises up to fill this space.

  The level of water rises to one-fifth of the glass jar. This is because one-fifth of air is used up in the jar. This shows that oxygen is one-fifth of air.

  Air is a mixture of various gases. It consists of the following gases:
  ‹‹
  ‹‹-Nitrogen 78%,
  ‹‹
  -Oxygen 21% (one-fifth of air),
  ‹‹
  -Rare gases like Argon 0.97%, and
  ‹‹
  -Carbon dioxide 0.03%.

  Besides these gases, dust particles, water vapour and smoke are also present in the air.

  7.3 Utility of Air Components in Daily Life

  Air has different components. Each component has some specific use. Some of them are:

  (a) Nitrogen

  

  If there was no nitrogen in air, everything would burn rapidly on the earth surface.

  Nitrogen prevents this rapid burning. Nitrogen is also used in the preparation of fertilisers.

  (b) Oxygen

  

  You will see that the cockroach in the second jar dies. This is because the burning candle has used the oxygen present inside the jar. Due to the lack of oxygen, the cockroach could not respire. This shows that 

  oxygen is used in respiration.

  

  The plant covered with bell jar did not wilt. This is because it got no oxygen for respiration.

  The plant which was kept open did not wilt. This is because it got oxygen for respiration.

  This shows that oxygen is necessary for respiration.

  

  

  You will find that seeds in flask B grow while seeds in flask A do not. In flask A, oxygen was absorbed by the pyrogallic acid and no germination took place. In flask A, there was oxygen and germination took place. This shows that oxygen is necessary for seed germination.

  
  

  The candle covered with the cup goes off after some time. This is because the supply of oxygen is interrupted. This shows that oxygen supports combustion.

  Thus, oxygen is used for the following purposes:

  (a) Respiration

  (b) Plant germination

  (c) Combustion

  (c) Argon

  
  

  Argon is used in the light bulb.

  (d) Carbon Dioxide

  
  

  This is the process of photosynthesis. In this process, green plants use carbon dioxide to prepare food.
  

  
  

  The grass covered with the brick cannot receive atmospheric carbon dioxide and light. So it is unable to prepare its food and becomes pale yellow.

  This shows that carbon dioxide is essential for green plants.

  
  

  In factory, carbon dioxide is pressurized into the soft drink bottle.

  Carbon dioxide is poorly soluble in water. When we open the bottle, carbon dioxide is quickly released. Therefore, releasing the pressure it produces fizz.

  
  

  Carbon dioxide is used in the fire extinguisher to put the fire off.

  Thus, carbon dioxide has the following uses:

  (a) Green plants use carbon dioxide to make their food.

  (b) Carbon dioxide is used for making industrial beverages like soda water.

  (c) Carbon dioxide is used in fire extinguishers to put the fire off.

  (e) Water Vapour

  
  

  Water vapour forms clouds and then falls as rain on earth. So it is essential for life processes on earth.

  7.4 Dangers of Components of Air

  (a) Carbon Dioxide and Water Vapour

  The atmospheric air contains a little amount of carbon dioxide and water vapour.

  These are the most powerful greenhouse gases.

  Charcoal stoves, brick kilns, factories and motor vehicles release carbon dioxide into the atmosphere. Bushfire also increases the amount of carbon dioxide in the atmosphere. This gas traps the heat released by the earth. As a result, the atmospheric temperature increases.

  
  

  Water vapour is produced during boiling of water. These vapours are suspended in the atmosphere as clouds. These clouds trap the heat released by the earth. As a result, the atmospheric temperature increases.

  The process of rising atmospheric temperature is called global warming.

  (b) Carbon Monoxide

  Carbon monoxide is a poisonous gas.

  
  

  You will see that the rat in the second jar gets unconscious. This is because the burning candle fills the jar with carbon monoxide. It shows that carbon monoxide is dangerous.

  Breathing carbon monoxide can cause headache, vomiting, nausea and loss of consciousness. It is invisible, tasteless and non-irritating. It is released from charcoal stoves, brick kilns, factories and motor vehicles when fuel burns. It is also released from bushfires.

  People in rural areas use wood/charcoal stoves to cook their food. Charcoal stoves are a source of carbon monoxide. So never cook food inside a closed room.

  
  

  
  

  
  

  7.5 Prevention from Global Warming

  To prevent atmosphere from global warming:

  1. Reduce fuel consumption.

  2. Walk, use bicycle or take public transport.

  3. Encourage people to plant trees to preserve the rainforests.

  4. Use solar and wind energy.

  5. Maintain your vehicle properly.

  6. Turn off your vehicles at the traffic lights.

  7. Buy energy-efficient appliances.

  7.6 Wind and its Types

  
  

  Moving air disturbs the flame. This moving air is called wind. It blows from a particular direction.

  
  

  Movement of air depends on the change in pressure and temperature of the atmosphere. Winds may be light, breezy or stormy.

  (a) Light Wind                                                                         

  The soft and pleasant movement of air is called light

  wind. Light wind can be noticed by smoke rising

  vertically from a mosquito coil.

  (b) Breeze Wind

  Wind with soothing feeling on a warm day is called

  breeze wind. It blows at a certain speed.

  (c) Storm Wind                                                        

  When wind blows very fast, it is called storm. A storm can uproot trees and blow away temporary houses. It can also damage bird’s nests, sheds, and crops. We must not go out of our homes during a storm.

  7.7 Uses of Air and Wind

  Air and wind help animals and human in many ways.

  

     Air helps the bird to fly in the sky.

  

   Hold your breath for some time.

  How do you feel? Discuss why?

   

   You will feel uneasy. This is because air is necessary for breathing.

  
  

   1. Collect millet, sorghum and a winnower.

  2. Go to an open area.

  3. Stand on a high platform.

  4. Allow the grain to fall down from a height.

  What is this process called?

  
  

  This process is called winnowing. Wind helps in winnowing. In this process, farmers separate lighter husk particles from heavier grains like corn, millet and sorghum.

  
  

    1. Take two wet clothes.

    2. Hang them in the open.

    3. Observe these clothes just after two hours.

  What do you observe?

  
  

  After two hours, you will find the clothes become dry. What make the clothes dry?

  The moving air helps the clothes to dry.

  
  

                                      

  1. What does the picture show?

  2. What helps the clouds to move for rain distribution?

  Moving air helps the clouds to move for rain distribution.

  

  

  1. What does the picture show?

  2. What helps the boat to sail on water?

  Moving air helps the boat to sail on water.

  

  

  1. What does the picture show?

  2. What helps the wheel of the windmill to rotate?

  The moving air rotates the wheel of the windmill to generate electricity.

  7.8 Dangers of Wind

  Air helps us in many ways. But sometimes it is very dangerous.
  

  
  

  
  

  1. Observe the pictures above and state what is happening?

  2. What do strong winds do to trees and electric poles?

  3. How can strong wind damage houses and properties?

  4. Why is it unsafe to fly an airplane on a stormy day?

  5. Why is it unsafe to sail a boat on a stormy day?

  The following are some dangers of wind:

  1. Strong winds can uproot the plants and electric poles.

  2. It can damage our houses and other properties.

  3. It can damage our crops.

  4. On a stormy day, an airplane can lose its control and may crash.

  5. Strong wind can make a boat sink.

  Can you add some more dangers to this list?

  Field Trip

  Organise a visit to an area spoiled by the wind. Observe and list the effects of wind on environment.
  

    7.9 Prevention of Dangers of Wind

  
  

    

   The boy plants trees around his house. Trees can block the wind speed and protect the house from damage.

   We can prevent dangers of wind in the following ways:

  1. Trim the branches of trees. It allows the wind to pass through. It lowers the chance of trees tumbling over.

  2. Ask the fishermen not to go for fishing on a stormy day.

  3. Check the roof for loose tiles. They can get displaced by strong wind and hurt some one.

  4. Never go on a stormy day. You can get hurt.

  5. Make people aware the dangers of wind.

  

   

  
  

  7.10 Sound

  
  

    Sound is a form of energy. It comes from all around us. It comes from:

  ‹‹ people when they talk.

  ‹‹ radios when they play.

  ‹‹ airplanes when they fly.

  Even breathing makes a low sound.

  (a) Sound Production

  Sounds may be soft or loud, high or low, and pleasant or unpleasant. Still, all kinds of sounds are made in the same way.

  
  

   

  When we hit the drum, its membrane moves back and forth very quickly. This fast movement is called vibration. It makes the sound. The vibrations cause paper pieces to jump on the membrane.

  (b) Nature of Sound

  
  

  
  

  
  

  The sound becomes fainter as you suck the air. This is because the air has been removed from the glass. It shows that sound needs a medium to travel. It cannot travel in vacuum.

  Some other nature of sound are:

  1. Sound is a form of energy, just like electricity and light.

  2. It is always produced by a source.

  3. Sound waves cannot be transmitted through vacuum.

  4. Speed of sound varies in all three media.

  (c) Sound Propagation and Transmission

  
  

  
  

  
  

  
  

  1. Play a music system.

  2. Put your hand on its speaker.

  What do you feel?

  You will feel vibration of the speaker. Its back and forth movements make the sound propagate towards your ears. Propagation means the transmission of sound in different states of matter. When any object vibrates, it causes movement of the air particles. These particles push the particles close to them. It makes them vibrate too. This movement creates sound waves. If your ear is within range of the vibrations, you hear the sound.

  
  

  
  

  
  

  1. Take two paper cups.

  2. Make a hole at the bottom of each cup.

  3. Insert a string in both the holes and tie a knot.

  4. Give one cup to your friend. Ask him/her to hold it to his/her ear.

  5. Walk away until the string is stretched taut.

  6. Speak into your cup. Can your friend hear you? Your friend can hear you. Try it the way  round.

  This activity shows that sound transmits through solids.
  

  
  

  1. Go to your school playground.

  2. Let each of you try to talk to each other.

  Do you hear each other?

  You hear one another. Here the sound transmits through air.

  

  1. Take a bucket and fill it with water.

   2. Take a small bell in one hand.

   3. Shake this bell inside the water to produce sound. Make sure that the bell does not touch the body of the bucket.

  

  4. Place your ear gently on the water surface. Be careful: water should not enter in your ear. Can you hear the sound of the bell?

  You can hear the sound of the bell. This shows that sound transmits through liquid.

  Thus, sound can transmit through the following:

  (a) Solids

  (b) Air

  (c) Liquids

  (d) Production of Echo: Reflection of Sound

  
  

  A faint sound similar to original sound is heard after some time. This can also be experienced in big and empty rooms or halls. Sound hits the solid surface and reflects around. This reflection of sound waves is called echo.

  
  

  
  

  We hear different types of sound in our daily life. Some of them are pleasant to hear. Others are unpleasant to hear.

  The sounds which are pleasant to hear are pure or musical sounds. Musical sounds are produced by the regular vibrations. All musical instruments produce regular vibrations, for example, strings of guitar and violin.

  

                           Fig. 8. Music (pleasant sound) consists of regular, gently curving sound waves

  The sounds which are unpleasant to hear are called noise. Irregular vibrations produce noise. Grinding machine, hammer, motor vehicles and crackers produce irregular vibrations.

  

  (f) Damaging Effects of Noise

  
  

  1. Visit a nearby factory or a stone crusher.

  What type of sound does it produce?

  2. List some effects of such sounds on our health and environment.

  We hear sound or noise through our ears. If we hear loud noise, we get irritated.

  Prolonged exposure to noise has various harmful effects.

  1. Loud noise can damage our ears.

  2. Loud noise can also cause tinnitus. Tinnitus is like a ringing or buzzing in the ears or head.

  3. Noise leads to emotional and behavioural stress.

  4. Noise increases chances of diseases like headache, blood pressure and heart failure.

  5. Noise leads to noise pollution.

  (g) Protection of Ears from Noise

  
  

  
  

  The factory worker is wearing earmuffs to protect his ear from noise.
  

  The Way of Protecting Ears from Noise

  1. Stay away from noisy places.

  2. Turn the volume down and get used to listening to quieter sounds.

  3. Wear earmuffs.

  4. Protect the ears of children those who are too young to protect their own.

  5. Make people aware about the hazards of noise.

  
  

  
  

  7.11 Keywords

  ‹‹ Air: A mixture of gases.

  ‹‹  Combustion: The process of burning a substance, such as charcoal and wood, in the presence of oxygen.

  ‹‹ Echo: The reflection of sound waves.

  ‹‹ Germination: The process by which a plant grows from a seed.

  ‹‹ Global warming: The process of rising atmospheric temperature.

  ‹‹ Greenhouse: A glass housing in which temperature can be regulated to grow plants.

  ‹‹ Photosynthesis: The process through which green plants produce their food.

  ‹‹ Respiration: The process by which energy is obtained from food.

  ‹‹ Sound: A form of energy, just like electricity and light.

  ‹‹ Sound propagation: The transmission of sound.

  ‹‹ Syringe: A tube with a nozzle for sucking in and ejecting liquid in a thin stream.

  ‹‹ Tinnitus: Ringing or buzzing in the ear.

  ‹‹ Vibration: To and fro movement of something.

  ‹‹ Wind: The moving air.

  7.12 Summary

  ‹

  Air is a mixture of various gases. It has the following properties:

  (i) It occupies space.

  (ii) It has weight.

  (iii) It can be compressed.

  ‹‹ Oxygen is used by all living things. It is essential for germination, respiration and combustion.

  ‹‹ Carbon dioxide is an essential component of photosynthesis.

  ‹‹ Green plants use carbon dioxide to make their food.

  ‹‹Carbon dioxide and water vapour are the most powerful greenhouse gases.

  ‹‹The moving air is called wind. Winds may be light, breeze and stormy.

  ‹‹Sound is a form of energy.

  ‹‹Propagation means transmission of sound in different states of matter.

  ‹‹The reflection of sound is called echo.

  ‹‹The sounds which are pleasant to hear are pure or musical sounds. Musical sounds are produced by the regular vibrations.

  ‹‹The sounds which are unpleasant to hear are called noise. Irregular vibrations produce noise.

  7.13 Unit Review Exercises

  Do these review exercises in your exercise book.

  I. Fill in the blanks with the correct options:

  1. The percentage of nitrogen present in air is ............. .

  (a) 78%            (b) 21%

  (c) 0.17%         (d) none of these

  2. …………….. supports combustion.

  (a) Oxygen          (b) Argon

  (c) Nitrogen         (d) Water vapour

  3. …………. is a greenhouse gas.

  (a) Oxygen          (b) Carbon dioxide

  (c) Argon             (d) None of these

  4. …………. is used in light bulbs.

  (a) Oxygen               (b) Argon

  (c) Nitrogen             (d) Water vapour

  5. …………. is produced when something vibrates.

  (a) Sound                (b) Light

  (c) Air                     (d) Oxygen

  II. State whether the following statements are true or false:

  1. The vibrating body causes the medium around it to vibrate.

  2. Nitrogen is essential for respiration.

  3. Reflection of sound waves is called echo.

  4. Regular vibrations produce noise.

  5. Noise increases chances of diseases like blood pressure and heart failure.

  III. Match the following:

  Column A                                                  Column B

  1. Oxygen                                              (a) Greenhouse gas

  2. Carbon dioxide                                  (b) Produces sound

  3. Reflection of sound                           (c) Helps in winnowing

  4. Vibration                                           (d) Echo

  5. Wind                                                 (e) Used for respiration

  IV. Answer the following questions briefly:

  1. List different properties of air.

  2. Explain the composition of air.

  3. List at least two uses of the following:

  (a) Oxygen             (b) Carbon dioxide

  4. List the main types of wind.

  5. State some uses of air and wind.

  6. Define echo.

  7. What is the nature of sound wave?

  8. How can we protect our ears from noise?

  9. Differentiate between:

  (a) Breeze and storm

  (b) Music and noise

  V. Complete the crossword puzzle using the clues below:

  
  

  Clues:

  Across Down

  2. Sound is produced due to this.                1. It is a mixture of different gases.

  4. It is the reflection of sound.                      2. Sound waves cannot be transmitted through                                                                              it.

  5. It is the moving air. through it.                  3. This gas supports burning.

  Mark as done
• click here for a lesson on UNIT 7: Air wind and sound URL

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• click here for a lesson on Use of air components in daily life URL

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• click here for a lesson on Wind and It types URL

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• click here for a lesson on use of air and wind URL

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• click here for a lesson on Dangers of wind URL

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• click here for a lesson on sound URL

  Mark as done
• Soil is one of the non-living things. It is useful to plants, people and other animals. Plants grow in soil. People and other animals depend on plants for food

  

  Mix together tiny chips of rocks, dry leaves and water.
  Add bits of dried up caterpillars’ skin, birds’ feathers and air.
  What do you think? What is this a recipe for?
  It is the recipe for soil.

  

  8.1 Definition of Soil
  
  The topmost layer of the earth’s surface is called soil.

  

                                                            Fig. 1. Land is covered with soil

  

  Collect samples of soil from different places like lake side, farm and a construction site. Observe these samples thoroughly. Rub them with your fingers. Record your observations in the following table:

  

                                Table 1: Different Types of Soil and their Characteristics 

  There are three main kinds of soil:

  1. Loam. Loam is chiefly a mixture of sand and clay. It can hold enough water and air for plants. It feels smooth.

  2. Clay. Clay is made up of very fine particles. It can hold a lot of water but very little air. It feels sticky when wet and forms clumps when dry.

  3. Sand. Sandy soil is made up of very small rock particles. They are bigger than clay particles. Sand is found in desert areas. Sand cannot hold much water but it can hold much air. It feels gritty.

  

  

  In step (a), when soil is watered, water fills up the spaces between the grains of soil. The air is then pushed up as bubbles. This shows that air is trapped in the spaces between the grains of the soil.

  In step (b), you will see droplets of water on the sides of the jar. This shows that soil contains water or moisture.

  In step (c), you will see that the soil settles in different layers. The largest particles (stones) go down to the bottom. Above this layer, bigger grains of sands settle. Over the sand, you will find a layer of clay. On the top of water floats the humus. This shows that soil contains stone, sand, clay and humus.

  Thus, soil has the following components:

  1. Air
  2. Moisture or water
  3. Clay, sand, stones and humus.

  

  1. Collect samples of clayey, sandy and loamy soils.
  2. Take a fistful of soil from one of the samples.
  3. Remove any pebbles and rocks from it.
  4. Now add water drop by drop and knead the soil.
  5. Try to make a ball from the soil.
  6. On a flat surface roll the ball into a cylinder.
  7. Repeat this activity with other samples.

  Which soil is suitable for making different shapes? Why?

  

  

  

  1. Collect three same sized jam jars, three funnels, some clay, sand, loam and water.
  2. Put some cotton wool at the neck of the funnels.
  3. Put each type of soil in different funnels.
  4. Set up the jars as shown in the picture.
  5. Slowly pour the water onto each funnel. Wait for five minutes.

  

  The clayey soil does not allow water to pass through it easily. This is because its particles are closely packed. It has high water-holding capacity. It is suitable for cultivation.

  Soil that is used for cultivation should be fertile. Fertile soil should have the following characteristics:

  1. It should have adequate amount of humus.
  2. It should have high water-holding capacity.
  3. It should be well aerated.
  4. It should be deep because deep soil enables plants to grow well.
  5. It should be easy to dig.

  

  When water is poured on the soil, it washes away some soil. The process of carrying away of soil by wind, water or other agents is called soil erosion.

  Soil erosion reduces the fertility of soil. Farmers do not get good crops.

                    

                                                         Fig. 5. Soil erosion

  8.7 Agents of Soil Erosion

  There are many factors that are responsible for soil erosion. These are called agents of soil erosion

  

  

  

          1. Discuss various causes of soil erosion.
          2. Makes a list of these.
          3. Compare your list with others.

  

  

  

  

        1. After a heavy rainfall, visit an area where vegetation has been removed.
        2. Observe various types of soil erosion on a steep slope.
        3. Make a list of them.

  

  

  

  

  These are various methods to prevent soil erosion.

  (A) Afforestation
  
  Afforestation means planting of trees. The roots of plants and trees hold the soil and reduce erosion by water and wind.
  
  (B) Soil Cover
  
  After harvesting of crops, the land should be covered with grass. The roots of the grass bind the soil and protect it from being blown away.

  (C) Shelter Belts

  • You might have seen tall trees grown on all sides of a field. These are grown to
    
  • reduce the speed of blowing winds. They act as wind breakers.
    
    

  (D) Terrace or Step Farming

  • Soil erosion is maximum on hill slopes due to the speed of water being high.
    
  • Here the hills are cut into steps by farmers. It reduces the speed of flowing
    
  • water and prevents soil erosion.
    
    8.11 Keywords
    
    
  •  Clay: Soft soil when it is wet and hard when it is dry.
    
  •  Humus: A component of soil, made up of dead plant and animal remains.
    
  •  Loam: A kind of soil which is a mixture of sand and clay with some humus.
    
  •  Sand: Finely crushed stones found on beaches.
    
  •  Soil: The topmost layer of the earth’s surface.
    
  •  Weathering: Breaking of rocks into tiny pieces to form soil.
    
    

  8.12 Summary

  • Soil is the topmost layer of earth’s surface.
    
  • Soil contains air, water, clay, sand, stones and humus.
    
  • There are three types of soil, namely loam, clay and sand.
    
  • Fertile soil should have high water-holding capacity and adequate amount of humus.
    
  • The process of carrying away soil by wind, water or other agents is called soil erosion.
    
  • Water and wind are two main agents of soil erosion.
    
  • Deforestation, overgrazing and bushfires are main causes of soil erosion.
    

  8.13 Unit Review Exercises

  Do these review exercises in your exercise book.
  
  I. Fill in the blanks with the correct options:
  
  1. The topmost layer of the earth’s surface is called ............................ .

  (a) rock                                                         (b) soil
  (c) stone                                                       (d) none of these

  2. ............................ is trapped in the spaces between the grains of soil.

  (a) Water                                                       (b) Air
  (c) Roots                                                       (d) All of these

  3. ............................ soil is best for plant growth.

  (a) Sandy                                                        (b) Loamy
  (c) Clayey                                                        (d) None of these

  4. ............................ is a cause of soil erosion.

  (a) Step farming                                      (b) Afforestation
  (c) Deforestation                                     (d) Soil covering
  
  II. State whether the following statements are true or false:
  
  1. Soil contains water or moisture.
  2. Sandy soil has high water-holding capacity.
  3. Sheet erosion is caused by the direct impact of falling rain drops on soil particles.
  4. Tall trees or hedges grown on all sides of a field act as wind breakers.
  5. Fertile soil should have little amount of humus.

  III. Match the following:

  Soil type Uses

  1. Loam                                (a) Making bricks, toys and pottery items
  2. Sandy                               (b) Best for plant growth
  3. Clay                                  (c) Good for crops like groundnut

  IV. Answer the following questions briefly:
  
  1. Define soil.
  2. What are the different types of soil?
  3. What is the composition of soil?
  4. Write three uses of soil.
  5. Soil is home to many animals. Can you name any three animals?
  6. Write any three characteristics of fertile soil.
  7. Mention one agent of soil erosion.
  8. List different types of soil erosion.
  9. List three methods of preventing soil erosion.

  V. Complete the crossword puzzle using the clues below:

  

  Clues:

  Across

  2. It is the topmost layer of the soil.
  4. Soft when it is wet and hard when it is dry.
  5. Component of the soil, made up of dead plants and animal remains. 

  Down

  1. A kind of soil which is a mixture of sand and clay with some humus.
  3. Finely crushed stones found on beaches.

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• There are different types of animals in the world we live in. Many animals are quite similar to each other. Others are quite different. Animals can be classified based on their similarities.

  

  

  

      1. Which of these animals have a backbone?

       2. Which of these animals do not have a backbone?

  Animals such as cows, cats, frogs, pigeons and humans have a backbone. They are vertebrates. Other animals such as earthworms, grasshoppers, houseflies and butterflies do not have a backbone. They are invertebrates

  
  

  

  

  1. Are these animals vertebrates?

  2. What are their major characteristics?

  3. Group these animals according to their major characteristics.

  These are all vertebrates. The following are some major characteristics of vertebrates:

  1. Vertebrates have a backbone.

  2. They have an internal skeleton which protects their internal organs.

  3. They have two pairs of limbs or fins for movement.

  4. They have lungs or gills for breathing.

  5. They have closed circulatory system.

  There are different classes of vertebrates. The five most well-known classes of vertebrates are mammals, birds, reptiles, amphibians and fish.

  

  

  

  1. How do these animals feed their young ones?

  2. How is their skin?

  3. What are they called?

  They are mammals. They have the following characteristics:

  1. Mammals have hairs on their body.

  2. They (females) give birth to their young ones.

  3. They (mothers) feed milk to their young ones.

  Cow

  Cow is the best example of a mammal. It possesses a backbone, hair and mammary glands. It gives birth to its young ones.

  External Features of a Cow

  
  

  Identify the external body parts of a cow and label them in your notebook.

  
  

  
  

  The main external body parts of a cow are:

  A. Head: It contains the eyes, ears, mouth, horns and muzzle. This allows it to pick up sounds from more than one direction at a time.

  B. Tail: Tail is the section at the rear end of an animal’s body. It helps swat away biting insects that may carry diseases.

  C. Anus: Anus is the opening through which the waste is removed.

  D. Abdomen: It helps in digestion of food.

  E. Legs: Legs are used for locomotion.

  F. Udder: It is the mammary gland hanging near the back legs. There are four teats in the cow’s udder.

  Internal Features of a Cow

  
  

  
  

  Some of the internal organs of a cow are: lungs, livers, heart and alimentary canal.

  All these organs are shown in Fig. 1.

                                          

                                                 Fig. 1. Internal features of a cow

  A. Heart: It pumps blood throughout the body.

  B. Alimentary canal: It is a tube running from mouth to anus. It helps in digestion of food.

  C. Lungs: They help in breathing.

  D. Liver: It produces bile. Bile helps in digestion of fats.

  (b) Birds

  
  

  1. How do these animals make their young ones?

  2. What is their body made up?

  3. What are these animals called?

  These animals are called birds. They have the following characteristics:

  1. They have a backbone.

  2. They have streamlined body.

  3. They have a beak, wings and feathers.

  4. Their feet are covered with scale.

  5. They lay eggs.

  Hen

  Hen is the best example of a bird. It possesses a backbone, beak, wing and feathers.

  It lays eggs.

  External Features of a Hen

  
  

  The main external body parts of a hen are:

  A. Beak: Beak helps a hen to protect it from enemies. It is also used as teeth.

  B. Head: It bears eyes, ears, beak and wallet.

  C. Feathers: Feathers keep a hen’s body warm.

  D. Legs: Legs help the hen walk. It also scratches the soil with its legs.

  E. Scales: Scales are hard plates that cover a chicken’s toe.

     Internal Features of a Hen

  
  

  1. Observe various internal organs of a hen on a wall chart.

  2. Discuss the functions of each organ.

  3. Make a report on it and present it to your class teacher.

  The main internal body part of a hen is the alimentary canal. It is shown in Fig. 2.
  

  
  

                                 Fig. 2. Internal features of a hen

  
  

  Alimentary canal is a long tube-like organ. It starts at the beak and ends with the vent or cloaca in the abdominal region. It consists of foodpipe, crop, liver, gall bladder and intestines.

  ¨ The foodpipe carries the food from the mouth to the crop.

  ¨ The crop is a small sac-like structure where the food is stored for some time.

  ¨ Liver secretes bile which digests the fats.

  ¨ The gall bladder stores the bile produced by the liver.

  ¨ The small intestine absorbs nutrients from the digested food.

  ¨ The large intestine absorbs water and the remaining undigested food.

  (c) Fish

  
  

  1. What does the picture show?

  2. Where do fish live?

  3. Write some characteristics of a fish.

  The following are some characteristics of fish:

  1. Fishes live in water.

  2. They have a backbone.

  3. They have a streamlined body.

  4. They have scales on their skin.

  5. They breathe through gills.

  Examples: Tilapia and tuna

  Tilapia is the best example of a fish. It possesses backbone. It lives in water. It has scales on its body. It breathes through gills.

  External Features of Tilapia

  
  

  1. Identify external body parts of a Tilapia fish.

  2. Label them in your science notebook.

      

  
  

  The main external body parts of a Tilapia fish are:

  A. Nostrils: A fish uses it to detect food.

  B. Dorsal Fin: The fish uses it for balancing and protection.

  C. Scales: Scales are the protective cover on a fish. It is similar to skin.

  D. Caudal or Tail Fin: The fish uses it for steering.

  E. Pelvic Fin: The fish uses it for steering.

  F. Pectoral Fin: The fish uses it for turning.

  Internal Features of Tilapia

  The main internal body parts of a tilapia are gills. Fishes breathe through their gills.

  

                    Fig. 3. Internal features of tilapia

  (d) Reptiles

  
  

  
  

  1. How do these animals move?

  2. What is their body made up?

  3. What are these animals called?

  These animals are called reptiles. They have the following characteristics:

  1. They have a backbone.

  2. They move by crawling.

  3. They have scales on their body.

  4. They lay eggs on land.

  Snake

  Snake is the best example of a reptile. It possesses a backbone and scales on its body. It moves by crawling. It also lays eggs.

  External Features of a Snake

  
  

  Identify the external body parts of a snake and label them in your science notebook.

  
  

  The main external body parts of a snake are:

  A. Head: It contains eyes, nostrils, mouth and brain.

  B. Scales: Scales protect them from wearing away. Scales also help them move.

  C. Tail: It is the end part of the body.

  Internal Features of a Snake

  
  

  1. Observe various internal organs of a snake.

  2. Discuss the functions of each organ.

  3. Make a report on it and present to your teacher.

  The main internal body parts of a snake are the intestines. Water snakes also have gills.

  
  

                  Fig. 4. Internal features of a snake

  A. Gills: These help the snake to breathe in water.

  B. Liver: It secretes bile which helps in the digestion of fats.

  C. Stomach: It is the main internal organ in which digestion of food occurs.

  D. Small intestine: It is a long narrow coiled tube. It absorbs nutrient from the food.

  F. Large intestine: It absorbs water from wastes.

  (e) Amphibians

  
  

  1. Where do these animals live?

  2. What is their body made up?

  3. What are these animals called?

  These animals are called amphibians. They have the following characteristics:

  1. Amphibians have a backbone.

  2. They can live on both land and water.

  3. They have a smooth slimy skin.

  Frog is the best example of an amphibian. It possesses a backbone. It lives on both land and in water. It has no scales on its body.

  External Features of Frog

  
  

  1. Identify the external body parts of a frog.

  2. Label them in your science notebook

  
  

  The main external body parts of a frog are:

  A. Head: It contains the mouth, eyes, ears and nose. It protects internal organs like brain.

  B. Thorax: It is the part of the body between neck and abdomen. It protects internal body parts such as lungs and the heart.

  C. Abdomen: It protects the internal organs like stomach and intestines.

  D. Legs: The legs help a frog to jump.

  Internal Features of Frog

  The main internal body parts of a frog are: heart, stomach and intestines. These are shown in Fig. 5. 

  
  

    

  A. Heart: It pumps out blood throughout the body.

  B. Stomach: Its main function is to break down and digest food.

  C. Intestines: The small intestine absorbs nutrients from the food. The large intestine absorbs water from wastes.

  

  

  

  1. Do these animals have backbones?

  2. What are they called?

  3. Write their common characteristics

  These animals do not have backbones. These are all invertebrates. About 97% of all animals on our planet are invertebrates.

  The following are some major characteristics of invertebrates:

  1. They do not have a backbone.

  2. They cannot make their own food.

  3. Some of them have hard body covering.

  4. They make their young ones.

  Some organisms like earthworms and insects like grasshoppers, houseflies and butterflies are invertebrates.

  Insects

  
  

  
  

  1. How many legs do these animals have?

  2. How do they feed?

  3. What are these animals called?

  These animals are called insects. Some examples of insects are locust, butterfly, housefly, spider and bee.

  The following are some characteristics of insects:

  1. Insects have six legs.   

              

    2. Each insect has a pair of antennae or feelers.

  3. Insects like butterfly have a proboscis to suck nectar from flowers.

  4. Body of an insect is made up of head, thorax and abdomen.

  5. Most insects have wings and can fly.

  6. Insects breathe through their spiracles (or air holes).                                          

  

  Different animals have different breathing organs. On the basis of their breathing organs, animals are classified into various categories.

  (a) Animals Breathing through Lungs

  
  

                 

                   1. How do these animals breathe?

                    2. Can you name some other animals that breathe through lungs?

  These animals breathe through lungs.

  (b) Animals Breathing through Gills

        Aquatic animals such as fish breathe through gills.   Tadpoles (young ones of a frog) also breathe through gills.    

    

  c) Animals Breathing through Skin

  Some animals like earthworms and frogs breathe through their moist skin.

  
  

  (d) Animals Breathing through Spiracles

  
  

  1. Take two insects (e.g., cockroach and locust) and two glasses of water.

  2. Dip one insect in water by its abdomen and the other one by the head.

  3. Keep them in water for about 5 minutes.

  
  

   4. Remove these insects from water after 5 minutes.

  Which of these two insects died? Explain why?

  An insect breathes through spiracles. When the insect is dipped in water by the abdomen, it could not breathe. As a result of which it died. This shows that spiracles of insects are located near the abdomen. Spiracles are tiny pores located on the sides of the insect’s body (abdomen).

  
  

  Examples of such animals include caterpillar, grasshopper, housefly and butterfly.

  
  

  (e) Animals Breathing through Both Lungs and Skin

  
  

  
  

  1. How do these animals breathe?

  2. Can you name some other animals that breathe through lungs and skin?

  These animals breathe through both lungs and skin. When on land, an adult frog breathes through lungs. But it breathes through its moist skin, when it is under water.

  9.3 Classification of Animals According to the Locomotion Mode

  
  

  1. Visit a nearby zoo.

  2. Observe the movement of different animals like birds, lizards, rabbits elephants and crocodiles.

  3. Make a report on it and present to the science teacher.

  Animals move from one place to another. This movement of animals is called

  locomotion. Animals move in different ways.

  On the basis of locomotion, animals are classified into various groups.

  (a) Flying

  Animals such as birds fly with the help of wings.

   The following features help a bird to fly:

  1. It has a streamlined body.

  2. Its bones are filled with air.

  3. It has flight muscles.

  
  

  Besides birds, insects also fly. They can fly because they have wings.
  

  
  

  (b) Crawling

  Some animals such as crocodiles and tortoise use their legs to crawl. Their legs are short. So when they crawl, their bodies remain close to the ground. Insects also crawl on the ground. They use their six legs to crawl.

  

  

  (c) Jumping or Hopping

  Some animals such as rabbits, grasshoppers and frogs are good hoppers. They have strong back legs. These are longer than the front legs. The back legs provide power for these animals to hop.

  
  

  (d) Walking

  
  

  1. Stand up and get more space.

  2. Put one foot forward keeping the other on the ground.

  3. Then move the second foot forward keeping the first one on the ground.

  This is how most animals move.

  Can you say which other animals move like this?

  Animals like goat, dog and human can walk and run. They walk by putting one foot in front of the other on the ground.

               

  Can you name some other animals which move by walking?
  

  (e) Swimming

  Animals such as fish, ducks and crocodiles can swim in the water. They go through the water by moving their body and tail from side to side.

  The streamlined body of the fish helps in swimming.

  Different fins help the fish in different stages of swimming.

  

  

  Split your class into groups of 8-10 pupils each. Choose one member in each group as the judge. The other members of the group will imitate the locomotion mode of animals, e.g., walking, running, crawling and hopping. Finally, the judge will choose the best performer in the group.

  9.4 Classification of Animals According to the Feeding Mode

  
  

  
  

  
  

  1. What do these animals eat?

  2. Group them according to their feeding habits. Fill in the following table:

  
  

  
  

       Table 1: Classification of Animals According to the Feeding Mode
  

  Some animals like buffaloes and rabbits eat grass and leaves. They are herbivores.

  Can you name some more herbivores?

  Some animals like lizards and frogs eat insects. They are insectivores.

  Can you name some more insectivores?

  Some animals like tiger and wolf eat flesh of other animals. They are carnivores.

  Can you name some more carnivores?

  Some animals like human and bear eat both plants and animals. They are omnivores.

  Some animals like sparrows and squirrels eat grains. They are granivores.

  Can you name some more granivores?

  Some granivores like rats and squirrels have sharp front teeth. These teeth help

  them cut and bite nuts and seeds. They gnaw (constantly bite and chew) their food. They are rodents.

                   

  9.5 Classification of Animals According to their Reproductive Mode

  
  

  
  

  1. Which animals lay eggs?

  2. Which animals give birth to their young ones?

  3. How do these animals reproduce?

  All animals give birth to their young ones to continue their own kind on earth.

  This process is known as reproduction.

  Some animals like tigers, humans and dogs reproduce by giving birth to their young ones.

  Some other animals like hens, frogs and snakes reproduce by laying eggs.

  9.6 Keywords

  ‹‹Amphibians: Animals that live both on land and in water.

  ‹‹Carnivores: Animals that feed on other animals.

  ‹‹Crawling: Dragging the body close to the ground.

  ‹‹Granivores: Animals that eat grains.

  ‹‹Heart: Multi-chambered, muscular organ that pumps blood through the body.

  ‹‹Herbivores: Animals that eat grass, leaves, fruits, vegetables and nuts.

  ‹‹Insect: A small arthropod animal that has six legs.

  ‹‹Invertebrates: Animals lacking a backbone.

  ‹‹Reptiles: Egg-laying vertebrates having dry scaly skin, for example, snakes, lizards, crocodiles, turtles, and tortoises.

  ‹‹Udder: Mammary gland hanging near the back legs of a cow.

  ‹‹Vertebrate: Animals having a backbone.

  9.7 Summary

  ‹‹ The five most well-known classes of vertebrates are mammals, birds, reptiles, amphibians and fish.

  ‹‹ Insects are animals with jointed legs and segmented body.

  ‹‹All animals take oxygen from the air and give out carbon dioxide.

  ‹‹Aquatic animals such as fish breathe through gills. Gills are found on both sides of the head.

  ‹‹ Animals move from one place to another. This movement of animals is called locomotion.

  ‹‹ Herbivores eat grass, leaves, fruits, vegetables and nuts.

  ‹‹ Carnivores eat flesh of other animals.

  ‹‹ All animals give birth to their young ones to continue their own kind on earth. This process is known as reproduction.

  9.8 Unit Review Exercises

  Do these review exercises in your exercise book.

  I. Fill in the blanks with the correct options:

  1. Animals having backbones are called ............ .

  (a) vertebrates             (b) invertebrates

  (c) both                        (d) none of these

  2. Animals lacking backbones are called ............ .

  (a) vertebrates              (b) invertebrates

  (c) both (d) none of these

  3. .................. is a mammal.

  (a) Frog                    (b) Dog

  (c) Snake                 (d) Fish

  4. .................. is an amphibian.

  (a) Snake                (b) Lizard

  (c) Newt                  (d) Crocodile

  5. ............... is an egg-laying animal.

  (a) Bat                   (b) Hen

  (c) Whale              (d) Cat

  6. .................. is a rodent.

  (a) Sparrow                (b) Squirrel

  (c) Crow                    (d) Snake

  II. State whether the following statements are true or false:

  1. Mammals have hairs on their body.

  2. Reptiles move by crawling.

  3. An adult frog breathes though gills.

  4. Insects have four legs.

  5. Vulture is a granivore.

  III. Match the following:

  Column A                                    Column B

  1. Cow                                          (a) Amphibian

  2. Frog                                          (b) Mammal

  3. Hen                                           (c) Reptiles

  4. Locust                                       (d) Bird

  5. Lizard                                        (e) Insect

  IV. Answer the following questions briefly:

  1. Define vertebrates.

  2. List all five major classes of vertebrates.

  3. Name two reptiles that lay eggs on land.

  4. What do fish use for breathing?

  5. Name two animals that breathe through skin.

  6. Name two animals that breathe through gills.

  7. Name two animals that breathe through spiracles.

  8. Write the name of two amphibians.

  9. Define invertebrates.

  10. List any two properties of invertebrates.

  11. Write any two characteristics of an insect.

  12. Which group do rabbits and squirrels belong to?

  V. Complete the crossword puzzle using the clues below:

  
  

  Clues:

  Across

  3. Animals that eat grass, leaves, fruits, vegetables and nuts.

  5. Animals that feed on other animals.

  Down

  1. Animals having backbone.

  2. Animals that eat grains.

  4. Vertebrates having hairs or furs on their bodies

  .

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• Rabbits are small mammals. They are used for meat, fur and as pets. Rabbits can be found in woods, forests and grasslands. They live in the underground burrows. Pet rabbits live in the hutches.

  

  10.1 Conditions of a Good Rabbit Hutch

  Activity-1 Exploring the Conditions of a Good Rabbit Hutch

  1. Visit a local rabbit farm.
  2. Observe different conditions of a good rabbit hutch.
  3. Ask the farm owner different questions regarding a rabbit hutch.
  4. Make a report and discuss it in your class.

  A good rabbit hutch should provide enough exercise space for the rabbit. It should protect the rabbit from the predators. The following points should be taken care of while making the hutches.

           1. Hutches should be airy.

           2. Rabbits should have enough material to play with. For example, small toys, pipes and ramps.

           3. Hutches should be dry.

           4. Hutches should be clean.

           5. Litter areas should be lined with hay.

           6. The space required for an adult rabbit is about 0.18 sq.m.

  Activity -2 Building a Model Rabbit Hutch

           1. Take paper cartons, sticks, and dry grass to build a model rabbit hutch.

    2. Place things that you think will be good for the rabbits.

  

  10.2 Characteristics of Good Rabbits

  Activity -3   Exploring the Characteristics of Good Rabbits

      1. Visit a local rabbit farm.

      2. Observe different characteristics of a good male and female rabbit.

      3. Compare their characteristics and make a report on it.

  

  A female rabbit is commonly known as a Doe. It is      
  usually larger than the male of the same breed. A
  good female rabbit has the following characteristics:

           1. Should be a good milk producer.

           2. Can grow comfortably in your environment.

           3. Can have a large litter.

           4. Will give a large pelt per animal.

           5. Should be healthy and disease free.

  

  A male rabbit is known as a Buck. It is usually smaller than a female of the same breed. A good male rabbit has the following characteristics:                               
  
  1. Should grow very fast.                                           

  2. Should have strong and large muscles.

  3. Can grow comfortably in your environment.

  4. Should be healthy and disease free.

  5. Breeds with ease.

  6. Has high fertility and can have several offspring.

  10.3 Distinguishing Male from Female Rabbits

  Activity -4   Distinguishing a Male Rabbit from a Female Rabbit

           1. Visit a local rabbit farm.

           2. Observe rabbits of opposite sexes.

           3. Compare their characteristics and make a report on it.

  A male rabbit is different from a female rabbit in the following ways:

  1.The size of a female rabbit is comparatively large than a male rabbit of the same age in the same breed.

   2.The round face in females is unlike the block-like face in males.

   3.Old females have dewlaps but males haven’t.

   4.Males are more defensive than females.

   5.Males produce more urine than females during the mating period.

  10.4 Criteria for Choosing a Rabbit to Rear (Rabbit Breeding Guide)

  Activity -5  Discussing the Criteria for Choosing a Rabbit to Rear

   1. Visit a local rabbit farm.

   2. Discuss with the farm owner about some criteria for choosing a rabbit to rear.

   3. Make a report on it and present to the class.

  The following are different criteria to choose a rabbit to rear:

  (a) Breeds

  There are too many rabbit breeds. They are divided into three categories— Commercial, fancy and woolly.
  
  1. Commercial rabbit breeds should have excellent meat producing qualities. Examples: Californian, New Zealand and Satin.

  2. Fancy type rabbit breeds include Dutch, English Spot and Rex.

  3. Wool type rabbit breeds should have a wool coat. Examples: Jersey Woolly and Angoras.

  (b) Colour and Coat

  Colour and coat types are definitely a matter of personal preference. Some rabbits cannot tolerate bright light and some require constant grooming.

  (c) Age

  One thing to consider while choosing a rabbit is whether it is old enough to adopt. Eight weeks is a healthy age for an adoptable rabbit.

  (d) Health

  Rabbits are susceptible to diseases. A diseased rabbit can affect a healthy rabbit. So health is an important aspect of choosing a rabbit.

  (e) Environment

  Rabbits living in a clean environment are disease free. So choose a rabbit from a clean and healthy environment.

  10.5 Proper Feeding of Rabbits

  Activity -6   Proper Feeding of Rabbits

                1. Visit a local rabbit farm.

                2. Look at the feeding and watering troughs.

                3. Identify which one needs cleaning.

                4. Ask the farm owner to clean the troughs properly.

  Rabbits feed on green leafy vegetables, carrots,     

  beetroots, turnips and pellets. Pellets are

  manufactured animal feed. They provide

  complete nutrition to the rabbits.

  Rabbits should have a supply of water at

  all times. Water should be changed twice a day.

  10.6 Rabbit Health

  Rabbits are susceptible to health problems. So it is important to adopt sanitary measures.

  Activity -7 Exploring the Measures that the Farm Worker Adopts to Keep the Rabbit Healthy

   1. Visit a local rabbit farm.

   2. Observe various measures that the farm worker adopts to keep the rabbits healthy.

   3. Make a report on it and present to the class.

  The following are some sanitary measures to be taken:

  1. Clean the hutches and cages once in a week.

   2. Clean the feeding and watering troughs daily to avoid contamination.

   3. Feed the rabbits at least twice a day in proper time.

   4. Give them scope for enough physical exercise and mental stimulation by providing toys to play.

  5. Isolate sick rabbits for treatment.

  6. De-worm the rabbits at regular intervals.

  7. Keep the surroundings of the rabbit cage weed-free.

  10.7 Common Diseases in Rabbits

  Like other living animals, rabbits suffer from diseases.

  Activity -8   Discussing the Common Rabbit Diseases

  1. Visit a local rabbit farm.

  2. Discuss with the farm owner about some common rabbit diseases, their symptoms and prevention.

  3. Make a report on it and present to the class.

  The following are common diseases of rabbits.

  (a) Coccidiosis                                                      

  A rabbit with coccidiosis has:

       (i) Loose motion along with blood
       (ii) Loss of appetite
       (iii) Loss of weight
       (iv) Rough hair
       (v) Death in severe cases

  Prevention/Treatment

       (i) Isolate the affected rabbit.
       (ii) Start treatment under the supervision of a vet.

  (b) Ear Scabies                                              

  A rabbit with ear scabies has:

  (i) Brown scab inside the ear canal.
  (ii) Swelling and painful ear.
  (iii) Shaking of the head.

  Prevention/Treatment

  (i) Isolate the affected rabbit.

  (ii) Keep the hutch clean.
  (iii) Invite a vet for treatment.

  (c) Tapeworm                                                          

  

  A rabbit with tapeworm has:(i) Slow growth.

  (ii) Sometimes worms are seen in droppings.
  (iii) Inability to pass faeces.
  (iv) Death in severe cases.

  Prevention/Treatment

  (i) Keep the hutch clean.
  (ii) Before feeding, wash all food items.
  (iii) Invite a vet for treatment.

  (d) Pneumonia                                                            

  

  A rabbit with pneumonia has:(i) Fever.

  (ii) Sneezing.
  (iii) Bluish colour of lips, tongue and ears.
  (iv) Difficulty in breathing.

  Prevention/Treatment

  (i) Invite a vet for treatment.

  (ii) Use of antibiotics is effective.

  10.8 Importance of Rabbit Farming

  Commercial rabbit farming in Rwanda can be a great source of income and employment. One can use his/her family labour for rabbit farming.

  Activity -9 Discussing the Importance of Rabbit Farming

              1. Discuss the importance of rabbit farming.

              2. Make a report on it and present to your science teacher.

  Rabbits are sold in the market for the following purposes:

  

  

  10.9 Keywords

  • Buck: A male rabbit.
  • Coccidiosis: A series of specific infectious diseases caused by parasites.
  • Dewlap: A loose skin hanging from the neck or throat of an animal or bird, especially in cattle.
  •  Doe: A female rabbit.
  • Exotic: Originating in or characteristics of a foreign country.
  • Hutch: A box or cage, typically with a wire mesh front, for keeping rabbit.
  • Litter: A number of young animals born to an animal at one time.
  • Pelt: The skin of an animal with fur.
  • Scabies: A relatively contagious infection caused by a tiny mite.
  • Stimulation: Something that makes you active.
  • Susceptible: Prone to something.

  10.10 Summary

  • The optimum temperature of rabbit hutch should be between fifteen degrees celsius and twenty degrees Celsius.
  • The size of a female rabbit is comparatively large than a male rabbit of same age and same breed.
  • A female rabbit is known as Doe.
  • A male rabbit is known as Buck.
  • According to the breed of rabbits, they are divided into three categories, viz., commercial, fancy and woolly.
  • Rabbits feed on green leafy vegetables carrots, beetroots, turnips and pellets. Pellets are manufactured animal feed.

  10.11 Unit Review Exercises

  Do these review exercises in your exercise book.

  I. Fill in the blanks with the correct options:

  1. A good rabbit hutch should be ………………….. .

  (a) stuffy                                      (b) airy

  (c) oppressive                             (d) none of these

  2. The space required for an adult rabbit is …………………… .

  (a) 1.18 sq.m                              (b) 0.18 sq.m

  (c) 0.17 sq.m                              (d) all of these

  3. A female rabbit is …………………………. than a male rabbit of the same breed.

  (a) smaller                                  (b) larger

  (c) lighter                                    (d) none of these

  II. State whether the following statements are true or false:

  1. Pet rabbits live in burrows.

  2. A male rabbit is smaller than a female rabbit of the same breed.

  3. Rabbits should not have a supply of water at all times.

  4. To avoid ear scabies among the rabbits, hutches should be kept very clean.

  5. Sneezing is not a symptom of pneumonia of the rabbits.

  III. Match the following:

  Diseases                                                        Symptoms

  1. Coccidiosis                                          (a) Difficulty in breathing

  2. Ear scabies                                          (b) Worms might be seen in droppings

  3. Tapeworms                                          (c) Shaking of the head

  4. Pneumonia                                           (d) Loose motion along with blood

  IV. Answer the following questions briefly:

  1. List two conditions of a good rabbit hutch.

  2. Distinguish a male rabbit from a female rabbit.

  3. List two criteria for choosing a rabbit to rear.

  4. What does a rabbit feed on?

  5. List two points to keep a rabbit healthy.

  6. List four common diseases of a rabbit.

  7. Write two symptoms and prevention of the disease ‘ear scabies’.

  8. List any two importances of rabbit farming.

  9. How can we use the skin of a rabbit?

  V. Complete the crossword puzzle using the clues below:

                          

  Clues:

  Across

  3. The male of the rabbit.
  4. Originating in or characteristics of a distant foreign country.

  Down

  1. It is the house of a pet rabbit.
  2. The female of the rabbit.

  Mark as done
• click here for a video lesson on: Conditions of a Good Rabbit Hutch URL

  Mark as done
• click here for a video lesson on: Proper Feeding of Rabbits URL

  Mark as done
• click here for a video lesson on: Importance of Rabbit Farming URL

  Mark as done
• CLICK HERE FOR A VIDEO LESSON ON:DISTINGUISHING MALE FROM FEMALE RABBITS URL

  Mark as done
• Plants are living things. They grow from seeds. Most plants bear seeds. Seeds germinate and grow into new plants.

  11.1 Definition of Germination

  Activity-1 Germination of Seeds
  

  1. Take some gram seeds.

  2. Sow them in your school garden.

  3. Sprinkle water to keep the soil moist.

  4. Observe them daily for 3–4 days.

  When seeds get enough air, water and light, they grow into new plants or seedlings. The growing of seeds into seedlings is called germination.

  11.2 Conditions Necessary for Seed Germination

  Every seed needs certain favourable conditions to germinate.

  Activity-2 Experiment on Conditions Necessary for Germination

  You will need

  Four containers, cotton wool, some viable and non-viable cowpea seeds and a cupboard.

  Procedure

  1. Take four containers marked A, B, C and D as follows:

  A with dry cotton wool. B, C and D with moist cotton wool.

  2. Place 3–4 viable (healthy) cowpea seeds at the top of the cotton wool in containers A, B and D and non-viable (unhealthy) seeds in container C.

  3. Place containers A, B and C in sufficient light and air.

  4. Place container D in the cupboard.

  5. Observe them daily for 3–4 days.

  6. Discuss your findings in the class.

  Observation

  After 3–4 days, you may observe that seeds in containers A, C and D remain unchanged. The seeds in container B have germinated.

  Find out why.

  

  Discussion
  

  ♦ Container A received suitable temperature and oxygen but no moisture.

  ♦ Container C received suitable temperature, oxygen and moisture (water) but the seeds were not viable.

  ♦ Container D did not receive suitable temperature though it had oxygen and moisture (water).

  ♦ Only container B received suitable temperature, oxygen and moisture (water) with viable seeds. These conditions helped the seeds in container B to germinate.

  Conclusion

  Thus, oxygen, water and suitable temperature are the necessary conditions for viable seeds to germinate.

  11.3 Types of Germination

  Activity -3 Identifying the Types of Germinations
  

  
  

  1. What do these pictures represent?

  2. What difference do you observe?

  These two pictures represent germination of seeds.

  In picture (A), the seed leaves or cotyledons come out of the soil. This type of germination is called epigeal germination. This type of germination occurs in bean and gram seeds.

  In picture (B), the seed leaves or cotyledons remain under the surface of soil. This type of germination is called hypogeal germination. This type of germination occurs in maize, rice and corn seeds.

  11.4 Stages of Germination

  Activity -4 Identifying Main Stages of Germination
  

  1. Take a small plastic jar and fill it with soil.

  2. Take a viable bean or a maize seed and place it in the soil of the jar.

  3. Keep the jar in a bright airy place.

  4. Sprinkle water everyday and observe.

  Note: Make sure that soil is always damp. The seed needs water to grow.

  5. Record your observation in your science notebook.

  

  The process of germination occurs in the following four stages:
  

  ‹‹Stage 1: The seed takes in water and becomes swollen. The seed coat splits.

  ‹‹Stage 2: Baby root begins to grow. It grows downwards.

  ‹‹Stage 3: Baby shoot begins to grow.

  ‹‹Stage 4: The first leaves grow. The seed leaves shrivel. The food has been used up by the baby plant.

  11.5 Types of Plants

  Activity -5 Sorting Plants into Trees, Herbs and Shrubs

  1. Go on a nature walk.

  2. Observe various plants around you.

  3. Collect information on them.

  4. Sort them into trees, herbs and shrubs.

  There are different types of plants. Some of them are discussed below.

  (A) Trees

  Some plants are very tall. They have hard, strong, and thick stems called trunk.

  These plants are called trees. Trees live many years. Examples: mango tree, acacia tree, eucalyptus tree and avocado tree.

  

  (B) Shrubs

  Some plants are smaller than trees. They have hard stems with many branches.

  Such plants are called shrubs. They live for a few years. Examples: Hibiscus, cotton, rose and tea plant.

  

  (C) Herbs

  Some plants are very small. They have thin, soft stems. They live for one season or for a few months. Such plants are called herbs. Examples: grass, mint, spinach, coriander and garden eggplant.

  

  11.6 Parts of a Plant and their Functions

  Like other organisms, plants also have different parts. Each part has a specific function to perform. Let us know about them.

  Activity -6 Identifying the Parts of Flowering Plant and Discussing Function for Each Part

  1. Visit your school surroundings.

  2. Uproot a small flowering plant and observe its various parts.

  3. Name these parts.

  4. Also discuss their functions in the class.

  A flowering plant has many parts. These are roots, stems, leaves, flowers and fruits.

  

                                                              Fig. 4. Different parts of a plant
  

  A flowering plant has many parts. These are roots, stems, leaves, flowers and fruits.

  Functions of Parts of the Plant

  (a) Root

  It is the underground part of the plant. It has the following functions:

  1. Roots fix the plant into the soil.

  2. They absorb water and minerals from the soil. Water and minerals are important for plants to grow healthy.

  3. In some plants, roots store extra food. For example, carrot, radish and beetroot.

  (b) Stem

  It is the aerial part of a plant. It has the following functions:

  1. The stem supports branches which bear leaves, buds, flowers and fruits.

  2. It transports water and minerals from the roots to the leaves and fruits.

  3. In some plants, stems store extra food. We eat these stems. For example, Irish potato, ginger and sugarcane.

  

  (c) Leaf

  It is the most important part of a plant. Most plants have green leaves. Some functions of a green leaf are:

  1. A green leaf makes food for the plant.

  2. Air and water vapour go in and out of the leaf. Thus it helps the plant to breathe.

  3. In some plants, leaves store extra food. We eat these leaves. For example, spinach, cabbage and coriander.

  

  (d) Flower

  Flowers are colourful and pretty. They are the reproductive parts of a plant. Some functions of the flower are:

  1. Flowers turn into fruits.

  2. They give off a sweet smell. So they are used to decorate houses and gardens.

  3. Flowers like pyrethrum are natural insecticides.

  4. We eat some flowers, for example, cauliflower and broccoli.

  

  (e) Fruits

  Fruits are produced from the flowers. Fruits like mango and coconut are one seeded. Other fruits like pawpaw and guava are many seeded. Some functions of fruits are:
  

  1. Fruits protect the seeds.

  2. Fruits are a part of our diet.

  3. Fruits are rich in minerals and vitamins.   

                    They keeps us healthy.

  4. Fruits bear seeds which help in reproduction.

  5. Seeds of some fruits like black pepper are used as medicines and spices.

  

  Project Maintaining Plants to Protect Our Environment

  1. Plant a variety of seeds in your school garden.
  2. Maintain the new plants to protect your environment.

  11.7 Keywords

  • ‹‹Epigeal germination: The type of germination in which cotyledons come out of the ground.
  • Germination: The process by which a seed grows into a seedling.
    
  • ‹‹Herb: A flowering plant whose stem above the ground does not become woody.
  • ‹‹Hypogeal germination: The type of germination in which cotyledons remain below the ground.
  • ‹‹Seed: A small hard part of a plant from which a new plant grows.
  • ‹‹Shrub: A small to medium-sized woody plant.
  • ‹‹Stem: The stem is the main part of the shoot.
  • ‹‹Tree: A tall plant with a trunk and branches made of wood.
    

  11.8 Summary

  • ‹‹When seeds get enough air, water and light, they grow into new plants or seedlings. The growing of seeds into seedlings is called germination.
    
  • ‹‹During germination, cotyledons of some seeds come out of the ground.Such type of germination is called epigeal germination.
    
  • ‹‹During germination, cotyledons of some seeds remain under the surface of the soil. Such type of germination is called hypogeal germination.
    
  • ‹‹There are different types of plant such as trees, herbs and shrubs.
    
  • ‹‹Branch, fruit, flower, leaf, stem and root are the main parts of a plant.
    
  • ‹There are two types of roots—tap root and fibrous root.
    
  • ‹‹The stem is the main part of the shoot. Branches, leaves, buds, flowers and fruits grow on it.
    
  • ‹‹A green leaf makes food for the plant.
    
  • ‹‹Flowers are the reproductive parts of a plant.

  11.9 Unit Review Exercises

  Do these review exercises in your exercise book.

  I. Fill in the blanks with the correct options:

  1. When a seed gets enough air, water and sunlight, it grows into a seedling.

  This process is known as ..................... .

  (a) germination               (b) pollination

  (c) dispersion                  (d) none of these

  2. The tall plants are called ……………… .

  (a) shrubs                       (b) herbs

  (c) trees                          (d) none of these

  3. ………….. live for one season or for a few months.

  (a) Shrubs                       (b) Trees

  (c) Herbs                         (d) All of these

  4. Fruits are produced from ……………… .

  (a) roots                          (b) stems

  (c) leaves                        (d) flowers

  5. …………. transports water and minerals from the roots to the leaves and fruits.

  (a) Root                  (b) Leaf

  (c) Stem                 (d) Flower

  II. Match the following:

  Column A                                                         Column B

  1. Seeds                                                     (a) Fibrous root

  2. Hibiscus                                                  (b) Germinate and grow into new plants

  3. Spinach                                                   (c) Tap root

  4. Sugarcane                                               (d) Shrubs

  5. Carrot                                                      (e) Herbs

  III. State whether the following statements are true or false:

  1. Seeds germinate and grow into new plants.

  2. Epigeal germination occurs in maize seeds.

  3. Hypogeal germination occurs in bean seeds.

  
  

  4. Roots absorb water and minerals from the soil.

  
  

  5. Flowers are the reproductive parts of a plant.
  

  
  

  IV. Answer the following questions briefly:
  
  

  1. Define germination.
  

  2. List two types of germination.
  

  3. Define trunk of a tree.
  

  4. Write the names of two shrubs.
  

  5. Write any two functions of roots.
  

  6. We eat some flowers. Can you name any two flowers that we eat?
  

  7. Write any two functions of flower and fruit.

  
  

  V. Complete the crossword puzzle using the clues below:

  

  Clues:
  
  

  Across

  
  

  2. The part of the shoot which bears branches, leaves, flowers and fruits.
  

  3. A tall plant with a trunk and branches made of wood.
  

  4. A flowering plant whose stem is not woody.

  
  

  Down

  
  

  1. A small to medium-sized woody plant.
  

  2. A small hard part of a plant from which a new plant grows.
  

  Mark as done
• video on Lesson 6: Parts of the plant URL

  Mark as done
• Organs which help us to see, hear, smell, taste and feel are called sensory organs. The organs which help  us to know the world around us are eyes, ears, nose, tongue and skin. These are our sensory organs.

  

  12.1 Functional Mechanism of All Sensory Organs

  Activity-1 Research on Functional Mechanism of Sensory Organs
  

  1. Research on the functional mechanism of all sensory organs from library or search engines like Google or Yahoo.

  2. Make a report on it and present to the class.

  Sensory organs are connected to the brain through nerves. They work as follows:

  • Each sensory organ receives stimuli such as touch, heat, cold and pressure from the environment.

  • The sensory organ transmits this information to the brain through sensory nerves.

  • The brain interprets this information and gives feedback to the sensory organ through motor nerves.

  
  

  12.2 Structure, Function and Maintenance of Sensory Organs

  (a) Skin                                                                         

  Skin is the outermost covering of our body.

  It is the sensory organ for touch and feel.

  Activity -2  Identifying the Parts/Layers of Human Skin

  
  

                            

  Activity-3Exploring the Function of Skin

  1. Run around your school playground twice.

  2. Now observe your skin.

  What is formed on your body?

    The substance you see on your body is sweat. Others can say you are sweating.

      The main functions of the skin include:

      1. It allows us to have a sense of touch.

      2. It protects our body from harmful germs.

      3. It regulates our body temperature.

      4. It helps us to release waste products as sweat.

  Properties of Skin 

  Skin has the following properties:

      1. Different people have different skin colours. Some people have light skins. Others have dark skins.

      2. Skin may be oily and dry.

  Hygiene of Skin

  A clean skin cannot be attacked by diseases. So it is important to keep our skin clean.

  To keep the skin clean:

      1.Take a bath every day.

      2. Use good soap while bathing.

      3. Rub and wash every part of the body.

                                                      

     4. After taking bath, wipe your body with a clean towel.

     5. Wear clean and ironed clothes.

     6. Always eat healthy food and drink plenty of water.

     7. Always protect your skin from injuries.

  Activity -4 Exploring the Common Skin Diseases

  
  

  
  

  1. What do these pictures show?

  2. What are signs of each disease?

  3. List some other skin diseases.

  4. What should we do when we suffer from skin diseases?

  5. Search information on some common skin diseases from library books/search engines like Google and Yahoo.

  6. Make a report and discuss it.

  The following are some common skin diseases:

  (A) Ringworm

  Ringworm usually causes itching. It begins as a small red area. This grows larger. It appears as red, scaly ring. There may be one or several patches.

  Ringworm can be easily cured with medicine. The affected person should use his/her own comb, soap and towel.

  (B) Eczema

  Eczema is characterised by itching and inflammation. The inflamed skin may be dry, swollen and crusty. It may even ooze fluids.

  Eczema can be prevented if we wash our skin carefully with good soap. Doctors prescribe ointments and creams for early relief.

  (C) Scabies

  Scabies causes intense itching. It may affect any part of the body from neck down. It frequently involves skin between the fingers, under the arms, and on the wrists. It is caused by mites.

  Scabies spreads through skin contact. Doctors treat the disease with creams and lotions that kill the mites. Scabies can easily spread from one family member to another.

  (D) Leprosy

  Leprosy is an infectious disease. Its main symptoms include white or reddish patches on skin, loss of feeling in skin and thickened nerves. The fingers and toes may curl inward.

    Early detection and treatment can control leprosy.

  Activity -5 Exploring the Skin Accidents

  
  

  1. What do these pictures show?

  2. What are the causes and signs of each skin accident?

  Sometimes the skin gets injured in accidents. Injuries can happen at work or play, or walking across the street. Some common skin injuries are:

  (A) Wounds

  Wounds are injuries that break the skin. They include cuts, scrapes and scratches.

  First aid for the wound:

  1. Clean the wound with a cotton soaked with antiseptic lotion. It removes dirt.

  2. Put another ball of cotton soaked with antiseptic lotion. Tie a bandage around it. It will help to stop the blood flow.

  (B) Bruises

  A bruise is a black or blue mark on the skin. It is caused by blood trapped under the skin. Bruises are often painful and swollen.

  First aid for the bruises:

  1. Put an ice pack over the bruise. You can put a cloth soaked with cold water on the affected area.

  2. Rest the affected area.

  (C) Burns and Scalds

  A burn is a damage to your body’s skin caused by heat. Heat from chemicals, hot metal and burning are the most common causes of burns.

       Scald is a skin injury caused by wet heat. Hot liquids cause scalds.

       Both burns and scalds can cause swelling, blistering and scarring.

       First aid for the burns and scalds:

       1. Wash the affected area with cold running water.

       2. Put an ice pack over the affected area for about 5 to 10 minutes.

       3. Apply an antiseptic cream over the affected area.

  Activity-6    Role Playing a Skin Accident

  Situation:

  One of your friends has a skin accident. He/She has severe wounds on his/her skin. What would you do?

  Role play:

  1. Form a team of two students each.

  2. One member will act as a victim.

  3. The other member will provide him/her necessary first aid.

    (b) Tongue

  Activity-7   Identifying the Parts of the Tongue

  1. Look into a mirror.   

  2. Observe your tongue thoroughly.      

  What do you see on your tongue?   

  3. Discuss your findings in the class.                       

                                                                                                  

   Tongue is the sensory organ for taste. It is found inside the mouth. It is pink in colour.

  Parts of Tongue

  The surface of the tongue has small buds called taste buds.

  They are present in different areas of the tongue. These buds help us to taste salt, sugar and lemon.

  
  

  Activity -8    Tasting Food Samples
  

  1. Bring different food samples that are sweet, salty and sour.
  

  
  

  2. Using a toothpick, place each of the samples on different parts on the tongue at once.

  3. Find out which part of the tongue can detect which taste.

  Hint: Every part of the tongue detects a different taste.

   12.3 Functions of Tongue

  Activity -9    Exploring the Function of a Tongue
  

  1. Put your tongue out of the mouth.

  2. Hold it with your fingers.

  3. Now, try to talk to your neighbours.

  Are you able to speak properly? Why or why not?

  You have seen that the tongue helps us speak. As we speak, it moves up and down.

     The following are some other functions of the tongue:

     1. It enables us to detect various tastes.

     2. It helps in chewing food and rolls it into food pipe.

     3. It helps to clean food particles stuck between gums and teeth.

  12.4 Hygiene of Tongue

  Activity-10    Discussing the Hygiene of Tongue
  

  1. Discuss the following questions in groups:

  ‹‹How often should we clean our tongue?

  ‹‹Why should we clean our tongue?

  ‹‹List the things you use to clean your tongue.

  2. Make a report on it and present to the class.

  A clean tongue cannot be attacked by diseases. So it is important to keep our tongue clean.

           To keep your tongue clean:                                           

           1. Wash your mouth before and after taking food.

           2. Clean your tongue with a soft tongue cleaner.

           3. Clean your tongue twice daily—in the morning and at night.

  Proper Method of Cleaning Tongue

      1. Choose a cleaning tool (e.g., a tongue cleaner).

      2. Scrap the tongue first.

      3. Rinse the mouth with clean water.

  12.5 Tongue Disorders or Problems

  Activity-11    Identifying Common Tongue Disorders

  

  1. What do these pictures show?

  2. What are signs of each tongue disorder?

  3. List some other tongue disorders.

  4. What should we do when we suffer from tongue disorders?

  The following are some tongue disorders:

        (A) Sore: In case of sore, there are white or red patches seen on the tongue.

         Sores are often painful. A person with sore on the tongue finds eating spicy foods difficult. Sores may be caused by viruses. If you have sore:

         (a) Avoid hot and spicy foods.

         (b) Take soft foods and cold beverages until the sore heals.

         (B) Swelling of tongue: Sometimes tongue may suddenly swell up in size.

         It is a symptom of disease like tongue cancer. If you have such a problem, immediately consult a doctor.

         (C)  Black hairy tongue: In this case, the tongue appears to be hairy. It is  caused by a course of antibiotics.

          If you have black hairy tongue:

         (a) Scrap your tongue with a special tongue scrapper regularly.

         (b) Avoid smoking.

         (D) Loss of sense of taste: Sometimes people lose the ability to taste sour, salty, bitter, or sweet flavours partially or completely. 

         Poor oral hygiene  and dental problems are the causes of this.

          If you have a taste disorder, consult a doctor.

  Tongue Accident
  Activity -12     Identifying Tongue Accidents
  

  
  

  1. What do these pictures show?

  2. What are causes and signs of each tongue accident?

  Sometimes your tongue gets injured due to some accidents or hot food items. 

  Some of the tongue accidents include:

  (A) Tongue bite: People often bite their tongue while eating, talking or playing  games. They may also bite their tongue in road accidents. Most tongue bites get completely healed easily.

  If you have a tongue bite:

  (a) Apply ice pack on the affected area.

  (b) Avoid eating spicy food.

  (c) Rinse your mouth with warm salt water.

  (B) Burn of tongue: A burn of the tongue is a common ailment. It occurs when  you eat or drink something that is too hot. It injures the outermost layer of the  tongue. It is often painful. Redness, swelling, and blistering are signs of a burn of the tongue.

  If you have a tongue bite:

  (a) Rinse the area well with cool water for a few minutes.

  (b) Wet a clean cloth with cool water and hold it on top of the burn.

  (c) Avoid warm or hot liquids, which could irritate the burn.
  

  (d) If the burn does not improve, consult a doctor.

  (c) Nose

  The nose is the sensory organ for smell.

   Smells flow in air. Our nose picks up the air when we breathe in. Brain instantly tells whether the smell is good or bad. In the above activity, it was the nose which helped to smell the perfume.

  Activity-13  Exploring the Uses of Nose

  1. Spray some perfume into a cotton wool and leave it in one corner of the room.

  2. After a few minutes, call your friend in. Does the friend smell something?

  3. Name the organ which helped to smell the perfume.

  Activity -14  Identifying the Parts of a Human Nose

  1. Identify all parts of the nose and label them.

  2. Draw this picture in your science notebook.

                                                                              

  
  

  The nose consists of the following parts:                                   

  1. The nose has two holes called nostrils.

  Air enters the nose through the nostrils.

  2. Nasal cavity is the large air-filled space above and behind the nose. It is the continuation of nostrils.

  Activity -15  Discovering the Function of Nose

  Hold your nose tight.                                           

  What do you feel? Explain why.

  You will feel uneasy. This is because the nose helps us to breathe. Nose also helps us to smell.

  Activity-16      Discussing the Hygiene of Nose
  

  1. Discuss the following questions in group.

  ‹‹How often do you clean your nose?

  ‹‹Why is it essential to keep the nose clean?

  2. Make a report on it and present to the class.

    Proper nasal hygiene is essential to the good function of a nose. It is important to maintain proper nose care.

    You can take care of your nose in the following ways:

  
  

   Diseases of Nose and their Causes

  Activity-17    Identifying Common Nose Diseases
  

  
  

  1. What do these pictures show?

  2. What are signs of each disease?

  3. What should we do when we suffer from these diseases?

  The following are some common nose diseases:

  (A) Common Cold

  The common cold is a viral infectious disease. A person with common cold feels a runny nose. He/She sneezes from time to time. It causes headache and weakness.

  Causes of Common Cold

  The causes of common cold include:

          1. Transmission of cold viruses through air-borne droplets

          2. Cold weather condition such as rain or winter

          3. Poor immune functions

          4. Insufficient sleep and malnutrition.

  (B) Sinusitis

  It is an infection of the sinuses near the nose. When a person suffers from sinusitis, his/her nose is blocked. He/She does not breathe well. He/She has headache and facial discomfort.

  Causes of Sinusitis

  The causes of sinusitis include:

         1. Microorganisms such as virus, bacterium or fungus

         2. Abnormalities in the structure of the nose

         3. It can be caused by allergy and irritation of sinuses.

  Prevention of Nose Diseases

  The following measures should be taken to prevent nose diseases:

         1. Avoid close contact with the people who are sick.

         2. Wear face mask when you are in crowds.

         3. Cover your mouth and nose while others are sneezing or coughing.

         4. Wash your hands with a soap. It reduces the spread of viruses.

  Accidents of Nose

  Nose injuries often occur during play, sports and accidents. Some of the nose injuries include:

  Broken Nose

  A broken nose is a fracture in a bone in the nose. It commonly occurs with face injuries. Some causes of broken nose include: falling down and motor vehicle accidents.

           A person suffering from broken nose has the following symptoms:

           1. Nose pain.

           2. Swelling of the nose.

           3. Bruising around the nose or eyes.

           4. A runny nose or a nosebleed.

           5. Blocked nasal passages.

           In case of broken nose:

           1. If you have nose bleeding, sit upright and breathe through the mouth.

           2. To reduce swelling, apply an icepack on the nose.

           3. In severe cases, consult a doctor.

  Nosebleed

  Nosebleed is the flow of blood from one or both nostrils. It is caused due to minor injury to the nose.

            If you have nosebleed:

            1. Sit upright and breathe through the mouth

            2. Keep an icepack on the nose to stop bleeding

            3. In case of severe bleeding, consult a doctor.

    (d) Ear

  Activity-18      Exploring the Importance of Ears
  

  1. Ask your friend to clap his/her hands.

  2. Cover your ears. Can you hear your friend’s clapping?

  3. Ask your friend to blow a whistle. Can you hear the sound of the whistle?

    Ears are our sensory organs of hearing. We have a pair of ears on either side of our head.

    We hear sounds with our ears. When our ears are covered, we will not be able to hear sounds.

    Parts of Ear
  

    Activity -19     Identifying the Parts of a Human Ear

  1. Identify all parts of the ear and label them.

  2. Draw this picture in your exercise book.

  
  

    There are three major parts of a ear. These are the outer ear, the middle ear and the inner ear.

   1. The outer ear: It is the part of the ear which can be seen. It helps us to receive sound waves from the environment. Then it sends them towards the other parts of the ears. It has the following parts

  • The pinna: It is made up of a cartilage and skin. This is the entrance for the sound waves
    
  • The ear canal: It is a canal that guides the sound towards the inner ear. The glands which release ear wax are positioned in the ear canal.

  2. The middle ear: It is located in between outer and inner ears. It is a cavity filled with air. It converts sound waves into pressure waves with the help of these parts:

  • Eardrum: It is a delicate membrane. It separates the outer ear from the middle ear. When sound reaches it, it turns into mechanical energy.
  • Hammer: It is one of the three bones located next to the eardrum. It vibrates when sound reaches it.
  •  Anvil: It is another tiny bone which vibrates in response to the previous vibration.
  • Stirrup: It is the last bone of the ear. It receives the vibration from the other two bones and sends it into the inner ear.

  3. The inner ear: It is the last part of the ear. It is filled with a watery substance. It is made up of three parts which help in hearing.

  • Cochlea: It is a spiral shaped tube. It is covered with small hairs which contain nervous cells. Sound messages are picked from cochlea and sent to the brain.
  • Semi-circular canals: They are connected with the cochlea and are filled with fluid. They maintain the body balance and posture.
  •  The auditory nerve: It picks up sound messages from cochlea and sends them to the brain.

  
  

  Functions of Ears

  The following are some specific functions of the ears:

        1. They help in hearing sound.

        2. They help in balancing our body.

  Hygiene of Ears

  Activity -20   Discussing the Hygiene of Ears
  

  1. Discuss the following questions with your parents.

  •  Why do we clean our ears regularly?
  • What materials are suitable for cleaning ears?
  • Why is it unsafe to clean ears with sharp or hard objects?

  2. Make a report on it and present to the class.

    Regular cleaning of ears prevents some ear problems. Therefore, these should be cleaned properly.

          1. Do not clean your ears with toothpicks, matchsticks or any sharp objects.

               It can injure the delicate part of the ears.

          2. Use cotton buds to clean your ears.

          3. Keep you away from loud sound. Loud sound can damage the ears.

          4. Do not push things like beads and small stones into your ears.

   Diseases of Ears and their Causes
  

  Activity -21   Identifying Diseases of Ears
  

  
  

  1. Is this person able to hear clearly?

  2. What disease he is suffering from?

  3. List some possible causes of this disease.

  He is suffering from ear disease. Some common ear diseases are: hearing loss and deafness.

    Hearing Loss

    Hearing loss is the reduced ability to hear sound. It occurs when sound waves do not reach the brain.Basically, there are two types of hearing loss.

   Activity-22     Identifying Causes of Conductive Hearing Loss

  

  1. What is the child doing?

  2. Is it safe to enter such foreign materials into the ears? Explain why.

  The child is cleaning his ears using a matchstick. It is unsafe to enter such foreign materials into the ears. It may cause problems with ear canal, ear drums and middle ear. It may lead to conductive hearing loss.

    Some other causes of conductive hearing loss are:

       1. Infection in the ear canal.

       2. Tumour in the ear canal.

       3. Much ear wax in the ear canal.

    This disease is temporary. It can be cured by removing ear wax and other foreign materials from the ears.

  Activity -23 Identifying Causes of Sensory Hearing Loss
  

  

  1. What difference do you observe between these two pictures?

  2. What happens if the child hears loud noises every day?

  In the first picture, the child is hearing loud noise coming from vehicles and loud speakers. If he hears such loud noise for a long time, he will suffer from sensory hearing loss. Sensory hearing loss is due to the problem in the inner ear. A person with such disease cannot understand what he/she is hearing. This disease is nerve-related.

  Some other causes of sensory hearing loss are:

  1. Old age

  2. Injury to the ear canal

  3. Ear infection.

  This disease can be cured by:

  1. Treatment of ear infection

  2. Avoiding travel in the vehicles which produce loud sound

  3. Treatment of infection in the ear canal.

  Deafness

  Deafness is the complete inability to hear sound. It is caused by damage to the inner ear. Basically, there are three types of hearing loss. These are:

  Partial Deafness

  It is the condition in which a person is unable to hear properly.

  It can be caused by the following factors:

  1. Intrusion of foreign materials in the ear

  2. Much ear wax in the ear canal

  3. Holes in the ear drum.

  This disease is temporary. It can be cured by removing ear wax and other foreign materials from the ears.

  Permanent Deafness

  It is the condition in which a person is completely unable to hear. In some cases, deafness is inherited  from parents to their child. This type of deafness is permanent and cannot be cured.

  Sensory Deafness

  It is due to the problem in the nervous system. A person with such a disease cannot understand what he/she is hearing.

  It can be caused by the following factors:

  1. Disease of the blood vessels

  2. Loud noises or sounds

  3. Tumour in the ear canal

  4. Use of certain medicines (drugs) that are harmful to hearing.

  This disease can be cured by:

  1. Treating the diseases of the blood vessels.

  2. Avoiding working around loud noises every day.

  3. Removing tumour from the ear canal by surgery.

  (e) Eye

  The eyes are organs of sight. We have a pair of eyes. The eyes are located in the bony cavities of the skull They are protected by the  and eye lashes.

  
  

  
  

  Activity -24     Observing the Structure of Eyes

  1. Choose a partner and face each other.

  2. Look into the eyes of your partner closely.

  3. Observe and describe the parts you see.

  You can see a dark round part in the eye. There is a darker spot at the middle of it.

  It is the hole through which light enters into the eye.

  Activity -25 Identifying Different Parts of a Human Eye

  1. Identify all its parts of an eye and label them.

  2. Draw this picture in your exercise book.

  

  Layers of an Eye

  An eye is composed of three concentric layers:

  1. Outer layer: This layer contains the sclera and the cornea.

  •  Sclera: This is the white part of an eye. It protects the eye from injury.
  •  Cornea: It is a curved, transparent circular coat in front of the eyeball.

  It controls and focuses the entry of light into the eye.

  2. Middle layer (Vascular layer): This layer contains the iris, ciliary body and choroid.

  • Iris: It is a coloured, thin circular ball present in the centre of the eye. It determines eye colour.
  •  Ciliary body: It is a structure that releases a transparent liquid in the eye. It controls the shape of the lens. Lens is a solid body lying just behind the iris. It provides focus of light on the retina.
  •  Choroid: It is a vascular layer of the eye. It lies between retina and the sclera. It nourishes the outer layer of the retina.

  3. Inner layer: This layer is also called retina. It is the sensory part of an eye.

  •  Retina: It is a very delicate coat at the back of the eyes. Images are formed on the retina. The retina sends the images to the brain through nerves called optic nerves.

  
  
  

  Chambers of an Eye

  There are three chambers in the eye. They are:

  1. Anterior chamber: It is the space between cornea, iris and the lens. It is filled with a fluid called aqueous humour.

  2. Posterior chamber: It is the space between iris and ciliary body. It is also filled with aqueous humour.

  3. Vitreous chamber (or Internal chamber): It is the space behind lens and between iris and retina. It is filled with a clear jelly-like substance called vitreous humour.

    Activity -26     Exploring the Functions of Eyes

  1. Blindfold one of your friends.

  2. Put different objects in front of him/her.

  3. Is he/she able to see these objects? Explain why.

  The blindfolded pupil cannot see the things. It is because the eyes help us to see.

  Defects of Eyes and their Correction

  Activity -27     Identifying the Types of Eye Defects

  1. Search information from various sources (parents, peers, nearest health facilities, printed materials and XO laptops about eye defects and their prevention.

  2. Then share the information with your classmates.

  

  •  What do the pictures show?
  •  Which disease is the girl suffering from?
  •  Which disease is the lady suffering from?

   There are many types of eye defects. These are:

     (A) The girl is suffering from short-sightedness or myopia. She can see nearby objects very well, but cannot see objects well that are far.

      The following are some causes of short-sightedness:

          1. Increased size of the eyeball

          2. Weakness of eye muscles

          3. Insufficient supply of blood to the eyes.

  
  

  Correction

  This defect can be corrected by using a convex (converging) lens.
  

  
  

  (C) Presbyopia

  Presbyopia is a progressive form of long-sightedness. It affects most people by their early 60s.Most people find that the near point gradually diminishes.

  Cause and Cure

  It arises due to the gradual weakening of the eye muscles. Simple reading eyeglasses with convex lenses correct most cases of presbyopia. Sometimes, a person may suffer from both myopia and hypermetropia. Such people often require bi-focal lenses. In the bi-focal lens, the upper portion of the bi-focal lens is a concave lens, used for distant vision. The lower part of the bi-focal lens is a convex lens, used for reading purposes.

  (D) Astigmatism

  In astigmatism, a person cannot simultaneously focus on both horizontal and vertical objects.

  Causes

  This defect is usually due to the cornea that is not perfectly spherical.

  

  Correction

  This defect can be corrected using eyeglasses with cylindrical lenses.

  Activity-28Collecting Information on Prevention and Treatment of Eye Defects
  

  1. Go to your school library.

  2. Collect information on prevention and treatment of possible eye defects from textbooks in the library.

  3. Make a report on it and present to the class.

  To prevent eye defects, respect the following advice:

    1. Eat a healthy diet that includes fruit and green leafy vegetables.

    2. Avoid smoking.

    3. When you are outdoors, wear sunglasses that block sun’s harmful UV rays.

    4. Keep at least a distance of 25 cm when you are reading and watching TV.

    5. Have a regular checkup of your eyes by an eye doctor.

  12.6 Keywords

  • Auditory: Related to the sense of hearing.

  • Dermis: The middle layer of the skin.

  • Epidermis: The outermost layer of the skin.

  • Hygiene: Practice that you do to keep things healthy.

  •  Hypodermis: The bottom layer of the skin.

  •  Lens: A piece of glass with curved sides for concentrating or dispersing light rays.

  • Motor nerve: A nerve that carries feedback from brain to the sensory organs.

  • Scald: A skin injury caused by wet heat.

  • Sense: To become aware of something.

  •  Sensory organs: Eyes, ears, nose, tongue and skin are sensory organs.

  •  Sinuses: Air-filled cavities inside face and skull.

  •  Skull: A framework of bones that encloses the brain.

  • Tissue: A type of material from which plants and animals are made.
  • 
    
  • Tumour: A swelling of a part of the body.

  •  Wounds: Injuries that break the skin.

  
  

  12.7 Summary

  • Organs which help us to see, hear, smell, taste and feel are called sensory organs. The eyes, ears,  nose, tongue and skin are our sensory organs.
    

  • Skin is the outermost covering of our body. It is the sensory organ for touch and feel.

  •  If we do not clean our skin properly, diseases like ringworms and eczema will attack our skin. Some 
  • common skin diseases include: ringworm, scabies, leprosy and eczema.

  • Tongue is the sensory organ of taste.

  • Nose is the sensory organ for smell.

  •  Common cold and sinusitis are some common nose diseases.

  •  Ears are our sensory organs of hearing.

  •  Some common ear diseases include: hearing loss and deafness

  • Deafness is the complete inability to hear sound.

  • The eyes are organs of sight.

  •  In short-sightedness, a person can see nearby objects very well, but cannot see objects well that are far.
  •  In long-sightedness, a person can see distant objects clearly, but near objects with blurred vision.

  12.8 Unit Review Exercises

  Do these review exercises in your exercise book.

  I. Fill in the blanks with the correct options:

  1. Organs which help us to see, hear, smell, taste and feel are called ............. .

  (a) breathing organs                      (b) sensory organs

  (c) reproductive organs                  (d) none of these

  2. ………… is the sensory organ for touch and feel.

  (a) Ear                          (b) Eye

  (c) Skin                         (d) Nose

  3. ………… is the sensory organ of sight.

  (a) Ear                     (b) Eye

  (c) Skin                    (d) Nose

  4. ………… is the sensory organ of taste.

  (a) Ear                    (b) Eye

  (c) Skin                   (d) Tongue

  5. ………… is the sensory organ of hearing.

  (a) Ear                    (b) Eye

  (c) Skin                    (d) Nose

  6. ………… is the sensory organ for smell.

  (a) Ear                    (b) Eye

  (c) Skin                   (d) Nose

  II. Match the organs with their functions:

  
  

  III. State whether the following statements are true or false:

  1. Sensory organs are connected to brain through nerves.

  2. Tongue enables us to balance our body.

  3. The inner ear has three tiny bones.

  4. Retina is the outer layer of the eye.

  5. Short-sightedness can be corrected using a convex lens.

  IV. Answer the following questions briefly:

  1. Explain the mechanism of sensory organs.

  2. What are the specific functions of skin?

  3. List any two properties of skin.

  4. Name any three skin diseases.

  5. What are bruises?

  6. What are the specific functions of tongue?

  7. How can you take care of your tongue?

  8. List some tongue disorders and their causes.

  9. What are the specific functions of nose?

  10. Explain how to maintain the hygiene of tongue.

  11. List two nose diseases, their causes and preventions.

  12. State the functions of ears.

  13. Mention some ear diseases and their causes.

  14. List some eye defects and their corrections.

  15. How can you prevent eye defects?

  V. Complete the crossword puzzle using the clues below:

  
  

  Clues:

  Across

  5. Organs which help us to see, hear, smell, taste and feel.

  Down

  1. It is the sensory organ for taste.

  2. It is the sensory organ for smell.

  3. These are the sensory organs for sight.

  4. These are the sensory organs for hearing.

  5. It is the outermost covering of our body.

  Mark as done
• Skeleton supports our body. It is made up of bones. Without skeleton, we would not be able to stand up.

  13.1 Main Parts and Major Bones of the Skeleton

  Activity-1 Identifying Main Parts of Human Skeleton

  
  

  •  What would you look like if you had no skeleton?
  •  Would you be able to stand up?
  •  Would you be able to walk?
  •  What supports your body?

  Skeleton gives shape and support to our body. A skeleton comprises skull, arms and legs. Each of the major parts consists of some small bones.

  

  (a) Major Bones of Skull

  Activity -2   Exploring Bones in the Forehead

  Press the top of your forehead.

  Do you feel hard or soft?

  What do you think makes your forehead harder?

    Press the top of your forehead.
    Do you feel hard or soft?
    What do you think makes your forehead harder?                

  Inside our head, there is a bony framework that encloses the brain. It is called skull. It is the
  hardest of all bones in the body. All the bones in the skull are fixed. The major bones of the skull are:
  1. Cranium: It is the covering that protects and supports the brain. It consists of 8 bones.
  2. Facial bones: There are 14 facial bones in the face and the jaws. The only movable bone in the jaw is the lower jaw.

  (b) Major Bones of Trunk

  Activity -3   Identifying Major Bones of Trunk

    Look at the picture. Identify the major bones of trunk from the given options and write in your notebook. (RIBS, SPINE, PELVIS)

  

  The part of the body to which head and limbs are attached is called trunk. The major bones of the trunk are:
  
  The Backbone or Spine
  
  The backbone is made up of 33 ring-like bones called vertebrae. These 33 bones form a column called spine.
  Spine encloses and protects the spinal cord. It also supports the head, neck and body for upright posture.

  

  Ribs
  Ribs are curved bones. These are attached to the backbone at the back and breastbone at the front. All these ribs together form a cage-like structure called rib cage. Rib cage protects our heart and lungs. There are 12 pairs of ribs in this rib cage.

  
  Pelvis
  It is the lower part of the trunk. It supports the abdomen.
  It also protects the digestive organs. Legs and backbone are
  attached to the pelvis.

  

  (c) Major Bones of Legs and Arms

  Legs

  Activity -4 Identifying Major Bones of Legs

  
  

  1. What does the picture show?

  2. How many long bones are there in leg?

  3. Write their names in your science notebook.

  The legs are called the hind-limbs. Each leg has three long bones and several short bones. These bones make up the foot. Major bones of the leg are femur, tibia and fibula.
  The upper part of a leg has a long bone. It is called femur.
  The lower part of a leg is made up of two bones—tibia and fibula. Tibia is
  larger than fibula.

  

  1. What does the picture show?
  2. How many long bones are there in an arm?
  3. Write their names in your science notebook.

  The arms are called fore-limbs. Each arm has three long bones and several short bones. These bones form the fingers and the hands. Major bones of an arm are humerus, ulna and radius.
  The upper part of an arm has a long bone. It is called humerus.
  The lower part of an arm is made up of two bones—radius and ulna

  13.2 Functions of the Skeletal System

  Activity -6 Discussing the Functions of Skeletal System

  Discuss the following question in groups:

  • What would happen if we didn’t have skeleton?

  Without skeletal system we would be just a puddle of skin. The skeleton gives shape and support to our body. It has some other functions also. They are:
  1. Together with muscles it helps us to move.
  2. It protects all the delicate organs like brain and heart.
  3. Some bones produce blood cells in the bone marrow. Marrow is a soft
  tissue present inside the bone.
  4. Bone tissues store minerals like calcium and phosphorus.
  5. Bone regulates the release of hormones.
  6. The facial bones form jaws which help us in speaking and eating.
  7. The vertebral column or spine protects the spinal cord.

  13.3 Accidents of Bones
  When damages occur to the bones, it is called bone accidents. Fracture is one type of accident to the bone.

  

  The person is suffering from fracture. A break or crack in the bone is called a fracture. Fractures can occur to the bones of legs, arms, head and backbones. A sudden fall or an accident can cause fracture.
  The following are the signs and symptoms of fractures:
  1. Swelling or bruising over a bone.
  2. The injured limb appears shorter.
  3. Pain in the injured area.
  4. Loss of function in the injured area.

  (a) Types of Fractures
  There are two types of fractures. These are—open fracture and closed fracture.
  1. Open fracture: When a fracture punctures the skin, it is called an open
  fracture.
  2. Closed fracture: When a fracture does not puncture the skin, it is called closed fracture.

  

  (b) First Aid for Fracture
  In case of fracture:
  1. Do not move the fractured part.
  2. Apply a splint (rigid material) to the injury. Tie a cardboard with a piece
  of cloth around the fractured part.

  Note: Do not secure the splint too tight. The circulation of blood will be stopped.

  3. In case of hand fracture, use a sling to restrict the movement of the hand.
  A sling is a triangular piece of cloth.

  

  4. Rush the victim to a nearby health centre.

  (c) Prevention of Accidents of Bones
  To prevent bone accidents:
  1. Never play dangerous games.
  2. Never fight with your friends.
  3. Take a well-balanced diet to keep your bones healthy. Especially, eat food rich in calcium.
  4. Exercise regularly. It will make your bones strong.

  13.4 Bone Diseases

  Activity -8   Identifying the Bone Diseases

  1. Search information from different sources on different bone diseases from library, wallcharts and search engines like Google or Yahoo.

  2. Then share the information with your friends in the classroom.

  Diseases that affect our bones are called bone diseases. There are many kinds of bone diseases. Some of the common bone diseases are:

  (a) Rickets
  
  Rickets is the softening or weakening of bones. It is common in children of 6–24 months of age.
  Cause of Rickets
  1. Deficiency of Vitamin D
  2. In some cases it is genetic.
  Symptoms of Rickets
  Signs and symptoms of rickets include:
  1. Pain in bone
  2. Bending of legs and backbones
  3. Swelling at the wrists, knees and ankles
  4. Dental deformities.

  

  Prevention of Rickets
  1. Have daily sunlight exposure.
  2. Eat foods that include adequate amount of calcium and vitamin D.
  
  (b) Bone Cancer
  Bone cancer occurs when abnormal cells grow in the bones.

  

  Symptoms of Bone Cancer
  The main symptoms of bone cancer are:
  1. Painful bones and joints
  2. Joint swelling and stiffness
  3. Fever
  4. Unexplained weight loss
  5. Tiredness.
  
  Treatment of Bone Cancer
  1. Surgery is the primary treatment of bone cancer
  2. Use medicines to destroy the cancer cells
  3. Radiation therapy.

  (c) Deformities of Vertebral Column or Spine

  Activity -9 Identifying the Deformities of Spine

  
  

  1. What do these pictures show?

  2. What are the people suffering from?

  They have deformities of their spines.
  

  Deformity of spine is the abnormality of the shape of the vertebral column. The natural curvatures of spine are misaligned in some areas. There are three main types of deformities. These are summarised in Table 1.

  
  

                        Table 1: Different Types of Deformities of Vertebral Column

  13.5 Hygiene of the Skeleton

  Activity -10 Discussing the Maintenance of Skeleton

  1. Have a discussion to find out good practices of maintaining the skeleton and avoiding accidents.

  2. Make a report on it and present to the class.

   1. Have a discussion to find out good practices of maintaining the skeleton  and avoiding accidents.

    2. Make a report on it and present to the class. 

    The following steps can help us improve our bones’ health:

  1. Eat diet rich in calcium and Vitamin D. For example, egg, fish, milk
  and liver.
  2. Do physical exercise. Like muscles, bones become stronger with exercise.
  3. Drink plenty of water to maintain joint health.
  4. Prevent falls as it can cause bones to break  

  13.6 Prevention of Bone Diseases and Deformation of the Vertebral Columns

  Activity -11   Preventing Deformities of Vertebral Columns

  
  

  1. Is this person sitting in right posture?

  2. What happens if he sits in this posture daily?

  3. How can he prevent such type of problems.

  His spine will be deformed and he will have some bone diseases.
  To prevent bone diseases and deformation of vertebral columns:
  1. Sit correctly.
  2. Avoid carrying heavy schoolbags.
  3. Take regular exercise.
  4. Take calcium-rich food such as milk, cheese,yogurt, orange and lemon.
  5. Take Vitamin D rich food such as liver, fish and egg yolks.

  

  13.7 Keywords
  
   Breastbone: A thin, flat bone running down the centre of the chest.
   Deformity: Abnormality of shape or form.
   Fracture: A break or crack in the bone.
   Hygiene: Practice that you do to keep things healthy.
   Pelvis: The lower part of the trunk that supports the abdomen.
   Radiation: Energy that comes from a source and travels throughsome material or through space.
   Ribs: Curved bones that are attached to the backbone at the front andthe breastbone at the front.
   Skeleton: The framework of bones that supports our body.
   Skull: The bony framework that encloses the brain.
   Sling: A bandage or device used to support an injured part of the body.
   Splint: A device used for support or immobilization of a limb.
   Swayback: An abnormally hollowed back.
   Trunk: The part of the body to which the head and limbs are attached.

  13.8 Summary
   Skeleton gives shape and support to our body.
   The bony framework that encloses the brain is called skull. It consists
  of cranium and facial bones.
   The part of the body to which head and limbs are attached is called trunk. The major bones of the trunk are—the backbone, ribs and pelvis.
   When damages occur to the bones, it is called bone accidents.
   The backbone is made up of 33 ring-like bones called vertebrae.
   The major bones of a leg are—femur, tibia and fibula.
   Some bones produce blood cells in the bone marrow. Marrow is a soft tissue present inside the bone.
   A break or crack in the bone is called a fracture. Fractures can occur to the bones of legs, arms, head and backbones.
   There are two types of fractures. These are—open fracture and closed
  fracture.

   Diseases that affect our bones are called bone diseases. There are
  many kinds of bone diseases. Some of common bone diseases are—
  rickets, bone cancers.
   There are three main types of deformities. These include: scoliosis, lordosis and kyphosis.

  13.9 Unit Review Exercises
   Do these review exercises in your exercise book.
  I. Fill in the blanks with the correct options:
  1. Our body is supported by a framework of bones called ............... .
  (a) skeleton                  (b) tissue
  (c) muscle                    (d) none of these
  2. ………… encloses the brain.
  (a) Pelvis                      (b) Skull
  (c) Rib                           (d) None of these
  3. ………… is the lower part of the trunk.
  (a) Rib                            (b) Spine
  (c) Pelvis                        (d) None of these
  4. A break or crack in the bone is called ………… .
  (a) disease                      (b) fracture
  (c) deformity                    (d) none of these
  5. When the fracture punctures the skin, it is called ………… .
  (a) open fracture             (b) closed fracture
  (c) deformity                    (d) none of these
  6. ………… is the bone disease caused due to lack of Vitamin D.
  (a) Scoliosis                      (b) Bone cancers
  (c) Rickets                         (d) None of these
  II. State whether the following statements are true or false:
  1. Skeleton gives shape and support to our body.
  2. Pelvis is the hardest bone in our body.
  3. The legs are called forelimbs.
  4. Fracture is the break or crack in the bone.
  5. Kyphosis is characterised by an abnormally rounded upper back

  III. Match the bones with their functions

   Bones                                                                                  Function

      

        1.                                      (a) Protects the heart and lungs

                                                  (b) Supports the abdomen

                                                               
                                                                
                                              (c) Supports the head, neck and body for                                                                                                   upright posture

                                       (d) Protects the brain

  IV. Answer the following questions briefly:
  
  1. What is skeleton?
  2. Which part of the skeleton protects the brain?
  3. List major bones of the skull.
  4. List major bones of the trunk.
  5. List major bones of the legs.

  6. Name the bone found in the upper part of the leg.
  7. List major bones of the arms.
  8. Name the bone found in the upper arm.
  9. List at least three functions of the skeletal system.
  10. What is fracture?
  11. What are the two main types of bone fractures?
  12. Name some common bone diseases and deformation of vertebral column.
  
  V. Complete the crossword puzzle using the clues below:

  

  Clues:
  
  Across
  2. This is the bony framework that encloses our brain.
  3. This is a break or crack in the bone.
  Down
  1. This is the part of the body to which the head and limbs are attached.
  2. This is the framework of bones that supports our body.

                                                                       

  Mark as done
• What are Muscles?

  Activity-1 Muscles of Arms
  

  1. Make a fist.

  2. Bend your arm at the elbows and tighten your fist.

  You will see your arm bulging out.

  Do you know why this happened?

  
  

  It is because muscles contracted to help you fold your arm.

  Muscles are soft tissues found in our body. They cover our bones and help to move them. Bones and muscles work together to move our body.

  Need of Keeping Healthier Muscles

  Healthy muscles let us move freely. They also keep our body strong. They help us enjoy playing, dancing, walking and other activities.Strong muscles also help to keep our joints in good shape.

  Importance of Muscles

  Muscles are very important for human body.

  1. They help in the movement of human body.

  2. They support our body.

  3. They help maintain posture.

  14.1 Main Groups of Muscles

  Activity-2 Grouping Muscles
  

  
  

  1. Which of these muscles work at our will?

  2. Which of these muscles do not work at our will?

  The muscles of arms and legs work at our will. These are voluntary muscles.

  These muscles get tired and need rest. Can you name some other voluntary muscles?

  The muscles of heart and lungs do not work at our will. These are involuntary muscles. These muscles do not get tired and work continuously. Can you name some other involuntary muscles?

  Differences between Voluntary and Involuntary Muscles

  
  

  14.2 Major Voluntary Muscles of the Human Body

  Activity -3 Identifying the Major Voluntary Muscles of the Human Body

  1. Touch the body.

  2. Contract your muscles.

  3. Move organs like head, the trunk, legs and arms to discover the main muscles.

  We use voluntary muscles to perform different activities. Some of the major voluntary muscles are:

  (a) Major Muscles of the Head

  The muscles in our head help us move different parts of the face. They also move our jaw and scalp. There are various muscles in our head. Based on their functions, they are classified as:

  1. Eye muscles: Orbicularis oculi: These muscles are present around our eyes. They help us to open and close our eyes.

  2. Facial muscles: These muscles are associated with facial expressions. Some of the facial muscles include: Frontalis: This muscle covers the parts of the skull. Zygomaticus major: This muscle controls facial expression, drawing the mouth’s angle upward and outward. Orbicularis oris: This muscle encircles our mouth and enables our lips to move.

  3. Chewing muscles: These muscles help us to chew foods. Some of the chewing muscles include: Temporalis: This muscle is used for chewing. Buccinator: This muscle holds the cheek to the teeth and assists in chewing. Masseter: This muscle closes the mouth by raising our jawbones.

  4. Neck muscles: Sternocleidomastoid: This muscle helps rotate the head upward and side to side.

  

  (b) Major Muscles of the Trunk

  Our trunk has a large number of muscles. Some of these muscles are:

  1. Pectoralis major (or Chest muscles): These muscles keep the arms attached to the body.

  2. Rectus abdominis (or Abdominal muscles): These muscles help in breathing process.

  3. Deltoid (or Shoulder muscles): These muscles prevent joint dislocation.

  4. Serratus muscle: This muscle allows the forward movement of arm.

  
  

  (c) Major Muscles of the Legs

  Legs are used for standing, walking, jumping and other work. Major muscles of legs are:

  1. Gluteus medius (or Hip muscles): these muscles provide movement, strength, and stability to the hip joint.

  2. Popliteus (or Knee muscles): These muscles allow the body to walk, run and jump.

  3. Vastus lateralis (or Thigh muscles): These muscles allow the thigh to move.

  
  

  (d) Major Muscles of the Arms

  The arm’s curved shape comes from its major exterior muscles. These muscles also give the arm its strength.

  The major muscles of an arm are:

  1. Biceps: This muscle is on the front of the upper arm.

  2. Triceps: This muscle is on the back of the upper arm.

  Both biceps and triceps have opposite functions. When biceps muscle contracts, the arm bends and triceps muscle stretches. When triceps muscle contracts, the arm is stretched.    

                         

  14.3 Functions of Voluntary Muscles

  Activity -4 Discussing the Functions of Voluntary Muscles
  

  1. Have a discussion on the functions of voluntary muscles.

  2. Make a report on it and present to the class.

  Major functions of voluntary muscles are:

  1. Produce skeletal movement: Contraction and relaxation of muscles allow the bones to move.

  2. Maintain posture and body position: Good posture depends on the strength of muscles. A person with strong muscle can maintain upright posture.

  3. Stabilise the joints: The muscles around the knee keep the joints in a good shape. These also protect the knee from injury.

  14.4 Accidents of Muscles (Cramp) and First Aid

  Activity -5 Discussing the Cramps

  1. What is the footballer suffering from?

  2. What is muscle cramp?

  3. What are the causes of muscle cramps?

  
  

  Muscle cramps are sudden contractions of muscles. These contractions are often painful. Commonly affected muscles include the back of lower leg, the back of thigh, and the front of thigh. It is caused due to dehydration and muscle fatigue

  
  

  First Aid for Muscles (Cramp)

  Activity -6 Role Play a Muscle Accident Situation:

  One of your friends has muscle cramp. What would you do?

  Role play:

  Form a group of two pupils each. One member will act as a victim. The other member will provide him/her necessary first aids.

  If you have a muscle cramp:

  1. Stretch the cramped muscle to increase flexibility.

  2. Gently massage the cramped muscle.

  3. Drink plenty of water.

  4. Take a hot water bath.

  14.5 Hygiene of Muscles

  Activity -7 Discussing the Good Practices of Maintaining Muscles

  1. Have a discussion to discover good practices of maintaining muscles and avoiding their accidents.

  2. Make a report on it and present to the class.

  For healthy muscles, the following care should be taken:

  1. Take good food and pure air.

  2. Avoid dangerous games.

  3. Sit, walk and stand in a correct posture.

  4. Do physical exercise regularly.

  
  

  Maintaining Tone of a Muscle

  Muscle tone is an unconscious low level contraction of muscles at rest. The main purpose of muscle tone is to keep the muscles ready for action.

  The following things can be done to maintain tone of a muscle:

  1. Eat foods, such as whole grains, fruit and vegetables to reduce body fat.

  2. Drink plenty of water.

  3. Do strength training exercises to reduce fat?

  14.6 Prevention of Accidents

  During physical exercises, follow these tips to prevent accidents:

  1. Take five to ten minutes to warm up and cool down properly.

  2. Plan to start slowly and boost your activity level gradually.

  3. Do not exercise when you are sick.

  4. Choose clothes and shoes designed for your type of exercise.

  5. Avoid exercise in humidity and overheating condition.

  14.7 Keywords

  •  Cramps: Painful involuntary contraction of a muscle or muscles.
  •  Involuntary: Does not work at one’s own will.
  •  Joint: The point at which bones are joined.
  •  Muscles: Soft tissues found in our body.
  •  Strength training: A type of physical exercise specialised for minimising muscular contraction.
  •  Tissue: A type of material of which plants and animals are made.
  •  Voluntary: Works at one’s own will.

  14.8 Summary

  • Muscles are soft tissues found in our body.
  • There are two types of muscles in our body. They are: voluntary and involuntary muscles.
  • The muscles that work at our will are called voluntary muscles. Examples:Muscles attached to arms and legs.

  • The muscles that do not work at our will are called involuntary muscles. Examples: Muscles of our stomach and intestines.
  • Abdominal muscles help in breathing.
  • Biceps and triceps are two major muscles of arms.
  • Major functions of voluntary muscles are:

             - Produce skeletal movement

             - Maintain posture and body position

              - Stabilise the joints

  • Muscle cramps are sudden contractions that occur in various muscles. These contractions are often painful.
  • Muscle tone is an unconscious low level contraction of muscles at rest.

  The main purpose of muscle tone is to keep the muscles ready for action.

  14.9 Unit Review Exercises

  Do these review exercises in your exercise book.

  I. Fill in the blanks with the correct options:

  1. Muscles are the ............ found in the body.

  (a) tissues                                     (b) cells

  (c) organs                                      (d) none of these

  2. Muscles that work at our will are called ………… muscles.

  (a) voluntary                                 (b) involuntary

  (c) cardiac                                    (d) none of these

  3. Muscles that do not work at our will are called ………… muscles.

  (a) voluntary                                 (b) involuntary

  (c) cardiac                                    (d) none of these

  4. ………… muscle is on the front of the upper arm.

  (a) Biceps                               (b) Triceps

  (c) Involuntary                        (d) None of these

  5. ………… are the sudden contraction of muscles.

  (a) Cramps                             (b) Bruise

  (c) Cuts                                  (d) None of these

  II. State whether the following statements are true or false:

  1. Muscles together with bones help in the movement of body.

  2. Muscles of the arms and legs are involuntary muscles.

  3. Shoulder muscles prevent joint dislocations.

  4. Muscles keep the joints in good shape.

  5. In case of muscle cramp, we should take a cold water bath.

  III. Match the muscles to their functions:  Muscles Functions

  1. Facial muscles                                                  (a) Allow the body to run, jump and play

  2. Eye muscles                                                      (b) Prevent joint dislocation

  3. Shoulder muscles                                              (c) Enable us to open or close our eyes

  4. Knee muscles                                                    (d) Keep the arms attached to the body

  5. Chest muscles                                                   (e) Facial expression

  IV. Answer the following questions briefly:

  
  

  1. What are muscles?

  2. List the major groups of muscles of the human body.

  3. List any two major muscles of the head.

  4. What are the functions of voluntary muscles?

  5. Name the muscles labelled A and B.

  6. What are the causes of muscle cramps?

  7. What type of first aid should be given in case of muscle cramps?

  8. List some ways in which we can keep our muscles strong.

  V. Complete the crossword puzzle using the clues below:

  
  

  Clues:

  Across

  3. This type of muscle is present in heart and intestines.

  4. This is a painful contraction of muscle.

  Down

  1. This is the point at which bones are joined.

  2. Together with bones they help in the movement of our body.

  
  

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  UNIT 8: SOIL

  

  
  

  
  

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