CBSE Class 6

These NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Electricity and Circuits NCERT Solutions for Class 6 Science Chapter 12

Class 6 Science Chapter 12 Electricity and Circuits Textbook Exercise Questions and Answers

Question 1.
Fill in the blanks:
a. A device that is used to break an electric circuit is called ………………….
b. An electric cell has …………………. terminals.
Answer:
a. switch
b. two

Question 2.
Mark ‘True’ or ‘False’ for the following statements:
a. Electric current can flow through metals.
b. Instead of metal wires, a jute string can be used to make a circuit.
c. Electric current can pass through a sheet of thermocol.
Answer:
a. True
b. False
c. False

Question 3.
Explain why the bulb would not glow in the arrangement shown in the given figure.

Answer:
The bulb would not glow because one end of the tester/screwdriver is made up of plastic which does not allow the electric current to flow through it.

Question 4.
Complete the drawing shown in figure to indicate where the free ends of the two wires should be joined to make the bulb glow.

Answer:

Question 5.
What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them.
Answer:
An electrical switch is used to open the circuit or to close the circuit due to which electrical gadgets start or stop. Electrical switch is used in many electrical gadgets such as: television, washing machine, electrical mixer, toaster, heater, etc.

Question 6.
Would the bulb glow after completing the circuit shown in figure of Question 4, if instead of safety pin we use an eraser?
Answer:
No, since eraser is an insulator so it does not allow the current to pass through it. Hence, the bulb will not glow.

Question 7.
Would the bulb glow in the circuit shown in the given figure?

Answer:
No, the electric bulb has two terminals and both the wires are connected to one terminal of the bulb. Current will not flow from the bulb and it will not glow. To make it glow, we have to connect one wire to each terminal of the bulb.

Question 8.
Using the “conduction tester” on an object it was found that the bulb begins to glow. Is that object a conductor or an insulator? Explain.
Answer:
If the object is a good conductor of electricity, then current will pass through conduction tester and the bulb will glow. Hence, the object will be a conductor of electricity.

Question 9.
Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.
Answer:
Our body is a good conductor of electricity and rubber is an insulator. During repairing work, if the body comes in contact with current carrying wire then there will not be any accident as rubber does not allow the passage of current through it. Hence, electrician should use rubber gloves while repairing an electric switch.

Question 10.
The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them. Can you explain why?
Answer:
Plastic or rubber is an insulator which does not allow electric current to pass through it. The handles of the tools like screwdrivers and pliers used by electricians for repair have covering of plastic or rubber so that electric current may not pass through these tools to the body of the electrician to harm him.

NCERT Extended Learning Activities And Projects

Question 1.
Imagine there were no electric supply for a month. How would that affect your day-to-day activities and others in your family? Present your imagination in the form of a story or a play. If possible stage the play written by you or your friends in school.
Hint:
Do it yourself.

Question 2.
For your friends, you may set up a game “How steady is your hand?”. You will need a cell, an electric bulb, a metal key, two iron nails (about 5 cm in length), about one and a half metre long thick metal wire (with its plastic insulation scraped off) and few pieces of connecting wires. Fix two nails nearly one metre apart on a wooden board so that these can be used as a hook. Fix the wire between the nails after inserting it through the loop of the key. Connect one end of this wire to a bulb and a cell. Connect the other terminal of the cell to the key with a wire. Ask your friend to move the loop along the straight wire without touching it. Glowing of the bulb would indicate that the loop of the key has touched the wire.
Hint:
Do it yourself.

Question 3.
Read and find out about Alessandro Volta who invented the electric cell. You may also find out about Thomas Alva Edison who invented the electric bulb.
Hint:
Do it yourself.

Activity 1

Objective: To make an electric bulb light up
using an electric cell.
Materials Required: Bulb, cell and connecting wire.
Procedure:

• Take four lengths of electric wire with differently coloured plastic coverings.
• Remove a little of the plastic covering from each length of wire at the ends. This would expose the metal wires at the ends of each length.
• Fix the exposed parts of the wires to the cell and the bulb as shown in figure below.

• You can stick the wires to the bulb with the tape used by electricians. Use rubber bands or tape to fix the wires to the cell.
• Now, connect the wires fixed to the bulb with those attached to the cell in six different ways as has been shown below. For each arrangement, find out whether the bulb glows or not.

Observations: You connected one terminal of the electric cell to the other terminal through wires passing to and from the electric bulb. Note that in the arrangements shown in Fig. (a) and (f), the two terminals of the electric cell were connected to the two terminals of the bulb. Such an arrangement is an example of a closed electric circuit.

Conclusion: The electric circuit provides a complete path for electricity to pass (current to flow) between the two terminals of the electric cell. The bulb glows only when current flows through the circuit.

• Electric bulb: Electric bulb is the electrical device which converts electrical energy into light and heat energy.
• Filament: Filament is a thin wire in the bulb which is made up of tungsten metal and is used to emit light in the bulb. The Filament gets heated due to electric current. This heat is then converted into light.

Activity 2

Objective: To study the structure of a torch bulb.
Material Required: A torch bulb.
Procedure:

• Take out the bulb from a torch.
• Observe the bulb from outside and also from inside with a magnifying glass.
• List the various parts you could see.

Observations: The torch bulb consists of the following parts:

• Metal casing having grooves in the lower part.
• A small spiral of thin wire called filament is present.
• Two slightly thicker wires in the upper ends of the wires support the filament.
• The lower end of the one of the thicker wire is connected to the metal casing and that of the other wire to the metal tip at the bottom of the bulb.
• The metal tip and the metal casing are fixed in such a way that they do not touch each other.

Electric switch: Electric switch is a device by which an electric circuit can be easily completed or broken. The switch is ‘ON’ in a closed circuit and ‘OFF’ in an open circuit.

Activity 3

Objective: To make a simple and easy switch to use in our circuit.
Materials Required: Two drawing pins, a safety pin (or a paper clip), two wires and a small sheet of thermocol or a wooden board.
Procedure:

• Insert a drawing pin into the ring at one end of the safety pin and fix it on the thermocol sheet as shown in the figure.
• Make sure that the safety pin can be rotated freely.
• Now, fix the other drawing pin on the thermocol sheet in a way that the free end of the safety pin can touch it.
• The safety pin fixed in this way would be your switch in this activity.

• Now, make a circuit by connecting an electric cell and a bulb with this switch as shown. Rotate the safety pin so that its free end touches the other drawing pin and observe.
• Now, move the safety pin away and observe again.

Observations:

• The safety pin covered the gap between the drawing pins when you made it touch the two of them. In this position the switch is said to be ‘on’. Since the material of the safety pin allows the current to pass through it, the circuit was complete. Hence, the bulb glows.
• On the other hand, the bulb did not glow when the safety pin was not in touch with the other drawing pin. The circuit was not complete as there was a gap between the two drawing pins. In this position, the switch is said to be ‘off’.

Conductors: Conductors are the materials which allow the electric current to pass through them. Mostly metals are good conductors of electricity.
Insulators: Insulators are the materials which do not allow the electric current to pass through them. Rubber and wood are insulators.

Activity 4

Objective: To find out which object is a conductor and which is an insulator.
Materials Required: Three pieces of wire, a small torch bulb, a thick sheet of cardboard or wood, sticky tape, pencil cell and objects such as metal spoon, eraser, peel of wood, etc. Procedure:

• Connect a pencil cell to the socket which holds a small torch bulb.
• Attach clips to the bare ends of both wires.
• Hold various objects between the two clips.
• Observe if the bulb glows or not. Record your observations.

Observations:

• The bulb does not glow when the free ends of the wires are in contact with some of the materials you have tested. This means that these materials do not allow the electric current to pass through them.
• On the other hand, some materials allow electric current to pass through them, which is indicated by the glowing bulb.

Conclusion:
Materials which allow electric current to pass through them are conductors of electricity. Insulators do not allow electric current to pass through them.

Class 6 Science Chapter 12 Electricity and Circuits Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
How much voltage is given by a single dry cell?
Answer:
1.5 volts.

Question 2.
Name the two types of circuits.
Answer:
Open circuit and closed circuit are the two types of circuits.

Question 3.
Name two terminals that all electric cells contain.
Answer:
Positive terminal and negative terminal.

Question 4.
What is the work of an electric cell?
Answer:
An electric cell converts chemical energy into electrical energy.

Question 5.
Define battery.
Answer:
The combination of two or more than two cells is called a battery.

Question 6.
What is the work of a filament in a bulb?
Answer:
A filament gets heated and emits light in the bulb.

Question 7.
What is a solar cell?
Answer:
A solar cell is a device which converts solar energy into electrical energy.

Question 8.
Write one use of insulators.
Answer:
Insulators are used in making switchboards, handles of testers, screwdrivers, etc.

Question 9.
Name a device which is used to ‘open’ or ‘close’ a circuit.
Answer:
Switch.

Question 10.
How does an electric cell produce electricity?
Answer:
An electric cell produces electricity from chemicals stored inside it.

Question 11.
Is electricity pollution free and a useful form of energy?
Answer:
Yes.

Question 12.
Which terminal of the cell does have a metal cap?
Answer:
Positive terminal.

Question 13.
In a cell, the carbon rod is surrounded by which mixture?
Answer:
Manganese dioxide and powdered charcoal.

Short Answer Type Questions

Question 1.
Write two advantages of a dry cell.
Answer:
Two advantages of a dry cell are:

1. It converts chemical energy into electrical energy.
2. It is light in weight and small in

Question 2.
What is the difference between a conductor and an insulator?
Answer:
A conductor allows the passage of current through it whereas an insulator does not allow the passage of current through it.

Question 3.
How does a bulb start glowing with an electric cell?
Answer:
When the electric cell is connected with conducting wire and the wire ends are connected to the bulb, the bulb glows immediately.

Question 4.
If you touch an electric wire carrying current you get a shock, but if on the same wire, the birds sit they do not get any shock/current. Give reason.
Answer:
When we hold the wire carrying current then the circuit is closed and the current flows from our body and enters the earth but the birds sitting on the same wire do not get any current as the circuit is not complete. If the bird touches the earth wire, it will die due to electric shock.

Question 5.
What is a switch? When we switch on an electrical appliance, what changes are we making to the circuit?
Answer:
The switch is a simple device which is used to open or close a circuit. When the switch is turned on, the gap in the circuit is closed and a complete circuit is made. Due to complete circuit, electricity starts flowing in the circuit and electrical appliance will now start working.

Question 6.
Draw a diagram showing a bulb connected to a dry cell making a closed circuit.
Answer:

Question 7.
Describe the positive and negative terminals of a cell.
Answer:
The metal cap of the cell is considered as positive terminal. It is indicated by sign (+). The metal disc or the container of the cell is the negative terminal. It is indicated by sign (-).

Question 8.
What is a fused bulb? Why it does not glow?
Answer:
Bulb has a small filament inside it. If the filament of a bulb is broken, then such a bulb with broken filament is called fused bulb. The broken filament cannot complete the circuit. As a result, current cannot flow through the filament and fused bulb does not glow.

Question 9.
What are the essential components or elements of an electric circuit?
Answer:
The essential components or elements of an electric circuit are:

• Electric sources (cell, battery).
• Electric appliances (a device for using the electric current).
• Conductor (for providing a path for the flow of current).
• Switch or key (for opening and closing the circuit).

Long Answer Type Questions

Question 1.
What is an electric circuit? Describe the various types of electric circuits with the help of diagrams.
Answer:
The path along which electricity flows is called an electric circuit. There are two different types of electric circuits:
a. Closed circuit: The circuit in which electric current flows from one terminal of a cell or battery to the other is called a closed circuit.
b. Open circuit: The circuit in which electrical contact at any point is broken is called an open circuit. No current flows in an open circuit.

Question 2.
What is a torch? How does it work?
Answer:
A torch is a portable electric lamp which uses two or more cells to light a small bulb. A torch contains a simple electric circuit. In a torch, two (or more) cells are connected to a torch bulb through a sliding switch. When the torch is needed to provide light, we close the sliding switch by pushing it forward so that the circuit is completed and the bulb lights up.

Question 3.
What are the differences between conductors and insulators?
Answer:

Question 4.
Define the following terms: (a) Dry cell and (b) Secondary cell.
Answer:
a. Dry cell: An electric cell is used to operate objects like calculators and phones. It is a small source of electricity or electric current. It is also known as a pencil cell or dry cell. A dry cell has two terminals. One side that has a small circular metal cap is the positive terminal. It is marked with positive (+) sign. The other side has a flat metal plate behaves like the negative terminal and is marked with a negative (-) sign.

There are some chemicals inside a cell. These chemicals react to produce electricity. When the chemicals get used up, the cell stops producing electricity and the appliance stops functioning. These electric cells then . have to be replaced by new cells.

b. Secondary cell: Secondary cells are the cells that provide electrical energy to the gadget as a result of chemical reactions taking place in them. In these cells, electrical energy can be stored in the form of chemical energy and the stored chemical energy can be reconverted into electrical energy. Such cells are also called rechargeable cells. Lead accumulator and nickel- iron accumulators are two examples of secondary cells. They are mainly used in mobile phones, laptops and car batteries.

Question 5.
What is the importance of electricity in our life?
Answer:
We use a variety of things in our day-to-day life that run on electricity such as fans, lights, televisions, radio, refrigerator and computer. Electricity makes it possible to light our homes, roads, offices, markets and factories even after sunset. This helps us to continue working at night. In the field of communication, electricity is also used as a medium for the transmission of signals. The different fields of our life which depend on electricity are rather wide.

Question 6.
Mention the precautions that are advised while handling electric appliances.
Answer:
While handling electric appliances, the following precautions need to be taken.

• Do not operate an electric appliance or switch with wet hands.
• While using electric appliances, always wear rubber soled footwear. Rubber being a bad conductor of electricity prevents current from passing through our body.
• In case of a fire caused by electric spark, make sure that we should not throw water on electric appliances. Always use an extinguisher to put out electrical fires.

Picture-Based Questions

Question 1.
Observe the given circuits and tell in which of them will the bulb glow?

Answer:
Bulb will glow in case (a) and (d).

Question 2.
a. Identify the objects A and B.

b. Which of them will conduct electricity?
c. Which of them is an insulator?
Answer:
a. A-Rubber; B-Metal key.
b. Metal Key
c. Rubber.

These NCERT Solutions for Class 6 Science Chapter 11 Light, Shadows and Reflections Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Light, Shadows and Reflections NCERT Solutions for Class 6 Science Chapter 11

Class 6 Science Chapter 11 Light, Shadows and Reflections Textbook Exercise Questions and Answers

Question 1.
Rearrange the boxes given below to make a sentence that helps us understand opaque objects.

Answer:

Question 2.
Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:
Air, water, a piece of rock, a sheet of aluminium, a mirror, a wooden board, a sheet of polythene, a CD, smoke, a sheet of plane glass, fog, a piece of red hot iron, an umbrella, a lighted fluorescent tube, a wall, a sheet of carbon paper, the flame of a gas burner, a sheet of cardboard, a lighted torch, a sheet of cellophane, a wire mesh, kerosene stove, sun, firefly, moon.
Answer:
a. Opaque: A piece of rock, a sheet of aluminium, a minor, a wooden board, a wall, a sheet of cardboard.
b. Transparent: Air, water, a sheet of plain glass.
c. Translucent: A sheet of polythene, a CD, smoke, fog, a sheet of carbon paper, a sheet of cellophane.
d. Luminous objects: A piece of red hot iron, a lighted florescent tube, the flame of a gas burner, a lighted torch, sun, firefly, moon.
e. Non-luminous objects: An umbrella, a wire mesh, kerosene stove.

Question 3.
Can you think of creating a shape that would give a circular shadow if held in one way and a rectangular shadow if held in another way?
Answer:
Yes, there are many things which give a circular shadow if held in one way and a rectangular shadow if held in another way. For example, a cylinder, a circular disc, etc.

Question 4.
In a completely dark room, if you hold up a mirror in front of you, will you see a right left inverted image of yourself in the mirror?
Answer:
In a completely dark room, there is no source of light so, we cannot see our right left inverted image and we can see only our image in the mirror, when light is reflected from the mirror.

NCERT Extended Learning Activities And Projects

Question 1.
Make a row of your friends – A, B, C and D, standing in a line. Let one friend stand in front facing them and holding out a mirror towards them (Fig. 11.10 of NCERT).
Now, each person can tell who they are able to see in the Mirror. A, B, C, or D.
If, A is able to see B in the mirror then, can B also see A in the mirror? Similarly, for any two pairs amongst A, B, C, or D?
If A is not able to see B in the mirror, then, is B able to see A in the mirror?
Similarly, for any two pairs amongst A, B, C, or D?
This activity tells us something about the way light travels and gets reflected from mirrors. You will learn more about this in higher classes.
Hint:
Do it yourself.

Question 2.
Daavan-Baayan – Take a comb in your right hand and bring it up to your hair and look at yourself in the mirror. There is your familiar face, grinning at you. Wait, try and find out which is the hand holding the comb, in your mirror reflection. Is it the right hand or the left? You were holding it in your right hand, isn’t it?
While a pinhole camera seems to be giving us upside down images, a mirror seems to be turning right hand into left hand and the left into right hand. We will learn more about this in the higher classes.
Hint:
Do it yourself.

Question 3.
Magic Device – In the chapter on symmetry in your Mathematics textbook, you might have made an interesting device kaleidoscope, that uses reflections. Now, let us make another device, a periscope, that uses reflections to see around corners! Ask one of your friends to stand in the corridor just out side the entrance to the classroom with a mirror in hand. Ask another friend also holding a mirror, to stand in the middle of classroom in front of the entrance. Now ask your friends to adjust their mirrors in such a way that the image of object on the other side of the corridor becomes visible to you while you are standing inside the class (Fig. 11.11 of NCERT).
You can make a simple periscope by placing two mirrors in a ‘Z’ shaped box as shown in Fig. 11.12 of NCERT.

Activity 1

Objective: To show that light travels in a straight line path.
Materials Required: A lighted candle and a rubber tube.
Procedure:

• Fix a lighted candle on a table.
• Now, stretch the rubber tube and look through it at the flame of the candle with one eye (keep the other eye closed).
  You can see the candle light through it.
• Now, bend the rubber tube a little bit and look through it at the candle flame.
• You cannot see the candle flame this time.

Observations: When the rubber tube is straight, candle flame can be seen but when it is bent, the candle flame cannot be seen.
Conclusion: Light travels in a straight line.

• Obstacle: Obstacle is the object which comes in the way of light.
• Luminous objects: Luminous objects are the objects which produce their own light. For example, sun, stars, firefly, etc.
• Non-luminous objects: Non-luminous are the objects which do not produce their own light. For example, table, bag, book, etc.
• Transparent objects: Transparent objects are the objects which allow light to pass through them easily and we can see through them clearly. Example, air, water, etc.
• Translucent objects: Translucent objects are the objects which allow the light pass through them partially and we cannot see clearly through them. Example, wax paper, butter paper, etc.
• Opaque objects: Opaque objects are the objects which do not allow light to pass through them and we cannot see at all through them. Example, wood, stone, etc.
• Shadow: Shadow is the dark patch which is formed on the other side of the objects, i. e., opposite to the light source.

Activity 2

Objective: To show the various shadows of a hand.
Material Required: A torch.
Procedure:

• Light a torch in a dark room.
• Make the light of the torch fall on the wall of the room.
• Now fold your hands in different gestures and between the torch and the wall.
• Observe the wall.

Observations: You will see the different animals shapes on the wall.

Conclusion: Shadows can mislead about the shape of the objects. We have created shadow which do not match with the objects.

Activity 3

Objective: To show the formations of a shadow.
Materials Required: A torch, white cardboard and a ball.
Procedure:

• Light a torch in a dark room.
• Keep the sheet of the white cardboard vertically in front of the torch at some distance.
• Put the ball in front of the torch, close to the cardboard.

Observations: A shadow of the ball is formed on the cardboard screen.

Conclusion: The ball acts as an obstacle in the path of light of the torch. Because of this, rays from the torch light do not go behind the ball. So, the part of the cardboard screen behind the ball does not get any light and remains dark. This dark region on the screen is the shadow of the ball.

• Umbra: Umbra is the darkest part of the shadow which occurs in the centre and where light does not reach.
• Penumbra: Penumbra is the region which surrounds the umbra where some light reaches.

Pinhole Camera: Take two boxes (one large and the other small) so that one of them can slide into the other without any gap in between them. Cut open one side of each box. Make a small hole in the middle on the opposite face of the larger box. Cut out a square shape of about 5 to 6 cm in the middle of the opposite face of the smaller box. Cover this square with a tracing paper Slide the smaller box inside the larger one in such a way that the side with the tracing paper is inside. Your pinhole camera it is ready for use. Hold the pinhole camera and look through the open face of the smaller box. Use a piece of black cloth to cover your head while looking through the pinhole camera. Now look at the object that you want to capture in the camera. Make sure that the object is in bright sunlight. Move the smaller box forward or backward till you get a sharp image on the tracing paper. A pinhole camera forms an inverted image of the object on the screen. It is used to view images of objects, such as buildings and trees and for viewing solar eclipses.

Reflection of light: It is the phenomenon in which a ray of light falls on a smooth polished surface and bounces back in the same medium.

Mirror: Mirror is a smooth, highly polished reflecting surface that reflects the light falling on it. Incident may is the ray that falls on the mirror and reflected ray is the ray which bounces back.

Class 6 Science Chapter 11 Light, Shadows and Reflections Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
Name the energy which enables us to see.
Answer:
Light.

Question 2.
Which objects allow the light to pass through them?
Answer:
Transparent.

Question 3.
Whether the moon is a luminous or a non-luminous body?
Answer:
Non-luminous.

Question 4.
What is a shadow?
Answer:
The dark patch formed on the other side of the object, opposite to the light source, is called shadow.

Question 5.
Define umbra.
Answer:
The darker part of the shadow, which always occurs in the centre, is called the umbra.

Question 6.
Define penumbra.
Answer:
The partial dark region which surrounds the umbra is called the penumbra.

Question 7.
What is the principle that a pinhole camera is based on?
Answer:
Light travels in a straight line.

Question 8.
What is reflected ray of light?
Answer:
The ray of light that comes back after suffering reflection from a mirror is called reflected ray of light.

Question 9.
Name one natural source of light.
Answer:
Sun.

Question 10.
What is the essential condition for the formation of shadow?
Answer:
A shadow is formed only when there is a surface/screen behind the opaque object.

Question 11.
Does sun change its position from morning to evening?
Answer:
Yes.

Question 12.
Does the shadow of flying bird reach the earth?
Answer:
No.

Question 13.
What happens when the pinhole of the camera is turned towards a bright object?
Answer:
A real inverted image of the object is formed on the screen.

Question 14.
What is a mirror?
Answer:
A smooth, highly polished reflecting surface is called mirror.

Question 15.
Name a device which can be used to see things on the other side of a high wall.
Answer:
Periscope.

Question 16.
Are the edges of a shadow sharp and distinct?
Answer:
Yes.

Short Answer Type Questions

Question 1.
What is light? What is the main source of light on the earth?
Answer:
Light is a form of energy which enables us to see the objects around us. The main source of light on the earth is the sun.

Question 2.
What is the difference between a luminous and a non-luminous body?
Answer:
Luminous bodies emit light on their own. Example, sun, stars, burning candle etc. Non-luminous bodies do not emit light on their own. Example, moon, earth, blackboard, etc.

Question 3.
What is a pinhole camera? How does it work?
Answer:
The device which forms a photograph like image of a bright object on a screen is called pinhole camera. When the pinhole of the camera is turned towards a bright object a real inverted image of the object is formed on the screen.

Question 4.
Explain the structure of plane mirror.
Answer:
Plane mirror is the most common type of mirror. It is a thin, flat and a smooth sheet of glass having a shiny coating of silver metal on one side. The silver coating is protected by a layer of red paint.

Question 5.
Give two important differences between the pinhole image and the shadows.
Answer:
The important differences between the pinhole images and the shadows are:

1. The pinhole image of an object is inverted whereas the shadow of an object is erect.
2. The pinhole image of an object is of the same colour as the object but the shadow of an object is always black.

Question 6.
What are the essential conditions for the formation of shadow?
Answer:
The essential conditions for the formation of shadow are:

• There should be an opaque material in the path of light.
• There should be a source of light and screen.
• The object must be placed in the path of light.

Question 7.
Why can we clearly see a burning candle through a sheet of clear glass?
Answer:
If we look at a burning candle through a sheet of clear glass, we can see the candle and its flame clearly. This is because glass is a transparent material which allows all the light coming from the candle and its flame to pass through it.

Question 8.
How will you convert a glass sheet into a translucent sheet?
Answer:
There are following two methods to convert glass sheet into a translucent sheet:

• By smearing a thin layer of oil on the glass sheet.
• By covering a side of sheet by butter paper.

Question 9.
Though we cannot see the sun through clouds on a cloudy day but still there is some sunlight all around. Give reason.
Answer:
This is because being translucent, clouds allow some of the sunlight to pass through them due to which there is light on earth even in a cloudy day.

Long Answer Type Questions

Question 1.
On the basis of the passing of light through the object, what are the different type of objects? Explain them.
Answer:
Transparent objects: The objects which allow the light to pass through them easily and through which we can see clearly are known as transparent objects. Air, water, glass, etc., are transparent objects.

Translucent objects: The objects which allow the light to pass through them partially and we cannot see clearly through them are called translucent objects. Thin paper, oily paper etc., are translucent objects.

Opaque objects: The objects which do not allow the light to pass through them at all are called opaque objects. Walls, books, etc., are opaque objects.

Question 2.
What is a shadow? Write the characteristics of a shadow.
Answer:
The dark patch formed on the other side of objects, opposite to the light source, is called a shadow. The characteristics of a shadow are:

• The shadow of an object is formed on the opposite side of the light source.
• The position of the shadow changes with the position of the light source. This may be seen that as the position of the sun changes from morning to evening, the length and direction of the shadow also changes.
• The position of the shadow changes with the movement of the object.

Question 3.
What are the advantages and disadvantages of a pinhole camera?
Answer:
Advantages:

• In pinhole camera not focusing is required.
• There is no lens in pinhole camera. Therefore, the image is free from spherical and chromatic aberrations.

Disadvantages:

• The image formed does not give any details.
• Image is obtained on the screen so no permanent record of the image can be obtained.

Question 4.
Explain real images and virtual images with examples.
Answer:
The image which can be obtained on a screen is called a real image. In a cinema hall, we see the images of actors on the screen. So, the images formed on a cinema screen are an example of real image. Real images are formed when light rays from an object actually meet at a point after reflection from a mirror.

The image which cannot be obtained on a screen is called a virtual image. A virtual image can be seen only by looking into a mirror. The image of our face formed by a plane mirror cannot be obtained on a screen. It can be seen only- looking into the mirror. So, the image of our face in a plane mirror is an example of a virtual image.

Picture-Based Questions

Question 1.
a. Identify the device shown below.

b. What type of image is formed in in it?
Answer:
a. It is a pinhole camera.
b. Real and inverted imaged.

Question 2.
a. Name the device shown here.

b. Is the image formed here inverted or erect?
c. Give one use of this device.
Answer:
a. Periscope.
b. Erect image.
c. It is used in submarines to see things above water surface.

These NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and their Surroundings Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

The Living Organisms and their Surroundings NCERT Solutions for Class 6 Science Chapter 9

Class 6 Science Chapter 9 The Living Organisms and their Surroundings Textbook Exercise Questions and Answers

Question 1.
What is a habitat?
Answer:
The surroundings where animals dwell in comfort zone is called a habitat. The animals depend on their habitat for their shelter, food, water and other needs. Example: Lion lives in a forest.

Question 2.
How are cactus adapted to survive in a desert?
Answer:
A cactus is able to survive in a desert as it is adapted to hot and dry condition of the desert. To survive in a desert, the cactus has the following adaptations:

• It has long roots that go deep inside the soil for absorbing water.
• Its leaves are present in the form of spines to prevent water loss through transpiration.
• Its stem is covered with a thick waxy layer to retain water.

Question 3.
Fill up the blanks
a. The presence of specific features which enables a plant or an animal to live in a particular habitat is called ……………….
b. The habitats of the plants and animals that live on land are called ………………. habitats.
c. The habitats of plants and animals that live in water are called ………………. habitats.
d. Soil, water and air are the ………………. factors of habitats.
e. Changes in our surroundings that make us respond to them are called ……………….
Answer:
a. adaptation
b. terrestrial
c. aquatic
d. abiotic
e. stimuli

Question 4.
Which of the things in the following list are non-living?
Plough, Mushrooms, Sewing machine, Radio, Boat, Water hyacinth, Earthworm
Answer:
Plough, Sewing machine, Radio and Boat.

Question 5.
Give an example of a non-living thing which shows any two characteristics of living things.
Answer:
Car is an example of non-living thing which shows characteristics of living things.

• It can move from one place to another.
• It also requires energy just like living things.

Question 6.
Which of the following non-living things were once part of a living thing?
Butter, Leather, Soil, Wool, Electric Bulb, Cooking oil, Salt, Apple, Rubber
Answer:
Butter, leather, wool, cooking oil, apple and rubber were once part of a living thing.

Question 7.
List the common characteristics of the living things.
Answer:
Some common characteristics of the living things are:

• They require food.
• They respire and excrete waste material.
• They respond to stimuli in their environment.
• They reproduce to maintain their number.
• They move from one place to another.
• They grow and die.

Question 8.
Explain why speed is important for survival in grasslands for animals that live there. (Hint: there are few trees or places for animals to hide in grasslands habitats.)
Answer:
In grasslands, mainly grasses are found. Trees are very few in number. Predators such as lions, tigers, etc., that feed upon other animals are commonly found in these regions. It is very easy for these predators to locate their prey in grass.

Therefore, to protect themselves from these predators animals adapt themselves by increasing their speed. The increased speed of the animals help the weaker animals to escape their predator, thereby protecting themselves and increasing the chances for their survival.

NCERT Extended Learning Activities And Projects

Question 1.
Many magazines and newspapers talk about possibility of life outside the Earth. Read these articles and have a discussion in the class about what could be defined as life outside Earth.
Hint:
Do it yourself.

Question 2.
Visit a local zoo and find out what special arrangements are made for the animals that have been brought there from different habitats.
Hint:
Do it yourself.

Question 3.
Find out where are the habitats of the polar bear and the penguin. For each animal, explain two ways in which it is well adapted to its habitat.
Hint:
Both polar bears and penguins are found in polar regions covered with snow. They have thick fur and fatty layer under their skin to protect them from cold. They are also good swimmers as swimming keeps their body warm. They have the body colour that helps them in hiding in the white background of the snow.

Question 4.
Find out which animals live in the foot-hills of the Himalayas. Find out if the types and varieties of animals and plants changes as one goes higher into the mountain regions of the Himalayas.
Hint:
Snow leopards, takins. musk deer, red pandas, tigers, black bear, elephant, shrews, giant panda, golden eagle, alpine, etc., are found in this region. The biodiversity changes with change in altitude.

Question 5.
Make a habitat album. Try to obtain pictures of animals and plants that you have listed in Activity 1 (of NCERT textbook) and paste these under different habitat sections in the album. Draw the leaf shapes and structures for trees found in these different regions and include these in the album. In addition, draw the patterns of branching found in trees of these different regions and include these also in the album.
Hint:
Do it yourself.

Activity 1

Objective: To show the effect of some abiotic factors on the germination of seeds to form young plants.
Material Required: Moong seeds, water.
Procedure:

• Take some moong seeds.
• Keep some dry moong seeds completely submerged in water for a few days.
• Keep them soaked in water for a few days.
• Keep the soaked and wet moong seeds in sunlight for a few days.
• Keep some soaked and wet moong seeds in a completely dark place for a few days.
• Keep some soaked and wet moong seeds in a very cold place, like a refrigerator, for few days.
• Observe them carefully.

Observations: After a few days we will observe that:
i. The dry moong seeds do not germinate at all due to the lack of water and water is essential for the germination of seeds.
ii. The moong seeds submerged in water also do not germinate showing that air is also necessary for the growth of plants.
iii. The wet moong seeds kept in sunlight germinate and grow maximum showing that the sunlight is necessary for the growth of plants.
iv. The wet moong seeds kept in dark place do not grow at all.
v. The wet moong seeds kept in very cold place grow very slow showing that the temperature (heat or warmth is necessary for the growth of plants).

Conclusion: The abiotic factors such as water, air, sunlight and temperature are very important for the growth of plants.

A habitat can be classified into three major types:
i. Terrestrial Habitat: Terrestrial habitat is the habitat for living beings who live on land, for example, humans.
ii. Aquatic Habitat: Aquatic habitat is the habitat for living beings who live in water, for example, fish.
iii Aerial Habitat: Aerial habitat is the habitat for living things who spend most of their life in air, for example, birds.

• Adaptation: Adaptation is the presence of some specific features in the body which help a plant or an animal to live or survive in a particular condition. For example, camel is adapted to live in desert whereas penguin is adapted to live in very cold places near water.
• Xerophytes: Xerophytes are the plants like cactus, agave, etc., which grow in deserts or in very dry places where there is scarcity of water.
• Nocturnal: It is an adaptation in many desert animals who remain inactive during day time and become active during the night to prevent the loss of water from their body.
• Hibernation: Hibernation is the long sleep for eight to nine months in a year. Certain animals hide themselves in burrows with gelatinous secretions and hibernate for long time.

Some major terrestrial habitats are described below:
i. Deserts: These-ere extremely hot and dry habitats with scarcity of water. There are desert animals like rats and snakes, which do not have long legs like a camel has. To stay away from the intense heat during the day, they stay in burrows deep in the sand and come out only during the night, when it is cooler. Desert plants lose very little water through transpiration as the leaves in desert plants are either absent, very small, or they are in the form of spines. Photosynthesis in these plants is usually carried out by the stems. The leaves and stem of desert plants is also covered with a thick waxy layer, which helps to retain Most desert plants have roots that go very deep into the soil for absorbing water.

Activity 2

Objectives: To show that a desert plant such as cactus loses very little water through transpiration.
Materials required: A potted cactus plant and a potted leafy plant.
Procedure:

• Take a potted cactus plant and a potted leafy plant and tie some parts of both the plants with polythene bags separately.
• Keep both the plants in sunlight for few hours.
• Observe both the plants for a few days.

Observations: Only a very small amount of water droplets are present in the polythene bag tied to the cactus plant but more water drops are present in the polythene bag tied to the leafy plant.
Conclusion: Because of the process of transpiration, the cactus plant loses very little water.

ii. Mountains: These habitats are normally very cold and windy. In some areas, snowfall may take place in winters. The trees in such areas are normally cone shaped and have sloping branches with needle-like leaves. This helps the rainwater and snow to slide off easily. Animals living in the mountain regions have thick skin or fur to protect them from cold. For example, yaks have long hair to keep them warm. Snow leopard has thick fur on its body. The mountain goat has strong hooves for running up the rocky slopes of the mountains.

iii. Grasslands: These are the places covered with wide fields of grasses and sometimes forests. Animals like lion and deer are found in grasslands. Lions have long claws in their front legs and is light brown in colour. It helps it to hide in dry grasslands when it hunts for prey. The eyes in front of the face allow it to locate its prey accurately. A deer also lives in grasslands. It has strong teeth for chewing hard plant stems of the forest. It has long ears to hear movements of predators. The eyes on the side of its head allow it to look in all directions for danger. The speed of the deer helps them to run away from the predators.

Some major aquatic habitats are described below:
i. Oceans and seas: These are large water bodies that have saline (salty water). Sea animals have streamlined bodies to help them move easily in water. There are some sea animals, like squids and octopus, which do not have streamlined shape. They stay deeper in the ocean, near the seabed. Sea animals have gills to help them use oxygen dissolved in water. Dolphins and whales breathe in air through nostrils or blowholes that are located n the upper parts of their heads. This allows them to breathe in air when they swim near the surface of water. They can stay inside the water for a long time without breathing.

ii. Ponds and Lakes: These are small freshwater bodies. In aquatic plants, roots are much reduced in size and their main function is to hold the plant in place. The stems of these plants are long, hollow and light. The leaves and flowers, float on the surface of water. Some aquatic plants are completely submerged in water. Some of these plants have narrow and thin ribbon-like leaves. Frogs can stay both inside the water as well as move on land. They have strong back legs that help them in leaping and catching their prey. They have webbed feet which help them swim in water.

Characterises of Living organisms:

• Food: All living organisms, whether plans or animals, eat food to get energy to live.
• Growth: All living beings grow with times. Plants grow from a seed into a big tree.
• Response to stimuli: Changes in the surroundings are called stimuli. Living organisms react to various stimuli.
• Movement: All organisms moves. Humans and animals can move from one place to another. Plants move by bending towards light or curling their leaves as in mimosa plant.
• Respiration: Respiration is the process in which food taken by an organism combines with oxygen to release energy. In this process carbon dioxide is given out.
• Excretion: Excretion is the process of removal of waste substances from the body of living things.
• Reproduction: Reproduction is the process by which living things produce more organisms of their own kind. This process takes place in many different ways, for different organisms.

Activity 3

Objective: To show that living things produce more of their own kind through reproduction.
Materials required: A rose plant.
Procedure:

• Take a cutting from the plant which should have some buds on it.
• Burry its lower part into the soil.
• Observe it for a few days.

Observations: The cutting develops roots and grows into a new plant.
Conclusion: Plants reproduce to give new plants.

Class 6 Science Chapter 9 The Living Organisms and their Surroundings Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
Name some biotic components of the environment.
Answer:
Plants, animals, human beings, microorganisms.

Question 2.
Name some abiotic components of environment.
Answer:
Rocks, air, temperature, water, etc.

Question 3.
What things does a habitat provide to the living organisms?
Answer:
Food, shelter, favourable climate and conditions to survive.

Question 4.
List out the different types of habitats.
Answer:

• Terrestrial habitat
• Aquatic habitat

Question 5.
Name a few plants that live in ponds.
Answer:
Hydrilla, lotus, hyacinth, etc.

Question 6.
Which is the most common adaptation found in all animals living in cold places like mountains?
Answer:
They have thick skin or fur to protect themselves from cold environment.

Question 7.
Name two aquatic plants which are completely submerged in water.
Answer:
Lily and lotus.

Question 8.
What is common in all fishes?
Answer:
They have gills, streamlined body, fins and tails.

Question 9.
How does gills help a fish?
Answer:
Gills help to use oxygen dissolved in water.

Question 10.
Name an animal who uses its skin for the process of respiration.
Answer:
Earthworm.

Question 11.
Name some terrestrial habitats.
Answer:
Deserts, mountains, grasslands, forests, etc.

Question 12.
Name some aquatic habitats.
Answer:
Oceans, ponds, lakes, etc.

Question 13.
Define excretion.
Answer:
The process of getting rid of the body waste by the living organisms is known as excretion.

Question 14.
What is reproduction?
Answer:
The process by which living organisms produce more of their own kind is called reproduction.

Question 15.
What are blowholes?
Answer:
The organs by which dolphins or whales breathe in air are called blowholes or nostrils.

Short Answer Type Questions

Question 1.
What is the difference between terrestrial habitat and aquatic habitat? Give examples of each.
Answer:
Terrestrial Habitat:
The habitat of the plants and animals that live on land is called terrestrial habitat. Example, plants like banyan, pine, etc., and animals like elephant, lions, etc., live in the terrestrial habitats.

Aquatic Habitat:
The habitat of plants and animals that live in water is called aquatic habitat. Example, plants like Hydrilla, lotus, etc. and animals like fish and octopus live in aquatic habitats.

Question 2.
Define the term adaptation.
Answer:
The presence of specific features of certain habits which enable a plant or an animal to live in its surroundings is called adaptation.

Question 3.
Describe a desert region.
Answer:
The desert region is very hot in day time and cold at night. A very little amount of water is present in desert. Animals that live in deserts remain inactive during day and become active at night. Camels, lizards, snakes, etc., are some animals that live in desert.

Question 4.
What are the adaptations of fish that make help them to live in water?
Answer:

• The streamlined body of the fish helps in movement in water.
• The slippery scales/skin on the body of fish protect their body.
• They have flat fins and tails which help them to swim, change direction and to keep the body balance.
• Their gills help them to breathe in water.

Question 5.
What features of mountain goats help them to live in cold climate?
Answer:
a. The mountain goats have long hair to protect them from cold and keep warm.
b. The mountain goats have strong hooves for running up the rocky slopes of mountains for grazing.

Question 6.
Why do we need abiotic components?
Answer:
The abiotic components like air, water, light and heat are very important for the growth of plants. These abiotic components are also very important for the growth and the development of animals.

Question 7.
What are the various adaptations of carnivorous animals who live in grasslands?
Answer:

• Sharp and long claws in their front legs to catch, hold and tear the body of their prey.
• Light brown colour or patchy body helps them to hide them in dry grass.
• The eyes in front of the face help in locating their prey.
• Long and strong canines (front teeth) help them in tearing the body of their prey.

Question 8.
Write the important adaptations for aerial animals.
Answer:

• They have hollow bones containing air cavities to make the body light.
• Presence of feathers and wings to fly. The forelimbs are modified into wings for flying.
• Eye sight is very sharp.
• Joints in the bones are completely fused.

Question 9.
Write four main characteristics of living things.
Answer:

• All living things need food to grow and get energy.
• Living things respire to get energy.
• Living things excrete body waste.
• Living things respond to stimuli.

Long Answer Type Questions

Question 1.
What the adaptations of plants who grow in deserts?
Answer:
The plants that grow in deserts show adaptations in their roots, stems and leaves.

• Roots: Their long roots are spread to the deeper layers of the soil so that water can be absorbed.
• Stem: They have spongy stem to store water. The green stem takes over the functions of leaves. Thick waxy coating of the stem develops to prevent the loss of water due to the intense heat.
• Leaves: Their leaves are reduced to spines in order to reduce the loss of water from the surface of leaves.

Question 2.
Write the adaptations in snow leopard which helps it to live in extremely cold places.
Answer:

• The thick fur on the body of snow leopard protects it from cold and keeps it warm. It has fur on its feet and toes too. This protects its feet from cold when it walks on the snow.
• The thick layer of fat beneath its skin for insulation protects it from cold.
• Snow leopard has a rounded body and small ears to keep the body surface area to a minimum. This reduces the heat loss from the body of snow leopard.
• The snow leopard has big feet to spread the weight on snow and prevent it from sinking into the soiled snow.

Question 3.
How is a deer is adapted to forest habitat? Explain.
Answer:

• The deer has eyes on the sides of its head which enable it to see in all directions at the same time. The all round vision of deer helps it to see animals like lion, in all the area around it.
• The deer has big ears for good hearing. The big ears help the deer to hear the movements of predators like lion very easily.
• The deer is fast and agile animal. The speed of deer helps it to run away from the predators like lion which try to catch it.
• The deer has brown colour which helps it to hide in dry grasslands without being noticed by lion, etc.
• The deer has strong teeth for chewing hard plant stems of the forest.

Picture-Based Questions

Question 1.
a. Identify the habits A and B.

b. Given an example of an animal found in each of these habitats.
c. Write one adaptation of plants found in each of these regions.
Answer:
a. A – Desert; B – Mountain
b. Lizard is found in desert and snow leopard on mountains.
c. Desert plants have leaves reduced to spines.
Plants in mountains have needle like leaves.

Question 2.
a. Identify the living organism shown below.

b. What is its habitat?
c. Write one adaptive feature of this organism.
Answer:
a. Bird.
b. Aerial habitat.
c. Its forelimbs are modified into wings that help it in flying.

These NCERT Solutions for Class 6 Science Chapter 10 Motion and Measurement of Distances Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Motion and Measurement of Distances NCERT Solutions for Class 6 Science Chapter 10

Class 6 Science Chapter 10 Motion and Measurement of Distances Textbook Exercise Questions and Answers

Question 1.
Give two examples each of modes of transport used on land, water and air.
Answer:
Mode of transport on land: Buses, railways
Mode of transport in water: Boats, ships Modes of transport in air: Airplanes, gas balloons.

Question 2.
Fill in the blanks:
a. One metre is ……………… cm.
b. Five kilometre is ……………… m.
c. Motion of a child on a swing is ………………
d. Motion of the needle of a sewing machine is ………………
e. Motion of wheel of a bicycle is ………………
Answer:
a. 100
b. 5000
c. oscillatory motion
d. periodic motion
e. circular motion

Question 3.
Why can a pace or a footstep not be used as a standard unit of length?
Answer:
The pace or a footstep has different lengths for different persons. So they cannot be used as a standard unit of length.

Question 4.
Arrange the following lengths in their increasing magnitude:
1 metre, 1 centimetre, 1 kilometre, 1 millimetre.
Answer:
1 millimetre > 1 centimetre > 1 metre > 1 kilometre

Question 5.
The height of a person is 1,65 m. Express it into cm and mm.
Answer:
a. 165 cm, as one metre = 100 cm
= 1.65 × 100 cm = 165 cm
b. 1.65 × 100 × 10 mm = 1650 mm

Question 6.
The distance between Radha’s home and her school is 3250 m. Express this distance into km.
Answer:
As one km = 1000 m
So, 3250 m = 3250/1000 km = 3.250 km

Question 7.
While measuring the length of a knitting needle, the reading of the scale at one end is 3.0 cm and at the other end is 33.1 cm. What is the length of the needle?
Answer:
Length of needle = 33.1 cm – 3.0 cm = 30.1 cm.

Question 8.
Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on.
Answer:
The motion of a bicycle and a ceiling fan are in circular motion. Thus both show similar motion. But the ceiling fan moves without changing its position while the bicycle moves with changing its position with time. This shows dissimilarities between two motions.

Question 9.
Why would you not like to use a measuring tape made of an elastic material like rubber to measure distance? What would be some of the problems you would meet in telling someone about a distance you measured with such a tape?
Answer:
Elastic material will not give accurate measurement because its stretches in length and reduces in size when not stretched. While telling the measurement taken with an elastic tape, we have to tell whether the tape was stretched and by how much, which is very difficult.

Question 10.
Give two examples of periodic motion.
Answer:
The motion of pendulum of clock and the motion of child on a swing are the two examples of periodic motion.

NCERT Extended Learning Activities And Projects

Question 1.
Draw a map of your classroom. Roll a ball on the floor. In your map mark the points where the ball started and where it stopped. Show’ also the path it moved along. Did the ball move along a straight line?
Hint: The ball will move in a straight line unless a force is applied on it.

Question 2.
Using string and a scale, let each student measure the length of his/her foot. Prepare a bar graph of the foot length measurements that have been obtained for the whole class.
Hint: Do it yourself.

Activity 1

Objective: To measure the length of a table using hand span.
Materials Required: A table.
Procedure:

• Stretch your hand for measuring the length of the table.
• Move it along the length of the table.
• Count the number of hand spans you move along the length.
• Repeat the process thrice.

Observations: The number of hand spans is …………… each time.
Conclusion: The length of the table is …………… hand spans.

Measurement of Length: The SI unit of length is metre (m). While measuring length, following points should be kept in mind:
i. The scale should be placed along the length of object.
ii. The scale should be placed exactly in a straight line.
iii. Reading should be taken from the zero mark of the scale and not from its edge.

Activity 2

Objective: To measure the length of a curved line using a thread.
Materials Required: A thread.
Procedure:

• Draw a curved line on a sheet of paper.
• Place the paper on a smooth surface.
• Mark the beginning point of the line as point A and end point as point B.
• Take the thread and place it along the line keeping it touch with the help of your thumb or forefinger.
• Put the thread on the line from point A to point B.
• Now, stretch the thread along a metre scale and measure the length between the two marks.

Conclusion: The length of the curved line is ………………. cm.

Rest: Rest is when a body does not change its position over time.
Motion: Motion is when an object changes its position over time. There are various types of motion:
i. Linear Motion: Linear motion is the motion when a body moves along a straight line path. Eg., a car moving on straight road.
ii. Circular Motion: Circular motion is the motion when a body moves along a circular path. Eg., motion of the hands of a clock.

iii. Rotational Motion: Rotational motion is the motion when an object turns about a fixed axis. Eg., rotation of a top and the earth.
iv. Periodic Motion: Periodic motion is the motion which repeats itself after regular intervals of time. Eg, motion of a pendulum.

Activity 3

Objective: To classify the following objects at rest or in motion.
House, table, clock, a school bag, a stone lying on the ground, a flying bird, second’s hand of the clock, a moving train, a child on the swing, heart beat in a healthy person and a spin ball in cricket.
Observations :

• Objects at rest: House, table, clock, a school bag, a stone lying on the ground.
• Objects in motion: Flying bird, second’s hand of clock, moving train, child on a swing, heartbeat in a healthy person, spin ball in cricket.

Conclusion:

• The objects at rest do not change their position with respect to time.
• The objects in motion change their position with the time.

Class 6 Science Chapter 10 Motion and Measurement of Distances Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
In prehistoric times, which animals were used as means transport?
Answer:
Horses, camels, oxen.

Question 2.
Name two water transports and two air transports.
Answer:
Boats and ships are the means of water transport. Airplanes and hot air balloons are the means of air transport.

Question 3.
What is cubit?
Answer:
Cubit is a unit of measurement which includes the distance from elbow to the tip of the middle finger.

Question 4.
What is the standard unit of measuring length?
Answer:
Metre is the standard unit of measuring length.

Question 5.
What is the use of a ruler?
Answer:
Ruler is used to measure lengths of straight objects.

Question 6.
When is an object said to be in rest?
Answer:
When an object does not change its position with respect to time and the observer the object is said to be in rest.

Question 7.
When is an object said to be in motion?
Answer:
When the object changes its position with respect to time and the observer, the object is said to be in motion.

Question 8.
Which motion takes place in fixed direction?
Answer:
Linear motion.

Question 9.
Define periodic motion.
Answer:
The motion which repeats itself after regular intervals of time is called periodic motion.

Question 10.
Name the types of motion which a body undergoes during rolling.
Answer:
Translatory and rotatory motion.

Question 11.
Why do people need transport?
Answer:
To move from one place to another.

Question 12.
Which invention made a great change in the modes of transport?
Answer:
Invention of wheel.

Question 13.
Were one cubit or one pace accurate unit of measurement?
Answer:
No.

Question 14.
Which measuring device is required to measure the chest of a person?
Answer:
Measuring tape.

Question 15.
Which type of motion can be seen in the ball rolling on ground?
Answer:
Linear motion.

Short Answer Type Questions

Question 1.
Which units of measurement were derived from the length of some parts of human body?
Answer:
A pace or a footstep, a cubit that is the distance from the elbow to the tip of the middle finger, hand span and width of the fingers.

Question 2.
Define standard unit of measurement.
Answer:
A unit of measurement which has a fixed value and does not change from person to person or place to place is called a standard unit of measurement.

Question 3.
Which precautions should be taken while measuring the length with a metre scale?
Answer:

• The initial point of distance must coincide with the zero reading of metre scale.
• The eye should be kept in line with the point of measurement.
• The scale should be perfectly horizontal.

Question 4.
What is rotational motion? Give two examples of rotational motion.
Answer:
When an object turns about a fixed axis, it is called rotational motion. A spinning top and rotation of the earth on its axis are the examples of rotational motion.

Question 5.
Which types of motion are shown by a bicycle?
Answer:
Suppose a bicycle is moving on a straight road. The wheel of bicycle is rotating on its axis and also moving forward in a straight line path. So, a bicycle on a straight road has two types of motion: rotational motion as well as rectilinear motion.

Question 6.
Give a method to measure the thickness of one rupee coin.
Answer:
Collect ten one rupee coins and stack them. Measure the height of the stacked coins in millimetres. Tick the thickness of ten coins. Divide this thickness by 10. You will get the average thickness of one coin.

Question 7.
How does merry-go-round show two types of motion?
Answer:
Merry go round as a whole shows rotatory motion as it turns on its own axle. But the outer part of merry go round on which the children sit shows circular motion. Thus, the child sitting on a merry go round will exhibit circular motion.

Question 8.
How can a measured length be expressed?
Answer:
A measured length can be expressed by

• a number describing the numerical value.
• the unit in which that quantity is measured.

Question 9.
What are the advantages of using a measuring scale?
Answer:

• The scale can be easily taken from one place to another,
• The scale does not change during measurements.

Long Answer Type Questions

Question 1.
What is the standard unit of measurement? Why is it required?
Answer:
A unit of measurement which has a fixed value and which does not change from person to person or place to place, is called a standard unit of measurement. It is required to make our judgments more reliable and accurate. For proper dealing, measurement should be same for everybody. Thus, there should be uniformity in measurement. For the sake of uniformity we need a common set of units of measurements.

Question 2.
What is the proper way of using a measuring scale?
Answer:
a. The scale should be placed along the length to be measured. The scale should be placed very close to the object to be measured.

b. Keep your eye in line with the point of measurement. If the eye is not in line with the point of measurement, the measured length will be either shorter or longer than the actual length.

c. Do not start measurement from the worn out or damaged end of the scale. If the zero end of the scale is damaged, start measurement from some other mark of the scale. Then the actual length of the object is equal to the difference between the readings at the two points.

Question 3.
Define motion. Explain the different types of motion.
Answer:
When an object changes its position with respect to time and observer, it is said to be in motion. The different types of motion are:
a. Rectilinear motion: When a body moves along a straight line, it is called rectilinear motion. Motion of train on straight track and motion of a falling stone are the examples of rectilinear motion.

b. Circular motion: When a body moves along a circular path, it is called circular motion. Movement of the earth around the sun and movement of the moon around the earth the examples of circular motion.

c. Rotational motion: When an object turns about a fixed axis, it is called rotational motion. Spinning of top and spinning of the earth on its axis are the examples of rotational motion.

d. Periodic motion: The motion which repeats itself after regular intervals of time, is called periodic motion. Motion of second’s hand of clock and the revolutions of earth around the sun are the examples of periodic motion.

Picture-Based Questions

Question 1.
a. Identify the device shown below.

b. What type of motion does it exhibit?
c. Give one more example of such motion.
Answer:
a. Pendulum
b. Periodic motion
c. Motion of a child on a swing is periodic.

Question 2.
a. Identify the devices A and B.

b. What are they used for?
c. What is the SI unit of the quantity measured by these devices?
Answer:
a. A – Measuring scale.
B – Measuring tape.
b. They are used to measure length of objects.
c. Metre (m).

These NCERT Solutions for Class 6 Science Chapter 8 Body Movement Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Body Movement NCERT Solutions for Class 6 Science Chapter 8

Class 6 Science Chapter 8 Body Movement Textbook Exercise Questions and Answers

Question 1.
Fill in the blanks:
a. Joints of the bones help in the ……………. of the body.
b. A combination of bones and cartilage from the ……………. of the body.
c. The bones at the elbow are joined by a ……………. joint.
d. The contraction of the ……………. pulls the bones during movement.
Answer:
a. movement
b. skeletal
c. ball
d. muscles

Question 2.
Indicate true (T) and false (F) among the following sentences.
a. The movement and locomotion of all animals is exactly the same.
b. The cartilages are harder than bones.
c. The finger bones do not have joints.
d. The forearm has two bones.
e. Cockroaches have an outer skeleton.
Answer:
a. False
b. False
c. True
d. True
e. True

Question 3.
Match the items in Column I with one or more items of Column II.

Answer:
1. (d),
2. (a),
3. (e),
4. (f),
5. (b).

Question 4.
Answer the following questions.
a. What is a ball and socket joint?
b. Which of the skull bones are movable?
c. Why can our elbow not move backwards?
Answer:
a. The rounded end of bone fits into the cavity of the other bone. Such a joint allows movements in all directions. This type of joint is called ball and socket joint.
b. The facial bones of our skull comprise upper and lower jaw, in which lower jaw is movable.
c. Our elbow has hinge joint. These joints allow movement only in one plane like a door hinge and not more than 180 degrees.

Activity 1

Objective: To show that we are able to bend or rotate our body only at joints.
Materials Required: Wooden scale arid ropes threads.
Procedure:

• Straighten your right arm.
• Ask your teacher or friend to tie a wooden scale lengthwise under the arm in such a way that the elbow is in the centre.

Now, try to bend the arm.
Observations: After tying the scale, we cannot bend the arm at the elbow.
Conclusion: We can see that we can bend or move our body at joints only.

i. Fixed Joints: Fixed joints are the joints where two bones are held so tightly together by strong fibres that they cannot move at all. Fixed joints occur in our skull.
ii. Synovial Joints: Synovial joints are freely movable joints which allow free movements in one or more directions. Following are some synovial joints:

a. Ball and Socket Joint: Ball and socket joint allows movement of the bones in all the directions. Hip joint and shoulder joint have ball and socket joint.

Activity 2

Objective: To make a ball and socket joint.
Materials Required: A strip of paper, a rubber or plastic ball.
Procedure:

• Roll the paper strip into cylindrical shape.
• Make a hole in ball and push the paper cylinder into it.
• Put the ball in a small bowl. The ball and socket joint is ready.

Observation: This formation allowed free movement of the paper in the ball.
Conclusion: The rounded end of one bone fits into the cavity of the other bone is called the ball and socket joint.

b. Pivotal Joint: Pivotal joint allows movement in many planes. Skull makes such joint with the first two vertebrae.
c. Hinge Joint: Hinge joint allows movement only in one direction. Fingers have this type of joint.
d. Gliding Joint: Gliding joint allows a limited movement due to sliding nature of cartilages. Movable joints of the backbone are gliding joints.

Skeletal System: Skeletal system is the framework of bones and cartilages which supports the body. It consists of the following parts:
i. Skull: Skull is the bony part of head which is made of 22 bony plates joined together.

ii. Backbone: Backbone is a long hollow, rod like structure running from the neck to the hips inside the body.
Vertebrae are the small bones which make up the backbone.
iii. Ribcage: Ribcage is 12 pairs of ribs along with backbone making a cone-shaped cage which protects the lungs and the heart.

Activity 3

Objective: To feel the chest bones and the backbone.
Procedure:

• Take a deep breath and hold it for a little while. Feel your chest bones and the backbone by gently pressing the middle of the chest and back at the same time.
• Count as many ribs (bones of the chest) as possible.
• Observe the given figure carefully and compare with what you feel of the chest bones.
• We see that the ribs are curiously bent.
• Ask a friend to touch his toes without bending his knees.
• Put your fingers at the centre of his back. Feel some long and hard structure.
• Starting from the neck, move your fingers downwards on the back of your friend.

Observation: Rib join the chest bone and the backbone together to form a box. This is called the rib cage. Some important internal parts of our body lie protected inside this cage.
Conclusion: Backbone is made of many small bones. The rib cage is joined to these bones.

iv. Carpels: These are the several small bones forming the wrist.
v. Tarsals: These are the several small bones forming the ankle.
vi. Pectoral bones: These are the bones forming the shoulder join.
vii. Pelvic bones: These are the bones forming the hip joint.

Muscles can be classified into two types: i. Voluntary muscles: These are the muscles that can be moved with your own will. For example, you can move your hand up and down with your own will as it has voluntary muscles.
ii. Involuntary muscles: These are the muscles that cannot be moved by your will. For example, you cannot move the muscles of your ear pinna or the muscles of your scalp by your will.

Cartilage: Cartilage is a solid but semi-rigid and flexible tissue which smoothens bones surfaces at joints. It also helps in forming the framework of the body called skeleton. Nose, ear, trachea and larynx have cartilage.

Gait of Animals
i. Earthworm: The body of an earthworm is made up of many rings joined end to end. It lacks bones. It has muscles which help to extend and shorten the body. During movement, it first extends the front part of the body, keeping the rear portion fixed to the ground. Then it fixes the front end and releases the rear end. It then shortens the body and pulls the rear end forward. In this way, the earthworm can move through soil. Its body secretes a slimy substance to help the movement.

ii. Snail: It has a shell which is the outer skeleton of the snail, but is not made of bones. A thick structure, called foot, and the head of the snail may come out of an opening in the shell. The foot is made of strong muscles. The wavy motion of the foot can be seen in a snail.

iii. Cockroach: Cockroaches walk, climb as well as fly in the air. They have three pairs of legs that help in walking. Their body is covered with a hard, outer skeleton is made of number of plates joined together that permit movement. There are two pairs of wings attached to the body that help in flying.

iv. Birds: Birds fly in the air and walk on the ground. Some birds such as ducks and swans can also swim in water. Their bones are hollow and light. The bones of the hind limbs are used for walking and perching. The forelimbs are modified as wings. The shoulder bones are strong. The breastbones are modified to hold muscles of flight which are used to move the wings up and down.

v. Fish: The head and tail of the fish are smaller than the middle portion of the body. This body shape is called streamlined. This shape allow the fish to move in water. The skeleton of the fish is covered with strong muscles. The fish forms a curve while swimming. Then, quickly, the body and tail curve to the other side. This makes a jerk and pushes the body forward. This is helped by the fins of the tail. Fish also have other fins on their body which mainly help to keep the balance of the body and to keep direction while swimming.

vi. Snake: Snakes have a long backbone and many thin muscles. Muscles also interconnect the backbone, ribs and skin. The snake’s body curves into many loops, each loop giving it a forward push by pressing against the ground. The snake moves forward very fast and not in a straight line. It is called slithering movement.

Class 6 Science Chapter 8 Body Movement Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
Name two types of joints.
Answer:
Fixed joints and movable joints

Question 2.
Name four movable joints.
Answer:
a. Ball and socket joint
b. Pivotal joint
c. Hinge joint
d. Gliding joint

Question 3.
Give two examples of hinge joint.
Answer:
Elbow joint and knee joint.

Question 4.
Name the two main parts of skull.
Answer:
Cranium and facial bones.

Question 5.
What is backbone made of?
Answer:
The backbone is made up of small bones known as vertebrae.

Question 6.
Which internal organs are protected by rib cage?
Answer:
Heart, lungs and liver.

Question 7.
What is patella?
Answer:
Knee cap is called patella.

Question 8.
Which two types of muscles does an earthworm’s body have?
Answer:
Circular muscles and longitudinal muscles.

Question 9.
What is slithering?
Answer:
The movement of snake is called slithering.

Question 10.
Name an animal which swims in water by moving its tail from side to side.
Answer:
Fish.

Short Answer Type Questions

Question 1.
Where are these joints located in your body?
a. Ball and socket joint
b. Pivotal joint
c. Hinge joint
d. Gliding joint.
Answer:
a. Between shoulder and upper arm; between thigh and hip
b. Between the first vertebrae and axis vertebrae
c. Knee joint
d. Movable joints of backbone

Question 2.
What is a cartilage? Where is it present?
Answer:
A solid but semi-rigid and flexible tissue is called cartilage. It smoothens bone surfaces at joints. It is present in the nose tip, ear pinna, trachea and larynx.

Question 3.
Define endoskeleton with example.
Answer:
The skeleton which lies inside the body and is covered by soft parts like flesh is known as endoskeleton. Example, humans, elephants, dogs, etc., have endoskeleton.

Question 4.
Define tendons and ligaments.
Answer:
The bones are connected to muscles with the help of the connective tissues called tendons.
The bones are connected to each other at the joints with tissues called ligaments.

Question 5.
Differentiate between bones and cartilage.
Answer:

Question 6.
What are the main functions of the skull?
Answer:

• Skull protects the brain.
• Skull protects the sense organs of the face like eyes, ears and nose.
• Skull gives shape to our head.

Question 7.
How do muscles work?
Answer:
The muscles work in pairs. When one of them contracts, the bone is pulled in that direction. The other muscle of the pair relaxes. To move the bone in the opposite direction, the relaxed muscle contracts to pull the bone towards its original position while the first one relaxes.

Question 8.
How is the brain protected?
Answer:
The brain is located inside the skull of our body. The brain is protected by cranium, a bony box of the skull. Inside the cranium, the brain is contained in a fluid-filled balloon which provides further shock absorption for protection.

Question 9.
Describe the movements of:
(a) earthworm, (b) snail.
Answer:
a. Earthworm has muscles but no bones.
During the movement, earthworm first extends the front part of the body keeping the rear portion fixed to the ground. Then it fixes the front and releases the rear end. It then shortens the body and pulls the rear end forward. In this way, by repeating such muscular expansions and contractions, earthworm moves.

b. A snail moves with the help of a large, disc-shaped muscular foot. It has two sets of muscles in the foot. These muscles contract and expand alternately producing a kind of wave effect (from back to front). A series of waves in the muscles of the foot make the snail move forward.

Question 10.
How do fish move in water?
Answer:
The body of the fish is streamlined. The streamlined shape helps the fish to move in water. The skeleton of the fish is covered with muscles which make the front part of the body to curve to one side and the tail part swings towards the opposite side. This makes a jerk and pushes the body forward. In this way, it moves in the water.

Long Answer Type Questions

Question 1.
What is backbone? Describe its formation. Write its main functions.
Answer:
The backbone is a long, hollow structure running from the neck to the hips, inside our body. The small bones which make up the backbone are called vertebrae. It consists of 33 small ring-like vertebrae joined end to end. The first 24 vertebrae are joined serially by elastic cartilages. The main nerve cord passes through the hollow tube formed by the vertebrae. The 5 vertebrae of the hip are fuse and inseparable. 4 vertebrae of the tail are also fused.

Main functions of the backbone are:

• It provides main support to the body.
• It supports the head at its top.
• It attaches shoulder bones, ribs and hip bones.
• It protects the spinal cord.

Question 2.
Explain the various kinds of joints found in our body and give an example of each.
Answer:
a. Fixed joints: Those joints which do not allow movement are called fixed joints. Example: Skull bones.

b. Bali and socket joint: In this joint, one end of the bone has a round shape like a ball which fits into a socket in the other bone. It permits movements of the bones in all directions. Example, shoulder joints and hip joints have ball and socket joints.

c. Pivotal joints: Pivotal joint allows rotation only. It occurs between the first vertebrae and axis vertebrae.

d. Hinge joint: This joint allows movement only in one direction, forwards and backwards. Elbow joint and knee joint have this type of joint.

e. Gliding joint: This joint allow a limited movement due to sliding nature of cartilages. Movable joints of backbone are gliding joint.

Question 3.
What is a skeletal system? Write the functions of the skeletal system.
Answer:
The framework of bones and cartilages which supports the body of an animal or human is called the skeletal system.

The main functions of the skeletal system are:

• It holds the whole body together and gives it a shape.
• It protects the delicate internal organs like brain, kidney, heart, lungs, etc.
• It provides numerous points for the attachment of muscles of the body.
• Along with muscles, skeleton helps in the movement of body parts and in locomotion.

Question 4.
Why do animals need locomotion?
Answer:

• Animals move from place to place in search of food.
• It enables the animals to migrate from an unfavourable place or environment to a favourable place or environment.
• It helps the animals to escape from their enemies and predators.
• It helps animals to find their partners for reproduction, and to move to favourable areas for egg laying or rearing of young ones.

Question 5.
Describe the hip bone. Write its main functions.
Answer:
The hip bone forms a large basin shaped frame at the lower end of the backbone to which the legs are attached. The hip bone is also called pelvis. The hip bone encloses the position of our body below the stomach. The thigh bones of our legs are joined to the hip bone by the ball and socket joints.

The main functions of hip bone are:

• Hip bone supports and protects the lower organs of the body such as intestines, urinary bladder and internal sex organs.
• It attaches the legs to our body.
• It provides sides for the attachment of muscles that move legs, hips and trunk.

Question 6.
Explain the structure of leg.
Answer:
The leg includes the thigh, lower leg, ankle, foot and the toes.

• The thigh bone called femur, is the longest and strongest bone in the body.
• The lower leg consists of tw o bones: tibia and fibula.
• The ankle consists of several small bones.
• In the front part of the knee, there is a disc-like knee cap called patella.
• The foot has five longer bones called metatarsals.
• Each toe has three smaller bones.

The toe bones also help us in walking and running. They are called tarsals.

Picture-Based Questions

Question 1.
a. Identify the figure shown here:

b. What type of joint is present between these bones?
c. Give one function of this structure.
Answer:
a. Backbone
b. Gliding joint
c. It protects the spinal cord

Question 2.
a. Identify the figure shown below:

b. Name the type of joint in part marked A.
c. Is the joint marked B movable or not?
Answer:
a. Skull
b. Fixed joint
c. It is immovable.

These NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Getting to Know Plants NCERT Solutions for Class 6 Science Chapter 7

Class 6 Science Chapter 7 Getting to Know Plants Textbook Exercise Questions and Answers

Question 1.
Correct the following statements and rewrite them in your notebook.
a. Stem absorbs water and minerals from the soil.
b. Leaves hold the plant upright.
c. Roots conduct water to the leaves.
d. The number of petals and stamens in a flower is always equal.
e. If the sepals of a flower are joined together, its petals are also joined together.
f. If the petals of a flower are joined together, then the pistil is joined to the petal.
Answer:
a. Roots absorb water and minerals from the soil.
b. Stem holds the plant upright.
c. Stem conducts water to the leaves.
d. The number of petals and stamens in a flower may or may not be equal.
e. If the sepals of a flower are joined together, it is not necessary that petals are also joined together.
f. If the petals of a flower are joined together, then it is not necessary that the pistil is joined to the petal.

Question 2.
Draw (a) a leaf, (b) a taproot and (c) a flower.
Answer:

Question 3.
Can you find a plant in your house or in your neighbourhood, which has a long but weak stem? Write its name. In which category will you place it?
Answer:
It is a money plant. It is a climber.

Question 4.
What is the function of a stem?
Answer:
A stem performs following functions:

• Stem transfers water and minerals from roots to various parts of the plant.
• It transports food from leaves to various parts.
• It bears leaves, flowers and fruits,
• It holds the plant upright.

Question 5.
Which of the following leaves have reticulate venation?
Wheat, China rose, maize, tulsi, grass, coriander (dhania).
Answer:
Tulsi, Coriander and China rose have reticulate venation.

Question 6.
If a plant has fibrous root, what type of venation do its leaves have?
Answer:
Parallel venation.

Question 7.
If a plant has leaves with reticulate venation, what kind of roots will it have?
Answer:
Taproot.

Question 8.
Is it possible for you to find out whether a plant has taproot or fibrous roots by looking at the impression of its leaf on a sheet of paper?
Answer:
Yes, if leaf impression shows reticulate venation, the plant is likely to have taproot. However, if the leaf impression shows parallel venation, the plant is likely to have fibrous root.

Question 9.
What are the parts of a flower?
Answer:
The names of various parts of a flower from outside to inside are:

• Sepals
• Petals
• Stamens
• Pistil

Question 10.
From the following plants, which of them have flowers?
Grass, maize, wheat, chilli, tomato, tulsi, peepal, shisham, banyan, mango, jamun, guava, pomegranate, papaya, banana, lemon, sugarcane, potato, groundnut
Answer:
All the above plants have flowers.

Question 11.
Name the part of plant which produces food. Name the process.
Answer:
Leaves produces food and the process is called photosynthesis.

Question 12.
In which part of a flower, you will find the ovary?
Answer:
The ovary is found in pistil part of a flower.

Question 13.
Name two plants in which one has joined sepals and the other has separate sepals.
Answer:
Plants with joined sepals:

1. Dhatura
2. Loki

Plants with separate sepals:

1. China rose
2. Mustard

NCERT Extended Learning Activities And Projects

Question 1.
Become a leaf expert: Do this activity with a number of leaves over a period of few weeks. For every leaf that you wish to study, pluck it and wrap it in a wet cloth and take it home. Now, place the leaf between the folds of a newspaper and place a heavy book on it. You can also put it under your mattress or a trunk! Take out the leaf after a week. Paste it on a paper and write a poem or story about it. With your leaf collection pasted in a book, you can become an expert about leaves!
Answer:
Do it yourself.

Question 2.
Names of plant parts are hidden in this grid. Search them by going up, down, diagonally, forward or backward. Have fun!

Answer:

Activity 1

Objective: To show that water travels up through the stem of a plant.
Materials Required: Two glasses, red ink, freshly cut branches of a plant preferably bearing white flowers and blade.
Procedure:

• Take two glasses with little water in them. Label these glasses as A and B.
• Cut the lower end of the branches obliquely (or at an angle) with the help of a blade.
• Put one branch in each of the glasses. Add a few drops of red-ink into the water in glass A and shake it to mix the ink.

Leave the set up as such overnight. Observe the branches from inside and the flowers if the branches had flowers.
Observations: The branch from inside and the flower on it in glass A appears red. The colour of the branch and the flower in glass B remains unchanged.
Conclusion: Water travels up the stem through narrow tubes in it.

Leaf: It is the green part of the plant that prepares food. A leaf has following parts:
i. Lamina: Lamina is the broad, green part of the leaf.
ii. Petiole: Petiole is the thin stalk with which leaf is attached to the stem or branch.
iii. Midrib: It is the prominent line in the middle of the leaf blade.
iv. Veins: The various small, lateral lines arising from midrib and spread in lamina are called veins.

Venation: Venation is the arrangement of veins in the lamina. All the leaves contain veins. The arrangement of veins in the leaves of various plants is different. It can be of two types:
i. Reticulate venation: If veins make a net-like design on both sides of midrib, it is called reticulate venation. E.g., mango leaf, peepal leaf, etc.
ii. Parallel venation: If the veins are arranged parallel to each other and to the midrib, it is called parallel venation. E.g., grasses.

• Transpiration: Transpiration is the process by which water comes out from the leaves in the form of vapour. It helps the plant in cooling and absorbing nutrients from the root.

Activity 2

Objective: To show transpiration in plants. Materials Required: A potted plant, polythene bag and cello-tape.
Procedure:

• Take a well-watered potted plant having big leaves.

• Enclose a leafy stem (or branch) of the plant in a clean polythene bag and seal the mouth of polythene bag properly with cello-tape.
• Keep this potted plant in the sunshine for 2 to 3 hours.

Observations: A number of water droplets are seen on the inner side of the polythene bag.
Conclusion: The leaves of a plant lose water through transpiration.

• Photosynthesis: Photosynthesis is the process by which green leaves of plants prepare their food in the presence of sunlight, air, water and chlorophyll (a green coloured pigment present in the leaves).

Activity 3

Objective: To show that the leaf has starch in it.
Materials Required: A leaf, spirit, a beaker, test tube, burner, water, a plate and iodine solution.
Procedure:

• Boil a healthy leaf in water for about 10 minutes.
• Put the leaf in a test tube and pour spirit to completely cover the leaf.
• Now, put the test tube in a beaker half filled with water.

• Heat the beaker till all the green colour from the leaf comes out into the spirit in the test tube.
• Take out the leaf carefully and wash it in water.
• Put it on a plate and pour some iodine solution over it.

Observations: The leaf turns blue-black.
Conclusion: The blue-black colour indicates the presence of starch in leaves.

Root: It is the underground part of the plant that anchors it into the ground. Roots absorb water and minerals from the soil and conduct them to the upper parts of plant. Roots can be of two types:
i. Tap root: Tap root is the main root from which many branching roots grow sideways. Pea, radish, carrot, balsam, etc., are some plants that have tap root.
ii. Fibrous root: Fibrous root is the cluster of thin fibre-like roots at the base of the stem. Fibrous root is spread out in the soil. Wheat, maize, grass, etc., have fibrous root.

Flower: It is reproductive part of a plant. A flower consists of the following parts:
i. Sepals: Sepals are the small, green-coloured leaf-like structures seen in the flowers.
ii. Petals: Petals are the big, coloured leaf¬like structures seen in the flowers.
iii. Stamens: Stamens are the long filaments bearing anthers on their tip. They are seen in the flower on the removal of sepals and petals. These are the male parts of a flowers.
iv. Pistil: Pistil is the innermost part of a flower which we cannot see completely. It is the female part of the flower. It comprises of the following structures:
a. Style: Style is the narrow upper portion of pistil.
b. Stigma: Stigma is the sticky end at the top of the style.
c. Ovary: It is the lowermost bulged part of the pistil. It contains ovules that carry egg cells.
On maturation, ovary develops into fruit and ovules develop into seeds.

Very Short Answer Type Questions

Question 1.
What are the plants having green and tender stems called?
Answer:
Herbs.

Question 2.
What type of plant is the grape?
Answer:
Climber.

Question 3.
What is the food making process in green plants called?
Answer:
Photosynthesis.

Question 4.
Name the major parts of a plant.
Answer:
Stem, root, leaves and flowers.

Question 5.
Give two examples of shrubs.
Answer:
Lemon and orange.

Question 6.
Give two examples of trees.
Answer:
Banyan and apple.

Question 7.
Define nodes.
Answer:
The points on the stem where leaves and branches arise are called nodes.

Question 8.
What is lamina?
Answer:
The broad, green, flat part of leaf is called lamina.

Question 9.
What are the two main types of venation in the leaves?
Answer:
a. Reticulate venation
b. Parallel venation.

Question 10.
What are the two types of roots?
Answer:
a. Tap root
b. Fibrous root.

Question 11.
What do you mean by petals?
Answer:
The leaf-like coloured parts next to the sepals are called petals.

Question 12.
What is filament?
Answer:
Each stamen consists of a thin green stalk called filament.

Question 13.
Define ovary.
Answer:
The lower broad or bulged portion of the pistil is called ovary.

Question 14.
Name the agents of pollination.
Answer:
Insects, wind and water.

Question 15.
Name the various parts of stamen.
Answer:
Anther and filament.

Short Answer Type Questions

Question 1.
What are nodes and internodes in stem?
Answer:
Nodes are the points on the stem from where leaves and branches arise and internodes are the spaces between two adjacent nodes.

Question 2.
What is tuber in potato?
Answer:
Potato plant has special stem that grows underground- and stores food for the plant. This special stem is called tuber.

Question 3.
Write the functions of a leaf.
Answer:

• The leaves prepare food for the plant by the process of photosynthesis.
• The leaves get rid of excess water from the plant through transpiration.
• The leaves carry out the process of respiration in plants.

Question 4.
Define venation of the leaf.
Answer:
All the leaves contain veins. The arrangement of veins in the lamina of the leaf is known as venation of the leaf.

Question 5.
How does a climber differ from a creeper?
Answer:
Climber plant has a special organ called tendril on its stem which helps it to climb and grow while creeper has no such organ, so they grow on ground only.

Question 6.
Differentiate between the flowering plants and non-flowering plants.
Answer:
Flowering Plants:
The plants which have roots, stem and leaves, flower and fruits are known as flowering plants.
Examples: mango, guava, grapes, papaya, etc.

Non-flowering Plants:
The plants which do not have definite roots, stem, leaves and flowers are known as non-flowering plants.
Examples: fern, moss, algae, etc.

Question 7.
Write any two functions of roots.
Answer:

1. Roots help in holding the plant firmly in the soil.
2. Roots help in absorption of water and minerals from the soil.

Question 8.
How are leaf venation and type of roots in a plant related?
Answer:
Plants having the reticulate venation have tap roots while plants having the leaves with parallel venation have fibrous roots.

Question 9.
Which are the two gases involved in photosynthesis? How?
Answer:
Carbon dioxide and oxygen are involved in photosynthesis. Carbon dioxide is used whereas oxygen is released in photosynthesis.

Question 10.
What types of plants are called trees?
Answer:
Plants which are tall and have hard, thick brown woody stems are called trees. The stem has branches in the upper part, much above the ground.

Long Answer Type Questions

Question 1.
How are herbs, shrubs and trees different from each other?
Answer:
a. Herbs are small non-woody plants with soft stem. These plants are very small in size. These plants usually do not grow more than one metre in height. They have very short life span. These plants do not live for more than two seasons.

b. Shrubs are larger than herbs. These plants are hard and woody. These plants tend to branch near ground level, so many branches are seen rising just above the ground giving them a bushy appearance. Their life span is bigger than herbs but smaller than trees.

c. Trees are fully big plants. They have hard and woody stem. They have a trunk which usually gives out branches and leaves. The branches appear higher up on the stem much above the ground. Trees have a great life-span. They live for many years.

Question 2.
What is leaf venation? Explain the various types of leaf venation with an example for each.
Answer:
The design made by veins in a leaf is called leaf venation. The leaf venation have two main types: a. Reticulate venation: In this type of venation, the veins occur in an irregular way forming a net-like design. Pea plant, neem tree, mango tree, marigold, etc., have reticulate venation, b. Parallel venation: In this venation, the veins in a leaf run parallel to one another on both the sides of the midrib. Wheat, paddy, sugarcane, barley, etc., have parallel venation.

Question 3.
What are roots? Write the various functions of roots. Describe the two types of roots.
Answer:
Roots are the parts of plants which grow below the ground (in the soil). Various functions of roots are:

• Roots prevent the plant from being pulled out easily or blown away by the wind.
• Roots absorb water and minerals from the soil for manufacturing of food.
• Roots help in conservation of soil by holding it together.

The two main types of roots are: Taproot and Fibrous root

• Taproot is the main root from which many branching roots grow sideways. Pea plant, radish, mango, mustard, etc., have taproot.
• Fibrous root is a cluster of thin fibre like roots at the base of the stem. These roots spread out in the plants. Wheat, maize, grass, millet, etc., have fibrous roots.

Question 4.
Explain the structure of a leaf. What are the main functions of a leaf?
Answer:
The main parts of a leaf are:

• Petiole: The part of the leaf by which it is attached to the stem is called petiole.
• Lamina: The broad, green part of the leaf is lamina.
• Veins: There are various types of lines on the leaf which are called veins.
• Midrib: There is a thick vein in the middle of the leaf. This vein is called midrib.

There are following two main functions of a leaf:

• Transpiration: In the form of vapour, extra water comes out of the leaves. This process is called transpiration. It helps in cooling and absorbing water from soil by the roots.
• Photosynthesis: The process, by which leaves prepare their food from water and carbon dioxide, in the presence of sunlight and chlorophyll is called photosynthesis.

Question 5.
Explain how flower becomes a fruit.
Answer:
When the pollen grains fall on stigma, they move down through the tube called style and reach the ovary. In the ovary, the male sex cells present in pollens join with the female sex cells present in ovules. The joining together of male and female sex cells is called fertilization. After fertilization, the ovules grow and become seeds. The ovary of flower grows and becomes a fruit.

Picture-Based Questions

Question 1.
a. Identify the type of roots in figures A and B.

b. Which of the above roots is found in grasses?
Answer:
a. A-Taproot; B-Fibrous root
b. Fibrous root

Question 2.
a. Identify A and B.

b. Which of these is the male part of the flower?
c. Which of these is the female part of the flower?
Answer:
a. A-Stamen, B-Pistil
b. Stamen
c. Pistil