NCERT Solutions for Class 6th: Ch 16 Garbage in, Garbage out Science

NCERT Solutions for Class 6th: Ch 16 Garbage in, Garbage out Science

Page No: 164

Exercises

1. (a) Which kind of garbage is not converted into compost by the redworms?
(b) Have you seen any other organism besides redworms, in your pit? If yes, try to find out their names. Draw pictures of these.
Answer

(a) The garbage which are non-biodegradable in nature like iron strips, plastics, poly bags etc. are not converted into compost by the redworms.
(b) Yes, these organisms include maggots, flies, cockroaches etc.

 

2. Discuss :
(a) Is garbage disposal the responsibility only of the government?
(b) Is it possible to reduce the problems relating to disposal of garbage?

Answer

(a)  No, garbage disposal is not only the responsibility of the government. It is sole responsibility of both government and the people. Each and every citizen must be responsible for maintaining proper sanitation and disposable of waste materials produced. People should not litter at public places. They should also take care for the effective disposal of the waste produced at home, schools, hospitals etc.

(b) Yes, it is possible to reduce the problems relating to disposal of garbage by taking following measures:

(i) People should concern about generating less waste products and creating awareness among them.

(ii) Each and every product should be used efficiently.

(iii) Biodegradable and non-biodegradable wastes should be separated.

(iv) Waste products or garbage must be recycled and setting up centre for the treatment of them.

(v) We should minimize the use of plastic bags and use recyclable products.

3. (a) What do you do with the left over food at home?
(b) If you and your friends are given the choice of eating in a plastic plate or a banana leaf platter at a party, which one would you prefer and why?

Answer

(a) The left over food at home is given to animals on road, thrown in garbage or some times we use it to make compost.

(b) I will prefer to eat in banana leaf because it is a biodegradable product and environment friendly and can be decomposed.

4. (a) Collect pieces of different kinds of paper. Find out which of these can be recycled.
(b) With the help of a lens look at the pieces of paper you collected for the above question. Do you see any difference in the material of recycled paper and a new sheet of paper ?

Answer

(a)  Papers without having plastic coating on it can be recycled.

(b) The recycled is slightly yellowish in color than the new sheet of paper. Recycled paper is also rough and of low quality than new sheet of paper.

5. (a) Collect different kinds of packaging material. What was the purpose for which each one was used? Discuss in groups.
(b) Give an example in which packaging could have been reduced?
(c) Write a story on how packaging increases the amount of garbage.

Answer

(a) Different kinds of packaging materials and its uses:
(i) Paper packaging materials: Mostly used for packing of light and durable and hard products like soaps, blades, chocolates etc.
(ii) Plastic packaging materials: Used for liquid items and medium weighted too like oils, drinking water bottles, shampoo etc.
(iii) Poly bags: Used for carrying groceries, vegetables etc.
(iv) Clothes and Jute packaging materials: Used for heavy weighted as well as medium weighted too like carrying clothes, grains, vegetables, fruits etc.

(b) If people started carrying their own carry bags for buying groceries and vegetables and fruits then there will be no need for packing those materials by using plastics and thus the packaging could have been reduced.

(c) Packaging increase the amount of garbage as the it is quite useless ones the product is delivered or been utilised. These useless packaging materials are thrown away and just add loads to the garbage. Many packaging materials can't even be reused. Some of them are made of plastics and thus a non-biodegradable item which add hazards to the environment.

6. Do you think it is better to use compost instead of chemical fertilisers? Why?

Answer

Yes, i think it is better to use compost instead of chemical fertilisers because:
(i) It is environment friendly and add natural fertility to the soil.
(ii) It doesn't have adverse effect on nature and creates no pollution.
(iii) The food items grown are also healthy and do not contains any chemicals.
(iv) It is cheaper than the chemical fertiliser.
(v) Soil will never loss its fertility if we use compost.

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NCERT Solutions for Class 6th: Ch 15 Air Around us Science

NCERT Solutions for Class 6th: Ch 15 Air Around us Science

Page No: 153

Exercises

1. What is the composition of air?

Answer

Air contains some gases mainly nitrogen, oxygen, small amount of carbon dioxide, water vapour and
dust particles.

2. Which gas in the atmosphere is essential for respiration?

Answer

Oxygen gas in the atmosphere is essential for respiration.

3. How will you prove that air supports burning?

Answer

Step I: Two shallow containers are taken and burning candles are fitted into it.
Step II: Now, water is filled in the container at two different levels.
Step III: Both the candles are then covered with glass.
Step IV: After sometimes, we observed that the candles having less water in its container lights off.

This happened because the container having more water contains more oxygen and therefore it burnt for more time. Thus, it is proved that air supports burning.

4. How will you show that air is dissolved in water?

Answer

 Step I: Water in a pan is taken.
Step II: It is now boiled on stove.
Step III: We will observe tiny bubbles of water visible coming out from the bottom of the pan.

These tiny bubbles are coming due to the air dissolved in water. Thus, this proves that air is dissolved in water.

5. Why does a lump of cotton wool shrink in water?

Answer

The lump of cotton contains air in it. When it comes in contact with water, the air pushed out from the vacant space and dissolved in water and thus a lump of cotton wool shrink in water.

Page No: 154

6. The layer of air around the earth is known as ___________.

Answer

The layer of air around the earth is known as atmosphere.

7. The component of air used by green plants to make their food, is ___________.

Answer

The component of air used by green plants to make their food, is carbon dioxide.

8. List five activities that are possible due to the presence of air.

Answer

Five activities that are possible due to the presence of air:
(i) Helps in seed dispersal and pollination.
(ii) Sailing of ships.
(iii) Flying of the birds and kites.
(iv) Gives us oxygen to respire.
(v) Helps in the rotation of windmill.

9. How do plants and animals help each other in the exchange of gases in the atmosphere?

Answer

Plants take in carbon dioxide in during photosynthesis give out oxygen in the atmosphere while animals take in oxygen and breathe out carbon dioxide during respiration. In this way, plants and animals help each other in the exchange of gases in the atmosphere.

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NCERT Solutions for Class 6th: Ch 14 Water Science

NCERT Solutions for Class 6th: Ch 14 Water Science

Page No: 145

Exercises

1. Fill up the blanks in the following:
(a) The process of changing of water into its vapour is called _________________.
(b) The process of changing water vapour into water is called _________________.
(c) No rainfall for a year or more may lead to _________________ in that region.
(d) Excessive rains may cause _____________ .

Answer

(a) The process of changing of water into its vapour is called evaporation.
(b) The process of changing water vapour into water is called condensation.
(c) No rainfall for a year or more may lead to drought in that region.
(d) Excessive rains may cause floods.

2. State for each of the following whether it is due to evaporation or condensation:
(a) Water drops appear on the outer surface of a glass containing cold water.
(b) Steam rising from wet clothes while they are ironed.
(c) Fog appearing on a cold winter morning.
(d) Blackboard dries up after wiping it.
(e) Steam rising from a hot girdle when water is sprinkled on it.

Answer

(a)   Condensation
(b)   Evaporation
(c)   Condensation
(d)   Evaporation
(e)   Evaporation

3. Which of the following statements are “true” ?
(a) Water vapour is present in air only during the monsoon. ( )
(b) Water evaporates into air from oceans, rivers and lakes but not from the soil.( )
(c) The process of water changing into its vapour, is called evaporation.( )
(d) The evaporation of water takes place only in sunlight.( )
(e) Water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler.( )

Answer

(a) Not true
(b) Not true
(c) True
(d) Not true
(e) True

Page No: 146

4. Suppose you want to dry your school uniform quickly. Would spreading it near an anghiti or heater help? If yes, how?

Answer

Yes, spreading it near an anghiti or heater will surely help as heater and anghiti are source of heat which vaporize the water of the wet clothes and thus help in drying.

5. Take out a cooled bottle of water from refrigerator and keep it on a table. After some time you notice a puddle of water around it. Why?

Answer

The puddle of water seen around the cooled bottle of water is due to the condensation effect as the water vapour present in the air around the bottle get condensed after colliding with bottle.

6. To clean their spectacles, people often breathe out on glasses to make them wet. Explain why the glasses become wet.

Answer

Water vapour also gets released during exhalation process along with carbon dioxide. These water vapour gets attached with the glasses of the spectacles and then condensed in the presence of air surrounding it and thus making it wet.

7. How are clouds formed?

Answer

When the air moves up, it gets cooler and cooler and after reaching sufficient heights, the air
becomes so cool that the water vapour present in it condenses to form tiny drops of water called droplets which remain floating in air and thus clouds are formed.

8. When does a drought occur?

Answer

Drought occurs when an area does not receive rainfall for a period of year or more. Also, the soil continues to lose water by evaporation and transpiration and becomes dry and the ground water may also become scarce which may lead to drought.

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NCERT Solutions for Class 6th: Ch 14 Fun with Magnets Science

NCERT Solutions for Class 6th: Ch 14 Fun with Magnets Science

Page No: 134

Exercises

1. Fill in the blanks in the following
(i) Artificial magnets are made in different shapes such as __________, __________ and ____________.
(ii) The Materials which are attracted towards a magnet are called________.
(iii) Paper is not a ______ material.
(iv) In olden days, sailors used to find direction by suspending a piece of ___________.
(v) A magnet always has __________ poles.

Answer

(i) Artificial magnets are made in different shapes such as bar magnets, horse-shoe magnet and cylindrical or a ball-ended magnet.
(ii) The Materials which are attracted towards a magnet are called magnetic materials.
(iii) Paper is not a magnetic material.
(iv) In olden days, sailors used to find direction by suspending a piece of magnet.
(v) A magnet always has two poles.

2. State whether the following statements are true or false
(i) A cylindrical magnet has only one pole.
(ii) Artificial magnets were discovered in Greece.
(iii) Similar poles of a magnet repel each other.
(iv) Maximum iron filings stick in the middle of a bar magnet when it is brought near them.
(v) Bar magnets always point towards North-South direction.
(vi) A compass can be used to find East-West direction at any place.
(vii) Rubber is a magnetic material.

Answer

(i) False
(ii) False
(iii) True
(iv) False
(v) True
(vi) True
(vii) False

3. It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic. Name a material that might have been used to make some part of it.

Answer

The blade of the sharpener is made up of iron which is a magnetic substance which gets attracted by both the poles of a magnet although its body is made of plastic.

4. Column I shows different positions in which one pole of a magnet is placed near that of the other. Column II indicates the resulting Acids

Column I	Column II
N-N	_____________
N-___________	Attraction
S-N	____________
__________-S	Repulsion

Answer

Column I	Column II
N-N	Repulsion
N-S	Attraction
S-N	Attraction
S-S	Repulsion

5. Write any two properties of a magnet.

Answer

Two properties of a magnet:
(i) Magnet aligns in North-South direction when suspended freely.
(ii) A magnet has two magnetic poles.

 6. Where are poles of a bar magnet located?

Answer

Poles of a bar magnet located at its two ends.

7. A bar magnet has no markings to indicate its poles. How would you find out near which end is its north pole located?

Answer

To locate its north pole, we would do the following steps:
(i) A bar is taken and suspended freely from the middle with the help of thread.
(ii) Allow the magnet to comes into rest.
(iii) The North pole of the magnet will face the north direction and South pole will face the south direction.
(iv) Mark the north pole of the magnet with the marker.

8. You are given an iron strip. How will you make it into a magnet?

Answer

Steps to make an iron strip into bar magnet:
(i) A flat strip of iron is taken.
(ii) On the iron strip, a bar magnet is placed and rubbed against it horizontally only in one direction.
(iii) When you reached the end of the strip, lift the magnet and again start rubbing from the initial position.
(iv) This process is repeated more than 40-50 times.
(v) After this, the iron strip will attained the property of magnet.

9. How is a compass used to find directions?

Answer

A compass has a magnetic needle attached to it which can rotates freely. The magnet always points to north-south direction which is marked on compass and thus helps in finding direction.

10. A magnet was brought from different directions towards a toy boat that has been floating in water in a tub. Affect observed in each case is stated in
Column I. Possible reasons for the observed affects are mentioned in
Column II. Match the statements given in Column I with those in Column II.

Column I	Column II
Boat gets attracted towards the magnet	Boat is fitted with a magnet with north pole towards its head
Boat is not affected by the magnet	Boat is fitted with a magnet with South pole towards its head.
Boat moves towards the magnet if North pole of the magnet is brought near its head.	Boat has a small magnet fixed along its length.
Boat moves away from the magnet when North pole is brought near its head.	Boat is made of magnetic material.
Boat floats without changing its direction.	Boat is made up of non-magnetic material.

Answer

Column I	Column II
Boat gets attracted towards the magnet	Boat is made of magnetic material.
Boat is not affected by the magnet	Boat is made up of non-magnetic material.
Boat moves towards the magnet if North pole of the magnet is brought near its head.	Boat is fitted with a magnet with South pole towards its head.
Boat moves away from the magnet when North pole is brought near its head.	Boat is fitted with a magnet with North pole towards its head.
Boat floats without changing its direction.	Boat has a small magnet fixed along its length.

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NCERT Solutions for Class 6th: Ch 12 Electricity and Circuits Science

NCERT Solutions for Class 6th: Ch 12 Electricity and Circuits Science

Page No: 123

Exercises

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) A device that is used to break an electric circuit is called electric switch.
(b) An electric cell has two terminals.

2. Mark 'True' or 'False' for 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 thermo col.

Answer

(a) True
(b) False
(c) False

3. Explain why the bulb would not glow in the arrangement shown in Fig. 12.13.

Answer

Bulb will not glow in the arrangement because the holder of the tester used in the connection is made of plastic which is an insulator. Thus, current will not flow in the circuit.

Page No: 124

4. Complete the drawing shown in Fig 12.14 to indicate where the free ends of the two wires should be joined to make the bulb glow.


Answer

Earlier, the connection is not complete as one of the end of the cell is not connected to the switch and hence the bulb. Thus, there will be no flow of current in the circuit.
To complete the circuit, one of the end of the cell must be connected to the switch and then to the bulb. After this, bulb will start glowing as shown in the figure.

5. What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them.

Answer

An electric switch helps in making as well as breaking the circuit without removing the connection. When switch is ON, the current will flow and when switch is OFF, the current will not flow in the circuit. Thus, it also saves electricity and make the use of appliances easier.
Some electric gadgets are: Television, Iron, Washing Machine Refridgerator etc.

 6. Would the bulb glow after completing the circuit shown in Fig. 12.14 if instead of safety pin we use an eraser?

Answer

No, the bulb will not glow when we will use an eraser instead of safety pin even after circuit is complete because rubber is an insulator and current will not flow through it.

7. Would the bulb glow in the circuit shown in Fig. 12.15?

Answer

No, the bulb will not glow because the wires from both terminals of the battery are connected to the one terminal of the bulb. In order to make the bulb glow, wires should be connected to the both terminals of the bulb.

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

That object must be an insulator because it allows the current to flow through it and thus helped in the glowing of bulb.

9. Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.

Answer

Rubber gloves are insulator which do not allow the current to flow through it. Therefore, an electrician use rubber gloves while repairing an electric switch at your home because it protect them from the shock of electricity and for the safety purpose.

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

The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them as plastic is an insulator which protect the electricians from severe electric shocks and accidents.

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NCERT Solutions for Class 6th: Ch 11 Light, Shadows and Reflections Science

NCERT Solutions for Class 6th: Ch 11 Light, Shadows and Reflections Science

Page No: 113

Exercises

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

Answer

Opaque Objects Make Shadow

Page No: 114

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

Opaque objects : a piece of rock, a sheet of aluminium, a mirror, a wooden board, a CD, an umbrella, a wall, a sheet of carbon paper, a sheet of cardboard

Transparent objects : Air, Water, a sheet of polythene, a sheet of plane glass, a sheet of cellophane, a wire mesh

Translucent objects : smoke, fog

Luminous objects : A piece of red hot iron, a lighted fluorescent bulb, the flame of a gas burner, a lighted torch, kerosene torch, sun, firefly

Non-luminous object : 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, an umbrella, a wall, a sheet of carbon paper, a sheet of cardboard, a sheet of cellophane, a wire mesh, moon.

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

A cylindrical shape can give a circular shadow when light is incident from its top or bottom. It will give a rectangular shadow when light is incident from its side.

4. In a completely dark room, if you hold up a mirror in front of you, will you see a reflection of yourself in the mirror?

Answer

No, we will not be able to see our reflection in the mirror because there is no source of light in the room.

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NCERT Solutions for Class 6th: Ch 10 Motion and Measurement of Distances Science

NCERT Solutions for Class 6th: Ch 10 Motion and Measurement of Distance Science

Page No: 106

Exercises

1. Give two examples each, of modes of transport used on land, water and air.

Answer

Modes of transport used on land - Buses and Trains.
Modes of transport used on water - Ships and Boats.
Modes of transport used on air - Helicopters and Aeroplanes.

2. Fill in the blanks:
(i) One metre is ______________ cm.
(ii) Five kilometre is ______________ m.
(iii)Motion of a child on a swing is ______________.
(iv)Motion of the needle of a sewing machine is ______________.
(v) Motion of wheel of a bicycle is______________.

Answer

(i) One metre is 100 cm.
(ii) Five kilometre is 5000 m.
(iii)Motion of a child on a swing is periodic motion.
(iv)Motion of the needle of a sewing machine is periodic motion.
(v) Motion of wheel of a bicycle is circular motion.

3. Why can a pace or a footstep not be used as a standard unit of length?

Answer

The length of pace or a footstep varies from person to person. If the length of footstep will be used as standard unit for measurement of length then two measured quantity will not be same. Hence, footstep or pace is not a constant quantity and cannot be used as a standard unit of length.

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

5. The height of a person is 1.65 m. Express it into cm and mm.

Answer

1.65 m = 1.65 × 100 cm  = 165 cm
1.65 m = 1.65 × 100 × 10 mm  = 1650 mm

6. The distance between Radha's home and her school is 3250 m. Express this distance into km.

Answer

1km = 1000 m
3250 m = 3250/1000 km = 3.25 km

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

The actual count of the length of the needle start from 3.0 cm instead of 0 cm. Thus, the actual length of the needle is (33.1 - 3.0) cm = 30.1 cm

8. Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on.

Answer

Similarities:
(i) Both the ceiling fan and the wheels of a bicycle show circular motion.
(ii) Both are fixed at point.
Differences:
(i) A bicycle shows rectlinear motion while a ceiling fan does not.

9. Why could you not use an elastic measuring tape to measure distance? What would be some of the problems you would meet in telling someone about a distance you measured with an elastic tape?

Answer

An elastic tape is flexible and can be stretched. Thus, each time it will give different readings for the same length measured. Therefore, it is impossible to measure accurate distance from an elastic measuring tape.

10. Give two examples of periodic motion.

Answer

Two examples of periodic motion:
(i) Motion of a pendulum clock.
(ii) Motion of a swing.

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NCERT Solutions for Class 6th: Ch 9 The Living Organisms and Their Surroundings Science

NCERT Solutions for Class 6th: Ch 9 The Living Organisms and Their Surroundings Science

Page No: 93

Exercises

1. What is a habitat?

Answer

The surrounding where a living organism lives is called its habitat.

2. How are cactus adapted to survive in a desert?

Answer

Adaption to survive in a desert:
(i) Leaves are modified into spines which prevent the loss of water.
(ii) Stem is modified into leaf like structures which store water and perform photosynthesis.
(iii) Stem are spongy and have waxy coating which prevents transpiration.
(iv) Roots are deep which can access water from depths.

3. Fill up the blanks
(a) The presence of specific features, which enable 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 _____________ habitat.
(c) The habitats of plants and animals that live in water are called ____________ habitat.
(d) Soil, water and air are the _____________ factors of a habitat.
(e) Changes in our surroundings that make us respond to them, are called _____________.

Answer

(a) The presence of specific features, which enable a plant or an animal to live in a particular habitat, is called adaption .
(b) The habitats of the plants and animals that live on land are called terrestrial habitat.
(c) The habitats of plants and animals that live in water are called aquatic habitat.
(d) Soil, water and air are the abiotic factors of a habitat.
(e) Changes in our surroundings that make us respond to them, are called stimuli.

4. Which of the things in the following list are nonliving?
Plough, Mushroom, Sewing machine, Radio, Boat, Water hyacinth, Earthworm

Answer

Plough, sewing machine, radio, boat

5. Give an example of a non-living thing, which shows any two characteristics of living things.

Answer

Car (shows motion and creates sound) is an example of a non-living thing which shows two characteristics of living things.

6. Which of the non-living things listed below, 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, rubber

7. List the common characteristics of the living things.

Answer

(i) It shows growth.
(ii) Needs nutrition.
(iii) It reproduce.
(iv) It responds to stimuli.
(v) It respires.

8. Explain, why speed is important for survival in the grasslands for animals that live there. (Hint: There are few trees or places for animals to hide in grasslands habitats.)

Answer

Speed is important for survival in the grasslands for animals that live there because it help them in protecting themselves from their predators. In grasslands, there are very less numbers of suitable places available there where animals can hide so speed help them in escaping from their predators.

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NCERT Solutions for Class 6th: Ch 8 Body Movements Science

NCERT Solutions for Class 6th: Ch 8 Body Movements Science

Page No: 77

Exercises

1. Fill in the blanks:
(a) Joints of the bones help in the ____________ of the body.
(b) A combination of bones and cartilages forms 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) Joints of the bones help in the movement of the body.
(b) A combination of bones and cartilages forms the skeleton of the body.
(c) The bones at the elbow are joined by a hinge joint.
(d) The contraction of the muscles pulls the bones during movement.

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 fore arm has two bones. ( )
(e) Cockroaches have an outer skeleton. ( )

Answer

(a) False
(b) False
(c) False
(d) True
(e) True

Page No. 78

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

Column I	Column II
Upper jaw	have fins on the body.
Fish	has an outer skeleton.
Ribs	can fly in the air.
Snail	is an immovable joint.
Cockroach	protect the heart.
-	shows very slow movement.
-	have a streamlined body.

Answer

Column I	Column II
Upper jaw	is an immovable joint.
Fish	have fins on the body, have a streamlined body.
Ribs	protect the heart.
Snail	shows very slow movement.
Cockroach	has an outer skeleton, can fly in the air.

4. Answer the following:
(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) In a ball and socket joint, the rounded end of one bone fits into the cavity (hollow space) of the other bone. It can allows movement in all directions.
(b) Lower jaw bone (Mandible bone) is the only movable bone in skull bone.
(c) Elbow joint has hinge joint. This joint allows movement in a plane only and hence it is not able to move backwards.

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NCERT Solutions for Class 6th: Ch 7 Getting to Know Plants Science

NCERT Solutions for Class 6th: Ch 7 Getting to Know Plants Science

Page No:64

Exercises

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 sepals 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) Root absorbs water and minerals from the soil.
(b) Stem holds the plants upright.
(c) Stem conducts water to the leaves.
(d) The number of petals and sepals in a flower may be equal or different.
(e) If the sepals of a flower are joined together, then its petals may or may not be joined together.
(f)If the petals of a flower are joined together, then the stamen may or may not be joined to the petal.

2. Draw (a) a leaf, (b) a taproot and (c) a flower, you have studied for Table 7.3.

Answer

(a) a leaf of rose plant

(b) Tap root of rose plant

(c) Flower of rose plant

3. Can you find a plant in your house or in your neighborhood, which has a long but a weak stem? Write its name. In which category would you classify it?

Answer

Yes, i can find in my neighborhood which has a long but a weak stem.
Its name is cucumber or money plant or pea. It comes under the category of climber plants.

4. What is the function of a stem in a plant?

Answer

Functions of stem in a plant:
(i) It provides supports to the branches of plant.
(ii) It bears buds, flowers, leaves and fruits
(iii) It carries water and minerals from roots to different parts of the plant.
(iv) It also carries prepared food from leaves to the different parts of the plants.

5. Which of the following leaves have reticulate venation?
    Wheat, tulsi, maize, grass, coriander (dhania), China rose

Answer

The arrangements of veins in lamina of the leaf is called venation.
The leaves of Tulsi, Coriander and China rose have reticulate venation.

6. If a plant has fibrous root, what type of venation do its leaves likely to have?

Answer

The plants having fibrous root more likely to have parallel venation.

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

Answer

Plants with reticulate venation will have tap root.

8. Is it possible for you to recognize the leaves without seeing them? How?

Answer

Yes, it is possible for to recognize the leaves without seeing them by smelling or touching them. Leaves of some plants have aroma which can be recognized by smelling.

9. Write the names of the parts of a flower.

Answer

The parts of a flower are sepals, petals, stamens and pistil.

(i) Sepal: It is the small leaf-like structures which is the most prominent part in a bud.
(ii) Petals: It is the prominent parts of the open flower which is of different colours.
(iii) Stamens: It is the male reproductive part of the flower.
(iv) Pistil: It is the female reproductive part of the flower.

10. Which of the following plants have you seen? of those that you have seen, which one have flowers?
Grass, maize, wheat, chilli, tomato, tulsi, pipal, shisham, banyan, mango, jamun, guava, pomegranate, papaya, banana, lemon, sugarcane, potato, groundnut

Answer

The plants which have flowers are:
Grass, maize, wheat, chilli, tomato, tulsi, papal, shisham, banyan, mango, jamun, guava, pomegranate, papaya, banana, lemon, potato, groundnut.

11. Name the part of the plant which produces its food. Name this process.

Answer

Leaves produces the food of the plant. The process of making food in the presence of sunlight is called photosynthesis.

12. In which part of a flower, you are likely to find the ovary?

Answer

Ovary is present in the pistil of the flower.

13. Name two flowers, each with joined and separated sepals.

Answer

Two flowers with joined sepals: China rose and Cotton.
Two flowers with separated sepals: Rose and Jasmine.

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NCERT Solutions for Class 6th: Ch 6 Changes Around us Science

NCERT Solutions for Class 6th: Ch 6 Changes Around us Science

Page No: 51

Exercises

1. To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?

Answer

Yes, this change be reserved as dress can be unfolded.

2. You accidentally dropped your favourite toy and broke it. This is a change you did not want. Can this change be reversed?

Answer

No, this change can't be reversed.

3. Some changes are listed in the following table. For each change, write in the blank column, whether the change can be reversed or not.

S. No.	Change	Can be reversed (Yes/No)
1.	The sawing of a piece of wood
2.	The melting of ice candy
3.	Dissolving sugar in water
4.	The cooking of food
5.	The ripening of a mango
6.	Souring of milk

Answer

S. No.	Change	Can be reversed (Yes/No)
1.	The sawing of a piece of wood	No
2.	The melting of ice candy	Yes
3.	Dissolving sugar in water	Yes
4.	The cooking of food	No
5.	The ripening of a mango	No
6.	Souring of milk	No

4. A drawing sheet changes when you draw a picture on it. Can you reverse this change?

Answer

We can reverse this change if the picture is made by pencil on drawing sheet.
We can't reverse this change if the picture is made by pen, oil colour or sketch pen.

5. Give examples to explain the difference between changes that can or cannot be reversed.

Answer

(i) Paper can be folded to make different shapes. This is reversible change as shapes of paper can be unfolded back into paper sheet. But when paper is burnt and turned into ash, it can't be reversed.
(ii) If we fill balloon with air, the shape and size of the balloon changes. This change can be reversed but if balloon burst while inflating then this change can't be reversed.
(iii) The shape of rubber band can be changed by stretching which can be reversed

6. A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?

Answer

No, the change in POP can't be reversed as it became hard on drying and new product is formed which cannot be changes back in its original form. It is type of chemical change.

7. A bag of cement lying in the open gets wet due to rain during the night. The next day the sun shines brightly. Do you think the changes, which have occurred in the cement, could be reversed?

Answer

No, the changes which have occurred in the cement couldn't be reversed. When sunlight falls on the wet cement, chemical changes occur which is a irreversible process.

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NCERT Solutions for Class 6th: Ch 5 Separation of substances Science

NCERT Solutions for Class 6th: Ch 5 Separation of substances Science

Page No: 44

Exercises

1. Why do we need to separate different components of a mixture? Give two examples.

Answer

We need to separate different components of a mixture:
• to separate harmful or non-useful substances that may be mixed with it.
• to separate even useful components if we need to use them separately.

Two examples are:
• Milk or curd is churned to separate the butter
• Grain is separated from stalks, while harvesting.

2. What is winnowing? Where is it used?

Answer

Winnowing is method of  separating components of a mixture. It is used to separate heavier and lighter components of a mixture by wind or by blowing air. This method is commonly used by farmers to separate lighter husk particles from heavier seeds of grain.

3. How will you separate husk or dirt particles from a given sample of pulses before cooking?

Answer

To separate husk or dirt particles from a given sample of pulses before cooking, we need to wash the pulses with water. Husk or dirt particles being lighter keep floating in water and pulses grain will settle down so we can easily remove them. Then, water with impurities can be removed by decantation.

4. What is sieving? Where is it used?

Answer

Sieving is a method of separation which allows the fine flour particles to pass through the holes of the sieve while the bigger impurities remain on the sieve. It is used at home to separate pebbles and stones from sand.

5. How will you separate sand and water from their mixture?

Answer

We can separate sand and water from their mixture by:

• Sedimentation and decantation: Being sand insoluble and heavier than water, it settles down at the bottom. Then after we can easily separate water from sand.

• Filtration: The mixture of sand and water is poured on a piece of cloth or filter paper so that water goes down through it and sand remains on the piece of cloth or paper.

6.  Is it possible to separate sugar mixed with wheat flour? If yes, how will you do it?

Answer

Yes, it is possible to separate sugar mixed with wheat flour. This can be done through the process of sieving The mixture of sugar and wheat flour is allowed to pass through a sieve. The fine wheat flour passes through the sieve while sugar remains on the sieve.

7. How would you obtain clear water from a sample of muddy water?

Answer

By the method of filtration, we can obtain clear water from a sample of muddy water. The sample of muddy water is passed through a filter paper. Clear water will pass through the filtering medium while mud will remain on water

8. Fill up the blanks:

(a) The method of separating seeds of paddy from its stalks is called ___________.
► Threshing

(b) When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai) is left behind on it. This process of separating cream from milk is an example of ___________.
► Filtration

(c) Salt is obtained from seawater by the process of ___________.
► Evaporation

(d) Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top. The process of separation used in this example is called ___________.

► Sedimentation and decantation

9. True or false?

(a) A mixture of milk and water can be separated by filtration.
► False

(b) A mixture of powdered salt and sugar can be separated by the process of winnowing.

► False

(c) Separation of sugar from tea can be done with filtration.

► False

(d) Grain and husk can be separated with the process of decantation.

► False

Page No: 45

10.  Lemonade is prepared by mixing lemon juice and sugar in water. You wish to add ice to cool it. Should you add ice to the lemonade before or after dissolving sugar? In which case would it be possible to dissolve more sugar?

Answer

We should add ice after dissolving sugar because the dissolving power of water decreases with decrease in temperature. So, if we add ice before dissolving sugar, less amount of sugar will get dissolved.

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NCERT Solutions for Class 6th: Ch 4 Sorting materials into groups Science

NCERT Solutions for Class 6th: Ch 4 Sorting materials into groups Science

Page No: 33

Exercises

1. Name five objects which can be made from wood.

Answer

Five objects which can be made from wood
• Table
• Chair
• Desk
• Door
•

2. Select those objects from the following which shine:
Glass bowl, plastic toy, steel spoon, cotton shirt

Answer

Glass, bowl, steel spoon

3. Match the objects given below with the materials from which they could be made. Remember, an object could be made from more than one material and a given material could be used for making many objects.

Object	Material
Book	Glass
Tumbler	Wood
Chair	Paper
Toy	Leather
Shoes	Plastics

Answer

Object	Material
Book	Paper
Tumbler	Glass, Plastic
Chair	Wood, Plastic
Toy	Wood, Paper, Plastic
Shoes	Leather

4. State whether the statements given below are 'True' or 'False'.

(i) Stone is transparent, while glass is opaque.
► False

(ii) A notebook has lustre, while an eraser does not.

► False

(iii) Chalk dissolves in water.
► False

(iv) A piece of wood floats on water.
► True

(v) Sugar does not dissolve in water.
► False

(vi) Oil mixes with water.
► False

(vii) Sand settles down in water.
► True

(viii) Vinegar dissolves in water.

► True

Page No: 34

5. Given below are the names of some objects and materials:

Water, basket ball, orange, sugar, globe, apple, and earthen pitcher
Group them as:
(a) Round shaped and other shapes
(b) Eatables and non-eatables

Answer

(a) Round-shaped: Basketball, orange, globe, apple, earthen pitcher
Other shapes: Water, sugar
(b) Eatables: Water, orange, sugar, apple
Non-eatables: Basketball, globe, earthen pitcher

6. List all items known to you that float on water. Check and see if they will float on an oil or kerosene.

Answer

Sponge's piece, Plastic Bottle, Paper's piece, Thermocol's piece, Wood, Plastic ball, Cork are the known to you that float on water. No, they will not float on an oil or kerosene.

7. Find the odd one out from the following:

(a) Chair, Bed, Table, Baby, Cupboard
► Baby as it is living being while others are non-living.

(b) Rose, Jasmine, Boat, Marigold, Lotus

► Boat as it is used for transportation purpose while others are flowers.

(c) Aluminium, Iron, Copper, Silver, Sand

► Sand as it non-metal while others are metals.

(d) Sugar, Salt, Sand, Copper sulphate

►Sand as it is insoluble in water while others are soluble in water.

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NCERT Solutions for Class 6th: Ch 3 Fibre to Fabric Science

NCERT Solutions for Class 6th: Ch 3 Fibre to Fabric Science

Exercises

Page No: 24

1. Classify the following fibres as natural or synthetic:

nylon, wool, cotton, silk, polyester, jute

Answer

Natual: wool cotton, jute, silk

Synthetic: nylon, polyester

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

a) Yarn is made from fibres.

► True

b) Spinning is a process of making fibres.

► False

c) Jute is the outer covering of coconut.

► False

d) The process of removing seed from cotton is called ginning.

► True

e) Weaving of yarn makes a piece of fabric.

► True

f) Silk fibre is obtained from the stem of a plant.

► False

g) Polyester is a natural fibre

► False

3. Fill in the blanks:

a) Plant fibres are obtained from_________ and ________ .

► Fruits and stems

b) Animals fibres are __________ and ___________ .

► Wool and silk

4. From which parts of plants cotton and jute are obtained?

Answer

Cotton fibres are obtained from fruit of the cotton plants and jute is obtained from the stem of Jute plant.

5. Name two items that are made from coconut fibre.

Answer

Ropes and doormats are made from coconut fibre.

6. Explain the process of making yarn from fibre.

Answer

Fibres from a mass of cotton wool are drawn out and twisted. This brings the fibres together to form a yarn.

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NCERT Solutions for Class 6th: Ch 2 Components of food Science

NCERT Solutions for Class 6th: Ch 2 Components of food Science

Page No: 17

Exercises

1. Name the major nutrients in our food.

Answer

The major nutrients in our food are Carbohydrates, proteins, Fats, Vitamins and minerals.

2. Name the following:

(a) The nutrients which mainly give energy to our body.
► Carbohydrates and fats

(b) The nutrients that are needed for the growth and maintenance of our body.
► Proteins and minerals

(c) A vitamin required for maintaining good eyesight.
► Vitamin A

(d) A mineral that is required for keeping our bones healthy.
► Calcium

3. Name two foods each rich in:

(a) Fats
► Mustard oil and Meat

(b) Starch
► Rice and Mango

(c) Dietary fibre
► Pulses and Potato

(d) Protein

► Gram and Milk

4. Tick (✓) the statements that are correct.

(a) By eating rice alone, we can fulfill the nutritional requirement in our body. ( )

► (✘)

(b) Deficiency diseases can be prevented by eating a balanced diet. ( )
► (✓)

(c) Balanced diet for the body should contain a variety of food items. ( )
► (✓)

(d) Meat alone is sufficient to provide all nutrients to the body. ( )

► (✘)

5. Fill in the blanks:

(a) _________ is caused by the deficiency of vitamin D.
► Rickets

(b) Deficiency of _________ causes a disease known as beri-beri.
► Vitamin B1

(c) Deficiency of vitamin C causes a disease known as _________.
► Scurvy

(d) Night blindness is caused due to deficiency of _________ in our food.

► Vitamin A

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NCERT Solutions for Class 6th: Ch 1 Food Where does it come from? Science

NCERT Solutions for Class 6th: Ch 1 Food Where does it come from? Science

Exercises

Page No: 6

1. Do you find that all living beings need the same kind of food?

Answer

No, the food requirements of all living organisms are different. Depending on the food requirements, living organisms are grouped into three categories:
• Herbivores: Animals which eat only plants and plant products are called herbivores. For example: Cow, elephant, rabbit, horse, etc.
• Carnivores: Animals which eat other animals are called carnivores. For example: Lion, tiger, lizard, etc.
• Omnivores: These animals eat both plants and animals. For example: Dog, cat, crow, etc.

2. Name five plants and their parts that we eat.

Answer

Plants - edible parts

Carrot - root

Potato - stem

Carrot - root

Apple - fruit

Cabbage - leaf

3. Match the items given in Column A with that in Column B

Column A	Column B
Milk, curd, panner ghee	eat other animals
Spinach, cauliflower, carrot	eat plant and plants products
Lions and tigers	are vegetables
Herbivores	are all animal products

Answer

Column A	Column B
Milk, curd, panner ghee	are all animal products
Spinach, cauliflower, carrot	are vegetables
Lions and tigers	eat other animals
Herbivores	eat plant and plants products

Page No: 7

4. Fill up the blanks with the words given:

Herbivore, plant, milk, sugarcane, carnivore

(a) Tiger is a _________ because it eats only meat.
► carnivore

(b) Deer eats only plant products and so, is called _________.
► Herbivore

(c) Parrot eats only _________ products.
► plant

(d) The _______that we drink, which comes from cows, buffaloes and goats is an animal product.
► milk

(e) We get sugar from _________ .

► sugarcane

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