Class 6 - Science - CH9 - The Living Organisms and Their Surroundings

Class 6 - Science - CH9 - The Living Organisms and Their Surroundings

The Living Organisms and Their Surroundings

Cockatoo - Can it survive without mangrove?

(NCERT Chapter Solution and other Q & A)

Q1: What is a habitat?
Answer: The surroundings where plants and animals live, is called their habitat. A habitat provides suitable climatic conditions like food and shelter so that plants and animals can live there.

Q2: Do all organisms live in same habitat?
Answer: No all organisms do not live in same habitat. Some may share the habitat e.g. lion and deer. For example camel can live in deserts only while frogs can survive in fresh/rain water.


Q3 Are all forests habitats of tigers or lions? 
Answer: No all forest are not habitats of tigers and lions. For example, tigers can live in forests which have thick forests, water (ponds and streams) and rich supply of food (e.g. deer).


Q4: How are cactus adapted to survive in a desert?
Answer: Cactus survive in deserts due to following adaptations:

• It has flat green stem to store water and prepare food by photosynthesis.
• The stem is also covered with a thick waxy layer, which helps to retain water.
• Its roots that go very deep into the soil for absorbing water.
• Leaves are turned into spines to prevent loss of water.

 Q5. Fill up the blanks
Answer:
(a) The presence of specific features, which enable a plant or an animal to live in a particular habitat, is called adaptation.

(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 stimuli called.

(f) Fish have  streamline shaped body that help them to move inside water.

(g) Dolphins and whales breathe through nostrils or blowholes.

(h) In the mountain regions, the trees are normally cone shaped and have sloping  branches.

Q6: Which of the things in the following list are nonliving?Plough, Mushroom, Sewing machine, Radio, Boat, Water hyacinth, Earthworm

Answer: Non-living Things: Plough, Sewing machine, Radio, Boat,

Mountain Region - Sonmarg

Q7: Name two plants and two animals of mountain regions.

Answer:  Animals: Yak, Snow leopard, mountain goat.

Plants: Pines, Spruce, Fir, Cedar

Q8: Give an example of a non-living thing, which shows any two characteristics of living things.

Answer: A bus or a car which shows movement and consume energy (petrol).


Q9: 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: Following are the things which were once part of living beings:

• Butter: Obtained from milk from dairy animals.
• Leather: From animal skin of buffaloes, cows etc.
• Wool: From hair of sheep and goat
• Cooking oil: seeds of plants (e.g. mustard) or by grinding whole plant (e.g. olive), 
• Apple: fruit from apple tree
• Rubber: Latex of rubber tree.

Following things were never part of living beings: soil, electric bulb, salt.

Q10: List the common characteristics of the living things.
Answer:

1. Movement: All organisms show movement of one kind or another. Animals can move from one place to another. While plants also show movement e.g. bend towards light.
2. Respiration: All organisms breathe and respire. They intake oxygen and release carbon di-oxide.
3. Feeding: They consume food to stay fit and grow.
4. Growth and Death: All living beings grow i.e. with age they become larger in size and eventually die.
5. Excretion: They remove waste material their bodies.
6. Reproduction: Living being bear children.
7. Stimuli or Sensitivity: All living beings react to external changes around them.

Q11: 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:  In the grassland there are less number of trees and places to hide. The animals are vulnerable to predators (e.g. lions, tigers, wolves etc.). They can only survive and escape if they run very fast. Therefore speed is important for survival in the grasslands for animals (e.g. deer) that live there.

Q12: Give examples of animals which give birth to young ones.

Answer: Humans, dogs, cats (mammals) give birth to young ones.

Q13: Give examples of Terrestrial habitats.

Answer: Deserts, forests, grasslands, coastal region, mountain regions.

Q14: Give examples of aquatic habitats. 

Answer: Aquatic habitat includes rivers, ponds, lakes, ocean and swamps.

Q15: What is Acclimatization? How it is different from adaptation?

Answer: The small adjustments by the body to overcome small changes in the surrounding atmosphere for a short period of time are called acclimatization. While in adaptation, it takes thousands of years for a livings being to adapt to its habitat.

Q16: What are the two components of habitat?
Answer:

• Biotic component
• Abiotic component

Q17: Why is adaptation necessary? What does happen to those animal who do not adapt to the environment?

Answer: Over thousands of years, the abiotic factors of a region change. To survive animals and plants must adapt to these changes. Those animals which cannot adapt to these changes die out, and only the adapted ones survive.

Q18: Do animals have the same kind of adaptations? Explain with an example.

Answer: Animals adapt to different abiotic factors in different ways. For example, to survive in deserts, camels have long legs and padded feet. While desert animals like snakes and rats do not have long legs, but they stay in burrows deep in the sand and come out during night, when it is cooler.


Q19: Name four important abiotic factors needed for growth of plants.

Answer: 

• Soil
• Air
• Water 
• Sunlight

Concept Map on Types of Habitat

Habitats

(In progress...)

CBSE Class 6 - Science - CH 16 - Garbage In Garbage Out

CBSE Class 6 - Science - CH 16 - Garbage In Garbage Out

Garbage In Garbage Out

Trash Cans
(Green Bin:Recyclable,
Red Bin:Non Recyclable garbage)
credits: By Scott Meltzer

(NCERT Chapter Answers and Q & A)

Q1: Fill in the blanks

Answer:
1. Converting plant and animal waste including that from kitchen, into manure, is calledcomposting.
2. A garbage dump is also used as landfill.
3. The method of making compost from kitchen garbage using redworms is called vermicomposting.
4. Consuming food packed in such plastic bags could be harmful to our health.



Q2: (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.

redworms - friends of farmers
credits: Petr Kratochvil

Answer: Non bio-degradable waste like pieces of cloth, polythene bags, broken glass, aluminium wrappers, nails, old shoes and broken toys cannot be converted into compost by the redworms.

(b) Besides redworms there are spiders, small bugs, flies, moulds and small insects etc. can be seen in the pit. Compost is also rich of microbes which can't be seen with unaided eye.



Q3: 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) Garbage Disposal is the responsibility of every citizen. If we continue to generate so much garbage, very soon our beautiful earth will convert into a big garbage-bin. Non-biodegradable waste like plastic is harmful to our environment as well as to our health. We must ensure ways to reduce production of garbage. Wherever possible, we must use recyclable material in our daily use.

(b) Yes it is possible to reduce the problems relating to disposal of garbage to a large extent. We should use those materials which are recyclable. We should avoid or reduce the use of non-biodegradable materials at minimum level. While throwing out garbage in trash can, we should separate biodegradable waste from non-biodegradable and throw them in separate bins.

Q4: (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) Left over food can be collected and be converted into compost. We can feed our pet animals with left over food. If enough food is left  (e.g. after a party), we may distribute the food to shelter homes.

(b) Banana leaf is a better choice. It is bio-degradable and can be disposed easily. On the other hand, eating in plastic plate is not good. Plastic material may contain harmful substance which can make the contained food toxic. which is harmful to our health. Also plastic is non-biodegradable, it will not dispose off easily.

Q5: (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) Almost all kinds of paper are recyclable i.e. newspapers, magazines, papers, notebooks, envelopes etc.

(b) The difference between new sheet and recycle paper is subtle. Usually hand made recycled paper is of coarse quality.

Q6:  (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 used commonly are:

1. Cardboard - used as shoe boxes
2. Plastic Bags - Toys covers, sarees bags
3. Wooden Boxes - Fruit baskets
4. Jute Bags - School bags, shopping bags

(b) Since plastic is harmful to our environment and is non-biodegradable. We should avoid using plastic packaging.

(c)  The basic purpose of packaging is to protect the product from tampering and to maintain its freshness. However, most of the packaging material is used to beautify the boxes and make them look attractive on the shelves. Unfortunately a large volume of packaging material goes waste and is thrown into dustbin. For example, if you go to any park, there dustbins are full of potato chips wrappers. It unnecessarily increases the amount of garbage. It also increase the cost of the product due to unnecessary packaging. We should seriously consider how to reduce unnecessary packaging. We should prefer buy products carry less packaging material.

Q7: Do you think it is better to use compost instead of chemical fertilisers? Why?

Answer:  No doubt compost is better to use than chemical fertilizers due to following reasons:

1. Compost is much easier to prepare.
2. Compost is environment friendly whereas fertilizers can harm our health and the environment.
3. Compost does not pollute our environemnt.
4. Compost decomposes bio-degradable waste into natural soil. It conserves our environment.

Q8: How do redworms prepare vermicompost?

Answer: Red worms have a special structure called gizzards in their bodies with which they grind food material and covert it into manure.

Q9: What will happen if garbage is not disposed off?

Answer: If garbage is not properly disposed off, these garbage dumps turn into breeding grounds for micro-organisms, flies, cockroaches and mosquitoes, that may cause diseases.

Q10: Why is it illegal to burn leaves and other plant wastes?

Answer: Burning of leaves and other plant wastes produces smoke and gases that are harmful to
our health. They may lead to asthma and lung diseases. Instead of burning, these plant wastes must be converted into manure.

Q11: Why should we not throw plastic bags or wrappers carelessly on roads and other places?

Answer: The plastic bags thrown away carelessly on roads and other places get into drains and the sewer system. As a result, drains get choked and the water spills on the roads. During heavy rains,
it might even create a flood like situation.
Sometimes, these bags are eaten by stray animals like cows, dogs etc. These bags are toxic in nature and affect their health.

CBSE class 6 - Science - CH 15 - Air Around Us

CBSE class 6 - Science - CH 15 - Air Around Us

Air Around Us

Air Balloon

NCERT Solution and Q & A

Q1: What is the composition of air?
Answer: Air is a mixture gases, water vapours and dust particles. Largely it consists of:

1. Nitrogen (79%)
2. Oxygen (20%)
3. Carbon Di-Oxide (1%)
4. Other gases like Helium, Hydrogen etc.
5. Water Vapours
6. Dust particles

Q2: What are the important properties of air?

Answer: Important properties of air are:

1. Air occupies space.
2. Air is present every where including water and soil.
3. Air is transparent.
4. Air is colourless.
5. Air is essential for life on earth.

Q3: Which gas in the atmosphere is essential for respiration?
Answer:  Oxygen is essential for living organisms.


Q4: How will you prove that air supports burning?

Answer: Place a burning candle in a tray. Cover it with a glass jar. To make it air-tight, fill tray with water. After sometime, burning candle dims and goes off. Water level also rises up in the jar. It shows air support burning.

Explanation: During burning, oxygen is consumed and carbon-dioxide is released. After sometime no oxygen is left inside the jar and flame goes out. Once the candle goes off, the temperature surrounding the candle cools down and volume of air (carbon dioxide) decreases. Thus water rises up little in the jar.

Q5: How will you show that air is dissolved in water?

Answer: Take some water in a glass vessel or beaker. Heat it slowly on a tripod stand. Well before the water begins to boil, look carefully at the inner surface of the vessel. These bubbles come from the air
dissolved in water.


Q6: Why does a lump of cotton wool shrink in water?

Answer: Air is present in the cotton wool. When dipped in water, air present in wool escape and it shrinks.

Q7: Fill in the blanks:

Answer: 
1.  The layer of air around the earth is known as _atmosphere_.

2. The component of air used by green plants to make their food, is _carbon dioxide__.

3. Air occupies _space_.

4. Aquatic animals use _dissolved_ air in water for respiration.

Q8: List five activities that are possible due to the presence of air.

Answer:

1. Animals use air for respiration.
2. Plants use air to prepare their food. (photosynthesis)
3. Power generation by wind mills.
4. Burning of fuels and substances.
5. Air helps in the scattering of seeds and pollens of plants. (pollination).
6. Air helps in the movements of sailing yachts, gliders, parachutes and aeroplanes.

Q9: How do plants and animals help each other in the exchange of gases in the atmosphere?

Answer:  There is the interdependence of plants and animals. Both plants and animals respire i.e. they inhale oxygen and gives out carbon dioxide in the atmosphere. Plants take carbon dioxide from the atmosphere and prepare food. This is called photosynthesis. During this process, plants give out oxygen to the atmosphere. Therefore plants and animals help each other in the exchange of gases in the atmosphere.

Q10:Why do why earthworms come out of the soil, only during heavy rains?

Answer: Most of the small organisms like earth worms, rodents live inside the soil. They usually live in burrows and holes in the soil. These burrows also make spaces available for air to move in and out of the soil. However, when it rains heavily, water fills up all the spaces occupied by the air in the soil. In this situation, animals living in the soil have to come out for respiration.

Q11: What is the use of Nitrogen?

Answer: Nitrogen is used in protein synthesis. Nitrogen is an important constituent of amino-acids which manufacture proteins, Proteins are required by living organisms to grown and repair their body parts.

Q12: How Oxygen is removed from the atmosphere?

Answer:

1. Through combustion or burning of substances,
2. Through respiration by living beings.
3. Rusting of iron.

CBSE Class 6 - Science - CH 12 - Electricity and Circuits Electricity and Circuits

CBSE Class 6 - Science - CH 12 - Electricity and Circuits

Electricity and Circuits

NCERT Chapter Solutions and Q & A

Q1. Fill in the blanks :
(a) A device that is used to break an electric circuit is called _______________.
(b) An electric cell has _______________ terminals.
(c) Electric cell is a device which converts energy of chemicals into ________________energy.
(d) The electric energy which is supplied in our home comes from electric  _______________houses.
(e) An electric ______________ is a continuous path along which the current flows.
(f) If the filament of a bulb breaks, it is said to be ______________.
(g) Rubber is a good example of electric ______________.
Answer:
(a) switch
(b) two terminals
(c) electrical
(d) poles nearby
(e) circuit
(f) fused
(g) insulator

Q2: Mark 'True' or 'False' for following statements:


Answer:
(a) Electric current can flow through metals. (✓ True)
(b) Instead of metal wires, a jute string can be used to make a circuit. (✗ False)
(c) Electric current can pass through a sheet of thermocol. (✗ False)
(d) When current flows through a circuit, the circuit is called open circuit. (✗ False)
(e) An electric bulb has one terminal (✗ False)

Q3: What is an electric cell?

Answer: An electric cell is a device which converts chemical
energy into electric energy. It has two different metal plates:

• one is the positive terminal
• the other is the negative terminal

These plates are kept inside a chemical called electrolyte, which stores the chemical energy.

Q4: Explain why the bulb would not glow in the arrangement shown in Fig. below:

Answer: The handle of the screw driver acts as an insulator. It does not allow current to flow and circuit is still open. Therefore the bulb does not glow in the arrangement.

Q5: Complete the drawing shown in Fig  below to indicate where the free ends of the two wires
should be joined to make the bulb glow. 

Answer: The bulb will glow when circuit is complete i.e. one end of the wire from clip is connected to positive terminal. Second end of the wire from the clip is connected to the bulb.

Q6: Would the bulb glow after completing the circuit shown in Fig. above (Q5) if instead of safety pin we use an eraser?

Answer: No. An eraser is made of rubber which is a poor conductor of electricity. Therefore, bulb would not glow.

Q7: What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them. 

Answer: An electric switch is a simple device which is used to break or complete an electric circuit. Switches are widely used in different electrical or electronic gadgets. A few are:

• Toggle switches used in houses.
• Pushbutton switches used in microwaves, water pump, mixer etc.
• Joystick switches used in Video Games Controllers, Toy Cars etc.

Q8: Do all materials allow electricity to pass through them?

Answer: No.

Q9: Would the bulb glow in the circuit shown in Fig. below?

Answer: The electric bulb has two terminals, both the wires are connected to the one terminal of the bulb. Current will not flow from the bulb and it will not glow. To make glow, the two wires should be connected to each terminal of the bulb, as shown below.

Q10: What are the components of an electric circuit?

Answer: In general a circuit has the following components:

1. A cell or battery : source of electricity.
2. Connecting wires
3. Bulb or electric device
4. Key or switch.

Q11: How many terminals are there in an electric cell?

Answer:An electric cell has two terminals; positive and negative. The metal cap is the positive terminal of the cell. The metal disc is the negative terminal.

Q12: 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:Since the object allows current to flow and completes the circuit. Due to this bulb begins to glow. It means the object is a conductor of electricity.


Q13: What are conductors? Give examples.

Answer:  The materials which allow electric current to pass through them are called conductors.
Examples are: All metals (copper, silver, iron) are good conductors. Water usually contains impurities and traces of salt is also a good conductor. Human body is also a conductor.


Q14: What are insulators? Give examples.

Answer: Materials that do not allow electricity to pass through them are called insulators. Insulators oppose electric current and so they are used as protection from the dangerous effects of electricity.
Examples of  insulators are glass, air, plastic, cotton, thermocol, wood and rubber.

Never touch electric circuit boards
(image credits: Phillip Martin)

Q15: Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain


Answer: Electricians need to touch copper wires or they may accidentally come in contact with live wires (wires carrying current). Since human body is also a good conductor, electricians may get shock. Rubber is good insulator. To prevent themselves from electric shock or flow of current, the electricians use rubber gloves while repairing.

Q16: 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: Without the help of insulators, the use of electrical tools like pliers and screwdrivers is impossible. Wood and plastics are insulators and help in avoiding direct contact with electric current.  When electricians touch these live electric wires with the tools covered with plastic and wood, current does not flow in their body avoid any accident.

Q17(MCQ): In an electric bell, the electric energy is transformed into ____________energy.
(a)Mechanical energy
(b) Magnetic energy
(c) Sound energy
(d) Light energy

Answer:  (b) Magnetic energy

Q18(MCQ): The tiny coiled metal wire present inside the bulb is called____________.
(a) Element
(b) Conductor
(c) Filament
(d) None of these

Answer: (c) Filament


Q19(MCQ): Which of the following is NOT a good conductor of electricity?


(a) Mercury
(b) Copper
(c) Plastic
(d) Aluminum foil


Answer: (c) Plastic


Q20(MCQ): Which of the following is a good conductor of electricity?

(a) Wood
(b) Paper
(c) Glass
(d) Graphite

Answer:  (d) Graphite


Q21: What will happen if you join the two terminals of a cell without connecting them through a switch or a bulb?

Answer: By doing so, the chemicals in the electric cell get used up very fast and the cell will no longer produce electric current. It will stop working.

Q22: Why do an electric bulb and an electric cell have two terminals?

Answer: Because the two terminals (positive and negative) can be connected to form an electric circuit.

Q23: Is Distilled water a conductor of electricity?

Answer: No. The distilled water is the purest water and it acts as an insulator. Therefore, it used in batteries as an insulator. The tap water, sea water contains some traces of salts and impurities, due to which it becomes good conductor of electricity.

CBSE-Class 6 - Science - Ch8 - Body Movements NCERT Chapter Solutions and other Q & A

CBSE-Class 6 - Science - Ch8 - Body Movements

NCERT Chapter Solutions and other Q & A

Bones help in movement
(credits:bestanimatios.com)

Q1: Fill in the blanks:

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 _muscle_ pulls the bones during movement.




Q2: Indicate true (T) and false (F) among the following sentences.


Answer:

(a) The movement and locomotion of all animals is exactly the same. (False)
(b) The cartilages are harder than bones. (False)
(c) The finger bones do not have joints. (False)
(d) The fore arm has two bones. (True)
(e) Cockroaches have an outer skeleton. (True)

Q3: Match the items in Column I with one or more items of Column II.

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

Q4:What is a ball and socket joint?

Answer: A ball and socket joint is a moveable joint. It has a rounded end of one bone fit into the cavity (hollow space) of the other bone. It allows movement in all directions. Example: shoulder joints.

Q5: Which of the skull bones are movable?

Answer: Only the lower jaw in skull bones is movable.

Q6: Why can our elbow not move backwards?

Answer: Elbow joint is an example of hinge joint which allows movement back and forth. Therefore, we cannot move our elbow backwards.

Q7: What are joints?

Answer: The place where two bones meet in a skeleton is called a joint.


Q8: How do animals move from place to place? Fill the table.


Answer:

Animal	Body part used              for moving from               place to place	How does the animal move?
Cow	Legs	Walk
Humans	Legs	Walk
Snake	Whole body	Slther
Bird	Feather	Fly
Insect	Wings, Legs	Fly, Hop
Fish	Fins, Whole Body	Swim

Q9: What are bones made up of?

Answer: Bones are made up of Calcium, Phosphorus, and other minerals.

Q10: What is a skeleton? 

Answer: The framework of the body formed by the bones and cartilages is called skeleton.

Q11: What are the functions of skeleton?

Answer:

1. Skeleton provides framework and shape to the body.
2. It protects the internal organs (like heart, lungs, brain etc.) of the body.
3. Bone marrow (present in long bones) produces red blood cells and platelets.
4. It acts as lever and helps in movement and locomotion.

Q12: Name the longest bone in the human body.

Answer: The longest bone in the human body is the thigh bone or femer.  It is about 45cm long.

Q13: Name the smallest bone in the human body.

Answer: Stapes is the smallest bone present inside the ear.

Q14: How many bones usually a human body has?

Answer: Human body has 206 bones.

Q15: Why do doctors use X-Ray images?

Answer: Sometimes when we are hurt, or have an accident, doctors use these X-ray images to find out if there is any injury to the bones. The Xrays show the shapes of the bones in our bodies.

Q16: List some important parts of the skeleton.
Answer: 

1. Skull
2. Ribcage
3. Backbone
4. Pelvic bones
5. Shoulder bones
6. Arms bones and leg bones

Q17: What is a Ribcage? How does it help to our body? 

Answer: Ribcage is box like structure which is a part of our skeletal system. It consists of 12 pairs of curved bones called ribs. They join the chest bone and the backbone together to form a box. Ribcage protects the internal organs of the body like heart, lungs.

Q18: What is a skull? What is its function?

Answer: The bony part of head is called skull. The skull is made up of many bones joined together. Only the lower jaw bone is movable. It protects the brain.

Q19: How does human body perform its movement activities?

Answer: Human body perform all these activities with the help of the movements of the bones and muscles.

Q20: Do muscles push and pull both?

Answer: No, muscles can pull only. That;s why to move a bone, a pair of muscles act in opposite directions.

Q21: What is the difference between bone and cartilage?

Answer: Bone is hard and inflexible. E.g. femur (thigh bone). While cartilage is soft and flexible. E.g. Ear and nose bones are actually cartilage.