Author name: Prasanna

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

These NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Sorting Materials into Groups NCERT Solutions for Class 6 Science Chapter 4

Class 6 Science Chapter 4 Sorting Materials into Groups Textbook Exercise Questions and Answers

Question 1.
Name five objects which can be made from wood.
Answer:
Table, chair, doors, boat and bed.

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

Question 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.

ObjectsMaterials
BookGlass
TumblerWood
ChairPaper
ToyLeather
ShoesPlastic

Answer:

ObjectsMaterials
BookPaper
TumblerGlass and Plastic
ChairWood and Plastic
ToyPlastic and Wood
ShoesLeather

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Question 4.
State whether the statements given below are True or False:
a. Stone is transparent, while glass is opaque.
b. A notebook has lustre while eraser does not.
c. Chalk dissolves in water.
d. A piece of wood floats on water.
e. Sugar does not dissolve in water.
f. Oil mixes with water.
g. Sand settles down in water.
h. Vinegar dissolves in water.
Answer:
a. False
b. False
c. False
d. True
e. False
f. False
g. True
h. True

Question 5.
Given below are the names of some objects and materials:
Water, basketball, orange, sugar, globe, apple and earthen pitcher
Group them as:
a. Round shaped and other shapes
b. Eatables and non-eatables
Answer:
a. (i) Round shaped: Basketball, apple, orange, globe, earthen pitcher
(ii) Other shapes: Water, sugar

b. (i) Eatables: Water, orange, sugar and apple
(ii) Non-eatables: Basketball, globe and earthen pitcher

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

  • Dried leaves
  • Paper
  • Wax
  • Ice
  • Oil

All these materials float on water and they sink in oil or kerosene.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Question 7.
Find the odd one out from the following:
a. Chair, Bed, Table, Baby, Cupboard
b. Rose, Jasmine, Boat, Marigold, Lotus
c. Aluminium, Iron, Copper, Silver, Sand
d. Sugar, Salt, Sand, Milk, Milk powder
Answer:
a. Baby
b. Boat
c. Sand
d. Milk

NCERT Extended Learning Activities and Projects

Question 1.
You may have played a memory game with your friends. Several objects are placed on a table, you are asked to observe them for a few minutes, go into another room and write down the names of all objects that you can remember. Play this game, with a difference! Ask all the participants in the game to remember objects with some particular property’ while playing this memory game – remember and write down the names of objects that were made of wood or objects that are edible and so on. Have fun!
Hint:
Do it yourself.

Question 2.
From a large collection of materials, make groups of objects having different properties like transparency, solubility in water and other properties. In later chapters you will also learn about properties of materials related to electricity and magnetism. After making different groups from the collected materials, try and find out if there are any patterns in these groups. For instance, do all materials which have lustre conduct electricity?
Hint: It is not necessary to find a correlation between all properties. For example, mirror has lustre but does not conduct electricity.

Activity 1

Objective: To study whether the given material is soluble or insoluble in water.
Materials Required: Water, sugar, chalk, washing soda, sand, copper sulphate and sulphur.
Procedure:

  • Take 6 beakers and fill each of them to half with water.
  • Add a pinch of sugar, chalk powder, washing soda, sand, copper sulphate and sulphur in separate beakers.
  • Stir the contents of each beaker well and allow them to stand for a while.
  • Observe after few minutes.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups 1
Observations: Particles of sugar, washing soda and copper sulphate have disappeared. Chalk powder, sand particles and sulphur are left as such.
Conclusion: Sugar, washing soda and copper sulphate are soluble in water. Sand, chalk powder and sulphur are insoluble in water.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Activity 2

Objective: To study the solubility of different liquids in water.
Materials Required: One spoon each of vinegar, lemon juice, honey, milk, coconut oil, mustard oil, kerosene and seven glass tumblers with water.
Procedure:

  • Add a small amount of vinegar to the first glass, lemon-juice to the second and similarly, add small amounts of the other liquids into other glasses containing water.
  • Stir contents of each of them with a spoon. Wait for 5 minutes.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups 2
Observations: Vinegar, lemon juice, honey and milk have completely dissolved in water. Such liquids are miscible liquids. Liquids like coconut oil, mustard oil and kerosene have not dissolved. Such liquids are immiscible or insoluble liquids.

  • Metal: It is a hard, shiny, usually solid material which is able to be shaped and can conduct or allow electricity and heat to pass through it.
  • Transparency: Light can pass through certain objects. Due to this, we are able to see through the objects. This property of materials to allow light to pass through them and enable visibility is called transparency. On this basis, objects can be of three types:

i. Transparent: If almost all the light can pass through an object, it is called transparent. We can see clearly through transparent materials such as air, water and a clear glass.
ii. Opaque: If no light can pass through an object, it is called opaque. We cannot see through an opaque material at all, such as cardboard, milk, stone and metal.
iii. Translucent: If light can pass through an object partially, it is called translucent. We cannot clearly see through a translucent material such as a frosted glass, turbid water and dust-laden air. Such materials allow partial visibility.

Activity 3

Objective: To distinguish between transparent, opaque and translucent materials.
Materials Required: Apiece of a clear glass, a cardboard, oily paper and torch.
Procedure:

  • Take a torch and point it to each of the three objects-a clear glass, a cardboard and oily paper one by one.
  • Write down what happens when light is pointed to each of the objects.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups 3
Observation: Light passes through the piece of glass. No light passes through the cardboard. Only a little amount of light passes through the oily paper.
Conclusion: Glass is a transparent material as it allows the light to pass through it. Cardboard is an opaque material as it does not allow the light to pass through it. The oily paper is a translucent material as it allows only some light to pass through it.

  • Rough or Smooth: An object having an uneven or irregular surface is said to be rough, such as sandpaper. On the other hand, object having a smooth and levelled or a polished surface is said to be smooth. For example, mirror and metals.
  • Floatation: Many materials float, whereas many others sink in water. This property is called floatation. Materials such as wool, leaves and feathers float on the water whereas rocks and metals sink.
  • Density: The mass per unit volume of a substance is known as its density. Materials which are less dense than water float on it. Materials denser than water sink in it.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Activity 4

Objective: To classify different materials on the basis of floatation.
Materials Required: Wooden piece, dry leaf, pebble, eraser, iron nail, pencil, table tennis ball and a bucket half-filled with water.
Procedure:

  • Take all these materials at a time and drop them in the bucket of water.
  • Observe whether each material float on water or sink to the bottom of the bucket.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups 4
Observations: Some materials like dry leaf, pencil, wooden piece and table tennis ball float on the surface of water. Materials like eraser, pebble and iron nail sink to the bottom of the bucket.
Conclusion: Some materials float on water while others sink.

Materials can also be grouped on the basis of whether the object is solid, liquid or gas, whether it is conductor of heat or it is a non-conductor of heat. For example, metals are conductors of heat but wood and plastics are non-conductors of heat.

Need to Group Materials: We group materials due to the following uses:

  • Sorting of materials into groups makes it convenient for us to view them.
  • We can store similar things together and hence can locate them easily.
  • Dividing materials into groups makes it convenient to study their properties and the patterns in these properties.

Class 6 Science Chapter 4 Sorting Materials into Groups Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
Why do we need to group materials? Give reason.
Answer:
We often group materials for our convenience. It helps to describe their properties.

Question 2.
Is a substance which can be compressed soft or hard?
Answer:
Soft.

Question 3.
Choose a lustrous material out of the following substances:
Wood, aluminium, plastic, cotton
Answer:
Aluminium.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Question 4.
Name two objects made from opaque materials.
Answer:
Wooden doors and blackboard.

Question 5.
What is a translucent object?
Answer:
Materials that allow light to pass through them partially are called translucent.

Question 6.
Name three things made from glass.
Answer:
Bowls, mirrors and windowpanes.

Question 7.
Name any three materials that can be used to make school bags.
Answer:
Cotton, jute and leather.

Question 8.
Name two gases which are insoluble in water.
Answer:
Hydrogen and nitrogen.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Question 9.
Name any three objects having rough surface.
Answer:
The bark of tree, rock and sand paper are objects having rough surface.

Question 10.
Define density.
Answer:
Density is mass per unit volume of a substance.

Short Answer Type Questions

Question 1.
Why is a tumbler not made with a piece of cloth?
Answer:
We use tumblers made of glass, plastic and metal to keep a liquid. These substances can hold a liquid. A tumbler made of cloth cannot hold a liquid because:

  • cloth piece is not hard enough to hold liquids, and
  • cloth piece has very minute pores through which the liquid oozes out.

Question 2.
Make a table and state whether the following materials mix with water or not.
Vinegar, lemon juice, mustard oil, coconut oil and kerosene.
Answer:

LiquidsMixes well/Does not mix
1. VinegarMixes well
2. Lemon juiceMixes well
3. Mustard oilDoes not mix
4. Coconut oilDoes not mix
5. KeroseneDoes not mix

Question 3.
Name five objects each which can be made from the following materials:
wood, cotton, leather, paper
Answer:

Material

Objects

1. WoodTable, chair, doors, windows, book-rack
2. CottonFabric (clothes), pillows, mattresses, quilts, wicks
3. LeatherShoes, bags, purses, suitcase, sofa
4. PaperBooks, notebooks, newspaper, calendars, envelopes

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Question 4.
Metals generally occur in solid state and are hard in form. Name a metal that exists in liquid state and a metal that is soft and can be cut with knife.
Answer:
Mercury is a metal that exists in liquid state. Sodium and Potassium are soft metals and can be cut with knife.

Question 5.
Why do we cook food in utensils made of aluminium or other metallic materials?
Answer:
Cooking utensils which are used to cook food are made from aluminium or other metals. The reason is that metals are good conductors of heat. They allow the transmission of heat through them and food cooks quickly. Therefore, utensils are made of metals.

Question 6.
Universal solvent (water) is very essential for the human body. Why?
Answer:
The universal solvent is able to dissolve a number of substances. So it is essential for the human body. It constitutes a major part of the cells located in human body. All materials are transported across the body in dissolved form.

Question 7.
Classify the following into transparent, translucent and opaque materials.
Butter paper, cardboard, ground glass, clear glass, water, air, brick, wall, aluminium sheet
Answer:
Transparent: Clear glass, water, air
Translucent: Butter paper, ground glass
Opaque: Cardboard, brick, wall, aluminium sheet

Question 8.
Classify the following into hard materials and soft materials.
Cotton, iron, diamond, chalk, wood, wax, clay, sponge, bone, feathers
Answer:
Hard materials: Iron, diamond, wood, bone, chalk
Soft materials: Cotton, wax, clay, sponge, feathers

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Question 9.
Write three common characteristics of materials.
Answer:

  1. All materials can be felt by one or more of our senses.
  2. All materials occupy space.
  3. All materials possess mass.

Question 10.
Write a short note on texture.
Answer:
Materials may be rough or smooth. The surface of paper or a glass tumbler feels smooth since there are no uneven surfaces. The bark of tree, rock and sandpaper are rough to touch because their surfaces are uneven and bumpy. So, materials can be classified on the basis of their texture.

Question 11.
Write a short note on floatation.
Answer:
Many materials float, whereas many others sink in water. This property is called floatation. Materials such as wood, leaves and feathers float on the water whereas rocks and metals sink. If you weigh equal volumes of cotton and water, the cotton weigh less than water as cotton is less dense than water.

Long Answer Type Questions

Question 1.
What is classification? How is it useful? Explain with examples.
Answer:
The method of grouping objects on the basis of certain similarities and dissimilarities is called classification. We can understand the importance of classification with the help of simple examples.

a. The things in your house are the most common examples. You classify or group them while arranging them. You keep the utensils in the kitchen, the books in the study room and the bed in the bedroom. It helps in locating the things easily.

b. Classification also enables us to make a systematic study of anything. For example, if you observe the way things have been stocked in your kitchen, you will find that various items are classified. Certain items are classified as spices and stocked together.

Other items may be required for a common activity, say, making a tea. Hence, these are stocked together. You also classify your items and arrange your study table in such a way that you do not have to waste time trying to locate a given item.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Question 2.
Define solubility of materials in water. Give examples.
Answer:
Some materials are soluble in water whereas some are insoluble. For example, sugar is soluble in water whereas sand is insoluble. Actually, water causes all molecules in a solid piece of sugar to break apart. The individual molecules, when separated, are so small that we cannot see them. We can say that sugar is soluble in water. Some solids like sugar and common salt are soluble in water.

On the other hand, sand is insoluble in water. It settles down in water and does not dissolve even on stirring. Some solids are insoluble in water, e.g., wood, stone, chalk and wax. Materials in each state can therefore be classified on the basis of their solubility in water.

Question 3.
Define the properties of matter.
Answer:
Some important properties of matter are discussed below:

  • Appearance: Materials can be classified on the basis of their appearance. Different materials have different appearance.
  • Lustre: Materials can be classified on the basis of their lustre or shine. Some shine a lot whereas others are quite dull.
  • Texture: Different materials feel different when touched, so they have different textures. Some can be rough and others can be smooth.
  • State: Most materials can be placed into one of the three states: solid, liquid or gas.
  • Solubility in water: Some materials are soluble in water whereas some are insoluble. Miscible liquids mix with each other while immiscible liquids do not.
  • Transparency: If almost all the light can pass through an object, it is called transparent. If no light can pass through an object, it is called opaque. If light can pass through an object partially, it is called translucent.

Picture-Based Questions

Question 1.
Observe the given picture and answer the questions.
NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups 5
a. Why should we not use a tumbler made of cloth?
b. What inference can we draw from it?
Answer:
a. Tumbler made of cloth cannot hold water.
b. We should choose a material to make an object depending on its properties and the purpose for which the object is to be used.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups

Question 2.
a. Identify the objects A, B, C and D shown below.
NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups 6
b. Which of these can float on water?
c. Which of these will sink in water?
Answer:
a. A-Leaf, B-Iron, C-Feather, D-Wood.
b. Leaf, feather and wood.
c. Iron.

NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups Read More »

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

These NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Fibre to Fabric NCERT Solutions for Class 6 Science Chapter 3

Class 6 Science Chapter 3 Fibre to Fabric Textbook Exercise Questions and Answers

Question 1.
Classify the following fibres as natural or synthetic.
nylon, wool, cotton, silk, polyester, jute
Answer:
Natural fibres: wool, cotton, jute, silk
Synthetic fibres: Nylon, polyester

Question 2.
State whether the following statements are ‘true’ or false’.
a. Yam is made from fibres.
b. Spinning is a process of making fibres.
c. Jute is the outer covering of coconut.
d. The process of removing seeds from cotton is called ginning.
e. Weaving of yarn makes a piece of fabric.
f. Silk fibre is obtained from the stem of a plant.
g. Polyester is a natural fibre.
Answer:
a. True
b. False
c. False
d. True
e. True
f. False
g. False

Question 3.
Fill in the blanks.
a. Plant fibres are obtained from …………. and ………….
b. Animal fibres are …………. and ………….
Answer:
a. cotton plants, jute plants
b. wool, silk

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Question 4.
From which parts of the plant cotton and jute are obtained?
Answer:
Cotton fibres are obtained from cotton seeds. They are the hair of cotton seeds. Jute fibres are obtained from the stems of jute plants by retting process.

Question 5.
Name two items that are made from coconut fibres.
Answer:
a. Ropes
b. Coir in mattresses

Question 6.
Explain the process of making yarn from fibre.
Answer:
The process of making yarn from fibres is called spinning. In this process, fibres from a mass of cotton wool are drawn out and twisted. This brings the fibres together to form a yam.

NCERT Extended Learning Activities and Projects

Question 1.
Visit a nearby handloom or power loom unit and observe the weaving or knitting of fabric.
Hint: Do it yourself.

Question 2.
Find out if any crop is grown in your region for obtaining fibre. If yes, what is it used for?
Hint: Do it yourself.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Question 3.
India has been a major producer of cotton and its fabric. India exports cotton fabrics and items to many other countries. Find out, how it helps us?
Hint: We export and import cotton fabrics so that we may make money and earn foreign currency. It helps in the development of the country and also used as income of a family.

Activity 1

Objective: To make yam from fibres.
Materials Required: Cotton wool.
Procedure:

  • Take some cotton wool in one hand.
  • Hold some cotton between the thumb and forefinger of the other hand.
  • Gently start pulling out the cotton, while continuously twisting the fibres. We are able to make a yarn.

Observations: Twisting of fibres results in the formation of yarn.
Conclusion: Spinning converts fibres into yarn.

  • Charkha was popularised by Mahatma Gandhi during independence movement. He promoted the use of a homespun fibre called khadi. To popularise khadi, the Indian Government Constituted Khadi and Village Industries Commission in 1956.
  • Fabric: It refers to a woven material, a textile or other material resembling woven cloth. Fabric is made up of yarns. A fabric made by the two main processes known as weaving and knitting.

i. Knitting: The process in which a single yam is used to make a piece of fabric is called knitting. Knitting is done by hand by using knitting needles and also on machines.

Activity 2

Objective: To study the structure of various clothing materials.
Materials Required: One piece of each type of fabric such as cotton, polyester, silk, wool and a magnifying glass.
Procedure:

  • Take each piece of cloth on the table.
  • Observe each one of them with the help of a magnifying glass.
  • Now try to pull out a thread with the help of a needle. This loose thread is called yarn.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric 1

Observations: All fabrics do not appear continuous. These appear to consist of very thin threads crossing each other at right angles. Conclusion: The fabric is made up of yarns arranged at right angles to each other.

ii. Weaving: The process of making a fabric by arranging yarns passing in one direction with other yams at right angles to them is called weaving.

Activity 3

Objective: To try weaving using paper.
Materials Required: Two square chart papers of different colours, scale, pen and scissors.
Procedure:

  • Fold the square sheet in half.
  • Cut evenly-spaced slits starting from the folded edge and continuing up to about half an inch from the opposite edge. It may be helpful to draw vertical lines to use as guide while you cut.
  • Cut coloured paper strips. The strips should be longer than the length of your square’s side.
  • Take one paper strip and weave it horizontally across the slits, going over and under the slits.
  • Push the woven strip to the top and start with another one. The second strip should be woven in an opposite pattern as the first.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric 2
Observation: A pattern is obtained after weaving all the strips.
Conclusion: This demonstrates the process of weaving.

History of Clothing: In ancient times, people used to cover their body using bark and big leaves of trees, animal furs or animal fibres. Later, agricultural communities learnt to weave twigs and grass into mats and baskets. They twisted together animal fleece/ hair or vines into long strands. Early Indians wore cotton fabrics of cotton grown near Ganga river. In ancient Egypt, cotton and flax were cultivated near Nile river. Since, stitching was not known at that time, people used to drape fabrics in different ways. With invention of sewing needle, fabrics were now stitched into clothes. Today, stitched clothes have a wide variety or variations.

Clothing is Necessary: Clothing is necessary for protection against wind and weather, against injury, maintenance of body temperature and decoration of the body to look good.

Class 6 Science Chapter 3 Fibre to Fabric Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
What are fabrics?
Answer:
Fabric is a cloth or other material produced by weaving cotton, nylon, wool, silk or other threads together.

Question 2.
What are yarns made of?
Answer:
Yams are made up of thin strands called fibres.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Question 3.
What material is used for making wicks for oil lamps?
Answer:
Cotton wool.

Question 4.
Where does cotton wool come from?
Answer:
Cotton wool comes from cotton bolls.

Question 5.
Define knitting.
Answer:
The process of making fabric by forming a series of connected loops of a single yam is called knitting.

Question 6.
In which region was the cotton crop grown in India in early days?
Answer:
The early Indians grew cotton crops in the regions near river Ganga to obtain cotton fibres.

Question 7.
Name two products obtained by weaving ‘twigs’ and ‘grasses’.
Answer:
Mats and baskets.

Question 8.
Name the two types of plants which were cultivated near the river Nile in ancient Egypt to obtain fibres for making fabrics.
Answer:
Cotton and flax crops were cultivated near the river Nile and their fibres were used for making fabrics.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Question 9.
Name one synthetic fibre.
Answer:
Polyester.

Question 10.
Which fabric is obtained from the stem of flax plant?
Answer:
Linen.

Question 11.
What are the fibres on the outer covering of coconut called?
Answer:
Coir.

Question 12.
Who encouraged people in India to wear clothes made of homespun yarn?
Answer:
Mahatma Gandhi.

Question 13.
Name the four types of fabrics which are still used in unstitched form in our country.
Answer:
Saree, dhoti, lungi and turban.

Short Answer Type Questions

Question 1.
Why do we need clothes?
Answer:
We need clothes to protect our body from extreme weather conditions, like heat, cold, rain, etc. They protect us from harmful insects, bacteria, dirt, wind and injury. They protect us from foreign, harmful substances falling on our body. Clothes make us look presentable.

Question 2.
What are natural fibres? Explain with examples.
Answer:
The fibres which are obtained from plants and animals are called natural fibres. Fibres of fabrics like cotton, jute, silk, wool, etc., are natural fibres.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Question 3.
What are man-made fibres? Explain with examples.
Answer:
The fibres which are synthesised in industry from simple chemicals obtained from petroleum are called synthetic fibres. Fibres of polyester, nylon, acrylic etc., are synthetic fibres.

Question 4.
List the various steps involved in the preparation of fabrics.
Answer:
The following steps are involved in the preparation of fabrics:

  • Obtaining fibre.
  • Preparation of yarn from fibres by spinning.
  • When two sets of yam are involved, yarns are woven on looms to make a fabric. When a single yam is used, the fabric is prepared by knitting.

Question 5.
Explain how jute is obtained from the jute plant.
Answer:
Jute is sown during the rainy season. The jute plant is normally harvested at flowering stage. The cut plants are allowed to dry in the sun for a few days. When most of the leaves dry and fall off, plants are now tied into small bundles. The bundles are made to sink in stagnant water of a pond for few days where the gummy skin rots out to separate fibres. This process is called retting. These fibres are converted into yams to make fabrics.

Question 6.
What happened to clothing when people began to settle in agricultural communities?
Answer:
When people began to settle in agricultural communities, then they learnt to weave twigs and grasses into mats and baskets. Vines, animal fleece or hair were twisted together into long strands. These strands were woven into fabrics.

Question 7.
When we burn wool, why do we get the smell of hair burn?
Answer:
Wool is an animal fibre. It is obtained from the fleece of sheep, goat, yak, etc. This is the reason why the smell of burning wool resembles that of burning hair.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Question 8.
How was clothing developed?
Answer:
In ancient times, people used to cover their body using bark and big leaves of trees, animal furs or animal fibres. Later, agricultural communities learnt to weave twigs and grasses into mats and baskets. They twisted together animal fleece/hair or vines into long strands. Early Indians wore cotton fabrics of cotton grown near Ganga river. In ancient Egypt, cotton and flax were cultivated near Nile river.

Since, stitching was not known at that time, people used to drape fabrics in different ways. With invention of sewing needle, fabrics were now stitched into clothes. Today, stitched clothes have a wide variety or variations.

Question 9.
What type of soil and climate are good for growing cotton? Name any two states of our country where cotton is mainly grown.
Answer:
Cotton is usually grown at places having black soil and warm climate. In India, cotton is mainly grown in the states of Maharashtra and parts of Andhra Pradesh, Madhya Pradesh and Gujarat.

Question 10.
Differentiate between cotton and jute.
Answer:
Cotton is a white fibrous substance covering the seeds of cotton plant. Cotton plants are grown as a crop to obtain cotton. Cotton plants are usually grown at places having black soil and warm climate. Jute, on the other hand, is obtained from the stem of jute plant, often called Putson. Jute is mainly grown in West Bengal, Bihar and Assam.

Question 11.
Write some uses of jute.
Answer:
Jute fibres are used for making gunny bags, cheap rugs, carpets, curtains, coarse clothes, ropes, potato sacks, etc. Nowadays, fine quality of jute is used in making jute fabric.

Long Answer Type Questions

Question 1.
Describe the process of formation of yarn from cotton wool.
Answer:
Cotton fibres are obtained from the cotton plant. Fibres are obtained from the fruit, called boll, of the plant. When the boll matures, it splits exposing the raw cotton fibres. The heat of the sun dries the fibres. The dried bolls are harvested (i.e. picked) and cotton fibres are separated from the seeds. The process of separating cotton fibres from seeds is called ginning. It is done by hand or by machine. These fibres are then converted into yam by using spinning machines.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Question 2.
How will you differentiate between cotton, wool, silk and synthetic fabrics?
Answer:
We can differentiate between the cotton, wool, silk and synthetic fabrics by performing the burning test as follows: Take a small piece of the fabric to be tested. Pull out a fibre from it. Hold one end of the fibre with a pair of tongs and bring the other end of the fibre over the flame of a burner.
NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric 3

  • If the piece of fabric bums vigorously giving a smell of burning paper, then it is cotton fabric.
  • If the piece of fabric burns giving a smell of burning hair, then it is woollen fabric.
  • If the piece of fabric bums giving the smell of charred meat, then it is silk fabric.
  • If the piece of fabric bums giving the smell of burning plastic, then it is a synthetic fabric.

Question 3.
What is a loom? For what purpose is it used? What is the difference between handloom and power-loom?
Answer:
A device for making fabrics by weaving yarn or threads is called a loom. The weaving of the yarn to make fabrics is done by using looms.

  • Handloom: It is a cloth weaving machine which is manually operated. In many parts of our country, handloom cloth is produced in large quantities.
  • Power-loom: It is a medium-sized weaving machine run on power. It is used to produce cloth on large scale in cloth producing industry.

Question 4.
Name the plants and their parts used for making clothes.
Answer:
The following plants and their parts are used for making clothes:

  • Cotton plants: Cotton fibres are obtained from their seeds. Their seeds have white fluffy fibres attached to them, wherefrom threads are made and then cloth is prepared.
  • Jute plants: The stem of jute plant is removed and processed and then yam is prepared from them.
  • Coconut: The fruits of coconut bear fibres which are used for preparing yam.
  • Mango trees: The seeds of mango have fibres which are also used for preparing clothes.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Question 5.
Describe the process of spinning and weaving.
Answer:
Spinning: The process of making yarn from fibres is called spinning. In this process fibres from a mass of cotton wool are drawn out and twisted. By this, fibres come together to form a yarn. Spinning can be done by hand, by takli and charkha. On a large scale, spinning is done with the help of machines.

Weaving: The process of arranging two sets of yams together to make a fabric is called weaving. The process of weaving can be done on looms. The looms are either hand-operated or power-operated.

Picture-Based Questions

Question 1.
Identify the following picture and name who popularised the use of this device.
NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric 4
Answer:
The diagram shows a charkha. The use of charkha was popularised by Mahatma Gandhi.

Question 2.
a. Observe the following picture and tell what the woman is doing in the picture.
NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric 5
b. Name the device by which this process can be done.
Answer:
a. The woman is weaving fabrics on loom by hand.
b. This process can be done using hand-operated or power-operated looms.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Question 3.
Identify the following picture. Name the process.
NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric 6
Answer:
The process is knitting. It is used to convert a single yarn into fabric.

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric Read More »

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

These NCERT Solutions for Class 6 Science Chapter 2 Components of Food Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Components of Food NCERT Solutions for Class 6 Science Chapter 2

Class 6 Science Chapter 2 Components of Food Textbook Exercise Questions and Answers

Question 1.
Name the major nutrients in our food.
Answer:
The major nutrients in our food are carbohydrates, proteins, fats, vitamins, minerals, dietary fibres and water.

Question 2.
Name the following:
a. The nutrients which mainly give energy to our body.
b. The nutrients that are needed for the growth and maintenance of our body.
c. A vitamin required for maintaining good eyesight.
d. A mineral that is required for keeping our bones healthy.
Answer:
a. Carbohydrates and fats
b. Proteins
c. Vitamin A
d. Calcium

Question 3.
Name two foods each rich in:
a. Fats
b. Starch
c. Dietary fibre
d. Proteins
Answer:
a. Fats: Butter and ghee
b. Starch: Raw potato and rice
c. Dietary fibre: Spinach and cabbage
d. Proteins: Milk, eggs, fish and meat

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

Question 4.
Tick (✓) the statements that are correct.
a. By eating rice alone, we can fulfil nutritional requirement of 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.
Answer:
a. Incorrect
b. Correct
c. Correct
d. Incorrect

Question 5.
a. ………………. is caused by deficiency of Vitamin D.
b. Deficiency of ………………. causes a disease known as beri-beri.
c. Deficiency of Vitamin C causes a disease known as ……………….
d. Night blindness is caused due to deficiency of ………………. in our food.
Answer:
a. Rickets
b. Vitamin B1
c. Scurvy
d. Vitamin A

NCERT Extended Learning Activities and Projects

Question 1.
Prepare a diet chart to provide balance diet to a twelve year old child. The diet chart should include food items which are not expensive and are commonly available in your area.
Answer:
Do it yourself.

Question 2.
We have learnt that excess intake of fats is harmful for the body. What about other nutrients? Would it be harmful for the body to take too much of proteins or vitamins in the diet? Read about diet related problems to find answers to these questions and have a class discussion on this topic.
Answer:
Excessive intake of any nutrient may prove harmful and can lead to several health related problems.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

Question 3.
Test the food usually eaten by cattle or a pet to find out which nutrients are present in animal food. Compare results obtained from the whole class to conclude about balanced diet requirements for different animals.
Answer:
Animals eat a variety of food and fodder. It comprises of various nutrients including proteins, carbohydrates, fibres, vitamins, minerals, etc. They also eat a large amount of cellulose from the leaves and grasses.

Activity 1

Objective: To test the presence of starch in potato.
Materials Required: A potato, knife, iodine solution and dropper.
Procedure:

  • Take a piece of freshly cut potato.
  • Put 2-3 drops of dilute iodine solution on the freshly cut surface of the potato piece with the help of a dropper.
  • If the colour of the cut surface of potato becomes blue-black, then it indicates the presence of starch in it.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food 1
Observation: The potato turns iodine solution to blue-black colour.
Conclusion: The appearance of blue-black colour shows that potato contains starch.

ii. Fats: The energy-providing substances in the food are called fats. They are the richest source of energy. Fats produce more energy than carbohydrates, e.g., ghee, oiL, butter, etc. Food containing fats and carbohydrates are called energy giving foods.
NCERT Solutions for Class 6 Science Chapter 2 Components of Food 7

Activity 2

Objective: To test the presence of fats in the given food sample.
Materials Required: Foods sample (groundnut) and paper.
Procedure:

  • Take some solid food item and wrap it in a piece of paper.
  • Crash the food in the paper without tearing it.
  • Open and observe the paper carefully.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food 2
Observation: An oily patch appears on the paper.
Conclusion: The oily patch on paper indicates the presence of fats.

iii. Proteins: Proteins are called the body building food. They are essential for the growth and repair of the body tissues. Milk, pea. pulses. nuts, eggs and meat are sources of proteins.
NCERT Solutions for Class 6 Science Chapter 2 Components of Food 8

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

Activity 3

Objective: To test the presence of protein in a solid foodstuff.
Materials Required: Crushed foodstuff, copper sulphate solution, sodium hydroxide solution, water, test tube and Bunsen burner.
Procedure:

  • Take some crushed foodstuff such as sprouted seeds, in a test tube.
  • Put in some water to the test tube and shake it, keeping its mouth covered with your thumb.
  • Fleat the test tube for sometime over burner.
  • After it has cooled down, add a two drops of copper sulphate solution and ten drops of sodium hydroxide solution to the test tube.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food 3
Observation: A violet colour develops in the solution.
Conclusion: The violet colour indicates that the given foodstuff contains proteins.

iv. Vitamins: The substances which are required in very small quantities by our body to keep eyes. bones, teeth and gums healthy are called vitamins. They do not provide energy. They are called protective food.
NCERT Solutions for Class 6 Science Chapter 2 Components of Food 9

VitaminFood SourceFunction
Vitamin ACarrot, papaya, mangoKeeps skin and eyes healthy
Vitamin BWheat, rice, liverEnhances energy and brain functioning
Vitamin COrange, tomato, lemon, amla, guavaHelps body to fight against diseases
Vitamin DFish, egg, liverHelps body to use calcium for our bones and teeth

v. Minerals: The substances which are required by our body in very small quantities and protect our body are called minerals. They do not provide energy. They are also protective food.
NCERT Solutions for Class 6 Science Chapter 2 Components of Food 10

MineralSources
1. IodineSpinach, ginger, fish
2. PhosphorusMilk, banana, grains
3. IronApple, spinach, liver
4. CalciumMilk, eggs
  • Cellulose is a tasteless white powdery material. It is present in plant cell-wall, wood, cotton, etc. Human beings cannot digest cellulose.
  • Roughage: It consists of the tough parts of vegetables and grains that help you to digest your food and help your bowels to work properly. These are also called dietary fibres and are mainly present in plant products such as whole grains, pulses, fresh fruits and vegetables.
  • Our body also needs water to absorb nutrients from food and removing waste in the form of urine, sweat, etc. We can get water through liquids such as drinking water, tea, milk and eating cooked food.
  • Balanced diet: A diet which contains adequate amounts of all essential nutrients, namely, carbohydrates, fats, proteins, vitamins, minerals and roughage, in the right proportions is called a balanced diet. Examples of foods that contain a lot of nutrients include pulses, soybean, groundnut, sprouted seeds, fermented foods, jaggery, sattu, etc.
  • Cooking of Food: Vegetables and fruits should be washed before peeling them to avoid washing away of nutrients. The skins of some fruits and vegetables is also rich in vitamins and minerals and hence should be consumed. Cooking may result in loss of certain nutrients. For example, vitamin C is destroyed on heating. Hence we should prepare and cook food carefully.
  • Obesity: It is a condition which arises by eating fat rich food in excess. It may further cause many problems like increase in body weight, heart diseases, hypertension, etc.
  • Deficiency Diseases; The diseases which arise due to the lack of nutrients like carbohydrates, fats, proteins, minerals or vitamins in our diet are called deficiency diseases, e.g., goitre, anaemia, beri-beri, scurvy, etc.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food 11

Vitamin/MineralDeficiency disease/disorderSymptoms
Vitamin ALoss of visionPoor vision, loss of vision in darkness (night), sometimes complete loss of vision
Vitamin B1Beri-beriWeak muscles and very little energy to work
Vitamin CScurvyBleeding gums, wounds take longer time to heal
Vitamin DRicketsBones become soft and bent
CalciumBone and tooth decayWeak bones, tooth decay
IodineGoitreGlands in the neck appear swollen, mental disability in children
IronAnaemiaWeakness

Class 6 Science Chapter 2 Components of Food Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
Do all foods contain all the required nutrients?
Answer:
No, all foods do not contain all the nutrients required by our body.

Question 2.
Name any two substances which provide carbohydrates.
Answer:
Potato, rice, wheat, sugar, etc.

Question 3.
What are the two nutrients which protect the body from diseases?
Answer:
Vitamins and minerals.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

Question 4.
What type of food is called the body-building food?
Answer:
The food containing proteins is called body-building food.

Question 5.
Name a vitamin which represents a group of vitamins.
Answer:
Vitamin B-complex.

Question 6.
Define roughage.
Answer:
The food containing plant fibres which are also known as dietary fibres is called roughage.

Question 7.
What is the main function of roughage?
Answer:
The main function of roughage is to help our body get rid of undigested food.

Question 8.
Name the food items which provide roughage.
Answer:
Whole grains, fresh fruits and vegetables are the main sources of roughage.

Question 9.
A person decides to take only milk and nothing else in his diet for certain reasons. After a year his gums started bleeding. What could be the cause of gum bleeding?
Answer:
Deficiency of vitamin C is the main cause of gum bleeding which leads to the disease called scurvy. This is because milk does not contain vitamin C.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

Question 10.
Which disease is caused due to the deficiency of calcium, phosphorus and vitamin D?
Answer:
Rickets in children and osteomalacia in adults.

Question 11.
What is obesity?
Answer:
Obesity is a disease in which a person becomes over-weight and bulky due to excessive accumulation of fats in the body.

Question 12.
Which vitamin is present in large amounts in citrus fruits?
Answer:
Vitamin C.

Short Answer Type Questions

Question 1.
What are the nutrients? Name the major nutrients.
Answer:
The components of food which are needed by our body for growth and development are called nutrients. Carbohydrates, fats, proteins, vitamins and minerals are the major nutrients.

Question 2.
Explain the importance of proteins in the human body.
Answer:
Proteins are one of the most important nutrients. They are called body-building food. They help in the growth and repair of damaged cells and tissues of the body. They also help our body to fight against infections. They make our nails, hair and muscles.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

Question 3.
State two conditions which necessitate a high protein diet.
Answer:

  1. A growing child needs a high-protein diet to make the body tissues required for rapid growth.
  2. A caring mother who breast-feeds her baby needs a protein rich diet for the formation of milk in her body.

Question 4.
What are the causes of the disease ‘Kwashiorkor’? How can it be prevented?
Answer:
The disease Kwashiorkor occurs due to the deficiency of proteins in the diet of children. This happens when the child is weaned too soon from proteins-rich breast milk of the mother and given protein-deficient diet. This disease can be prevented by giving the child a sufficient amount of protein-rich diet consisting of wheat, gram, peanuts, soybean and jaggery.

Question 5.
Define fats. Name some fat containing substances.
Answer:
The energy rich sources of food are called fats. Fats provide energy to the body. All types of nuts, mustard seeds, milk and butter are the major sources of fat.

Question 6.
How can we test for the presence of fat in a food item?
Answer:
Take small quantity of the food item. Mash it on a piece of white paper. Observe carefully and you will find that the piece of white paper shows an oily patch on it which indicates that the food item contains fat.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

Question 7.
Define vitamins. Name the various types of vitamins.
Answer:
Vitamins are protective compounds with no energy value. They help in proper body functioning and are required by the body in very small quantities. Various kinds of vitamins are-Vitamin A, Vitamin B-complex, Vitamin C, Vitamin D, Vitamin E and Vitamin K.

Question 8.
Explain the functions of water in our body.
Answer:
Water helps our body to absorb nutrients from the food. It also helps in removing the waste materials from the body in the form of urine and sweat.

Question 9.
What are the functions of minerals?
Answer:
Minerals are the protective part of our foods occurring naturally. They are needed by our body in small amounts. They are essential for proper growth of the body and to maintain good health. They do not provide energy. The main sources of minerals are milk, salt, eggs and green leafy vegetables.

Long Answer Type Questions

Question 1.
Explain deficiency diseases. Name the diseases caused by the deficiency of vitamins and minerals respectively.
Answer:
The diseases which occur due to the lack of adequate and balanced diet are called deficiency diseases. The deficiency diseases arise due to the lack of nutrients like carbohydrates, fats, proteins, minerals or vitamins in the diet of a person.

  1. Diseases caused by the deficiency of vitamins are: Night-blindness, beri-beri, scurvy, rickets and anaemia.
  2. Diseases caused by the deficiency of minerals are: Anaemia, cretinism, goitre, rickets and osteomalacia.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

Question 2.
Describe the sources of various vitamins and their deficiency diseases.
Answer:

  • Vitamin A: It is a fat-soluble vitamin. Its good sources are fish oil, milk, milk products and carrots. Its deficiency causes night-blindness.
  • Vitamin B: It is water soluble. It is found in wheat, rice, yeast extract, liver and kidney. Lack of vitamin B causes beri-beri.
  • Vitamin C: It is water soluble. It is found in citrus fruits and in many fresh vegetables. Lack of vitamin C causes scurvy.
  • Vitamin D: It is fat soluble. It is found in fish, eggs, milk and milk products. Its deficiency causes rickets.

Question 3.
List various types of nutrients and write the functions of each.
Answer:
The various types of nutrients are:

  • Carbohydrates: They are mainly energy-providing nutrients.
  • Fats: They provide energy for the body. They give much more energy than carbohydrates if consumed in same amount.
  • Proteins: They are called body-building foods. They help in the formation and repairing of the body parts. Skin, hair, muscles, enzymes, etc., are all made up of proteins.
  • Vitamins: They help in protecting our body against diseases. They also protect eyes, bones, teeth and gums.
  • Minerals: They are essential for proper growth of body and to maintain good health.

Question 4.
How would the balanced diet of a rickshaw puller differ from that of an office worker?
Answer:
The balanced diet of a rickshaw puller should include more of carbohydrates and fats than that of office workers. A rickshaw puller needs more energy for doing the hard physical work of pulling the rickshaw which can be provided by including more carbohydrate and fats in his diet. An office worker has no such requirement.

Question 5.
Four unlabelled test tubes containing sugar, starch, fat and proteins got mixed up. What tests will you perform to identify the nutrient in each test tube?
Answer:

  • The test tube whose contents give a blue-black colour on adding dilute iodine solution will contain starch.
  • The test tube whose contents give a red precipitate on heating with Benedict’s solution will contain sugar.
  • The test tube whose contents give a greasy spot when rubbed on a white sheet of paper contains fat.
  • The test tube whose contents give a violet colour on adding two drops of copper sulphate and ten drops of caustic soda will contain proteins.

Picture-Based Questions

Question 1.
Observe the following figures and answer the following questions:
NCERT Solutions for Class 6 Science Chapter 2 Components of Food 4
a. Which nutrients is mainly provided by these items?
b. Name the sources of these food items.
Answer:
a. They provide mainly fats.
b. The source of these food items is animals.

Question 2.
Observe the following diagrams and answer the following questions:
NCERT Solutions for Class 6 Science Chapter 2 Components of Food 5
a. Which nutrient is mainly provided by these items?
b. Name the sources of these food items.
Answer:
a. They provide mainly fats.
b. The source of these food items is animals.

NCERT Solutions for Class 6 Science Chapter 2 Components of Food

Question 3.
a. Identify the food items A and B.
NCERT Solutions for Class 6 Science Chapter 2 Components of Food 6
b. Which of the above contains vitamin A?
c. Deficiency of which of the above causes disease called rickets?
Answer:
a. A-Papaya
B-Eggs
b. Papaya
c. Eggs

NCERT Solutions for Class 6 Science Chapter 2 Components of Food Read More »

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From?

These NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From? Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Food: Where Does it Come From? NCERT Solutions for Class 6 Science Chapter 1

Class 6 Science Chapter 1 Food: Where Does it Come From? Textbook Exercise Questions and Answers

Question 1.
Do you find that all living beings need the same kind of food?
Answer:
No, different organisms eat different kinds of food. For example, animals such as buffalo and cow eat grass while human beings eat bread, rice, fruits and vegetables. In this way, we can say that different organisms eat different kinds of food.

Question 2.
Name five plants and their parts that we eat.
Answer:

Name of the plantParts that we eat
1. CarrotRoots
2. Wheat plantSeeds
3. Mustard plantSeeds and leaves
4. BrinjalFruits
5. LotusStem and leaf

Question 3.
Match the items given in column A with that in column B.
Answer:

Column AColumn B
1. Milk, curd, paneer, ghee(a) eat other animals
2. Spinach, cauliflower, carrot(b) eat plants and plant products
3. Lions and tigers(c) are vegetables
4. Herbivores(d) are all animals products

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From?

Question 4.
Fill up the blanks with the words given:
herbivore, plant, milk, sugarcane, carnivore

a. Tiger is a ………….. because it eats only meat.
Answer:
Tiger is a carnivore because it eats only meat.

b. Dear eats only plant products and so, is called …………..
Answer:
Dear eats only plant products and so, is called herbivore.

c. Parrot eats only ………….. products.
Answer:
Parrot eats only plant products.

d. The ………….. that we drink, which comes from cows, buffaloes and goats is an animal product.
Answer:
The milk that we drink, which comes from cows, buffaloes and goats is an animal product.

e. We get sugar from …………..
Answer:
We get sugar from sugarcane.

NCERT Extended Learning Activities and Projects

Question 1.
You must have seen a garden lizard around your home. Next time whenever you see it, observe carefully and find out what it takes for food. Is the food different from that of a house lizard?
Hint: Garden lizard feeds on crickets, moths, slaters, earthworms, grubs and caterpillars, grasshoppers, cockroaches, etc. House lizards eat flies, mosquitoes, small insects, etc.

Question 2.
Make a list (with pictures, when possible) of food items generally taken by people of different regions of India. Place these on a large outline map of India to display in your classroom.
Hint: Do it yourself.

Question 3.
Find out the names of plants that grow in water and which are eaten as food.
Hint: Some aquatic plants are used by humans as a food source. This includes wild rice, Chinese water chestnut, Indian lotus, water spinach, etc.

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From?

Question 4.
In Chapter 10, you will find out ways of measuring length of curved lines. In your mathematics classes you will learn to prepare bar graphs. After you learn these, try the following interesting project. Prepare some sprouts of moong as discussed in the chapter. Wash them in water everyday and drain all the water. Let them grow for a week until the whole of the seeds grow into young plants. Measure the lengths of the sprouts everyday using a string. Take care that they do not break. Prepare a bar graph of the number of sprouts having lengths in different ranges.
Hint: Do it yourself.

Activity 1

Objective: To list certain food items and mention their ingredients.
Materials Required: Various cooked dishes.
Procedure: Observe the procedure of cooking certain food items and guess the various ingredients.

Observations:

Food items (Dish)Major ingredients
1. Boiled riceRice and water
2. ChapatiAtta and water
3. CurryVegetable, salt, spices, oil and water
4. DalPulses, salt, spices, oil and water
5. OmeletteEggs, salt, spices, iol/butter and water

Conclusion: The various food items or dishes which we eat daily are usually made up of more than one ingredient.

Sources of Food Ingredients: The main sources of food ingredients are:
i. Plants: We get ingredients like fruits, vegetables, grains, cereals, etc., from plants.
ii. Animals: We get milk, eggs and meat from animals. Milk products such as butter, ghee, cheese, etc., are widely used in different food items.
NCERT Solutions for Class 6 Science Chapter 1 Food Where Does it Come From 1

Photosynthesis: It is the process by which green plants use sunlight to make food from carbon dioxide and water. Oxygen is released in this process which is used by us for breathing. This food prepared by photosynthesis gets stored in various plant parts. Since plants can make their own food, they are called producers.

Edible: Anything that people can safely eat ‘ is described as edible.

Plant Parts as Food: Various plant parts such as roots, stem, leaves, flowers, fruits, etc., are edible and used by us as food.
i. Root: carrot, radish, sweet potato, etc.
ii. Stem: Potato, ginger, onion, garlic, etc.
iii. Leaves: Spinach, cabbage, lettuce, etc.
iv. Fruit: Apple, orange, mango, banana, etc.
v. Flower: Cauliflower, sunflower, etc.
vi. Seeds: Mustard, soybean, pea, pulses, etc.

Sprouts: When the seeds begin to germinate by developing tiny roots in the form of small white structures, they are called sprouts.

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From?

Activity 2

Objective: To make moong sprouted seeds.
Materials Required: A small cup of moong seeds, water and muslin cloth.

Procedure:

  • Take a cup of moong seeds and soak them in water overnight.
  • Take out the seeds and drain out the water.
  • Wrap the seeds in wet muslin cloth and keep it for a day or two.

Observation: A small white structure growing out of the seeds is observed. This is the young plant (specifically the roots of the young plant). When the young plant appears, we say that the seed has sprouted.

Conclusion: Seeds can germinate under moist conditions are form sprouts which are highly nutritious.

  • Nectar: The sweet juices produced by some flowers are called nectar.
  • Honey: Honey is produced by honeybees from the nectar of flowers. They collect nectar, store it and convert it into honey in their beehives.

NCERT Solutions for Class 6 Science Chapter 1 Food Where Does it Come From 2

  • Herbivores: Animals that eat only plants are called herbivores. Example: Deer, cow, goat, etc.
  • Carnivores: Animals that eat only flesh of other animals are called carnivores. Example: Lion, tiger, etc.
  • Omnivores: Animals that eat plants or plant products, as well as flesh of other animals are called omnivores. Example: Crow, humans, dogs, etc.

Class 6 Science Chapter 1 Food: Where Does it Come From? Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
Name two plants where two or more parts are used as food.
Answer:
Mustard – seeds and leaves Pumpkin-fruits and flowers

Question 2.
Name two plants whose leaves are eaten as food.
Answer:
Spinach and lettuce.

Question 3.
Name two sugar producing plants.
Answer:
Sugarcane and sugar beet.

Question 4.
Can the ingredients of various food items have some common ingredients?
Answer:
Yes, they may have some common ingredients like water, sugar, salt, ghee and oil.

Question 5.
Give three examples of edible parts of plants.
Answer:
Root, fruits and leaves.

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From?

Question 6.
Which type of seeds gives more energy, sprouted seeds or normal seeds?
Answer:
Sprouted seeds give more energy than normal seeds.

Question 7.
Give an example of a non-green plant.
Answer:
Mushroom.

Question 8.
Name the ingredients in boiled rice.
Answer:
Rice and water.

Question 9.
What are sprouts?
Answer:
When the seeds begin to grow or germinate by developing tiny white roots, they are called sprouts.

Question 10.
What are the two common sources of most of the ingredients of food items?
Answer:
Plants and animals.

Question 11.
Give two examples of plants that give us oilseeds.
Answer:
Mustard plants and sunflowers.

Short Answer Type Questions

Question 1.
What do you understand by food?
Answer:
The edible substances eaten by humans and other animals to get energy for various activities for growth and development are called food.

Question 2.
Explain the importance of food for all living beings.
Answer:
Food provides energy to do various activities. It helps us in growth. It helps to repair and replace damaged parts of the body. It protects us from infections and diseases.

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From?

Question 3.
Explain the various sources of food items and ingredients with the help of examples.
Answer:
There are mainly two sources of ingredients of various food items.

  1. Plants: Plants provide us fruits, vegetables, pulses, grains, cereals, etc.
  2. Animals: Animals provides us milk, eggs, meat, etc.

Question 4.
How is cooking of food helpful?
Answer:
Cooking makes food eatable. It makes food items soft and easy to digest. It makes food tastier. It also kills the harmful germs present in raw food.

Question 5.
What do we get from bees? What is the value of honey as food item?
Answer:
Honey is produced by honeybees from the nectar of flowers. Extraction of honey from the beehives is carried out by honey extractors. Honey is rich in sugars, minerals and enzymes. It is a highly nutritious food and easily digestible too.

Question 6.
Describe how the milk which we get from cow actually comes from the plants.
Answer:
The animal’s food comes ultimately from the plants. This is because all the animals which give us various food products themselves eat plants or plant products. The milk comes from cows or buffaloes which eat grass or grains as food. Therefore, the milk which get from cows actually comes from the plants.

Question 7.
Define the term herbivores. Give examples.
Answer:
The animals which eat only plants or plant products are called herbivores. Cow, goat and buffalo are examples of herbivores.

Question 8.
Define the term carnivores. Give examples.
Answer:
The animals which eat other animals are called carnivores. Lion and tiger are examples of carnivores. Carnivores generally eat herbivores and other carnivores.

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From?

Question 9.
Define the term omnivores. Give examples.
Answer:
The animals which eat both the plants and animals are called omnivores. Cats, dogs and human beings are examples of omnivores.

Question 10.
How do plants make their own food?
Answer:
Plants make their own food, generally in leaves, with the help of sunlight, air and water. This process is called photosynthesis. Leaves are the kitchen of the plant. The chlorophyll in leaves traps the sunlight and uses it to make food. This process is called photosynthesis.

Question 11.
What are the food habits of people of southern region in India?
Answer:
The southern regions are closer to the sea and there is enough rainfall for production of rice. Hence the food items are mainly sea animals, fish and rice. Coconuts are also available in plenty and is used as an energy giving food.

Food items such as idli, sambhar and other preparations of rice, banana chips and coconut are famous in this region. People use coconut oil as medium for cooking.

Long Answer Type Questions

Question 1.
What are the characteristics of herbivores?
Answer:
a. Animals such as horse, cow, goat and buffalo are herbivores. They have wide blunt teeth and are able to pull plants off the ground. The grinding teeth are broad and strong for grinding grasses.

b. Animals such as cow, camel and buffalo fill their stomach with food without chewing. After a short time, they bring back the already swallowed food in the mouth for proper grinding which is called cuddling. This helps them in digesting hard plant products.

Question 2.
Make a flow chart for the preparation of chapati.
Answer:
Farmer cultivates the wheat crop → Ripened wheat is cut and transported to market → Flour mill buys wheat and grinds to make flour → Flour is brought from the market → Water and salt are added to flour to make dough → Dough is rolled into raw chapati → Chapati is cooked on the stove.

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From?

Question 3.
Make a flow chart depicting the preparation of honey.
Answer:
Nectar in flowers → Nectar is collected by honeybees → Stored in beehives → Converted into honey by honeybees → Honey is extracted from beehives.

Question 4.
What food materials come from animals?
Answer:
Animals give us food such as meat, fish, milk, eggs and honey.

  1. Meat: We get meat from animals such as hen and goat.
  2. Fish: Fishes may be of freshwater or seawater. The quality of food of both kinds of fish is good for health.
  3. Milk: We get milk from animals such as cows. goat and buffalo. Milk is used to make products such as paneer, cheese, butter, curd and ghee.
  4. Eggs: We get eggs from birds such as hen, goose and duck.
  5. Honey: We get honey from the hives of honeybees. Honeybees prepare honey using nectar from flowers.

Question 5.
What food materials come from different parts of plants? Explain.
Answer:
We eat different parts of plants such as root, stem, leaf, flower, fruit and seed.

  1. Root: Carrot, radish, turnip and beetroot are examples of roots that we eat.
  2. Stem: Potato, ginger, sugarcane, onion and garlic are examples of stems that we eat. These are special stems that we eat.
  3. Leaf: Lettuce, spinach, cabbage and mint are examples of leaves that we eat.
  4. Flowers: Cauliflower, flowers of pumpkin and banana plants are examples of flowers that we eat. Cloves used as spice are dried flower buds.
  5. Seeds: Cereals (e.g., rice, wheat and maize) and pulses (e.g., gram, moong and kidneys bean) are examples of seeds that we eat. Some other seeds such as cumin (Jeera) and fenugreek (methi) are used as spices. Cooking oil seeds include mustard, coconut, sunflower and sesame (til).

Picture-Based Questions

Question 1.
Draw and label the different parts of a plant.
Answer:
NCERT Solutions for Class 6 Science Chapter 1 Food Where Does it Come From 3

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From?

Question 2.
Connect the animals in the first row with the food they eat in the second row by an arrow.
NCERT Solutions for Class 6 Science Chapter 1 Food Where Does it Come From 4
Answer:
NCERT Solutions for Class 6 Science Chapter 1 Food Where Does it Come From 5

Question 3.
Observe the following figures and name the picture A and picture B. Which of these two has more food value?
NCERT Solutions for Class 6 Science Chapter 1 Food Where Does it Come From 6
Answer:
Picture A shows non-sprouted seeds of gram. Picture B shows sprouted seeds of gram. Sprouted seeds give more energy and vitamins. So, they have more food value.

NCERT Solutions for Class 6 Science Chapter 1 Food: Where Does it Come From? Read More »

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

These NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Improvement in Food Resources NCERT Solutions for Class 9 Science Chapter 15

Class 9 Science Chapter 15 Improvement in Food Resources InText Questions and Answers

Question 1.
What do we get from cereals, pulses, fruits and vegetables?
Answer:

  • Cereals provide us with carbohydrates. Also, they are a rich source of energy.
  • Pulses give us proteins.
  • Fruits and vegetables are a rich source of vitamins and minerals. A small amount of proteins, carbohydrates, and fats are also present in them.

Question 2.
How do biotic and abiotic factors affect crop production?
Answer:
A variety of biotic factors such as pests, nematodes, diseases, etc. can reduce net crop production. A pest causes damage to agriculture by feeding on crops. For example, boll weevil is a pest on cotton. It attacks the cotton crop, thereby reducing its yield. Weeds also reduce crop productivity by competing with the main crop for nutrients, light, and space.

Similarly, abiotic factors such as salinity, temperature, etc. affect the net crop production. Some natural calamities such as droughts and floods are unpredictable. Their occurrence has a great impact on crops sometimes, destroying the entire crop.

Question 3.
What are the desirable agronomic characteristics for crop improvements?
Answer:
The desirable agronomic characteristics for crop improvements are:

  • Tallness and profuse branching in any fodder crop.
  • Dwarfness in cereals.

These desirable agronomic characteristics help in increasing crop productivity.

Question 4.
What are macro-nutrients and why are they called macro-nutrients?
Answer:
Macro-nutrients are nutrients required in relatively large quantities for growth and development of plants. They are six in number. Since they are required in large quantities, they are known as macro-nutrient. The six macronutrients required by plants are nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 5.
How do plants get nutrients?
Answer:
Plants require sixteen essential nutrients from nature for their growth and development. All these nutrients are obtained from air, water, and soil. Soil is the major source of nutrients. Thirteen of these nutrients are available from soil. The remaining three nutrients
(carbon, oxygen, and hydrogen) are obtained from air and water.

Question 6.
Compare the use of manure and fertilizers in maintaining soil fertility.
Answer:
Manures increase soil fertility by enriching the soil with organic matter and nutrients as it is prepared by the decomposition of animal excreta and plant wastes. On the other hand, fertilizers are mostly inorganic compounds whose excessive use is harmful to the symbiotic micro-organisms living in soil. Their excessive use also reduces soil fertility. Hence, fertilizers are considered good for only short term use.

Question 7.
Which of the following conditions will give the most benefits? Why?
(a) Farmers use high-quality seeds, do not adopt irrigation or use fertilizers.
(b) Farmers use ordinary seeds, adopt irrigation and use fertilizer.
(c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures.
Answer:
(c) Farmers using good quality seeds, adopting irrigation, using fertilizers, and using crop protection measures will derive most benefits.

  • The use of good quality seeds increases the total crop production. If a farmer is using good quality seeds, then a majority of the seeds will germinate properly, and will grow into a healthy plant.
  • Proper irrigation methods improve the water availability to crops.
  • Fertilizers ensure healthy growth and development in plants by providing the essential nutrients such as nitrogen, phosphorus, potassium, etc.
  • Crop protection measures include various methods to control weeds, pests, and infectious agents. If all these necessary measures are taken by a farmer, then the overall production of crops will increase.

Question 8.
Why should preventive measures and biological control methods be preferred for protecting crops?
Answer:
Preventive measures and biological control methods should be preferred for protecting crops because excessive use of chemicals leads to environmental problems. These chemicals are also poisonous for plants and animals. Preventive measures include proper soil and seed preparation, timely sowing of seeds, intercropping and mixed cropping, usage of resistant varieties of crops, etc.

On the other hand, biological control methods include the usage of bio-pesticides that are less toxic for the environment. An example of bio-pesticides is Bacillus thuringenesis, which is an insect pathogen that kills a wide range of insect larvae. Therefore, both preventive measures and biological control methods are considered eco-friendly methods of crop protection.

Question 9.
What factors may be responsible for losses of grains during storage?
Answer:
During the storage of grains, various biotic factors such as insects, rodents, mites, fungi, bacteria, etc. and various abiotic factors such as inappropriate moisture, temperature, lack of sunlight, flood, etc. are responsible for losses of grains. These factors act on stored grains and result in degradation, poor germinability, discolouration, etc.

Question 10.
Which method is commonly used for improving cattle breeds and why?
Answer:
Cattle farming is commonly used for improving cattle breeds. The purpose of cattle farming is to increase the production of milk and draught labour for agricultural work. Dairy animals (females) are used for obtaining milk and draught animals (males) are engaged in agricultural fields for labour work such as carting, irrigation, tilling, etc. Crossbreeding between two good varieties of cattle will produce a new improved variety.

For example, the cross between foreign breeds such as Jersey Brown, Swiss (having long lactation periods) and Indian breeds such as Red Sindhi, Sahiwal (having excellent resistance power against diseases) produces a new variety having qualities of both breeds.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 11.
What management practices are common in dairy and poultry farming?
Answer:
Common management practices in dairy and poultry farming are:

  • Proper shelter facilities and their regular cleaning.
  • Some basic hygienic conditions such as clean water, nutritious food, etc.
  • Animals are kept in spacious, airy, and ventilated place.
  • Prevention and cure of diseases attire right time is ensured.

Question 12.
What are the differences between broilers and layers and in their management?
Answer:
Layers are meant for egg production, whereas broilers are meant for poultry meat. Nutritional, environmental, and housing conditions required by broilers are different from those required by egg layers. A broiler chicken, for their proper growth, requires vitamin rich supplements especially vitamin A and K. Also, their diet includes protein rich food and enough fat. They also require extra care and maintenance to increase their survival rate in comparison to egg layers.

Question 13.
What are the desirable characters of bee varieties suitable for honey production?
Answer:
Bee varieties having the following desirable characters are suitable for honey production:

  • They should yield high quantity of honey.
  • They should not sting much.
  • They should stay in the beehive for long durations. ‘
  • They should breed very well.

Question 14.
What is pasturage and how is it related to honey production?
Answer:
Pasturage is the availability of flowers from which bees collect nectar and pollen. It is related to the production of honey as it determines the taste and quantity of honey.

Class 9 Science Chapter 15 Improvement in Food Resources Textbook Questions and Answers

Question 1.
Explain any one method of crop production which ensures high yield.
Answer:
Crop rotation is one of the methods of crop production that ensures high yield. It is the method of growing two or more varieties of crops on the same land in sequential seasons. A crop utilises some particular nutrients in larger quantities from the soil. Then, if the same crop is grown in subsequent seasons those nutrients will get depleted in the soil. Therefore, crops having different nutrient requirements are rotated.

For example, legumes which have nitrogen-fixing bacteria in their root nodules supply the soil with nitrogen. Therefore, these legumes are rotated with nitrogen requiring cereals such as wheat and maize. This method reduces the need of fertilizers, thereby increasing the overall yield of crops.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 2.
Why are manures and fertilizers used in fields?
Answer:
Manures and fertilizers are used in A fields to enrich the soil with the required nutrients. Manure helps in enriching the soil with organic matter and nutrients. This improves the fertility and structure of the soil. On the other hand, fertilizers ensure a healthy growth and development in plants. They are a good source of nitrogen, phosphorus, and potassium. To get an optimum yield, it is instructed to use’s balanced combination of manures and fertilizers in the soil.

Question 3.
What are the advantages of inter-cropping and crop rotation?
Answer:
Inter-cropping and crop rotation both play an important role in increasing the yield of crops. Inter-cropping helps in preventing pests and diseases to spread throughout the field. It also increases soil fertility, whereas crop rotation prevents soil depletion, increases soil fertility, and reduces soil erosion. Both these methods reduce the need for fertilizers. It also helps in controlling weeds and controls the growth of pathogens and pests in crops.

Question 4.
What is genetic manipulation? How is it useful in agricultural practices?
Answer:
Genetic manipulation is a process where the gene for a particular character is introduced inside the chromosome of a cell. When the gene for a particular character is introduced in a plant cell, 9 transgenic plant is produced. These transgenic plants exhibit characters governed by the newly introduced gene.

For example, let us assume there is a wild plant that produces small fruits. If the gene responsible for a larger fruit size is introduced in this plant, this plant becomes transgenic, and starts producing larger fruits. Similarly, genes for higher yield, disease resistance, etc. can be introduced in any desired plant.

Therefore, gene manipulation plays an important role in agricultural practices. It helps in improving crop variety. It ensures food security and insect resistant crops. It also improves the quality and yield of Crops.

Question 5.
How do storage grain losses occur?
Answer:
There are various biotic and abiotic factors that act on stored grains and result in degradation, poor germinability, discolouration, etc. Biotic factors include insects or pests that cause direct damage by feeding on seeds. They also deteriorate and contaminate the grain, making it unfit for further consumption.

Abiotic factors such as temperature, light, moisture, etc., also affect the seed. They decrease the germinating ability of the seeds and make them unfit for future use by farmers. Unpredictable occurrence of natural calamities such as droughts and floods also causes destruction of crops.

Question 6.
How do good animal husbandry practices benefit farmers?
Answer:
Cattle farming is one of the methods of animal husbandry that is most beneficial for farmers. Using this method, better breeds of draught animals can be produced. Such draught animals are engaged in agricultural fields for labour work such as carting, irrigation, tilling, etc.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 7.
What are the benefits of cattle farming?
Answer:
Benefits of cattle farming:

  • Good quality and quantity of milk can be produced.
  • Draught labour animals can be produced for agricultural work.
  • New variety that are resistant to diseases can be produced by crossing two varieties with the desired traits.

Question 8.
For increasing production, what is common in poultry, fisheries and bee-keeping?
Answer:
The common factor for increasing production in poultry, fisheries, and beekeeping is the proper management techniques that are to be followed. Regular cleaning of farms is of utmost importance. Maintenance of temperature and prevention and cure of diseases is also required to increase the number of animals.

Question 9.
How do you differentiate between capture fishing, mariculture and aquaculture?
Answer:
Capture fishing involves the fishing or capturing of fishes from natural water reservoirs using fishing liner or fishing nets. A different varieties of the fishes are ended up being captured in the processes, some are edible while others are not being very young or inedible type hence, disturb the aquatic ecosystem.

Mariculture involves the culturing of fishes in fresh water and brackish water It also involves the culturing for sea food.

Aquaculture involves the culturing of inland fisheries and marine fisheries in which different type of edible fishes are reared and cultured in the artificially made ponds. It also involves the culturing of other aquatic animals like mussels, prawns, oysters, snails for pearls, etc.

Class 9 Science Chapter 15 Improvement in Food Resources Additional Important Questions and Answers

Multiple Choice Question
Choose the correct option:

Question 1.
Which one is an oil yielding plant among the following?
(a) Lentil
(b) Sunflower
(c) Cauliflower
(d) Hibiscus
Answer:
(b) Sunflower

Question 2.
Which one is not a source of carbohydrate?
(a) Rice
(b) Millets
(c) Sorghum
(d) Gram
Answer:
(d) Gram

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 3.
Find out the wrong statement from the following
(a) White revolution is meant for increase in milk production
(b) Blue revolution is meant for increase in fish production
(c) Increasing food production without compromising with environmental quality is called as sustainable agriculture
(d) None of the above
Answer:
(d) None of the above

Question 4.
To solve the food problem of the country, which among the following is necessary?
(a) Increased production and storage of food grains
(b) Easy access of people to the food grain
(c) People should have money to purchase the grains
(d) All of the above
Answer:
(d) All of the above

Question 5.
Find out the correct sentence
(i) Hybridisation means crossing between genetically dissimilar plants
(ii) Cross between two varieties is called as interspecific hybridisation
(iii) Introducing genes of desired character into a plant gives genetically modified crop
(iv) Cross between plants of two species is called as inter varietal hybridisation
(a) (i) and (iii)
(b) (ii) and (iv)
(c) (ii) and (iii)
(d) (iii) and (iv)
Answer:
(a) (i) and (iii)

Question 6.
Weeds affect the crop plants by
(a) killing of plants in field before they grow
(b) dominating the plants to grow
(c) competing for various resources of crops (plants) causing low availability of nutrients
(d) all of the above.
Answer:
(c) competing for various resources of crops (plants) causing low availability of nutrients

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 7.
Which one of the following species of honey bee is an Italian species?
(a) Apis dorsata
(b) Apis florae
(c) Apis cerana indica
(d) Apis mellifera
Answer:
(d) Apis mellifera

Question 8.
Find out the correct sentence about manure
(i) Manure contains large quantities of organic matter and small quantities of nutrients.
(ii) It increases fire water holding capacity of sandy soil.
(iii) It helps in draining out of excess of water from clayey soil.
(iv) Its excessive use pollutes environment because it is made of animal excretory waste.
(a) (i) and (iii)
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (iii) and (iv)
Answer:
(b) (i) and (ii)

Question 9.
Cattle husbandry is done for the following purposes
(i) Milk Production
(ii) Agricultural work
(iii) Meat production
(iv) Egg production
(a) (i), (ii) and (iii)
(b) (ii), (iii) and (iv)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer:
(a) (i), (ii) and (iii)

Question 10.
Which of the following are Indian cattle?
(i) Bos indicus
(ii) Bos domestica
(iii) Bos bubalis
(iv) Bos vulgaris
(a) (i) and (iii)
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (iii) and (iv)
Answer:
(a) (i) and (iii)

Question 11.
Which of the following are exotic breeds?
(i) Brawn
(ii) Jersey
(iii) Brown Swiss
(iv) Jersey Swiss
(a) (i) and (iii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)
Answer:
(b) (ii) and (iii)

Question 12.
Poultry farming is undertaken to raise following
(i) Egg production
(ii) Feather production
(iii) Chicken meat
(iv) Milk production
(a) (i) and (iii)
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (iii) and (iv)
Answer:
(a) (i) and (iii)

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 13.
Poultry fowl are susceptible to the following pathogens
(a) Viruses
(b) Bacteria
(c) Fungi
(d) All of the above
Answer:
(d) All of the above

Very Short Answer Questions

Question 1.
What is FYM?
Answer:
FYM refers to the farmyard manure. It enriches the soil with nitrogen and phosphorus.

Question 2.
What is vermicompost?
Answer:
The compost prepared because of the action of earthworm in decomposition is called vermiform compost.

Question 3.
What is green manuring?
Answer:
Green manuring involves the sowing of seeds of plants like sun hemp and gaur etc before ploughing. After some time they are mulched into soil by ploughing to improve soil fertility.

Question 4.
Name some of the common irrigation systems used in rural areas of India?
Answer:
Irrigation systems used in rural areas of India include dug well, tube well, rivers, canals and water tanks.

Question 5.
What are weeds?
Answer:
Weeds are the unwanted plants which grow at their own in a field.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 6.
Name the Indian breeds of (i) Cow and (b) Buffalo
Answer:
(a) Cow-Red sindhi, Sahiwal and Gir.
(b) Buffalo-Murrah, mehsana and Surti.

Question 7.
What are milch animals?
Answer:
Milch animals include the milk producing female population in cattle farming.

Question 8.
How is concentrate different from roughage in cattle diet?
Answer:
Roughage is meant for growing cattle that is poor in proteins and fats but the concentrate is meant for the lactating females which is rich in protein and fats along with vitamins.

Question 9.
Define the followings:
(a) Mixed cropping
(b) Inter cropping
(c) Mixed farming
(d) Crop rotation
Answer:
(a) Mixed cropping : It refers to the simultaneously growing of two or more crops to avoid the crop failure.
(b) Intercropping: It refers to the growing of two or more crops in a definite row pattern to increase the productivity per unit area.
(c) Mixed fanning: It is the cultivation of a crop or more on a field along with rearing and management of cattle for milk or any other animal food product.
(d) Crop rotation: It involves the growing of different crops on a piece of land in a preplanned succession. Mostly legume crop alternates with the cereal crop.

Question 10.
Which practices does the green revolution intend to be adopted to increase the crop production?
Answer:
Green revolution involves growing of large amount of cereal crops using high yielding plant varieties, chemical fertilizers, pesticides, better practices of irrigation, etc.

Question 11.
What are fumigants?
Answer:
These are chemicals sprayed in field or storage sites that in gaseous state are lethal to pests.

Question 12.
What do you man by the acronym HYV?
Answer:
The acronym HYV stands for High yielding variety.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 13.
What steps a farmer needs to take to control diseases in cattle?
Answer:
A farmer needs to vaccinate the cattle and isolate the sick cattle from the herd to prevent further infection.

Question 14.
List some of the common diseases of cattle.
Answer:
Cowpox, anthrax, foot and mouth disease and black quarter.

Question 15.
What is the average diet of a cow?
Answer:
A cow on an average needs 15-20 kg of green fodder and dry grass, 4-5 kg of grain mixture and 30-35 litre of water per day.

Question 16.
Name any four breeds of indigenous fowls.
Answer:
Aseel, Chattisgarh, Burosa and Kadakath

Question 17.
Name the two exotic breeds of fowls.
Answer:
Rhode Island Red and White leghorn.

Question 18.
What is the laving period for a layer in poultry farm?
Answer:
Laying period refers to period of time from sexual maturity to the end of the laying of eggs.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 19.
Name two technologies adopted in fishing.
Answer:
To have increased output from fishing, echo sounding and satellite imaging is used these days to locate tire fish shoals in oceans.

Question 20.
Name the three commercial products obtained from the bees in beehive.
Answer:
Honey, bee wax and bee venom.

Question 21.
Name some cultured finfishes.
Answer:
Mullets, Pearl spot and Bhekti.

Question 22.
What is the size of bee-hive made of wood?
Answer:
46 × 23 cm., with chambers for laying eggs and collection of honey.

Question 23.
List some of the common pests of bees.
Answer:
Wasp, wax moths, King crow and Green bee eater.

Short Answer Questions

Question 1.
What are micronutrients and macronutrients? Give examples.
Answer:
Micronutrients: The nutrients required in small quantities by plants are called micro nutrients e.g. zinc, copper, boron, etc.

Macronutrients: The nutrients required in large quantities by plants are called macro nutrients e.g. nitrogen, phosphorus, sulphur and potassium.

Question 2.
What are rabi and kharif crops?
Answer:
The crops grown in the winter season are called rabi crops. They are sown in November and harvested in April e.g. wheat, gram, peas, mustard and linseed.

The crops grown in summer season are called kharif crops or crops of monsoon season. They are sown in month of June to be harvested in October e.g. paddy, soyabean, maize and cotton.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 3.
How are manures prepared? Give their uses.
Answer:
Manures are prepared by the decomposition of the organic waste that include the plant waste, animal waste like cow dung etc. These wastes are placed ii) a ditch for a period of 1-2 months for decomposition after which they are taken out to be applied in the field.

Manures:

  • enrich the soil with organic matter that adds to soil fertility in long rim.
  • improves the water holding capacity of the soil.
  • help recycle the organic waste produced in a farm.

Question 4.
Differentiate in a manure and fertilizer.
Answer:
A manure is produced naturally by the decomposition of natural plant and animal waste products. It is poor in nutrients but when added to soil, it improves the soil’s water holding capacity.

A fertilizer is industrially manufactured inorganic compound drat is water soluble. When added to soil, it enriches the soil with nutrients but its continuous use leads to soil pollution and in long run leads to a decline in production.

Therefore, fertilizers give only short term benefits but manures give long term benefits.

Question 5.
What precautions should be kept in mind while using fertilizers?
Answer:
The precautions need to be observed when applying fertilizers are

  • Apply the fertilizers in terms of proper dose, at proper time after assessing the mineral quantity present in the soil.
  • Application of fertilizer must follow proper irrigation, excessive irrigation, may casue their washing away from field.

Question 6.
What is mixed cropping? Give examples.
Answer:
The simultaneous growing of two or more crops on a same piece of land is called mixed cropping. In mixed cropping the common combinations used are:
Maize + Urd bean
Wheat + Chick pea
Ground nut + Sunflower
Cotton + Mung bean
Wheat + Mustard

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 7.
What do you mean by hybridization? State its types.
Answer:
Hybridization is method of bringing improvement in the varieties of plants for higher yield. It helps produce

  • high yielding varieties.
  • varieties resistant to pest.
  • varieties resistant to drought.

The hybridization is of different types depending upon the selected crop used for the cross pollination by bagging or emasculation. It can be inter-generic, interspecific or inter-species.

Question 8.
Why is there a necessity for the variety improvement?
Answer:
The variety improvement is necessary for

  • Higher yield
  • Improved quality of agronomic product.
  • Biotic and abiotic resistance
  • Desirable agronomic characteristics
  • Desirable period of maturation time.

Question 9.
What are weeds? How are they controlled?
Answer:
Weeds are the unwanted plants in a cultivated field e.g. a barley or mustard plant in a wheat field. They grow at their own without their cultivation.

These weeds are not good for growing crops because

  • they compete with the crop plants for air, water and nutrients.
  • they act as alternate host for many pathogens.

Therefore, these weeds need to be removed. Their removal practices involve

  • Mechanical method: It involves their manual removal by trowel or hoe.
  • Chemical method: It involves the spraying of chemicals called herbicides or weedicides such as 2,4-D and 2,4,5-D.
  • Cultural method: It involves proper seed bed preparation, timely sowing of crops, using intercropping or crop rotation practices.

Question 10.
How insect pests harm the crop?
Answer:
Generally, the insect pests harm the crop plants in following ways:

  • They cut root, stem or leaf.
  • They suck cell sap from different plant parts.
  • They bore into stem, root or fruits.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 11.
How the diseases of diary animals are classified?
Answer:
The diseases of diary animals are classified as

  • Parasitic
  • Infectious
  • Non-infectious

Parasitic diseases can be caused by the internal parasites like worms or external parasites which cause skin diseases. Infectious diseases are caused by pathogens such as virus, bacteria, fungi, etc.

Question 12.
Name the indigenous and exotic breed of fowls reared in poultry farms.
Answer:
Indigenous breeds of fowl include Aseel, Chattisgarh and Burosa.

Exotic species include Rhode Island Red and White leg horn. Rhode Island Red is a dual type of breed because it has both a good layer and broiler. White leghorn is small size fowl but lay long white egg.

Question 13.
What are broilers? How are they produced?
Answer:
The fowls reared and managed for the purpose of flesh in a poultry farm are called broilers. The broilers chickens are raised for 6-7 weeks in a poultry farm. During this time, they are fed on diet rich in proteins, vitamin-A and vitamin-k and proper care is taken to avoid mortality, feathering and carcass quality. Once they are 750 g to 1.5 kg, they are marketed for flesh.

Question 14.
What are layers? List the factors which have the favourable effect on laying out put.
Answer:
The fowls reared and managed for the purpose of eggs in a poultry farm are called layers. The laying out put refers to the period from the sexual maturity till the end of egg laying period. It is affected by number of factors such as:

  • Feeding of the chickens, the feed needs to be rich in vitamins, minerals and micronutrients.
  • Feed needs to contain grains of limestone to prevent the laying of shell less eggs.
  • The intensity and duration of light is also known to have direct effect on the laying output of eggs.
  • Presence of sand bath for chickens to help them get rid of ticks or mites on their skin surface.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 15.
What causes diseases to the chicken in a poultry farm? How these diseases can be prevented?
Answer:
In a poultry farm, the different type of pathogens such as virus, bacteria, fungi, etc can cause diseases along with their malnutrition. These diseases can be prevented by

  • Proper cleaning and sanitation of the farm.
  • Spraying of disinfectants.
  • Timely vaccination of chickens.

Question 16.
Give examples of some Indian carps and some marine fishes.
Answer:
Indian carps: Rohu, Catla and Mrigal
Marine fishes: Sardine, Bombay duck, Hilsa, Salmon and Flying fish.

Question 17.
List the quality of the good variety of fishes.
Answer:
The qualities of the good variety of fishes include:

  • Good flesh quality.
  • Fast growing
  • Early maturity.
  • Not prone to infections.

Question 18.
State the importance of honey.
Answer:
Honey extracted from beehives

  • has value especially indigestion disorders and some liver ailments.
  • rich source of calcium and iron along with other minerals and vitamins.
  • used as source of sugar in confectioneries.

Question 19.
What are indigenous and exotic breeds of honey bees?
Answer:
Indigenous breeds: Apis cerenana Indica, Apis florae, Apis dorsata
Exotic breeds: Apis mellifera Apis mellifera is the species known for the higher yield of good quality honey.

Question 20.
Which milk will you prefer for making curd, milk of cow or buffalo? Why?
Answer:
The milk from a buffalo is of superior quality because it is richer in fats, tocopherols, proteins, calcium and phosphorus and has low percentage of sodium, potassium and cholesterol. Therefore, for making the dairy products like curd, khoa, ghee and cheese etc, buffalo milk is preferred to cow milk.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 21.
What determines the quality of an egg?
Answer:
The quality of an egg is determined by its

  • Weight and size.
  • Shape
  • Shell quality
  • Internal structure.

Question 22.
Why ovaprim is used in pisciculture?
Answer:
In pisciculture, to get the good quality of seedlings( very young fishes), hormones extracted from the pituitary gland of carps were used in the process called hypophysation. These days, the hormonal extract has been replaced by synthetic inducing agent containing hormones. This is called ovaprim. It is used to improve the breed of fish synthetically. The use of ovaprim leads to induced breeding of fish.

It is during breeding time of fishes from July to August which is the rainy season.

Question 23.
What is the use of nursery pond and rearing ponds in fish culture?
Answer:
Nursery pond has size of 0.02-0.04 hectare with depth of about one metre. Fish eggs are placed in this pond which has circulating or flowing water to ensure the 100% hatching of the eggs. The eggs after hatching are called fries which are latqr transferred to other pond.

Rearing pond is of size of 0.04 hectare to 0.08 hectare with depth of about 1.5 metre. These are the ponds in which fries are transferred. Here, a they are fed with nutritious food for early maturity.

Question 24.
Enlist some of the advantages of beekeeping.
Answer:
The advantages of beekeeping include

  • It is source of honey known for its medical value and source of sugar in confectionaries.
  • It is source of bee wax, royal jelly and bee venom,
  • It helps in cross pollination of flowers in pasturage,
  • It is a type of cheap investment as farmer along with cultivation can involve himself in apiculture to boost his income.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 25.
Is water harvesting during monsoon season a better exercise? If yes, why?
Answer:
Yes; water harvesting during rainy season is a good exercise. It involves the storage of water in tanks or in small dams constructed below the higher elevation of catchment area. These dams are local specific but play an important role in

  • recharging the underground water level.
  • Providing water during times of water scarcity to the local people and cattle.

Question 26.
Mention some of the factors which have helped increase the food production.
Answer:
Some of the factors which have contributed in increasing the food production include

  • Use of high yielding varieties of crops.
  • Use of manures, fertilizers and adoption of the practices like crop rotation and intercropping.
  • Protection of crops from pests and timely eradication of weeds.
  • Timely irrigation of field with required amount of water.
  • Better storage practices.

Question 27.
Preventive measures needs to be adopted to reduce the incidences of diseases in animals. Explain.
Answer:
The incidences of diseases in animals can be reduced if proper preventive measures are followed such as

  • Well desired shelter with proper sanitation and ventilation facilities.
  • Proper good nutritious food and good facility for drinking water.
  • Keeping the surrounding of the area clean to prevent growth of mosquitoes or othejr pathogens.
  • Frequent bathing of animals help reduce skin infections.
  • Timely vaccination of animals.

Question 28.
What is crop production? What are the different types of crops?
Answer:
The act of growing number of useful plants in a given area without causing any environmental disturbances is Called crop production. Different types of crops grown are:
Cereals : Wheat, maize, rice, sorghum, millets, etc.
Pulses: Gram pea, black gram, pigeon pea, lentil, kidney beans, etc.
Oil seeds : Mustard, sesame, soyabean, groundnut, sunflower, etc.
Vegetables : Potato, spinach, cabbage, carrot, radish, etc
Fruits: Mango, papaya, grapes, litchi, apple, pine apple, etc.
Fodder: Barseam, oat, etc Beverages: Tea, coffee, tobacco, etc.

Long Answer Type Questions

Question 1.
Write down the differences between mannure and fertilizers.
Answer:
The differences between mannure and fertilisers are given below.
Mannure:

  1. This is a mixture of organic and inorganic substances.
  2. This is prepared from vegetable and animal wastes by the action of microbes on decomposition.
  3. It has low concentration of nutrients.
  4. It is not specific in nature.
  5. It is bulky hence not easy to store and transport.
  6. It adds to water holding capacity of soil.

Fertilizers:

  1. This is an inorganic substance.
  2. These are synthesised from chemical substances.
  3. It has high concentration of nutrients.
  4. It is specific in nature e.g. nitrogenous or phosphatic.
  5. It is easy to store and transport.
  6. It has no effect on water holding capacity of soil.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 2.
Explain the role of workers in a honey bee colony.
Answer:
Workers the infertile female in the colony are the most active member. They have almost all responsibilities on their shoulders. In fact, they all are female by instinct but being the infertile female do not have the property to reproduce. Worker in their first half of life cycle do all indoor activities such as cleaning of the hive, taking care of hive as well as the queen.

In the second half of their life cycle they work as field workers i.e. collects the nectar, pollen, propolis. They also act as the security force of the colony i.e. work as the guards of colony. When any enemy comes, they sting it and then die off.

Question 3.
What are the preventive and control measures used before grains are stored for future use.
Answer:
Following are some control measures used before the grains are stored for future use:

  1. Drying: The grains should be properly dried in sun followed by drying in shade. So that the moisture contents in the grains should be less than 14%.
  2. Maintenance of Hygiene: Godowns and stores should be property cleaned Le., all sorts of dust, dirot, rubbish, webbing etc. of the previous grains should be swept away.
  3. Cracks and Holes in the wall, floor or ceiling should be properly sealed.
  4. New gunny bags should be used. If the old gunny bags are being used, then clean them properly, turn inside out and expose to the sun or fumigate them.
  5. If earthen pots are used then they should also be cleaned and properly exposed to the sun.
  6. Fumigation: Chemicals which can exist in gaseous state in sufficient concentration to be lethal against the pest are known as fumigants. These should be used according to the prescribed dose as Aluminium Phosphide can be used at the rate of 2 tablets per tonnes of grain.

Question 4.
What are the objectives of crop-varietal improvement?
Answer:
Common objectives of crop-varietal improvement are as follows:
1. Improved yield: The aim is to improve the productivity of economic produce. This improvement can be brought about by developing high yielding varieties.

2. Better Quality of agronomic products.

3. Biotic and Abiotic resistance: Crops suffer due to bioitic stress under different situtations. Developing varieties which have resistance to these stresses can bring significant improvement in crop production.

4. Early and uniform maturity: Early maturing varieties can make the crop fit into double and multiple cropping systems. This will also reduce the cost of production of crop. Uniform maturity will make the harvesting process easy and reduce the loss of produce harvesting.

5. Desirable Agronomic Traits: Tallness, high tillering and profuse branching are desirable characters for fodder crops. Drawfness is desired in cereals. Thus, developing varietis of desired agronomic traits will help increase the productivity.

6. Water Adaptability: This property will help in stablising the crop production under different environmental conditions.

Question 5.
What is artificial insemination? What are its advantages?
Answer:
Artificial insemination: It is the process of collection of the semen of male animal of desired quality by artificial means. Then its examination, preservation, transportation later it is injected into the vagina of female animals.

This is used only to improve the livestock found at distant places.
Advantages: 1. Artificial insemination makes the selective breeding of animals easier, because the semen from a desired high yielding breed of bull can be transported to distant places for impregnating cows.

2. This process is economical. Semem from a single bull can be used to impregnate 3000 cows at distant places. Thus is because semen of the bull is preserved, packed and sent for artificial insemination.

Question 6.
What practices are employed for rearing of diary animals? Describe essential feature of any two of these practices and their effects on the health and yield of animals.
Answer:
Practices for raising diary animals include:

  1. Proper feeding
  2. Proper shelter
  3. Protection from diseases
  4. Breeding

1. Proper feeding: Animals also require balanced diet in adequate quantity according to their work, special conditions, age and health. Animal requirements is of two types (1) Roughages (2) Concentrate. Green fodder, berseem, maize, jowar, bajra, provide them with some minerals. Cereals, grains, cotton, seeds, oil cakes and gram provide them with concentrate consisting proteins, fats and vitamins at the time of lactation.

Effect of Proper feeding. The poor quality of food material is the main .reason for the overall low yield. Their deficiency may cause diseases and affect the general health of the animals. Proper feeding maintain general health as well as raises the yield of the animal product.

2. Breeding: It is also very important factor for rearing dairy animals. Our indigenous varieties yield low milk, eggs and meat evert on their proper feeding Traditional breeds of animals are improved by crossing them, with high yielding breeds.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 7.
What is the important points to remember in poultry farming?
Answer:
The important points to remember in poultry farming are following:

  1. Thr iMpNiwiii poultry breeds should be developed and fanned to produce layers for eggs and broilers for meat.
  2. We should improve their breed by cross breeding the indigenous with exotic breeds according to their use (layers or broilers).
  3. Their housing, shelters and feed should be kept in mind as layers require enough space as compared to broilers, layers also need proper light. Food is also different for broilers towhom we have to supply more protein rich diet with adequate fat. The layers are fed with vitamins, minerals and micronutrients.
  4. The keeper should practice proper sanitation, spraying of disinfectant at regular intervals to avoid the spread of diseases.
  5. Appropriate vaccination to reduce loss of poultry during an out break of disease, so, keeper should also keep in mind the vaccination process.

Question 8.
How bee colony works? What values can be seen in organisation of colony?
Answer:
Bees, live in a colony and show the best example of teamwork. The colony has three types of bees (1) Queen (2) Drones (3) Workers.

1. Queen: Is only one in one colony. Works as a mother of the colony, is responsible for laying eggs. In each season 2000 eggs are laid per day, eggs are fertile as well as.unfertile. Queen and workers emerges from fertile teggs where as drones come out of unfertile eggs.

2. Drones: They work as male in colony and mate with the queen. They live., sleep and eat in the colony. Their role is only in the breeding season hence, they are made to leave the colony after the breeding seasons. They are hundreds in number in one hive.

3. Workers: These are the most active members of the colony. They are female by instinct but unable to reproduce. During their first half life period, they perform the indoor duty as cleaning of hive etc. In the second half of their life, they have to do the outdoor duties such as collection of nectar, pollen, bee glue and protection of the queen. They are the security guards hence, sting the enemies and die off. They are 40,000 to 100,000 in a hive.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources

Question 9.
Explain what will happen if in a cultivated field only mannures are supplied and in another field only fertiliser are supplied while keeping all other conditions similar.
Answer:
In a cultivated field if we supply the manures, it will enrich the soil with nutrients as well as with organic matter. Manures increase the water holding capacity of the soil but in clayey soil the organic matter of manure helps in drainage and avoid water logging. Manure protect our environment and by applying it, we recycle the farm waste which is of so costly. But manure supply the small quantities of nutrients. The result would be slow plant growth.

In the another field we supply only fertilisers, the plants then have the healthy vegetative growth giving rise to healthy plants. Fertilisers are commercially produced for giving nutrients to plants and can supply only Nitrogen, Phosphorus or potassium (NPK). We can obtain high yield but only in high cost farming practices. We have also to keep in mind the pre and post application precautions for their utilization. Fertiliser is to be applied in terms of proper dose and time.

This results that when the farmer apply only fertiliser, he will get better cultivation and high yield as compared to when we only the manures. However, fertilizers if applied in excess would promote desertification.

NCERT Solutions for Class 9 Science Chapter 15 Improvement in Food Resources Read More »

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

These NCERT Solutions for Class 9 Science Chapter 14 Natural Resources Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Natural Resources NCERT Solutions for Class 9 Science Chapter 14

Class 9 Science Chapter 14 Natural Resources InText Questions and Answers

Question 1.
How is our atmosphere different from the atmospheres on Venus and Mars?
Answer:
Earth’s atmosphere is different from those of Venus and Mars. This difference lies essentially in their compositions. Earth’s atmosphere is a mixture of nitrogen (79%), oxygen (20%), and a small fraction of carbon dioxide, water vapours and other gases. This makes the existence of life possible on Earth. However, the atmospheres on Venus and Mars mainly consist of carbon dioxide. The amount of carbon dioxide on these planets can range from 95% to 97%.

Question 2.
How does the atmosphere act as a blanket?
Answer:
The atmosphere acts as a blanket by performing the following functions:
(a) It keeps the average temperature of the Earth fairly constant during daytime and even during the course of whole year.
(b) It prevents a sudden increase in the temperature during daytime.
(c) It slows down the escape of heat from the surface of the Earth into outer space during nighttime.

Question 3.
What causes winds?
Answer:
An uneven heating of the Earth’s surface causes winds. On being heated, air becomes lighter and rises up. As a result, a region of low pressure is created. Then, air from a high pressure region moves to a low pressure region, causing wind.

Question 4.
How are clouds formed?
Answer:
During daytime, on being heated, a large amount of water evaporates from various water bodies and goes into the air. A part of this water vapour also reaches the atmosphere through biological activities such as transpiration and respiration. This causes the air in the atmosphere to heat up. When this heated air rises, it expands and cools, which results in the condensation of water vapour forming water droplets. The presence of dust and other suspended particles in air also facilitates the process of condensation. The formation of water droplets leads to the formation of clouds.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 5.
List any three human activities that you think would lead to air pollution.
Answer:
The following three human activities would lead to air pollution:

  1. Burning of fossil fuels such as coal and petroleum
  2. Industrialization
  3. Deforestation

Question 6.
Why do organisms need water?
Answer:
Organisms need water for the following reasons:

  • All cellular processes need water as a medium. Usually, the reactions that take place in our body or within the cells occur between substances that are dissolved in water.
  • Since most of the substances are transported in a dissolved form, water is necessary.

Question 7.
What is the major source of fresh water in the city/town/village where you live?
Answer:
River is a major source of freshwater.

Question 8.
Do you know of any activity which may be polluting this water source?
Answer:
The discharge of wastewater from homes, industries, hospitals, etc. into the river pollutes this freshwater source.

Question 9.
How is soil formed?
Answer:
Soil is formed by breaking down of rocks at or near the surface of the Earth through various physical, chemical, and biological processes by various factor such as the sun, water, wind, and living organisms.
(i) Sim:
During day time, the rocks are heated. This
causes the rocks to expand. During nighttime, these rocks cool down and contract. Since all parts of the rock do not undergo expansion and contraction at the same rate, this causes the formation of cracks in these rocks. These cracks lead to the breaking up of huge rocks into smaller pieces.

(ii) Water:
Water catalyses the process of formation of soil in two ways.
(a) Water goes into the cracks and crevices formed in the rocks. When this water freezes, its volume increases. As a result, the size of the cracks also increases. This helps in the weathering of rocks.
(b) Running water wears away hard rocks over long periods of time. Water moving in fast speed carries big and small particles of rock downstream. These rocks rub against each other, resulting in breaking down of rocks. These smaller particles are carried away by running water and deposited down its path.

(iii) Wind:
Strong winds carry away rocks, which causes rubbing of rocks. This results in the breaking down of rocks into smaller and smaller particles.

(iv) Living organisms:
Some living organisms like lichens help in the formation of soil. Lichens also grow on rocks. During their growth, lichens release certain substances, which cause the rock surface to powder down forming a thin layer of soil. On this thin layer of soil, some small plants like moss also grow. They further cause the breaking down of the rock particles.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 10.
What is soil erosion?
Answer:
The blowing away or washing away of land surface by wind or water is known as soil erosion.

Question 11.
What are the methods of preventing or reducing soil erosion?
Answer:
The methods of preventing or reducing soil erosion are:

  • Prevention of deforestation
  • Plantation of trees

Question 12.
What are the different states in which water is found during the water cycle?
Answer:
During the water cycle, water is found in solid state (snow, ice, etc.), liquid state (ground water, river water, etc.), and gaseous state (water vapours).

Question 13.
Name two biologically important compounds that contain both oxygen and nitrogen.
Answer:
Two biologically important compounds that contain both oxygen and nitrogen are:

  1. Amino acids
  2. Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)

Question 14.
List any three human activities which would lead to an increase in the carbon dioxide content of air.
Answer:

  1. Burning of fuels in various processes like heating, cooking, transportation, and industry.
  2. Human induced forest fires
  3. The process of deforestation includes the cutting down of trees. This decreases the uptake of carbon dioxide for photosynthesis. Eventually, the content of carbon dioxide increases.

Question 15.
What is the greenhouse effect?
Answer:
Some gases like carbon dioxide, methane, nitrous oxide prevent the escape of heat from the Earth’s surface by trapping it. This increases the average temperature of the Earth. This is called the greenhouse effect. An increase in the content of such gases would lead to a situation of global warming.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 16.
What are the two forms of oxygen found in the atmosphere?
Answer:
The two forms of oxygen found in the atmosphere are:

  1. Diatomic molecular form with chemical formula O2.
  2. Triatomic molecular form with chemical formula O3 known as ozone.

Class 9 Science Chapter 14 Natural Resources Textbook Questions and Answers

Question 1.
Why is the atmosphere essential for life?
Answer:
The atmosphere is essential for life because it maintains an appropriate climate for the sustenance of life by carrying out the following activities:

  • Atmosphere keeps the average temperature of the Earth fairly constant during daytime.
  • It prevents a sudden increase in temperature during daytime.
  • It also slows down the escape of heat from the surface of the Earth into outer space during nighttime.

Question 2.
Why is water essential for life?
Answer:
Water is essential for life because of the following reasons:

  • Most biological reactions occur when substances are dissolved in water. Thus, all cellular processes need water as a medium to take place.
  • Transportation of biological substances needs water as a medium.

Question 3.
How are living organisms dependent on the soil? Are organisms that live in water totally independent of soil as a resource?
Answer:
Almost all living organisms are dependent on soil. Some depend directly, while some depend indirectly.

Plants need soil for getting support as well as nutrients to prepare their food. On the other hand, organisms depend on plants for food and other substances that are essential for life. Herbivores depend directly upon plants, and carnivores depend upon animals, which in turn depend upon plants for food. This makes them depend on soil indirectly.

Organisms that live in water are not totally independent of soil as a resource. These organisms depend on aquatic plants for food and other substances. These aquatic plants in turn require minerals for their sustenance. These minerals are carried to water bodies from soil by rivers, rainwater, etc. Without the supply of minerals from the soil to the water bodies, it is impossible to imagine aquatic life.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 4.
You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather?
Answer:
The meteorological department of the government collects data on the elements of weather such as maximum and minimum temperatures, maximum and minimum humidity, rainfall, wind speed, etc. They are able to study these elements using various instruments. The maximum and minimum temperature of a day is measured by a thermometer known as the maximum-minimum thermometer. Rainfall is measured by an instrument known as the rain gauge. Wind speed is measured by anemometers. There are various instruments used to measure humidity.

Question 5.
We know that many human activities lead to increasing levels of pollution of the air, water-bodies and soiL Do you think that isolating these activities to specific and limited areas would help in reducing pollution?
Answer:
Yes. Isolating human activities to specific areas would help in reducing levels of pollution. For example, setting up of industries in isolated regions will control pollution to some extent. The pollution caused by these industries will not contaminate water resources, agriculture land, fertile land, etc.

Question 6.
Write a note on how forests influence the quality of our air, soil and water resources.
Answer:
Forests influence the quality of our air, soil, and water resources in various ways. Some of them are:

  • Forests balance the percentages of carbon dioxide and oxygen in the atmosphere. The increasing amount of carbon dioxide caused by human activities is balanced by a larger intake of carbon dioxide by plants during the process of photosynthesis. Simultaneously, a large amount of oxygen is released.
  • Forests prevent soil erosion. Roots of plants bind the soil tightly in a way that the surface of the soil cannot be eroded away by wind, water, etc.
  • Forests help in the replenishment of water resources. During the process of transpiration, a huge amount of water vapour goes into the air and condenses to form clouds. (These clouds cause rainfall that recharge water bodies.

Class 9 Science Chapter 14 Natural Resources Additional Important Questions and Answers

Choose the correct option:

Question 1.
The atmosphere of the earth is heated by radiations which are mainly
(a) radiated by the sun
(b) re-radiated by land
(c) re-radiated by water
(d) re-radiated by land and water
Answer:
(d) re-radiated by land and water

Question 2.
If there were no atmosphere around the earth, the temperature of the earth will
(a) increase
(b) go on decreasing
(c) increase during day and decrease during night
(d) be unaffected
Answer:
(c) increase during day and decrease during night

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 3.
What would happen, if all the oxygen present in the environment is converted to ozone?
(a) We will be protected more
(b) It will become poisonous and kill living forms
(c) Ozone is not stable, hence it will be toxic
(d) It will help harmful sun radiations to reach earth and damage many life forms.
Answer:
(b) It will become poisonous and kill living forms

Question 4.
One of the following factors does not lead to soil formation in nature
(a) the sun
(b) water
(c) wind
(d) polythene bags
Answer:
(d) polythene bags

Question 5.
The two forms of oxygen found in the atmosphere are
(a) water and ozone
(b) water and oxygen
(c) ozone and oxygen
(d) water and carbon-dioxide
Answer:
(c) ozone and oxygen

Question 6.
The process of nitrogen-fixation by bac¬teria does not take place in the presence of
(a) molecular form of hydrogen
(b) elemental form of oxygen
(c) water
(d) elemental form of nitrogen
Answer:
(b) elemental form of oxygen

Question 7.
Rainfall patterns depend on
(a) the underground water table
(b) the number of water bodies man area
(c) the density pattern of human population in an area
(d) the prevailing season in an area
Answer:
(b) the number of water bodies man area

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 8.
Among the given options, which one is not correct for the use of large amount of fertilisers and pesticides?
(a) They are eco-friendly
(b) They turn the fields barren after some time
(c) They adversely affect the useful component from the soil
(d) They destroy the soil fertility
Answer:
(a) They are eco-friendly

Question 9.
The nitrogen molecules present in air can be converted into nitrates and nitrites by
(a) a biological process of nitrogen fixing bacteria present in Soil
(b) a biological process of carbon fixing factor present in soil
(c) any of the industries manufacturing nitrogenous compounds
(d) the plants used as cereal crops in field
Answer:
(a) a biological process of nitrogen fixing bacteria present in Soil

Question 10.
One of the following processes is not a step involved in the water-cycle operating in nature
(a) evaporation
(b) transpiration
(c) precipitation
(d) photosynthesis
Answer:
(d) photosynthesis

Question 11.
The term “water-pollution” can be defined in several ways. Which of the following statements does not give the correct definition?
(a) The addition of undesirable substances to water-bodies
(b) The removal of desirable substances from water-bodies
(c) A change in pressure of the water bodies
(d) A change in temperature of the water bodies
Answer:
(c) A change in pressure of the water bodies

Question 12.
Which of the following is not a greenhouse gas?
(a) Methane
(b) Carbon dioxide
(c) Carbon monoxide
(d) Ammonia
Answer:
(d) Ammonia

Question 13.
Which step is not involved in the carbon-cyicle?
(a) Photosynthesis
(b) Transpiration
(c) Respiration
(d) Burning of fossil fuels
Answer:
(b) Transpiration

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 14.
‘Ozone-hole’ means
(a) a large sized hole in the ozone layer
(b) thinning of the ozone layer
(c) small holes scattered in the ozone layer
(d) thickening of ozone in the ozone layer
Answer:
(b) thinning of the ozone layer

Question 15.
Ozone-layer is getting depleted because of
(a) excessive use of automobiles
(b) excessive formation of industrial units
(c) excessive use of man-made compounds containing both fluorine and chlorine
(d) excessive deforestation.
Answer:
(c) excessive use of man-made compounds containing both fluorine and chlorine

Question 16.
Which of the following is a recently originated problem of environment?
(a) Ozone layer depletion
(b) Greenhouse effect
(c) Global warming
(d) All of the above

Very Short Answer Questions

Question 1.
Define the term natural resource.
Answer:
Any useful material obtained from the nature is called a natural resource.

Question 2.
What are two types of natural resources?
Answer:
The two types of natural resources are renewable resources and non-renewable resources.

Question 3.
Which zone of atmosphere is the closet to the earth?
Answer:
Troposphere

Question 4.
Name the three important constituents of the air.
Answer:
The three important constituents of soil are nitrogen, oxygen and carbon dioxide.

Question 5.
Where on earth the British researchers have found the ozone hole in 1985?
Answer:
Over South Antarctica.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 6.
Montreal protocol in 1986 had banned on the emission of a pollutant to protect the ozone layer. Name the pollutant.
Answer:
Montreal protocol had banned the emission of CFCs (Chlorofluro carbon)

Question 7.
Name some of the greenhouse gases.
Answer:
Carbon dioxide, methane, sulphur dioxide and CFCs.

Question 8.
Which two types of components are found in biosphere?
Answer:
Biotic (living) components and abiotic (Non-living) components.

Question 9.
List the factors which contribute to the weathering of rocks in soil formation.
Answer:
The factors are temperature, air, water and living organisms like lichens.

Question 10.
Which factor is responsible for deciding the type of soil?
Answer:
The average particle size decides the type of soil.

Question 11.
Which type of soil causes early waterlogging conditions?
Answer:
Clayey soil

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 12.
Why is there a need to conserve the natural resources?
Answer:
The conservation of natural resources is essential for the sustainable development.

Question 13.
What is biosphere?
Answer:
The life supporting zone, of the earth where the lithosphere, hydrosphere and atmosphere interact is called biosphere.

Question 14.
What do you understand by top soil?
Answer:
The top soil is the uppermost layer of soil that contains humus and living organisms in addition to soil particles. It also holds the plants.

Question 15.
Name the three forms of nitrogen fixation.
Answer:
The three forms of nitrogen fixation are atmospheric fixation, biological fixation and industrial fixation.

Short Answer Questions

Question 1.
What is atmosphere? State its importance to life on the earth.
Answer:
A thick blanket of air present around the earth is called atmosphere. It is a bad conductor of heat as during day time, the atmospheric gases prevents excessive rise in surface temperature of the earth for the survival of life and at night time the same gases prevent the escape of heat from earth surface to keep it warm.

The air present in atmosphere also contains life supporting gases such as oxygen and carbon dioxide.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 2.
Mention the different constituents of the soil.
Answer:
The different constituents of soil are

  • Powdered rock particles formed after the weathering of rocks.
  • Micro-organisms included in the decomposition of organic matter.
  • Water droplets
  • Organisms like earthworm for whom the top soil acts as their habitat.

Question 3.
Why is soil important for plants?
Answer:
Soil is important to plants because it is a source of

  • water required by the plants.
  • mineral nutrients required by the plants
  • support required by plants to stand erect even in windy or stormy conditions.

Question 4.
What is soil pollution?
Answer:
The removal of useful components of soil and the addition of other substances which interfere with the soil fertility and harm the diversity of microorganisms present in soil is called soil pollution. The application of chemical fertilizers, pesticides and addition of domestic and industrial waste to soil, along with increased degree of soil erosion are the major causes of soil pollution.

Question 5.
Differentiate in water table and water depth.
Answer:
The minimum depth fo soil where all pore spaces in soil are filled with water make up the water table. Thus, the upper level zone of saturation is called water table.The depth of water level is expressed with reference to mean sea level.

The vertical distance from place on the surface of the earth to the water table is called the water level.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 6.
Differentiate in the two types of components found in the biosphere.
Answer:
The types of the components found in the biosphere are biotic and abiotic components. The biotic components include all living organisms from microorganisms to higher plants and animals. The abiotic components include all non-living components such as air, water and soil.

Question 7.
Why do we need to conserve the natural resources?
Answer:
The conservation of natural resources means their wise and judicious use. It is essential to conserve the different natural resources to ensure

  • The availability of natural resources for a longer time.
  • The maintenance of the quality of the natural resources.
  • To achieve the sustainable development.

Question 8.
List two ways in which carbon dioxide is fixed in nature.
Answer:
The carbon dioxide is fixed in nature by

  1. Green plants who produce sugar by the reduction of carbon dioxide in photosynthesis.
  2. Aquatic mostly marine animals molluscs who use carbonates present in seawater to make their protective shell

Question 9.
Mention some of the pollutants of air.
Answer:
Any undesirable substance added to air that causes the decline in the quality of air is called air pollutant. The different air pollutants include:

  • Oxides of sulphur such as SO2 and SO3.
  • Oxides of nitrogen such as NO and NO2
  • Greenhouse gases such as methane and carbon dioxide
  • Unburnt particles of carbon called soot.
  • Carbon monoxide
  • Dust and smoke

Question 10.
What is smog?
Answer:
The presence of oxides of sulphur, oxides of nitrogen, greenhouse gases such as methane and carbon dioxide, unburnt particles of carbon, dust and smoke in air mixes with fog to form smog in cold weather conditions. The smog formation reduces the visibility that harms the productivity because of the delay in travelling times, corrosion of metallic and marble structures.

Question 11.
Describe ozone as a chemical weed.
Answer:
Ozone is considered as a chemical weed because when on earth surface as a bluish gas, it is toxic to life but high up in stratosphere, it protects the life from the UV-rays present in solar radiations. The UV rays have harmful effects on human life because they are considered responsible for

  • Increasing incidences of skin bums and skin cancer.
  • Increasing cases of cataract.
  • Reducing crop production by more than 20%.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 12.
Which chemicals have reduced the thickness of ozone layer in stratosphere?
Answer:
Man made compounds called CFCs (Chlorofluro carbons) are very stable compounds. These compounds released from refrigerators and air conditioners cannot be degraded by any biological process. When they reach the ozone layer, the chlorine present in them combines with the monatomic oxygen produced on the dissociation of ozone to form stable compound. This continuously occurring reaction causes fire depletion of ozone layer.

Nitric oxide (NO) released in air also contributes to the depletion of the ozone layer.

Long Answer Questions

Question 1.
How the two biological processes respiration and photosynthesis are interrelated? Give an example to support your answer.
Answer:
The two biological processes, photosynthesis and respiration are interrelated because the end products of cellular respiration i.e. carbon dioxide and water are the raw materials in the process of photosynthesis and the end products of photosynthesis i.e. sugar and oxygen are the raw materials used in the process of cellular respiration.
Respiration,
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy
Photosynthesis,
6CO2 + 12H2O + Solar energy → C6H12O6 + 6H2O + 6O2

Therefore, in green plants during early morning and later evening, no gaseous exchange takes place as at this time, rate of photosynthesis equals the rate of respiration taking place in their cells.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 2.
Explain the water cycle with the help of a diagram.
Answer:
The water cycle involves

  • the evaporation of water in form of its vapours from the earth surface and hydrosphere under the heating effect of solar radiations.
  • the condensation of water vapours high up in atmosphere to form clouds containing water in its condensed form of water droplets.
  • the precipitation that returns the water back to earth in form of rain, hail or snow.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources 1

Question 3.
Draw and explain nitrogen cycle in nature.
Answer:
Nitrogen is almost chemically inert gas but is the major constituent of the atmospheric air. (78%) It cannot be directly used by the plants and animals but is essential for all living organisms being the major constituent of proteins and nucleic acids. Therefore, the atmospheric nitrogen is first fixed in form of compounds that can easily be absorbed by the plants.

In nature nitrogen fixation occurs in three possible ways. These are

  • Atmospheric fixation, when lightning occurs during thunder storm. The nitrogen combines with oxygen to form its oxide or nitrogen combines with hydrogen to form ammonia. These oxides being water soluble reach the earth with rainwater.
  • Biological fixation which is carried out by the free nitrogen fixing cyanobacteria like nostoc and anabena or by the bacteria named Rhizobium present in the root nod-ules of legume plants.
  • Industrial fixation involves the formation of nitrogen compounds by chemical fertilizer producing companies.

The nitrogen compounds present in soil in form of nitrites undergo nitrification by bacterial action to form nitrate ions that are absorbed by the plants and used up in synthesis of proteins and nucleic acids. From plants, the nitrogen compounds reach animals in form of amino acids and nitrogenous bases for their growth.

The plant and animal waste or their dead parts later undergo either decomposition to produce nitrite or nitrates or undergo bacterial denitrification to release the nitrogen in gaseous state in nature.
NCERT Solutions for Class 9 Science Chapter 14 Natural Resources 2

Question 4.
How is carbon cycle completed in nature?
Answer:
Carbon is incorporated into plants by process of photosynthesis. The process converts the gaseous carbon dioxide present in atmosphere or dissolved in water into glucose molecules. These molecules are the source of energy after their oxidation in the process of respiration. The process involves the release of carbon dioxide back in the atmosphere.

The compounds of carbon in different forms of carbohydrates, proteins and fats passes into animals for their survival.

The process of combustion of fuels also adds carbon dioxide to the atmosphere. The combustion involves the oxidation of compounds of carbon or carbon alone to produce energy in the form of heat and light. A small percentage of carbon in gaseous state is also released on the decomposition of organic matter by decomposers. A small percentage of carbon dioxide dissolved in water is also involved in formation of carbonates that are used by aquatic animals to make shells.

Hence, carbon in form of carbon dioxide cycles in nature between living organisms and atmospheric air.
NCERT Solutions for Class 9 Science Chapter 14 Natural Resources 3

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Question 5.
Explain the oxygen cycle in nature.
Answer:
Oxygen gas is very important for most of the living organisms and is also abundantly available in atmospheric air, 21% by volume of the total atmospheric air. It is also present in form of its compounds in lithosphere such as metallic oxides and form of oxides of carbon, sulphur and nitrogen in air. In living organisms, it is the major constituents of essential organic compounds like carbohydrates, fats, etc.

In atmosphere, the oxygen is used in three processes i.e. respiration, combustion and formation of oxides. The used oxygen is returned to atmosphere by the process of photosynthesis in which it is released as the end product.
NCERT Solutions for Class 9 Science Chapter 14 Natural Resources 4

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources Read More »

error: Content is protected !!