Notesale: Turn your study into money

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1

Food:
Where Does It Come From?

W

hat did you eat at home
today? Find out what your
friend ate today
...
1 FOOD VARIETY
Activity 1
Ask your friends in the school about the
items they would be eating during a day
...
List all the items in your
notebook as given in Table 1
...

Table 1
...
What are these
food items made of?
Think about rice
cooked at home
...
Just two materials
or ingredients are needed to prepare a
dish of boiled rice
...
To
prepare vegetable curry, we need
different kinds of vegetables, salt, spices,
oil and so on
...
1 and try to find out what
ingredients are used to prepare these,
by discussing with your friends and
elders at home
...
2
...
Add
some more items to this list
...
2 Food items and their
ingredients
Food Item

Ingredients

Roti/chapati

Atta, water

Dal

Pulses, water, salt, oil/
ghee, spices

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So, where do these ingredients come from?

1
...
2
...
Where do they come from? Plants,
of course! What are the sources of rice or wheat? You may
have seen paddy or wheat fields with rows and rows of
plants, which give us these grains
...


Activity 3
Let us take the food items listed earlier
and try to find out where they come from
— the ingredients and their sources
...
3
...
3 and add
more examples to this list
...
3 Ingredients used to
prepare food items and
their sources
Food Item Ingredients
Idli

Rice

Sources
Plant

Urad dal
Salt
Water
Chicken
curry

Chicken

Animal

Spices
Oil/ghee

Plants/
Animals

Water
Kheer

Milk

Animal

Rice

Plant

Sugar
2

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Animals provide
us with milk, meat products and eggs
...

Milk and milk products like butter,
cream, cheese and curd are used all over
the world
...
3 PLANT PARTS AND ANIMAL
PRODUCTS AS FOOD
Plants are one source of our food
...
We eat
fruits of some plants
...
Have

you ever eaten Flower
pumpkin flowers
dipped in rice
paste and fried?
Bud
Try it!
Stem
Some plants
Leaf
have two or more
edible (eatable)
parts
...
Can
you think of the
different parts of a banana plant that
are used as food? Think of more
examples where many parts of a single
plant are used as food
...


From all the food items you have listed
in Table 1
...

Which part of a plant? Identify these
and list the food items and plant parts
as shown in Table 1
...


Table 1
...
Brinjal curry

Ingredients/source

Seed

2
...

FOOD: WHERE DOES IT COME FROM?

3

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Activity 5
Take some dry seeds of moong or chana
...
Next day, drain the water
completely and leave the seeds in the
vessel
...
The following day,
do you observe any changes in the seed?

Do you know where honey comes
from, or how it is produced? Have you
seen a beehive where so many bees keep
buzzing about?
Bees collect nectar
(sweet juices) from
flowers, convert it
into honey and
store it in their
hive
...
So,
bees store this
nectar for their use
all through the
year
...


1
...
If so, the seeds have
sprouted
...

The next day, see if the seeds have
sprouted
...
They can also be
boiled
...

4

DO

ANIMALS EAT?

Do you have cattle or a pet that you
take care of? A dog, cat, buffalo or a
goat? You will then surely be aware of
the food, the animal eats
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eat is also given
...


plant products in Group 1
...
There are some
animals which eat other animals
...
These animals
are called carnivores
...

These are called omnivores
...
6 and enter
these separately in the three columns,
as shown
...
6

Activity 7
Have a look again at Table 1
...

Place animals which eat only plants or

Herbivores Carnivores Omnivores
Cow

Lion

Dog

Table 1
...
6
...
We need to find ways by which
more food can be grown in the country
...

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The main sources of our food are plants and animals
...

Animals which eat only animals are called carnivores
...


1
...


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


Match the items given in Column A with that in Column B
Column A
Milk, curd, paneer, ghee,

eat other animals

Spinach, cauliflower, carrot

eat plants and plant products

Lions and tigers

are vegetables

Herbivores

6

Column B

are all animal products

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Fill up the blanks with the words given:
herbivore, plant, milk, sugarcane, carnivore
(a) Tiger is a ____________________ because it eats only meat
...

(c) Parrot eats only _________________ products
...

(e) We get sugar from ___________________
...


You must have seen a garden lizard around your home
...
Is the
food different from that of a house lizard?

2
...
Place these on a large outline map of
India to display in your classroom
...


Find out the names of plants that grow in water and which are eaten
as food
...


In Chapter 10, you will find out ways of measuring length of curved lines
...
After
you learn these, try the following interesting project
...
Wash them in water everyday and
drain all the water
...
Measure the lengths of the sprouts everyday using
a string
...
Prepare a bar graph of the
number of sprouts having lengths in different ranges
...


Does everyone around you get enough food to eat? If not, why?

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2

Components of Food

n Chapter 1, we made lists of the
food items that we eat
...

A meal could consist of chapati, dal
and brinjal curry
...
Yet another meal
could be appam, fish curry and
vegetables
...
Some
examples of meals from different regions
are given in Table 2
...
Select food items
you depicted on the map in Chapter 1
...
1
...
If we are
travelling, we may eat whatever is
available on the way
...

There must be some reason though,
why meals usually consist of such a
distribution
...
1 WHAT DO DIFFERENT FOOD
ITEMS CONTAIN?

Our meals usually have at least one item
made of some kind of grain
...
It may also include items like

We know that each dish is usually made
up of one or more ingredients, which
we get from plants or animals
...
1 Some common meals of different regions/states
Region/
State
Punjab
Andhra
Pradesh

8

Item of grain

Item of
dal/meat

Vegetables

Rajma
Sarson saag
Makki (cor n) roti (Kidney beans) (Mustard leaf curry)
Rice

Tuar dal and
rasam (charu)

Kunduru (dondakai)

Others
Curd, ghee
Butter milk, ghee,
pickle (aavakai)

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These
components are called nutrients
...
In addition, food contains
dietary fibres and water which are also
needed by our body
...
The tests for presence
of carbohydrates, proteins and fats
are simpler to do as compared to the
tests for other nutrients
...
2
...
You will also
need a few test tubes and a dropper
...
Table 2
...
Some food items are
given in this table
...
Do these tests
carefully and do not try to eat or taste
any chemicals
...

Let us begin by testing different
food items to see if they contain
carbohydrates
...
The main
carbohydrates found in our food are in
COMPONENTS OF FOOD

A dilute solution of iodine can be
prepared by adding a few drops of
tincture iodine to a test tube half filled
with water
...

10 g of caustic soda dissolved in
100 mL of water makes the required
solution of caustic soda
...
We can
easily test if a food item contains starch
...
Put 2-3 drops of dilute
iodine solution on it (Fig
...
1)
...
Did it turn blue-black?

Fig
...
1 Testing for starch
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Repeat this test with other food items
to find out which of these contain starch
...
2
...
2
...
Shake well and let
the test tube stand for a few minutes
...

Now, you can repeat this test on other
food items
...
If the food you want to
Table 2
...

Grind or mash a small quantity
of the food item
...

Now, using a dropper, add
two drops of solution of copper
sulphate and ten drops of
solution of caustic soda to the

Food item
Raw potato
Milk
Groundnut

Starch
(present)

Protein
(present)

Fat
(present)

Yes
Yes
Yes

Uncooked
powdered
rice
Cooked rice
Dry coconut
Uncooked
tuar dal
(powdered)
Cooked dal
A slice of any
vegetable
A slice of any
fruit
Boiled egg
(white
portion)

Fig
...
2 Testing for protein
10

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Wrap it in a piece of paper and crush it
...

Now, straighten the paper and observe
it carefully
...
Are you
able to see the light faintly, through
this patch?
An oily patch on paper shows that
the food item contains fat
...
Therefore, after you have rubbed
an item on paper, let the paper dry for a
while
...
If no oily patch shows
up after this, the food item does not
contain any fat
...
There are also other nutrients
like vitamins and minerals that are
present in different food items
...
2 WHAT

VARIOUS NUTRIENTS
BODY?

DO

FOR OUR

Sweet potato

Potato

Sugarcane
Papaya

Wheat
Melon
Mango
Rice
Bajra

Maize

Fig
...
3 Some sources of carbohydrates

Nuts

Groundnuts

Til
(a)

Meat

DO

Carbohydrates mainly provide energy
to our body
...

In fact, fats give much more energy
as compared to the same amount of
carbohydrates
...
2
...
2
...

Proteins are needed for the growth
and repair of our body
...
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Gram

Moong

Dal
Beans

Peas

small quantities
...
Vitamin C helps
body to fight against many diseases
...
Foods that
are rich in different vitamins are shown
in Fig
...
6 to Fig
...
9
...
Each one is essential

Soyabeans
(a)

Meat

Fig
...
6 Some sources of Vitamin A

Fish

Liver
Fig
...
7 Some sources of Vitamin B
Eggs

Paneer
(b)

Fig
...
5 Some sources of proteins: (a) plant
sources and (b) animal sources

containing proteins are often called
‘body building foods’ (Fig 2
...

Vitamins help in protecting our body
against diseases
...

Vitamins are of different kinds
known by different names
...
There is also a group
of vitamins called Vitamin B-complex
...
2
...
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Some sources of
iodine

Our body also prepares Vitamin D
in the presence of Sunlight

Some sources of
phosphorous

for proper growth of body and to
maintain good health
...
2
...

Most food items, usually, have more
than one nutrient
...
2
...
For example, rice has more
carbohydrates than other nutrients
...

Besides these nutrients, our body
needs dietary fibres and water
...

Roughage is mainly provided by plant
products in our foods
...

Roughage does not provide any nutrient
to our body, but is an essential
component of our food and adds to its
bulk
...

COMPONENTS OF FOOD

Some sources
of iron

Some sources
of calcium

Fig
...
10 Sources of some minerals
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It also helps in
throwing out some wastes from body as
urine and sweat
...
In addition, we add water
to most cooked foods
...


Activity 3
Take a tomato or a fruit like lemon
...
Do your hands get
wet while doing so?
Carefully
observe
whenever
vegetables and fruits are being cut,
peeled, grated or mashed at your
home
...
To some
extent, our body needs are met by this
water
...


2
...
For growth and maintenance of
good health, our diet should have all
the nutrients that our body needs, in
right quantities
...
The diet
should also contain a good amount of
roughage and water
...

Do you think that people of all ages
need the same type of diet? Do you also
14

think that, what we need for a balanced
diet would depend on the amount of
physical work that we do?
Prepare a chart of whatever you eat
over a period of a week
...

Pulses, groundnut, soybean,
sprouted seeds (moong and Bengal
gram), fermented foods (South Indian
foods such as idlis), a combination of
flours (missi roti, thepla made from
cereals and pulses), banana, spinach,
sattu, jaggery, available vegetables and
other such foods provide many
nutrients
...

Eating the right kind of food is not
enough
...
Are you aware that some nutrients
get lost in the process of cooking and
preparations?
If the vegetables and fruits are
washed after cutting or peeling them, it
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The skins of many vegetables and fruits
contain vitamins and minerals
...

We all know that cooking improves
the taste of food and makes it easier to
digest
...

Many useful proteins and considerable
amounts of minerals are lost if excess
water is used during cooking and is
then thrown away
...
Would it not be
sensible to include some fruits and raw
vegetables in our diet?
Boojho thought that fats would be
the best foods to eat, all the time
...

Do you think he was right? No, of
course not! It can be very harmful for
us to eat too much of fat rich foods and
we may end up suffering from a
condition called obesity
...
4 DEFICIENCY DISEASES
A person may be getting enough food to
eat, but sometimes the food may not
contain a particular nutrient
...

Deficiency of one or more nutrients can
cause diseases or disorders in our body
...

If a person does not get enough
proteins in his/her food for a long time,
he/she is likely to have stunted growth,
swelling of face, discolouration of hair,
skin diseases and diarrhoea
...
Such a person becomes very
lean and thin and so weak that he/she
may not even be able to move
...
Some of these are
mentioned in Table 2
...

All deficiency diseases can be
prevented by taking a balanced diet
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Table 2
...
This distribution, we find, ensures that
our meals have a balance of the different nutrients
needed by the body
...
In addition, food also contains dietary fibres and water
...

Proteins and minerals are needed for the growth and the maintenance
of our body
...

Balanced diet provides all the nutrients that our body needs, in right
quantities, along with adequate amount of roughage and water
...

16

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Name the major nutrients in our food
...


Name the following:
(a) The nutrients which mainly give energy to our body
...

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


3
...


Tick (√) the statements that are correct
...
( )
(b) Deficiency diseases can be prevented by eating a balanced diet
...
( )
(d) Meat alone is sufficient to provide all nutrients to the body
...
Fill in the blanks
...

(b) Deficiency of ______________ causes a disease known as beri-beri
...

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


Prepare a diet chart to provide balance diet to a twelve year old child
...


2
...
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
...


Test the food usually eaten by cattle or a pet to find out which nutrients are
present in animal food
...


COMPONENTS OF FOOD

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They were very excited and decided to
use the prize money to buy clothes for
their parents
...
3
...
The shopkeeper
explained that some clothes or fabrics
were cotton and some were synthetic
...
There were many silk sarees as
well
...

They touched and felt these different
fabrics
...

After their visit to the cloth shop,
Paheli and Boojho began to notice
various fabrics in their surroundings
...
Even their school bags and
the gunny bags were made from
some kind of fabric
...
Can you also identify
some fabrics?

3
...

Collect cuttings of
fabrics leftover after
stitching
...
Now,
try to label some
of the fabrics as
Fig
...
2 Enlarged view
cotton, silk, wool of a piece of fabric
or synthetic after
asking for help from the tailor
...

Now, look at it closely
...
3
...
3
...
Now, try to find a
loose thread or yarn at one of the edges
and pull it out (Fig
...
3)
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Fig
...
3 Pulling a thread from a fabric

yarns are visible, you can gently pull
one out with a pin or a needle
...
What are these
yarns made of?

3
...
Place this piece of yarn on the
table
...
Scratch the other end
of the yarn along its length with your
nail as shown in Fig
...
4
...
3
...
3
...
Many a time, the end of the
thread is separated into a few thin
strands
...
The thin strands of thread that
we see, are made up of still thinner
strands called fibres
...

Where do these fibres come from?
The fibres of some fabrics such as
cotton, jute, silk and wool are obtained
from plants and animals
...
Cotton and jute
are examples of fibres obtained from
plants
...
Wool is obtained from the
fleece of sheep or goat
...
Silk fibre is drawn from the
cocoon of silkworm
...
In the last hundred years or so,
fibres are also made from chemical

Boojho has seen in the
museums, items like the
one shown here
...
He
wants to know if these
are made of some
kinds of fibre
...
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substances, which are not obtained
from plant or animal sources
...
Some examples
of synthetic fibres are polyester, nylon
and acrylic
...
3 SOME PLANT FIBRES
Cotton
Have you ever made wicks for oil lamps?
What do you use for making these
wicks? This cotton wool is also used for
filling mattresses, quilts or pillows
...
What do you
observe? The small, thin strands that
you see are made up of cotton fibres
...
Cotton
plants are usually grown at places
having black soil and warm climate
...
After maturing, the bolls
burst open and the seeds covered with
cotton fibres can be seen
...
3
...
3
...

From these bolls, cotton is usually
picked by hand
...

This process is called ginning of cotton
...
3
...
These days, machines are also
used for ginning
...
3
...
8)
...
In India, jute is
mainly grown in
West Bengal, Bihar
and Assam
...

The stems of the
harvested plants
are immersed in
water for a few
days
...

Fig
...
8 A jute plant
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3
...
How is
it done?

3
...


Activity 4
Hold some cotton wool in one hand
...
Now, gently start
pulling out the cotton, while
continuously twisting the
fibres (Fig
...
9)
...

In this process, fibres from a
mass of cotton wool are drawn
out and twisted
...

A simple device used
for spinning is a hand
spindle, also called takli
(Fig
...
10)
...
3
...
3
...
Use of charkha was A Takli
FIBRE TO FABRIC

Fig
...
11 Charkha

popularised by Mahatma Gandhi as part
of the Independence movement
...

Spinning of yarn on a large scale is
done with the help of spinning
machines
...


3
...
The two main
processes are weaving and knitting
...
The process of
arranging two sets of yarns together to
make a fabric is called weaving
...


Activity 5
Take two sheets of paper of different
colours
...

Now, fold both the sheets into half
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(a)

(b)
(c)

(d)

Fig
...
12 Weaving with paper strips

Fig 3
...
3
...
Cut both the sheets
along the dotted lines and then unfold
...
3
...
Fig
...
12 (d) shows the
pattern after weaving all the strips
...
14 Knitting

used to make a piece of fabric (Fig
...
14)
...
Socks and
many other clothing items are made of
knitted fabrics
...

Fig
...
13 Handloom

In a similar manner, two sets of yarn
are woven to make a fabric
...
3
...
The looms are either
hand operated or power operated
...
What are these
fibres normally used for?

Knitting
Have you noticed how sweaters are
knitted? In knitting, a single yarn is
22

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These fabrics are used for a variety of
clothing items
...
6 HISTORY OF CLOTHING MATERIAL
Have you ever wondered what materials
people used in ancient times for clothes?
It appears that in those times people
used the bark and big leaves of trees or
animal skins and furs to cover
themselves
...
Vines, animal fleece or hair were
twisted together into long strands
...
The early Indians
wore fabrics made out of cotton that grew
in the regions near the river Ganga
...

In ancient Egypt, cotton as well as flax
were cultivated near the river Nile and
were used for making fabrics
...
People simply draped the fabrics
around different parts of their body
...
With the invention of the
sewing needle, people started stitching
fabrics to make clothes
...
But, is it not
amazing that even today saree, dhoti,
lungi or turban is used as an un-stitched
piece of fabric?
Just as there is a large variety in the
food eaten all over our country, a large
variety exists also in fabrics and
clothing items
...

FIBRE TO FABRIC

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Fibres are either natural or synthetic
...

Fibres like cotton and jute are obtained from plants
...

Fabric from yarns is made by weaving and knitting
...


Classify the following fibres as natural or synthetic:
nylon, wool, cotton, silk, polyester, jute

2
...

b) Spinning is a process of making fibres
...

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

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


3
...

b) Animals fibres are __________ and ___________
...


From which parts of the plant cotton and jute are obtained?

5
...


6
...


SUGGESTED PROJECTS AND ACTIVITIES
1
...


Find out if any crop is grown in your region for obtaining fibre
...


24

Visit a nearby handloom or powerloom unit and observe the weaving or knitting
of fabric
...
India exports cotton
fabrics and items to many other countries
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4
...


5
...
Pull out six to eight yarns from the fabric
...

Observe carefully
...

If these are cotton yarns, they burn but do not shrink or melt
...
The silk yarn shrinks away
from the flame and burns but does not melt
...

The wool yarn also shrinks and burns but does not melt
...
The synthetic yarns shrink and burn
...


Boojho knows that burning of
cotton yarn gives an odour similar
to burning paper
...


FIBRE TO FABRIC

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1 OBJECTS AROUND

US

We saw that our food and clothes have
so much variety in them
...
We see around us,
a chair, a bullock cart, a cycle, cooking
utensils, books, clothes, toys, water,
stones and many other objects
...
4
...

Look around and identify objects
that are round in shape
...
If we include objects that
are nearly round, our list could also
include objects like apples, oranges, and
an earthen pitcher (gharha)
...
We might include all the items
that we have listed in Tables 1
...
2
and 1
...
We might also
find that some of those round shaped
objects we just listed out, are also in
this group
...

Buckets, lunch boxes, toys, water
containers, pipes and many such
objects, may find a place in this group
...

All objects around us are made of one
or more materials
...
Can you think of
more examples of materials?

Activity 1

Fig
...
1 Objects around us
26

Let us collect as many objects as
possible, from around us
...
What will we have
in our collection? Chalk, pencil,
notebook, rubber, duster, a hammer,
nail, soap, spoke of a wheel, bat,
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For example,
wall, trees, doors, tractor, road
...
This way we have divided all objects
into two groups
...

Similarly, we could separate the things
that are used for preparing food
...
List
all objects collected, in Table 4
...
Try to
identify the materials that each one is
made of
...
It
may seem difficult to find out the
materials out of which some of these
objects are made
...

Table 4
...
2 lists some common materials
...


Column 1 that are known to you
...

Table 4
...


Paper

Books, notebooks,
newspaper, toys,
calendars,
...
We then found that
objects around us are made of different
materials
...
An object could also
be made of many materials
...
What
decides which material should be used
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4
...
Therefore, would it not be silly,
if we were to make a tumbler out of cloth
(Fig 4
...
Similarly,
it would not be wise to use paper-like
materials for cooking vessels
...
4
...

So, what are all the properties of
materials that would be important for
their usage? Some properties are
discussed here
...
Wood looks very different
from iron
...
At the same time,
there may be some similarities between
iron, copper and aluminium that are not
there in wood
...
Do any of these
appear shiny? Separate the shiny
materials into a group
...
4
...
What do
you notice? Does the freshly cut surface
of some of these materials appear shiny?
Include these objects also in the group
of shiny materials
...

Instead of cutting, you can rub the
surface of material with sand paper to
see if it has lustre
...
4
...
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Materials that have such lustre are
usually metals
...
Some
metals often lose their shine and
appear dull, because of the action of air
and moisture on them
...
When you visit an
ironsmith or a workshop, look out for
freshly cut surfaces of metal rods to see
if they have lustre
...
Fill each one of them about twothirds with water
...
Stir the contents
of each of them with a spoon
...
Observe what happens to
the substances added to water (Fig
...
4)
...
3
...
Take a metal key and try
to scratch with it, the surface of a piece
of wood, aluminium, a piece of stone, a
nail, candle, chalk, any other material
or object
...
Materials which can
be compressed or scratched easily are
called soft while some other materials
which are difficult to compress are called
hard
...

In appearance, materials can have
different properties, like lustre,
hardness, be rough or smooth
...
Take five glasses or
SORTING MATERIALS INTO GROUPS

Fig
...
4 What disappears, what doesn’t?

Table 4
...
We say that these
substances are soluble in water
...
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long time
...

Water plays an important role in the
functioning of our body because it can
dissolve a large number of substances
...
Some
others do not mix with water and form
a separate layer when kept aside for
some time
...
Take a glass tumbler
...
Add a few
spoonfuls of one liquid to this and stir
it well
...

Observe whether the liquid mixes with
water (Fig
...
5)
...
Write your
observations in Table 4
...

Table 4
...
4
...

Paheli is curious to know
whether gases also dissolve
in water
...
Water, usually,
has small quantities of some gases
dissolved in it
...


Objects may float or sink in
water
While doing Activity 4, you might have
noticed that the insoluble solids
separated out from water
...
Some of these materials that
did not mix with water, floated to the
surface of water
...
4
...
Dried
leaves fallen on the surface of a pond, a
stone that you throw into this pond, few
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6 Some objects float in water while
others sink in it

drops of honey that you let fall into a
glass of water
...
What
about testing these same materials to
see if they float or sink in other liquids
like oil?

Transparency
You might have played the game of hide
and seek
...
Why did you choose
those places? Would you have tried to

hide behind a glass window? Obviously
not, as your friends can see through that
and spot you
...
4
...

Glass, water, air and some plastics are
examples of transparent materials
...
4
...
4
...

On the other hand, there are some
materials through which you are not
able to see
...
You cannot tell what is kept
in a closed wooden box, a cardboard
carton or a metal container
...

Do we find that we can group all
materials and objects, without any
confusion, as either opaque or
transparent?

Activity 6
Fig
...
7 Looking through opaque, transparent or
translucent material
SORTING MATERIALS INTO GROUPS

Take a sheet of paper and look through
it towards a lighted bulb
...
Now, put 2-3 drops
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Look again towards the lighted
bulb through that portion of the paper
on which the oil has been spread
...
The materials through
which objects can be seen, but not
clearly, are known as translucent
...

Paheli suggests
covering the glass
of a torch with your
palm at a dark
place
...
4
...

light pass through
your palm?
She wants to know

whether palm of your hand is opaque,
transparent or translucent?
We learnt that materials differ in their
appearance and the way they mix in
water or other liquids
...
Materials can be
grouped on the basis of similarities or
differences in their properties
...
At home, we
usually store things in such a manner
that similar objects are placed together
...
Similarly, a grocer usually
keeps all type of biscuits at one corner
of his shop, all soaps at another while
grains and pulses are stored at some
other place
...
Dividing
materials in groups makes it convenient
to study their properties and also
observe any patterns in these properties
...


Hard
Insoluble

Rough

Lustre

Soluble

Material

T ranslucent

Metals
32

Opaque

T ransparent
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A given material could be used to make a large number of objects
...

Different types of materials have different properties
...
Some are
rough, some smooth
...

Some materials are soluble in water whereas some others are insoluble
...
Some materials are translucent
...

Things are grouped together for convenience and to study their
properties
...


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


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

3
...
Remember, an object could be made from more than one material and a
given material could be used for making many objects
...


Glass

Plastics

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


(ii)

A notebook has lustre while eraser does not
...


(iv)

A piece of wood floats on water
...
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(v)
(vi)

Oil mixes with water
...


(viii)
5
...


Vinegar dissolves in water
...


List all items known to you that float on water
...


7
...


2
...
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
...
Have fun!
From a large collection of materials, make groups of objects having different
properties like transparency, solubility in water and other properties
...
After making different groups from the collected materials,
try and find out if there are any patterns in these groups
...
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5

Separation of Substances

T

here are many instances when we
notice a substance being
separated from a mixture
of materials
...
5
...


Fig
...
2 Butter is taken out by churning milk or
curds

Fig
...
1 Separating tea leaves with a strainer

Grain is separated from stalks, while
harvesting
...
5
...
As we
learned in Chapter 3, we gin cotton to
separate its seeds from the fibre
...
If you
found that it had
chillies in it, you may
have carefully taken
them out before eating
...
What would you
do? Pick out one kind and place them
in a separate container, right?
Seems easy, but what if the materials
we want to separate are much smaller

than mango or guava? Imagine you are
given a glass of sand with salt mixed in
it
...


Activity 1
In Column 1 of Table 5
...
The purpose
of separation and the way separated
components are used is mentioned in
Column 2 and 3 respectively
...
Can you match each

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1 Why do we separate substances?
Separation
process

Purpose for which we do
the separation

1) Separate
stones from rice

What do we do with the
separated components?

a) To separate two different, i) We throw away the soild
but useful components
...


2) Chur ning milk b) To remove non-useful
to obtain butter
components
...


3) Separate tea
leaves

iii) We use both the
components
...


process with its purpose and the way
separated components are used?
We see that, befor e we use a
substance, we need to separate harmful
or non-useful substances that may be
mixed with it
...

The substances to be separated may
be particles of different sizes or
materials
...
So, how do we separate
substances mixed together if they have
so many different properties?

5
...

This method of handpicking can
be used for separating slightly larger
sized impurities like the pieces of dirt,
stone, and husk from wheat, rice or
pulses (Fig
...
3)
...

In such situations, we find that
handpicking is a convenient method of
separating substances
...
You may come across some of
these methods being used in day to day
activities
...
5
...
Now, spread
the grain on a sheet of paper
...
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harvesting the crop
...
Each stalk has many grain
seeds attached to it
...
But, grain seeds are
much smaller than mangoes or guavas
...
How does one
separate grain seeds from their stalks?
The process that is used to separate
grain from stalks is threshing
...
5
...
Sometimes,

this mixture on a plate or a newspaper
...
Can the
two different components be made out
easily? Are the sizes of particles of the
two components similar? Would it be
possible to separate the components by
handpicking?
Now, take your mixture to an open
ground and stand on a raised platform
...
Hold the plate or the sheet of
paper containing the mixture, at your
shoulder height
...

What happens? Do both the
components — sand and sawdust (or
powdered leaves) fall at the same place?
Is there a component that blows away?
Did the wind manage to separate the
two components?
This method of separating
components of a mixture is called
winnowing
...


Fig
...
4 Threshing

threshing is done with the help of
bullocks
...


Winnowing
Activity 3
Make a mixture of dry sand with
sawdust or powdered dry leaves
...
5
...
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This method is commonly used by
farmers to separate lighter husk particles
from heavier seeds of grain (Fig
...
5)
...
The seeds of grain get
separated and form a heap near the
platform for winnowing
...


Sieving
Sometimes, we may wish to prepare a
dish with flour
...
What do we do? We use a sieve
and pour the flour into it (Fig
...
6)
...

In a flour mill, impurities like husk
and stones are removed from wheat
before grinding it
...
The
sieving removes pieces of stones, stalk
and husk that may still remain with
wheat after threshing and winnowing
...
5
...
5
...
5
...


Activity 4
Bring a sieve and a small quantity of
flour from home, to the class
...

Now, make a fine powder of chalk pieces
and mix it with the flour
...


Sedimentation, Decantation
and Filtration
Sometimes, it may not be possible to
separate components of a mixture by
winnowing and handpicking
...
How are such impurities
separated from rice or pulses before
cooking?
Rice or pulses are usually washed
before cooking
...
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particles get separated
...
Now, what will sink to the
bottom of the vessel — rice or dust?
Why? Have you seen that the vessel is
tilted to pour out the dirty water?
When the heavier component in a
mixture settles after water is added to
it, the process is called sedimentation
...
5
...
Let us find a
few other mixtures that can be separated
through
sedimentation
and
decantation
...
For example,
oil and water from their mixture can be
separated by this process
...
The
component that forms the top layer can
then be separated by decantation
...
After preparing tea,
what do you do to remove the tea leaves?
Try decantation
...
But,
do you still get a few leaves in your tea?
Now, pour the tea through a strainer
...
5
...
5
...
Which method of separating
tea leaves from prepared tea is better,
decantation or filtration?
Let us now consider the example
of water that we use
...
The water collected from
ponds or rivers may also be muddy,
especially after rains
...


Activity 5
Collect some muddy water from a pond
or a river
...
Let it stand for
half an hour
...

Does some soil settle at the bottom
of water? Why? What will you call this
process?
Now, slightly tilt the glass without
disturbing the water
...
5
...

What will you call this process?
Is the water in the second glass still
muddy or brown in colour? Now filter
it
...
In a piece of cloth, small holes or
pores remain in between the woven
threads
...

If the water is still muddy, impurities
can be separated by a filter that has even
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A filter paper is one such
filter that has very fine pores in it
...
5
...
A filter paper folded
in the form of a cone is fixed onto a
funnel (Fig
...
10)
...
Solid
particles in the mixture do not pass
through it and remain on the filter
...
5
...
5
...
5
...
The
method of filtration is also used in the
process of preparing cottage cheese
(paneer) in our homes
...
This gives a mixture of particles
of solid paneer and a liquid
...


Evaporation
Activity 6
Heat a beaker containing some water
...
If you continue
heating, would the water turn into steam
40

and disappear completely? Now, add two
spoons of salt to water in another beaker
and stir it well
...
5
...
Let the water boil away
...

The process of conversion of water
into its vapour is called evaporation
...

Where do you think, salt comes
from? Sea water contains many salts
mixed in it
...
When sea water is allowed
to stand in shallow pits, water gets
heated by sunlight and slowly turns into
water vapour, through evaporation
...
5
...
Common salt is then
obtained from this mixture of salts by
further purification
...
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Fig
...
12 Obtaining salt from sea water

Use of more than one method
of separation
We have studied some methods for
separation of substances from their
mixtures
...
In such
a situation, we need to use more than
one of these methods
...
How
will we separate these? We already saw
that handpicking would not be a
practical method for separating these
...
Leave the beaker
aside for some time
...
What does the decanted liquid
contain? Do you think this water
contains the salt which was there in the
mixture at the beginning?
Now, we need to separate salt and
water from the decanted liquid
...

Heat the kettle for some time
...
Hold the plate just above the spout
of the kettle as shown in Fig
...
13
...

When the steam comes in contact
with the metal plate cooled with ice, it
condenses and forms liquid water
...
The process of conversion of
water vapour into its liquid form is
called condensation
...

Paheli faced a problem while
recovering salt mixed with sand
...
5
...
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amount of sand
...
She found, however,
that she could recover only a small part
of the salt that she had taken
...
We say that these substances
are soluble in water
...
Pour half a cup
of water in the beaker
...
14)
...
Go on adding salt, one teaspoonful
at a time, and stir
...
The
solution is now said to be saturated
...

Perhaps the quantity of salt was much
more than that required to form a
saturated solution
...
14 Dissolving salt in water

would have remained mixed with the
sand and could not be recovered
...

Suppose, she did not have sufficient
quantity of water to dissolve all the salt
in the mixture
...


Activity 9
Take some water in a beaker and mix
salt in it until it cannot dissolve any
more salt
...

Now, add a small quantity of salt to
this saturated solution and heat it
...
Does the
salt appear to settle at the bottom of the
beaker again?
The activity suggest that larger
quantity of salt can be dissolved in water
on heating
...
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Does water dissolve equal amounts
of different soluble substances? Let us
find out
...
2
Substance

Activity 10
Take two glasses and pour half a cup
of water in each of them
...
Go on adding salt, one
teaspoon at a time, till the solution
saturates
...
2
...
Repeat this with
some other substances that are soluble
in water
...
2?
Do you find that water dissolves different
substances in different amounts?

Number of spoons of
substance that
dissolved in water

Salt
Sugar

We have discussed a few methods of
separating substances
...

We also learnt that a solution is
prepared by dissolving a substance in a
liquid
...


Chur ning

Saturated solution

Condensation

Sedimentation

Decantation

Sieving

Evaporation

Solution

Filtration

Threshing

Handpicking

Winnowing

Handpicking, winnowing, sieving, sedimentation, decantation and
filtration are some of the methods of separating substances from their
mixtures
...
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Husk and stones could be separated from grains by handpicking
...

Difference in the size of particles in a mixture is utilised to separate
them by the process of sieving and filtration
...

Filtration can be used to separate components of a mixture of an insoluble
solid and a liquid
...

Evaporation can be used to separate a solid dissolved in a liquid
...

More of a substance can be dissolved in a solution by heating it
...


1
...


2
...


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


What is sieving? Where is it used?

5
...


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

7
...


Fill up the blanks
(a) The method of separating seeds of paddy from its stalks is called ___________
...
This process of separating cream from milk is an
example of ___________
...

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


True or false?
(a) A mixture of milk and water can be separated by filtration
...


44

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(d) Grain and husk can be separated with the process of decantation
...
Lemonade is prepared by mixing lemon juice and sugar in water
...
Should you add ice to the lemonade before or after dissolving
sugar? In which case would it be possible to dissolve more sugar?

SUGGESTED PROJECTS AND ACTIVITIES
1
...

2
...
Sometimes, the water obtained after employing all these processes could
still be a little muddy
...

Take this filtered water in a glass
...

Suspend the piece of alum in the water and swirl
...
Talk to some elders
in your family to find out whether they have seen or used this process
...
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6

Changes Around us

W

hat fun if you suddenly get
some magical powers to
change anything around you!
What are the things you would want to
change?

Can some of the changes be grouped
together?
How can we group various changes?
It might help, if we find some similarities
between them
...
1 C AN ALL C HANGES A LWAYS B E
REVERSED?
Activity 1
Take a balloon and blow it
...
The shape and
size of the balloon have changed
(Fig
...
1)
...

We do not have magical powers, of
course
...

Can you list a few things you can
change around you, with no magic
involved?
Many changes are taking place
around us on their own
...

Sometimes, leaves fall from trees, change
colour and dry out
...
Are any changes
happening in your body? Your nails
grow, your hair grows, you grow taller
and your weight increases as you grow
...
1 A balloon changes its size and shape on
blowing air into it

Activity 2
Take a piece of paper and fold it as
shown in Fig
...
2
...
You
may have lots of fun in flying this plane
...

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Blow it to its full size and
tie its mouth with a string tightly
...

Oops! It burst
...
2 A toy aeroplane made by folding paper

Activity 3
Take some dough and make a ball
...
6
...
May be you
are not happy with its shape and
wish to change it back into a ball of
dough again
...
Draw an aeroplane
on it and cut along its outline (Fig
...
4)
...
6
...
3 A ball of dough and a rolled out roti

Now, think about the three changes
you observed in Activity 1, 2 and 3
...
Now, let
us repeat the same activities with
a difference
...
6
...


Fig 6
...
What would your
answers be, now?
We see that, the changes which have
occurred in the Activity 4, 5 and 6 can
not be reversed
...
With
repeated use, their shape and size
changes
...
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You must have seen a potter working
on his wheel
...
Can this change be reversed?
He then bakes the pot in an oven
...
1
...

Table 6
...
2 COULD THERE BE OTHER WAYS
TO BRING A CHANGE?
We all have seen the tools which are used
to dig the soil (Fig
...
6 )
...
Normally, the ring is slightly
smaller in size than the wooden handle
...
Now, the handle easily fits
into the ring
...


Batter to idli
Wet clothes to dry clothes
Woollen yar n to knitted
sweater
Grain to its flour
Cold milk to hot milk
Straight string to coil
string
Bud to flower
Milk to paneer
Cow dung to biogas
Stretched rubber band to
its nor mal size
Solid ice cream to molten
ice cream
48

Fig
...
6 Tools are often heated before fixing
wooden handles

Such a change is also used for fixing
the metal rim on a wooden wheel of a
cart as shown in Fig
...
7
...
On heating, the rim
expands and fits onto the wheel
...

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...
6
...
If we
continue to heat further, the quantity
of water in the pan begins to decrease
...

In Activity 7, Chapter 5 you have
observed that water vapour gets changed
into liquid water when it is cooled
...
Ice melts
when it is heated
...


Paheli wants to know if
you have ever seen a
blacksmith making some
tools
...
It then becomes soft and is
beaten into a desired shape
...
Now, fix it at a
suitable place and light it
...
Now blow out the candle
and measure its length again (Fig
...
8)
...
6
...
6
...

He wants to know whether the
change caused in tar, by
heating, is reversible?

Fig
...
9 Heating wax
CHANGES AROUND US

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Wait till it burns away completely
...
These are
ash and some gases
...
Can this change
be reversed? And what about the
change, which occurred in the
matchstick you used for lighting the
candle or incense stick?
So far we have discussed the changes
occurring in a given object or its
material
...
Do you think a change occured
in salt or in water? Is it possible to
reverse this change? Wait, in Chapter
5, we learnt how to separate salt from
its solution in water
...
A small quantity of curd is
added to warm milk
...
In a few hours, the milk changes
into curd
...
We also find that some
changes can be reversed, while some
others cannot be reversed
...
It is possible that some of
them could be reversed
...
In higher classes, you will
learn more about the ways in which
changes can be made and the way these
can be grouped
...

A change may occur by heating a substance or by mixing it with some
other
...
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1
...
Can this change be reversed?

2
...
This is a change you
did not want
...


Some changes are listed in the following table
...

S
...


Change

1
...


The melting of ice candy

3
...


The cooking of food

5
...


Can be reversed (Yes/ No)

Souring of milk

4
...
Can you reverse this
change?

5
...


6
...
It becomes hard on drying to keep the fractured bone
immobilised
...


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

SUGGESTED PROJECTS AND ACTIVITIES
1
...
Cut the lemon and squeeze
out its juice in a cup
...
Let the paper dry and you find that the letters of your message
become invisible
...
As the
paper gets warm, invisible letters change into dark brown colour
...

2
...
Identify two changes that can
be reversed
...
Maintain a record for one year of the seasonal changes in vegetables, clothing,
nature and events around you
...


CHANGES AROUND US

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Do you see
that some plants are small,
some very big, while some are just
patches of green on the soil?
Some have green leaves,
while some others have
reddish ones
...
We do see a
variety of plants existing all
around us — near our
homes, in the school
ground, on the way to the
school, in the parks and
gardens, isn’t it?
Let us get to know the different
parts of any plant
...
Can you label
the stem, branches, roots, leaves, and
flowers of the plant shown in Fig
...
1?
Colour the parts of the plant
...
7
...
7
...


7
...
7
...
Plants much smaller than you
...
Plants that are about your size, and
3
...

Feel their stem and try to bend them
gently to see if they are tender or hard
...
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Table 7
...

Hug the tall plants to see how thick their
stems are!
We also need to notice from where the
branches grow in some plants — close to
the ground or higher up on the stem
...
1
...
You can fill the Columns 1,
Suggestion: Work in groups of 4-5
students in doing activities suggested
in this Chapter so that a minimum
number of plants are uprooted
...
Do you know what weeds
are? In crop fields, lawns, or in pots,
often some unwanted plants or
weeds start growing
...
Fill
Column 4 after you have studied later
part of this section
...
An
example of each is shown in Fig
...
3
...
7
...
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Plants with green and tender stems
are called herbs
...
7
...

Some plants have the stem
branching out near the base
...
Such plants
are called shrubs [Fig
...
3(b)]
...
The stems
have branches in the upper part, much
above the ground
...
7
...

Based on the above characteristics
can you now correctly classify the plants
listed by you and complete column 4 in
Table 7
...

Perhaps there are some plants in
your school or at home that you take
care of
...


7
...

Pour water to fill one-third of the
glass
...
Cut the base of the stem of the

Paheli wonders what kind of stem — the
money plant, beanstalk, gourd plants and
grape vines have
...
How are these different from a herb,
a shrub or a tree? Why do you think
some of them need support to climb
upwards?

Plants with weak
stems that cannot stand
upright and spread on
the ground are called
creepers, while those
that take support on
neighbouring structures
and climb up are called
climbers ( Fig
...
4 )
...
7
...
7
...
7
...
Observe it the next day
...
7
...

From this activity we see that water
moves up the stem
...
Just like the red ink,
minerals dissolved in water also move
up in the stem, along with the water
...
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7
...
7
...

Paheli did this activity with herbs
having white flowers
...
She did a funny thing
with another branch
...
7
...
She put a few drops of red

Look at leaves of plants around you and
draw them in your notebook
...
The broad,
green part of the leaf is called lamina
(Fig
...
8)
...
7
...


Activity 3

Fig
...
7 Paheli’s flowers

ink in glass B and blue ink in glass C
...

When you had cut across the stem
in Activity 2, did you notice a number
of spots of red colour arranged in a ring
inside the stem? Does this explain the
results that Paheli obtained? Try this
activity yourself!
GETTING TO KNOW PLANTS

Put a leaf under a white sheet of paper
or a sheet in your notebook
...
7
...
Hold your
pencil tip sideways and rub it on the
portion of the paper having the leaf below
it
...
Do you see
Fig
...
9 Taking an
impression of a leaf
a thick vein in the
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...
7
...
The design made by veins in a
leaf is called the leaf venation
...
7
...
In the leaves of grass you
might have seen that the veins are parallel
to one another
...
7
...
Observe the venation in
as many leaves as you can without
removing them from the plant
...

Shall we now find out some of the
functions of a leaf?

Activity 4
We will require a herb, two transparent
polythene bags and some string
...
Use a healthy, well watered
plant that has been growing in the sun,
for this activity
...
7
...
Tie
up the mouth of the empty polythene
bag and keep it also in the sun
...
What do you see?
56

Fig
...
11 What does the leaf do?

Are there any droplets of water in any
of the bags? Which bag has the droplets?
How do you think they got there? [Don’t
forget to remove the polythene bag after
the activity!]
Water comes out of leaves in the form
of vapour by a process called
transpiration
...
We will
learn more about this in Chapter 14
...
Can you think of these and
name the process that makes water
drops appear on the polythene bag?
Leaves also have another function
...


Activity 5
We would require a leaf, spirit, a beaker,
test tube, burner, water, a plate and
iodine solution for this activity
...
Now,
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7
...
Heat the beaker till all the
green colour from the leaf comes out
into the spirit in the test tube
...

Put it on a plate and pour some iodine
solution over it (Fig
...
12)
...

What do you observe? Compare your
observations with those done in
Chapter 2, when you tested food for
presence of different nutrients
...
Potatoes get this starch from
other parts of the plant and store it
...
For
this, they use water and carbon dioxide
from air
...
Oxygen is given out in
this process
...

How do we know that the leaf has
prepared the starch and not received it
from another part of the plant? To test
this, the above activity can be repeated
with a little difference
...

Now, cover a portion of a leaf of the plant
completely with black paper and leave
the plant in the Sun for a day
...

What do you see? Which part of the
leaf shows the presence of starch? Does
this help us understand that leaves
produce starch in the presence
of sunlight?
We see that the stem supplies leaf
with water
...
The leaves also lose water
through transpiration
...
4 ROOT
Look at Fig
...
13
...
7
...
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Which part of the plant is in the soil?
Let us learn more about this part from
the following activities
...
This activity is to be
done in groups of 4-5 students
...

Take care that their roots do not break
...
7
...
Cut off the roots from
the other weed and plant it in the soil
in pot B [Fig
...
14 (b)]
...
Observe the plants after a
week
...

Take two katoris
...
Put 3 or 4 seeds
of gram in one and maize in the other
...
After a week
try to separate the young plants from
the cotton wool (Fig
...
15)
...
7
...
7
...

58

Was it easy to separate the cotton wool
from the roots? Why?
In Activity 6, we could not easily pull
out the plants from the soil, right? We
dug them out
...
They are said
to anchor the plant to the soil
...
Do the roots
also show a variety? Let us find out
...
7
...

Now, look at the roots of the gram plants
you have pulled out from the cotton
wool
...
7
...
7
...
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(a)
Fig 7
...

In what way are the roots of gram
and maize similar? In what way are they
different? There seem to be two different
types of roots, isn’t it? Are there also
other types of roots? Let us find out
...
Dig out a few weeds,
wash the soil off the roots and observe
them
...
7
...
7
...
7
...
Plants with roots as shown
in Fig
...
17 (b) do not have any main
root
...

Separate the weeds you have collected
into (a) those that have tap roots and
(b) those that have fibrous roots
...

What kind of venation do they have?
What kind of venation do you see for
plants of Group (b)?
Do you notice that leaf venation and
the type of roots in a plant are related
in a very interesting way? In Table 7
...

He just has to look at its leaves!

Table 7
...
7
...
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other parts of the plant
...
This food travels through
the stem and is stored in different parts
of a plant
...
We also eat many other
parts of a plant where the food is stored
...
7
...


Which colour did you use for the
flower in Fig
...
1? Are all flowers
colourful? Have you ever seen flowers
on the plants of grass, wheat, maize,
mango or guava? If you see any flowers
in these plants, are they brightly
coloured?
Let us study a few flowers closely
...
You will learn in higher
classes that they are not single flowers,
but, groups of flowers
...
7
...
A stem as a two way street!

In the next section, we will study
about the structure of a flower
...
5 FLOWER
You are shown three branches of a rose
in Fig 7
...
Which one
will help you best to recognize the plant?

We would require one bud and two fresh
flowers each, of any of the following–
datura, china rose, mustard, brinjal,
lady’s finger, gulmohur
...

Observe Fig
...
20 carefully
...

These are the petals of the flower
...

Where do you think the petals are in a
closed bud? Which is the most prominent
part in a bud? Did you see that this part
is made of small leaf-like structures? They
Petals

(a)

(b)

(c)

Fig 7
...
7
...
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Table 7
...
Take a flower and
observe its petals and sepals
...
3)
...
Fill the
last two columns after you have gone
through the entire section
...
For example, in datura
and other bell shape flowers, the petals
have to be cut lengthwise and spread
out so that the inner parts can be seen
clearly (Fig
...
21)
...
Study the Fig
...
22
carefully, compare your flower with the
GETTING TO KNOW PLANTS

Pistil
Present/
absent
Present

illustration and identify the stamens and
pistil in your flower
...
23 carefully
...
7
...
7
...
7
...
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in different flowers
...

The innermost part
Fig
...
24 Parts of of a flower is called the
a pistil
pistil
...
Identify the parts of the pistil
with the help of Fig
...
24
...


Activity 11
Let us now study the structure of the
ovary of a flower (Fig
...
24)
...

We will cut this part to study how it looks
inside! Look at Fig
...
25 (a) and (b)
carefully to understand how to cut the
ovary of a flower
...
Cut them in two different

(a)

(b)

Fig
...
25 Cutting an ovary (a) longitudinal cut
and (b) transverse cut
62

Ovules

Fig
...
26 Inner structure of an ovary
(a) longitudinal cut, (b) transverse cut

w a y s a s s h o w n i n F i g
...
2 5
...

Observe the inner parts of the ovary
using a lens (Fig
...
26)
...
Draw and
label the inner parts of the ovary in your
notebook
...
Remember, not to pluck more
flowers than you need
...
3, answer the
following questions
...
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Do you now agree that the structure
of the flower is not always the same?
The number of sepals, petals, stamens
and pistils may also be different in
different flowers
...

We studied the structure of different
flowers
...
We will also
learn about fruits in higher classes
...

The stem bears leaves, flowers and fruits
...

The pattern of veins on the leaf is called venation
...

Leaves give out water vapour through the process of transpiration
...

GETTING TO KNOW PLANTS

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Roots are mainly of two types: tap root and fibrous roots
...

The stem conducts water from roots to the leaves (and other parts) and
food from leaves to other parts of the plant
...


1
...

(a) Stem absorbs water and minerals from the soil
...

(c) Roots conduct water to the leaves
...

(e) If the sepals of a flower are joined together, its petals are also joined
together
...


2
...
3
...


Can you find a plant in your house or in your neighborhood, which has a long
but a weak stem? Write its name
...


What is the function of a stem in a plant?

5
...


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

7
...


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

9
...


10
...
Name the part of the plant which produces its food
...

12
...
Name two flowers, each with joined and separated sepals
...
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SUGGESTED PROJECT AND ACTIVITIES
1
...
For
every leaf that you wish to study, pluck it and wrap it in a wet cloth and take
it home
...
You
can also put it under your mattress or a trunk! Take out the leaf after a
week
...
With your leaf
collection pasted in a book (a Herbarium), you can become quite an expert
about leaves!

2
...
Search for them by going up,
down, or even diagonally forward as well as backward
...
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8

Body Movements

S

it absolutely still
...
You must be blinking your
eyes, time to time
...
There are so many movements
that happen in our bodies
...
You also move
from one place to another — you get up
and go to your teacher or to the school
compound, or go home after school
...

Let us see how animals move from
place to place by filling up Table 8
...


Boojho wonders about movements
in plants
...
1 How do animals move
from place to place?

Animal

Body part used
How does
for moving
the animal
from place to
move?
place

Cow

Legs

Walk

Whole body

Slither

Humans
Snake
Bird
Insect
Fish

Walk, run, fly, jump, creep, crawl,
slither and swim – these are only a few
of the ways in which animals move from
one place to another
...
1 HUMAN BODY AND ITS MOVEMENTS
Let us look closely at some of our own
movements to begin with, before looking
at all these varieties of movements in
animals
...
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Let us try some of the many movements,
our body is capable of
...
How did you move
your arm? Did you rotate it at the
shoulder in a circular movement? Did
your shoulder also move? Lie down and
rotate your leg at the hip
...

Stretch your arm sideways
...
Which part of your arm did you
bend? Straighten your arm and try to
bend it downwards
...
2
...
8
...

Ask your friend to tie the scale and
your arm together
...

Are you able to do it?

Fig
...
1 Can you bend your
arm now?

Table 8
...
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Did you notice that we are able to
bend or rotate our body in places where
two parts of our body seem to be joined
together — like elbow, shoulder or neck?
These places are called joints
...

Do you get a feel of something hard
pressing against your fingers? The hard
structures are the bones
...
So
many bones!
Bones cannot be bent
...
It
is different bones joined together at the
elbow
...
We
can bend or move our body only at those
points where bones meet
...
Let us learn
about some of them
...
8
...
8
...
You
can also stick the cylinder on the ball
...
Is the ball
rotating freely inside the bowl? Is the
paper cylinder also rotating?
Now, imagine that the paper cylinder
is your arm and the ball is its end
...
The rounded
end of one bone fits into the cavity
(hollow space) of the other bone
(Fig
...
3)
...
Can you name another
such joint you can think of, recollecting
the body movements we tried at the
beginning of this section?

Ball and socket joints
Activity 2
Roll a strip of paper into a cylinder
...
8
...
It allows us to bend
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Try
these movements
...


Hinge joints
Open and close a door a few times
...

They allow the door to move back
and forth
...
Make a cylinder with
cardboard or thick chart paper, as
shown in Fig
...
4
...
Make a hollow
half cylinder from cardboard such that
the rolled up cylinder can fit inside it
easily
...
Try to move the
rolled up cylinder
...
8
...
8
...

What we have constructed in Fig
...
4 is
different from a hinge, of course
...
The elbow has a hinge
joint that allows only a back and forth
movement (Fig
...
5)
...
The
bones cannot move at these joints
...
When you
open your mouth wide, you can move
your lower jaw away from your head,
isn’t it? Try to move your upper jaw,
now
...

We discussed only some of the joints
that connect parts of our body
...
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Feel the bones in your forearm,
upper arm, lower leg and upper leg
...

Similarly, feel the bones of your ankle
and knee joints and compare these with
the X-ray images (Fig
...
7)
...
8
...

This framework is called the skeleton
(Fig
...
6
...
One way we could know this
shape better would be to look at X-ray
images of the human body
...
The Xrays show the shapes of the bones in
our bodies
...
7 X-ray images of ankle and knee joints

Bend your fingers
...
It seems to
have many bones, isn’t it (Fig
...
8)? Is
your wrist flexible? It is made up of
several small bones
...
8
...
Feel your chest bones and the
back bone by gently pressing the middle
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8
...
8
...

Count as many ribs (bones of the chest)
as possible
...
8
...
We see that the ribs are
curiously bent
...
This is called the rib cage
...

Ask a friend to touch his toes without
bending his knees
...
Can you feel
some long and hard
structure? Starting from
the neck, move your
fingers downwards on the
back of your friend
...

It is made of many small
bones (Fig
...
10)
...

If his backbone were
made up of only one long
Fig
...
10 The bone will your friend be
able to bend?
backbone
BODY MOVEMENTS

Make your friend stand with his
hands pressed to a wall
...
Do you see two bones
standing where his shoulders are? They
are called shoulder bones (Fig 8
...

Observe Fig
...
12 carefully
...
They
enclose the portion of your body
below the stomach
...


Fig
...
12 Pelvic bones
...
8
...
It encloses
and protects a very important part of
the body, the brain
...
There are

Fig
...
13 The skull
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These are called
cartilage
...
Do you find any hard
bony parts that can be bent
(Fig
...
14)? There do not seem to be any
bones here, isn’t it? Do you notice
anything different between the ear lobe
and the portions above it (Fig
...
15), as
you press them between your fingers?

(a)

(b)

Fig
...
16 Two muscles work together to move
a bone

Fig
...
14 Upper part of
ear has cartilage
Fig
...
15 The ear lobe

You do feel something in the upper parts
of the ear that is not as soft as the ear
lobe but, not as hard as a bone, isn’t it?
This is cartilage
...

We have seen that our skeleton is
made up of many bones, joints and
cartilage
...
Draw a neat figure of the
skeleton in your notebook
...
What makes the bones
move the way they do? Let us find out
...
8
...
Do
you see any change in your upper arm?
72

Touch it with the other hand
...
The muscle
bulged due to contraction (it became
smaller in length)
...
What
happened to the muscle? Is it still
contracted? You can observe similar
contraction of muscles in your leg when
you walk or run
...
It
pulls the bone
...
When one of
them contracts, the bone is pulled in
that direction
...
To move the bone in the
opposite direction, the relaxed musle
contracts to pull the bone towards its
original postion, while the first relaxes
...
It cannot push
...
8
...

Are muscles and bones always
required for movement? How do other
animals move? Do all animals have
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8
...
Gently lift it and place it
on a piece of blotting or filter paper
...
8
...
Then
place it on a smooth glass plate or any
slippery surface
...
Is it different from that on paper?
Do you find that the earthworm is able
to move easily on a hard slippery
surface?
The body of an earthworm is made
up of many rings joined end to end
...
The body secretes a slimy
substance to help the movement
...
The bristles
are connected with muscles
...

The earthworm, actually, eats its way
through the soil! Its body then throws
away the undigested part of the material
that it eats
...


Snail
Activity 6
Collect a snail from a garden
...
8
...
8
...
8
...
It has
muscles which help to extend and
shorten the body
...
Then it fixes
the front end and releases the rear end
...
This makes it move
forward by a small distance
...
The shell is a single unit
and does not help in moving from place
to place
...

Place the snail on a glass plate and
watch it
...
Observe its
movements from beneath
...
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the shell
...
Now, carefully
tilt the glass plate
...
Is the movement of
a snail slow or fast as compared to an
earthworm?

Cockroach
Activity 7
Observe a cockroach (Fig
...
19)
...
They have three pairs
of legs
...
The body
is covered with a hard outer skeleton
...
8
...
The shoulder bones are strong
...
8
...


Fish
Activity 8
Fig
...
19 A cockroach

units joined together and that permits
movement
...
The cockroaches have
distinct muscles — those near the legs
move the legs for walking
...


Make a paper boat
...
8
...
Did it go into the
water easily? Now hold the boat
sideways and push it into the water
from the broad side [Fig
...
21 (b)]
...
Some birds like ducks and
swans also swim in water
...
Their bones are hallow and
light
...
The
74

(a)

(b)
Fig
...
21 Playing with boats
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Did you ever
notice that under water divers wear fin
like flippers on their feet, to help them
move easily in water?
Fig
...
22 Fish

How do snakes move?

Have you noticed that the shape of a
boat is somewhat like a fish (Fig 8
...
This body
shape is called streamlined
...
The skeleton of the fish
is covered with strong muscles
...
The fish forms a curve as shown
in Fig
...
23
...
This makes
a jerk and pushes the body forward
...
This is helped by the fins of
the tail
...
8
...
They
have many thin muscles
...
They also
interconnect the backbone, ribs and skin
...
Each loop of the snake gives it a
forward push by pressing against the
ground
...

We have learned about the use of
bones and muscles for the movements
of different animals
...
So must you be having many
unanswered questions buzzing in your

Fig
...
23 Movement in Fish

Fig
...
24 Movement in a snake

BODY MOVEMENTS

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Why do
different animals have the body parts
that they do have and how do these
body parts help animals to move the
way they do? What are the similarities
and differences in these body parts
between different animals? How many
body parts are needed by different
animals for moving from place to

place? Why two legs for humans and
four for cows and buffaloes? Many
animals seem to be having an even
number of legs, why? Why is the
bending of our legs different from that
of our arms?
So many questions and perhaps
we have looked for some answers
through our activities in this chapter
and we need to look for many
more answers
...
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Bones and cartilage form the skeleton of the human body
...
It protects the
inner organs
...

The bones are moved by alternate contractions and relaxations of two
sets of muscles
...

Strong muscles and light bones work together to help the birds fly
...

Fish swim by forming loops alternately on two sides of the body
...
A large number of
bones and associated muscles push the body forward
...
The muscles of the breast connected with three pairs of legs
and two pairs of wings help the cockroach to walk and fly
...
Tiny bristles on the underside of the body help in gripping
the ground
...


1
...

(b) A combination of bones and cartilages forms the _______ of the body
...

(d) The contraction of the _____________ pulls the bones during movement
...


Indicate true (T) and false (F) among the following sentences
...
(
(b) The cartilages are harder than bones
...
(
(d) The fore arm has two bones
...
( )
BODY MOVEMENTS

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


Answer the following:
(a) What is a ball and socket joint?
(b) Which of the skull bones are movable?
(c) Why can our elbow not move backwards?

THINGS TO THINK ABOUT
We discussed the many movements our bodies are capable of
...

Some of us suffer from conditions that could make these movements not so easy
...
In Activity 1, for instance, you
tied a scale on your arm and disabled the elbow movement
...


78

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One such trip took
them to the river Ganga in Rishikesh
...
They
saw many kinds of trees on these
mountains — oaks, pines and deodars,
very different from the ones near their
home on the plains! In yet another trip,
they travelled to Rajasthan and moved
on camels through the hot desert
...
Finally, they went on a
trip to Puri and visited the sea beach,
dotted with casuarina trees
...
All
these places were so different from one
another, some were cold, some very hot
and dry, and some places so humid
...

They tried to think of a place on Earth
where there may not be any living
creatures
...
Inside the house, he tried the
cupboards
...
Outside the home too, there
did not seem to be any place, he could
think of, that did not have living creatures

of some kind or the other (Fig
...
1)
...
She read that people have
even found tiny living organisms in the
openings of volcanoes!

Fig
...
1 Search for living organisms

9
...
The
deserts had camels, the mountains had
goats and yak
...
The kinds of plants
found in each of these regions were so
different from the plants of the other
regions
...
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in these different regions? Were they
the same?

will discuss the table as we travel
through many more interesting places
...
2 HABITAT AND ADAPTATION

Let us start with a forest
...
List them in Column 1
of Table 9
...
List things, animals and
plants, found in the other regions that
are also shown in the table
...
1
...
You can also consult many
interesting books in libraries that talk
of animals, plants and minerals of
different regions
...
What
kind of objects will we find that may not
be animals or plants? Perhaps parts of
plants like dried leaves, or parts of
animals, like bones
...

Water in the oceans may have salts
dissolved in it as discussed in Chapter
5
...

As we go through the chapter, keep
adding more examples to Table 9
...
We

What do you find from the plants and
animals listed in Activity 1? Did you find
a large variety in them? Look at what you
have entered in the column for the desert
and the column for the sea in Table 9
...

Did you list very different kind of
organisms in these two columns?
What are the surroundings like, in
these two regions?
In the sea, plants and animals are
surrounded by saline (salty) water
...

There is very little water available in
the desert
...
The
animals and plants of the desert live on
the desert soil and breathe air from the
surroundings
...
The body structure of a camel
helps it to survive in desert conditions
...
1 Animals, plants and other objects found in different surroundings
In the forest

80

On mountains

In the desert

In the sea

Any other?

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9
...
They excrete small
amount of urine, their dung is dry and
they do not sweat
...

Let us look at different kinds of fish
...
9
...

There are so many kinds of fish, but, do
you see that they all have something
common about their shape? All the ones
shown here have the streamlined shape
that was discussed in Chapter 8
...

Fish have slippery scales on their bodies
...

We discussed in Chapter 8, that fish
have flat fins and tails that help them
to change directions and keep their body
balance in water
...

We see that the features of a fish help
it to live inside water and the features of
a camel help it to survive in a desert
...
9
...
In all this
variety of organisms, we will find that
they have certain features that help
them live in the surroundings in which
they are normally found
...
Different animals are
adapted to their surroundings in
different ways
...
The organisms
depend for their food, water, air, shelter
and other needs on their habitat
...
Several kinds of plants and
animals may share the same habitat
...
Some examples of terrestrial
habitats are forests, grasslands, deserts,
coastal and mountain regions
...
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There are some changes that can happen in an organism over a short period
of time to help them adjust to some changes in their surroundings
...

We need to breathe faster when we are on high mountains
...
Such
small changes that take place in the body of a single organism over short
periods, to overcome small problems due to changes in the surroundings, are
called acclimatisation
...

animals that live in water are called
aquatic habitats
...
There are
large variations in forests, grasslands,
deserts, coastal and mountain regions
located in different parts of the world
...

The living things such as plants
and animals, in a habitat, are its biotic
components
...
Sunlight and heat
also form abiotic components of
the habitat
...
Let us look at some abiotic factors
and their effect on seeds as they grow
into young plants
...

When the seed turned into a sprout, it
germinated
...

82

Collect some dry moong seeds
...
Divide the
soaked seeds into four parts
...
Do not disturb the dry seeds
and those submerged in water
...
Keep the last
part in very cold surroundings, say, in
a refrigerator or with ice around them
...
What do you notice, after a
few days? Do the seeds in all the five
parts germinate equally? Do you find
slower or no germination in any
of these?
Do you find that abiotic factors like
air, water, light and heat are very
important for growth of plants
...

We find that organisms exist in very
cold as well as very hot climates and
surroundings, isn’t it? How do they
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Adaptation does not take place in a
short time
...
Those
animals which cannot adapt to these
changes die out, and only the adapted
ones survive
...
The
result is variety of organisms present in
different habitats
...


Fig
...
4 Desert animals in burrows

9
...
What about other animals
and plants that are found in deserts?
Do they have the same kind of
adaptations?
There are desert animals like rats
and snakes, which do not have the long
legs that the camel has
...
4)
...

Fig
...
5 shows some typical plants
that grow in a desert
...
Tie polythene bags to
THE LIVING ORGANISMS AND THEIR SURROUNDINGS

Fig
...
5 Some typical plants that grow in desert

some parts of the two plants, as was
done for Activity 4 in Chapter 7, where
we studied transpiration in plants
...
What do you
see? Do you notice any difference in the
amount of water collected on the two
polythene bags?
Desert plants lose very little water
through transpiration
...
This helps in reducing loss of
water from the leaves through
transpiration
...
9
...
Photosynthesis in these plants
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The
stem is also covered with a thick waxy
layer, which helps to retain water
...

Mountain regions
These habitats are normally very cold
and windy
...

There is a large variety of plants and
animals living in the mountain regions
...
9
...
They may
have different kind of adaptations to
survive on the mountains
...
9
...
They have thick skin or fur to
protect them from cold
...
Snow
leopard has thick fur on its body

(a)

Fig
...
6 Trees of a mountain habitat

If you live in a mountain region or
have visited one, you may have seen a
large number of such trees
...
The leaves
of some of these trees are needle-like
...
There could be trees with
shapes very different from these that are
84

(b)

Fig
...
7 (a) Snow
leopards, (b) yak
and (c) mountain
goats are adapted
to mountain
habitats

(c)
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This protects its
feet from the cold when it walks on the
snow
...

As we go up in the mountainous
regions, the surroundings change and
we see different kinds of adaptations at
different heights
...
It is light
brown in colour
...
9
...
How
are the eyes placed in the face for these
two animals? Are they in the front or
on the side of the face? Lions have long
claws in their front legs that can be
withdrawn inside the toes
...
The eyes in
front of the face allow it to have a correct
idea about the location of its prey
...
It has strong teeth
for chewing hard plant stems of the
forest
...
It has long ears to hear movements
of predators
...
The speed of the deer helps them
to run away from the predators
...


Some Aquatic Habitats

(a)

(b)
Fig
...
8 (a) Lion and (b) deer
THE LIVING ORGANISMS AND THEIR SURROUNDINGS

Oceans
We already discussed how fish are
adapted to live in the sea
...
There
are some sea animals like squids and
octopus, which do not have this
streamlined shape
...

However, when they move in water they
make their body shapes streamlined
...

There are some sea animals like
dolphins and whales that do not have
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They breathe in air through
nostrils or blowholes that are located
on the upper parts of their heads
...
They can
stay inside the water for a long time
without breathing
...
Did you ever see this interesting
activity of dolphins in television
programme or films on ocean life?
Ponds and lakes
Have you seen plants growing in ponds,
lakes, rivers and even some drains? Go
on a field trip to a nearby pond, if possible,
and try to draw the kinds of plants that
are seen there
...
9
...
In terrestrial plants, roots
normally play a very important role in the

Fig
...
9 Some aquatic plants float on water
...
Some aquatic plants are compltely
submerged in water
...
However, in aquatic plants, roots
are much reduced in size and their main
function is to hold the plant in place
...
The stems grow up to
the surface of water while the leaves and
flowers, float on the surface of the water
...
All parts of such
plants grow under water
...
These can bend in the flowing
water
...

Frogs usually have ponds as their
habitat
...

They have strong back legs that help
them in leaping and catching their prey
...

We have discussed only a few
common animals and plants compared
to the wide variety that live in the
different habitats
...
Imagine the kind
of variety that you could see in a
herbarium of leaves of plants from all
regions of the Earth!

9
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animals
...
Suppose we stop a while
and think which examples in our list
are living? Let us think of examples from
a forest
...
Which of these are living?
Think of objects that you can see
around you at this moment and group
them as living and non-living
...
For
example, objects like chair or a table in
our homes we know that they are not
alive
...

able to th
Said the T
e table,
hair to th
t able!
Said the C
we are no
you know
’Now
lk,
shly you ta
not walk!’
’How fooli
ow we can
en you kn
’Wh
a sigh,
able with
Said the T
to try,
no harm
’It can do
you,
ny legs as
’I’ve as ma
on two?’
we walk
’Why can’t

THE LIVING ORGANISMS AND THEIR SURROUNDINGS

Paheli and Boojho found the poem
so very funny, because they knew that
a chair or a table is not alive and it
cannot talk, walk or suffer from the
usual problems that all of us face
...
We
know that they are not alive
...
We also see
animals around us that are so full of
life — dogs, cats, monkeys, squirrels,
insects and many others
...

We are told that plants are living things,
but they do not appear to move like a
dog or a pigeon
...
Plants and animals
appear to grow in size with time
...
Does it mean that
clouds are living? No! So, how does one
distinguish between living and nonliving things? Do living things have
some common characteristics that
make them very different from the
non-living?
You are a wonderful example of a living
being
...
Look at
your list and mark those characteristics
that you have listed, which may also be
found in animals or plants
...

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We
have also learnt that plants make their
own food through the process of
photosynthesis
...

Food gives organisms the energy
needed for them to grow
...


Do all living things show
growth?
Does the kurta you had four years back,
still fit you? You cannot wear it any
more, isn’t it? You must have grown
taller during these years
...
(Fig 9
...

Young ones of animals also grow into
adults
...
9
...
A
chicken hatched
from an egg, grows
into a hen or a cock
...
11)
...

Look around you
and see a few plants
of a particular type
...
9
...
They grows into an adult
may all be in different stages of growth
...
You may find that some of them
have grown in size
...

Do you think, non-living things
cannot show growth?

Do all living things respire?
Can we live without breathing? When
we inhale, the air moves from outside to
the inside of the body
...
Breathing is part of a process
called respiration
...
We breathe
out the carbon dioxide produced in this
process
...
Observe any one of
these animals while they are taking rest,
and notice the movement of their
abdomen
...

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It is through respiration that
the body finally obtains energy from the
food it takes
...

For example, earthworms breathe
through their skin
...
The gills absorb oxygen from the
air dissolved in water
...
The leaves take in
air through tiny pores in them and use
the oxygen
...

We learnt that in sunlight, plants
use carbon dioxide of air to produce
their own food and give out oxygen
...
The
amount of oxygen released in the
process of food preparation by plants
is much more than the oxygen they use
in respiration
...
What
happens? Your eyes shut themselves
automatically for a moment till
THE LIVING ORGANISMS AND THEIR SURROUNDINGS

they adjust to the changed bright
surroundings
...
All of us respond
immediately to such changes
...

Do other animals also respond to
stimuli? Observe the behaviour of
animals, when the food is served to
them
...

Similarly, cockroaches begin to move to
their hiding places if the light in the
kitchen is switched on at night
...
In some plants flowers close after
sunset
...
These are some examples
of responses of plants towards changes
in their surroundings
...
9
...
Continue watering the
plant for a few days
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Do all living things
reproduce their
own kind?
Have you ever seen nests
of some birds like
pigeons? Many birds lay
their eggs in the nest
...
9
...

Fig
...
12 Plant respond to light

it is not growing upright
...


Living organisms and excretion
All living things take food
...
What
happens to the rest? This has to be
removed by the body as wastes
...
The process of getting rid of
these wastes by the living organisms is
known as excretion
...

However, the mechanisms in plants are a
little different
...
Some plants find it possible to
store the waste products within their
parts in a way that they do not harm the
plant as a whole
...

Excretion is another characteristics
common to all living things
...
9
...

The mode of reproduction may be
different, in different animals
...
Some animals give birth
to the young ones (Fig
...
14)
...
Like animals,
plants also differ in their mode of
reproduction
...
Plants produce seeds,

Fig
...
14 Some animals which give birth to
their young ones
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It
takes place in many different ways, for
different organisms
...
9
...
9
...

Some plants also reproduce through
parts other than seeds
...
16)
...
9
...
Would you like to grow a plant
in this way yourself?

Activity 5
Take a cutting from a rose or a menhdi
plant
...
What do you observe, after a
few days?
It may not be easy to grow plants from
cuttings
...
Talk to a gardner,
if possible, on the care to be given to
cuttings to make them grow into plants
...
They move
from one place to another and also show
other body movements
...
However, various substances
like water, minerals and the food
synthesised by them moves from one
part of the plant to other
...
A bus, car, a
small piece of paper, clouds and so on
...
Yet another common
characteristic is that living beings die
...
One
single organism may die without ever
reproducing, but, the type of organism
can exist only if there is reproduction
...
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We see that, all living things seem to
have some common characteristics
...

Do we find some non-living things that
also show some of these characteristics?
Cars, bicycle, clocks and the water in
the river move
...
A cloud grows in size right in front
of our eyes
...

Is this always true? Do we always find
that living things definitely show all the
characteristics of the living that we have
discussed? Do we always find that nonliving things may show only some of these
characteristics and never all of them?
To understand this a little better, let
us look at a specific example
...
Is it living? It can

stay in a shop for months and not show
any growth or some of the other
characteristics of life
...
Did
the seed — need food, did it excrete,
grow or reproduce when it was in the
shop for many months?
We see that there can be cases when
we cannot easily say that a thing has all
the characteristics that we have discussed,
for it to be called living
...
Do you find it is warm inside?
There is some heat being produced
inside the sack of wheat
...

We see that respiration is a process
that takes place in seeds even when
some of the other life processes may not
be very active
...
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The surroundings where plants and animals live, is called their habitat
...

The presence of specific features and habits, which enable a plant or an
animal to live in a particular habitat, is called adaptation
...

There is a wide variety of organisms present in different habitats
...

Rocks, soil, air, water, light and temperature are some of the abiotic
components of our surroundings
...


1
...


How are cactus adapted to survive in a desert?

3
...

(b) The habitats of the plants and animals that live on land are called
habitat
...

(d) Soil, water and air are the ———— factors of a habitat
...

called

4
...


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


Which of the non-living things listed below, were once part of a living thing?
Butter, Leather, Soil, Wool, Electric bulb, Cooking oil, Salt, Apple, Rubber

7
...


8
...
(Hint: There are few trees or places for animals to hide in
grasslands habitats
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SUGGESTED PROJECTS AND ACTIVITIES
1
...
Read these articles and have a discussion in the class about what
could be defined as life outside Earth
...


Visit a local zoo and find out what special arrangements are made for the
animals that have been brought there from different habitats
...


Find out where are the habitats of the polar bear and the penguin
...


4
...
Find out if the
types and varieties of animals and plants changes as one goes higher into
the mountain regions of the Himalayas
...


Make a habitat album
...
Draw the leaf shapes and structures for trees found in these
different regions and include these in the album
...


What is
its
name
and
habitat

94

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Someone had gone to their
native village by a train, then a bus, and
finally a bullock cart
...
Another spent
many days of his holidays going on
fishing trips in his uncle's boat
...
These vehicles were taken
by spacecraft all the way to Mars!
Meanwhile, Paheli had been reading
stories about ancient India and wanted
to know how people travelled from one
place to another in earlier times
...
1 STORY

OF

imitated the shapes of the animals living
in water
...

Invention of the wheel made a great
change in modes of transport
...
Animals were used
to pull vehicles that moved on wheels
...
The invention of steam
engine introduced a new source of
power
...


TRANSPORT

Long ago people did not have any means
of transport
...

For transport along water routes,
boats were used from ancient times
...
Later, people learnt to put
together different pieces of wood and
give shapes to the boats
...
1 Means of transportation

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Motorised boats
and ships were used as means of transport
on water
...
These were
later improved to carry passengers and
goods
...

Fig
...
1 shows some of the different
modes of transport
...

Are there any of the early modes of
transport that are not in use today?

10
...

In Paheli and Boojho's classroom,
there are large desks which are to be
shared by two students
...

96

On the teacher's suggestion, they
decided to measure the length of the
desk, make a mark exactly in the middle
of it and draw a line to separate the two
halves of the desk
...

Boojho brought a set of gilli and danda
with him
...
10
...

The desk seems to be having a
length equal to two danda lengths and
two lengths of the gilli
...

After a few days, the marked line gets
wiped out
...
Here is how, the length of the
desk seems to measure using the gilli
and danda (Fig
...
3)
...
10
...
10
...
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Hello! Now, when measured with the
new set of gilli and danda, the desk
length seems to be about two danda
lengths, one gilli length with a small
length still left out
...
Now what?
What would you suggest Paheli and
Boojho do, to measure the length of the
whole desk? Can they use a cricket
wicket and bails to measure the length
or do you think that this might create
the similar problem?
One thing they could do is to take a
small length of string and mark two points
on it
...
They
can measure the width of the desk in
string lengths (Fig
...
4)
...
Now, perhaps Paheli and
Boojho can measure the exact length of
the desk using the string
...

There are so many occasions when we
come across a need to measure lengths
and distances
...
A carpenter
needs to measure the height and width
of a cupboard to know how much wood
he would need to make its door
...

Suppose, you are asked how tall you
are? You want to tell the length of a
straight line from the top of your head
to the heel of your feet
...
They all concern distance
between two places
...

Let us do a few measurements to see
what exactly we need to do, when we
measure distances or lengths
...
3 SOME MEASUREMENTS
Activity 1
Fig
...
4 Measuring the length of the desk with
string lengths
MOTION AND MEASUREMENT OF DISTANCES

Work in groups and each of you do this
activity one by one
...
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unit of length, measure the length and
breadth of the classroom
...
Use a string
to measure the length of a part of your
foot as you did before
...
1
...
1 Measuring length and
breadth of classroom
Name of
student

Length of the
classroom

Width of the
classroom

Activity 2
Work in a group and each of you use
your handspan as a unit to measure
the width of a table or a desk in the
classroom (Fig
...
5)
...
10
...
Record all observations
in Table 10
...

We see that, measurement means the
comparison of an unknown quantity
98

Table 10
...
This known
fixed quantity is called a unit
...
One part is a number
...
For
example, if in Activity 1, the length of
the room is found to be 12 lengths of
your foot, then 12 is the number and
'foot length' is the unit selected for the
measurement
...
1 and 10
...
Are all
the measurements for the room using
everybody's foot, equal? Are everybody's
measurement, by handspan, of the
width of the table equal? Perhaps the
results could be different as the length
of your handspan and that of your
friends may not be the same
...
Therefore,
when you tell your measurement using
your handspan or length of foot as a
unit to others, they will not be able to
understand how big the actual length
is, unless they know the length of your
handspan or foot
...

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4 STANDARD UNITS
MEASUREMENTS

OF

In ancient times, the length of a foot,
the width of a finger, and the distance
of a step were commonly used as
different units of measurements
...

A cubit as the length from the elbow
to the finger tips was used in ancient
Egypt and was also accepted as a unit
of length in other parts of the world
...

The length of the foot used varied
slightly from region to region
...
The
Romans measured with their pace
or steps
...
Even today, we
can see flower sellers using their forearm
as a unit of length for garlands in many
towns of India
...

However, everyone's body parts could
be of slightly different sizes
...

In 1790, the French created a standard
unit of measurement called the
metric system
...
The
system of units now used is known as
the International System of Units (SI
units)
...

A metre scale is shown in Fig
...
6
...

Each metre (m) is divided into 100
equal divisions, called centimetre (cm)
...
Thus,
1 m = 100 cm
1 cm = 10 mm
For measuring large distances, metre
is not a convenient unit
...
It is called
kilometre (km)
...

Before we do that, we do need to know
the correct way of measuring lengths
and distances
...
5 CORRECT MEASUREMENT
LENGTH

OF

In our daily life we use various types of
measuring devices
...
10
...
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for measuring length
...
For measuring the length of
an object, you must choose a suitable
device
...
Measuring
tape is more suitable for this
...

In taking measurement of a length,
we need to take care of the following:
1
...
10
...

2
...
You may not be able to see
the zero mark clearly (Fig
...
8 (a)]
...
You can use any
other full mark of the scale, say,
1
...
10
...
Then you must
subtract the reading of this mark
from the reading at the other end
...
10
...
0 cm and
at the other end it is 14
...

Therefore, the length of the object is
(14
...
0) cm = 13
...


(a)

(b)
(a)

(b)
Fig
...
7 Method of placing the scale along the
length to be measured (a) correct and (b) incorrect
100

Fig
...
8 (a) Incorrect and (b) correct method of
placing the scale with broken edge

3
...

Your eye must be exactly in front of
the point where the measurement is
to be taken as shown in Fig
...
9
...
Note that from position
'B', the reading is 7
...
From
positions 'A' and 'C', the readings
may be different
...
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(A)

(B)

(C)

Fig
...
9 B is the proper position of the eye for
taking reading of the scale

Activity 3
Measure the height of your classmate
using hand span and then by using a
metre scale
...

Make a mark on the wall exactly above
his head
...
Let all other students
measure this length in a similar way
...
3
...
3 Measurement of height
Who measured Height in
the height?
handspans

Height in
cm

Study carefully results obtained by
different students
...
Look
MOTION AND MEASUREMENT OF DISTANCES

at the results in column 3 where the
measurements are done using a
standard scale
...
This could be due to small errors
in taking observations
...


10
...
We can use a thread to measure
the length of a curved line
...
10
...
Put a
knot on the thread near one of its ends
...
Now,
place a small portion of the thread along
the line, keeping it taut using your
fingers and thumb
...
Using the
other hand, stretch a little more portion
of the thread along the curved line
...
10
...
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on repeating this process till the other
end B of the curved line is reached
...
Now stretch the
thread along a metre scale
...
This
gives the length of the curved line AB
...
And, we need
some standard units and devices with
which we measure these distances and
can convey our results to others
...
7 MOVING THINGS AROUND
Activity 5

US

Think of some objects you have seen
recently
...
4
...

Which of these are moving? Which
are at rest?

How did you decide whether an object
is in motion or at rest?
You might have noticed that the bird
is not at the same place after some time,
while the table is at the same place
...

Let us look at the motion of an ant
closely
...

Ants are likely to be attracted to the
sugar and you will find many ants
crawling on the sheet of paper soon
...
10
...
Keep marking its position
after a few seconds as it moves along on
the sheet of paper
...
Connect the different points
you have marked, with arrows, to show
the direction in which the ant was

Table10
...
10
...
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moving
...

Motion seems to be some kind of a
change in the position of an object
with time, isn't it?
In Activity 5, where did you place
objects like a clock, a sewing machine
or an electric fan in your grouping of
objects? Are these objects moving from
one place to other? No? Do you notice
movement in any of their parts? The
blades of the fan or the hands of a
clock— how are they moving? Is their
movement similar to that of a train? Let
us now look at some types of motion to
help us understand these differences
...
8 TYPES

OF

In all these examples we see that the
objects move along a straight line
...


Activity 7
Take a stone, tie a thread to it and whirl
it with your hand
...
We see that the stone moves
along a circular path
...

This type of motion is called circular
motion (Fig
...
13)
...
10
...
What kind
of motion is this? Sprinters in a
100-metre race
also move along a
straight track
...
10
...
10
...

The electric fan or the clock by
themselves are not moving from one
place to another
...
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fan rotate and so do
the hands of a
clock
...

In some cases, an object repeats its
motion after some time
...
Take
the stone tied with a string that you
used in Activity 6
...
Pull the stone to one side with
the other hand and let it go
...
Something to have a lot of
fun with and something that will help
us understand about periodic motion
...
Can you help him
understand this? Remember
that the stone is held
with a string
...
10
...
10
...

Did you observe a sewing machine
as a part of Activity 5? You must have
observed that it remains at the same
location while its wheel moves with a
circular motion
...

Have you observed closely, the
motion of a ball on the ground? Here,
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Thus, the ball undergoes a
rectilinear motion as well as rotational
motion
...

We saw that motion is a change in the
position of an object with time
...
This allows us to know
how fast or slow a motion is
...

In ancient times, people used length of a foot, the width of a finger, the
distance of a step as units of measurement
...

Now, we use International System of Unit ( SI unit)
...

Metre is the unit of length in SI unit
...
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Motion in a straight line is called rectilinear motion
...

Motion that repeats itself after some period of time, is called periodic motion
...


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


Fill in the blanks:
(i) One metre is ______________ cm
...

(iii)Motion of a child on a swing is ______________
...

(v) Motion of wheel of a bicycle is______________
...


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

4
...


5
...
65 m
...


6
...
Express this
distance into km
...


While measuring the length of a knitting needle, the reading of the scale at one
end is 3
...
1 cm
...


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


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

10
...


SUGGESTED PROJECTS AND ACTIVITIES
1
...


106

Draw a map of your classroom
...
In your map mark the
points where the ball started and where it stopped
...
Did the ball move along a straight line?
Using string and a scale, let each student measure the length of his/her foot
...


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On the way to school we see
things like buses, cars, cycles, trees,
animals and sometimes flowers
...
What will
you see? Suppose you go inside a
completely dark room
...
Light helps us see
objects
...
The Sun, is another
familiar object that gives its own light
...
Objects like the sun that
give out or emit light of their own are
called luminous objects
...


W

11
...
If you are
able to see clearly through an object, it
is allowing light to pass through it and
is transparent
...
Such objects are known as
translucent
...
Try to look at something far away,
through each of these objects (Fig
...
1)
...
1
...
If we cannot see through an object at

Fig
...
1 Observing objects that do or do not
allow light to pass through them

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1
View through the object
possible (fully/ partially/
not at all)

Object/material

Object is opaque/
transparent/
translucent

Pencil
Rubber ball
Sheet of writing paper

Not very sure?

opaque depending on whether it allows
light to pass through it completely,
partially or not at all
...
2 WHAT EXACTLY

ARE

SHADOWS?

Activity 2
Now, one by one hold each of the opaque
objects in the sunlight, slightly above
the ground
...
Sometimes you can
identify the object by looking at its
shadow (Fig
...
2)
...
Hold a familiar opaque object
at some height, so that its shadow is
formed on the sheet of paper on the
ground
...
11
...
Draw outlines of the
shadows of other objects in a similar
way
...
How many objects are they
able to identify correctly?
Do you observe your shadow in a
dark room or at night when there is no
light? Do you observe a shadow when
there is just a source of light and
nothing else, in a room? It seems we
need a source of light and an opaque
object, to see a shadow
...
In the evening, go out in
an open ground with a few friends
...
Hold the torch close to the
ground and shine it upwards so that its
light falls on your friend's face
...
If there were no trees,
building or any other object behind your
friend, would you see the shadow of
your friend's head? This does not mean
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...
After all, the
light from the torch is not able to pass
through his body to the other side
...
Is
the shadow now seen on the cardboard
sheet (Fig
...
3)?
Thus, the shadow can be seen only
on a screen
...
4 Shadows of animals hidden in your hand
LIGHT, SHADOWS AND REFLECTIONS

a building, or other such surfaces act
as a screen for the shadows you observe
in everyday life
...
Sometimes,
shadows can also mislead us about the
shape of the object
...
11
...
Have fun!

Activity 4
Place a chair in the school ground on a
sunny day
...
Then, take a rectangular box
and look at its shadow
...
A red rose and a yellow rose,
for instance
...
When you move
the box around, you may see that the
size of the shadow changes
...

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3 A PINHOLE CAMERA
Surely we need a lot of complicated stuff
to make a camera? Not really
...


Activity 5
Take two boxes so that one can slide
into another with no gap in between
them
...

On the opposite face of the larger box,
make a small hole in the middle
[Fig
...
5 (a)]
...
Cover this open
square in the box with tracing paper
(translucent screen) [Fig
...
5 (b)]
...
11
...
Your pin hole camera is
ready for use
...
You should use a piece of black
cloth to cover your head and the pinhole
camera
...
Make sure that the
objects you wish to look at through your

(a)

pinhole camera are in bright sun shine
...

Are these pin hole images different
from their shadows?
Look through your pin hole camera
at the vehicles and people moving on
the road in bright sun light
...
We need a slightly
different set up for this
...
Hold the sheet
up in the Sun and let its shadow fall on
a clear area
...
Adjust your pin hole and
screen to get a clear image before the
eclipse is to occur
...
11
...
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the eclipse begins
...
Never ever
look directly at the Sun
...

There is an interesting pin hole
camera in Nature
...
11
...

These circular images are, in fact, pin
hole images of the Sun
...

These gaps are all kinds of irregular
shapes, but, we can see circular images
of the Sun
...
Surely,
all these results that we are seeing,
formation of shadows and pinhole
images are possible only if light moves
in a straight path?

Activity 6
Let us use a piece of a pipe or a long
rubber tube
...
Now
standing at the other end of the room
look at the candle through the pipe

(a)

(b)
Fig
...
7 Looking through a pipe pointed
(a) towards and (b) a little away from a candle
Fig
...
6 A natural pinhole camera
...
That
could be so much fun!
Boojho has this thought
...
What
about the images of the Sun? Did we
notice them to be upside down or
anything like that?
LIGHT, SHADOWS AND REFLECTIONS

[Fig
...
7 (a)]
...
11
...
Is the candle
visible now? Turn the pipe a little to your
right or left
...

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4 MIRRORS

AND

REFLECTIONS

We all use mirrors at home
...
What you see is a reflection
of your face in the mirror
...
Sometimes, we see
reflections of trees, buildings and other
objects in the water of a pond or a lake
...

This activity suggests that a mirror
changes the direction of light that falls
on it
...


Activity 7

Activity 8

This activity should be done at night or
in a dark room
...
Stand at another
corner with a torch in your hand
...
Adjust your fingers with a
small gap between them so that you can
get a beam of light
...
Do you see a patch of
light on the other side (Fig
...
8)? Now,

Fix a comb on one side of a large thermo
Col sheet and fix a mirror on the other
side as shown in Fig
...
9
...
Keep this in
sunlight or send a beam of light from a
torch through the comb
...
11
...


Fig
...
8 A mirror reflects a beam of light
112

Fig
...
9 Light travelling in a straight line and
getting reflected from a mirror
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Transparent objects allow light to pass through them and we can see
through these objects clearly
...

Shadows are formed when an opaque object comes in the path of light
...

Mirror reflection gives us clear images
...

Light travels in straight line
...


Rearrange the boxes given below to make a sentence that helps us understand
opaque objects
...
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2
...


3
...


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

SUGGESTED ACTIVITIES
1
...
Let one friend
stand in front facing them and holding out a mirror towards them (Fig
...
10)
...
A,B, C, or D
...
11
...
You will learn more about this in higher classes
...


Daayan-Baayan—Take a comb in your right hand and bring it up to your hair
and look at yourself in the mirror
...
Is it the right hand or the left? You were holding it in your right hand,
isn't it?
While a pin hole camera seems to be giving us upside down images, a mirror
seems to be turning right hand into left hand and the left into right hand
...


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Magic Device—In the chapter on
symmetry in your Mathematics
textbook, you might have made an
interesting device Kaleidoscope, that
uses reflections
...

Ask another friend also holding a mirror,
to stand in the middle of classroom in
front of the entrance
...
11
...
11
...

You can make a simple periscope by placing two mirrors in a ‘Z’ shaped box as
shown in Fig
...
12
...
11
...


Opaque objects cast shadows, isn't it? Now, if we hold a transparent object in
the Sun, do we see anything on the ground that gives us a hint that we are
holding something in our hand?

2
...
What happens if we place an opaque object in coloured light?
You can cover the face of a torch with a coloured transparent paper to do this
...
Here
are a few lines from this story, that has a lot of shadows
...
after ever so many days, they saw a great, high, tall forest full of tree trunks
all 'sclusively speckled and sprottled and spottled, dotted and splashed and
slashed and hatched and cross-hatched with shadows
...
)
'What is this,' said the Leopard, 'that is so 'sclusively dark, and yet so full of
little pieces of light?'
LIGHT, SHADOWS AND REFLECTIONS

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For example, we use
electricity to operate pumps that lift
water from wells or from ground level
to the roof top tank
...

Does your list include the use of
electricity for lighting? Electricity
makes it possible to light our homes,
roads, offices, markets and factories
even after sunset
...
A power station
provides us with electricity
...
In such
situations, a torch is sometimes used for
providing light
...
Where
does the torch get electricity from?

12
...
ELECTRIC CELL
Electricity to the bulb in a torch is
provided by the electric cell
...
Have you ever
carefully looked at an electric cell? You
might have noticed that it has a small
metal cap on one side and a metal disc
on the other side (Fig
...
1)
...
12
...
The metal disc is the
negative terminal
...

An electric cell produces electricity
from the chemicals stored inside it
...
It is to warn people that
electricity can be dangerous if not handled properly
...
Hence, you should never attempt to experiment
with the electric wires and sockets
...
Use only electric
cells for all activities related to electricity
...
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Filament

Caution: Never join the two terminals
of the electric cell without connecting
them through a switch and a device
like a bulb
...


Terminals
(a)

(b)

Fig
...
2 (a) Torch bulb and (b) its inside view

producing electricity
...

A torch bulb has an outer case of
glass that is fixed on a metallic base [Fig
...
2 (a)]
...

You can also take out the bulb with the
help of your teacher
...
12
...

The thin wire that gives off light is
called the filament of the bulb
...
12
...
One of these thick
wires is connected to the metal case at
the base of the bulb [Fig
...
2 (b)]
...
The
base of the bulb and the metal tip of the
base are the two terminals of the bulb
...

The electric bulbs used at home also
have a similar design
...
Why do
they have these two terminals?

12
...
A B ULB C ONNECTED
ELECTRIC CELL

TO AN

Let us try to make an electric bulb light
up using an electric cell
...

Remove a little of the plastic covering
from each length of wire at the ends
...
Fix the exposed
parts of the wires to the cell and the
bulb as shown in Fig 12
...
12
...


Fig
...
3 Electric cell with two wires attached to it
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12
...
Use
rubber bands or tape to fix the wires to
the cell
...
12
...
For each arrangement,
find out whether the bulb glows or not
...

Now, carefully look at the
arrangements in which the bulb glows
...
Can you find the
reason for the difference?
Keep the tip of your pencil on the
wire near one terminal of the electric cell
for the arrangment in Fig
...
5 (a)
...
Now, from the other terminal
of the bulb, move along the other wire
connected to the cell
...
12
...
Did the bulb glow for the
arrangements in which you could not
move the pencil from one terminal to
the other?

(b)

(e)

(c)

(f)

Fig
...
5 Different arrangements of electric cell and bulb
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3 AN ELECTRIC CIRCUIT
In Activity 2 you connected one terminal
of the electric cell to the other terminal
through wires passing to and from the
electric bulb
...
12
...
Such an arrangement is an
example of an electric circuit
...
The bulb glows only when current
flows through the circuit
...
12
...
When the

An electric bulb may fuse due to
many reasons
...
A break
in the filament of an electric bulb means
a break in the path of the current
between the terminals of the electric cell
...

Can you now explain why the bulb
did not glow when you tried to do so
with the arrangements shown in Fig
...
5 (b), (c), (d) and (e)?
Now we know how to make a bulb
light up using an electric cell
...

Remove the plastic covering at the two
ends of the wire as you did before
...
12
...
Fix
the other end of the wire to the negative
terminal of an electric cell with a rubber
band
...
12
...
This makes the bulb glow
...

This may happen if the bulb has fused
...
Is the
filament inside it intact?
ELECTRICITY AND CIRCUITS

Fig
...
7 A home made torch
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Will the
torch bulb glow in
the following
arrangement?

a drawing pin into the ring at one
end of the safety pin and fix it on the
thermo Col sheet as shown in Fig
...
8
...
Now, fix the other drawing
pin on the thermo Col sheet in a way
that the free end of the safety pin can
touch it
...


cell
...
Does the bulb remain
lighted? Is this not similar to what you
do when you switch your torch on or
off?

12
...
This was a simple
switch, but, not very easy to use
...


Activity 4
You can make a switch using two
drawing pins, a safety pin (or a paper
clip), two wires and a small sheet of
thermo Col or a wooden board
...
12
...
9 An electric circuit with a switch

Now, make a circuit by connecting
an electric cell and a bulb with this
switch as shown in Fig
...
9
...
What do you
observe? Now, move the safety pin away
...
In
this position the switch is said to be 'on'
(Fig
...
10)
...
12
...
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through it, the circuit was complete
...

On the other hand, the bulb did not
glow when the safety pin was not in
touch with the other drawing pin
...
In
Boojho has drawn the inside
of the torch as in Fig
...
11
...
Can you
draw a red line on the figure
indicating the complete circuit?

Reflector

this position, the switch is said to be
'off' as in Fig
...
9
...
The
switches used in lighting of electric
bulbs and other devices in homes work
on the same principle although their
designs are more complex
...
5 E LECTRIC C ONDUCTORS
INSULATORS

AND

In all our activities we have used metal
wires to make a circuit
...
Do you think that the
bulb will light up in such a circuit?
What materials can be used in electric
circuits so that the current can pass
through them? Let us find out
...
This would
leave you with two free ends of wires as
shown in Fig
...
12 (a)
...
Does the bulb light up?
You can now use this arrangement to test
whether any given material allows current
to pass through it or not
...
12
...
12
...
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Collect samples of different types of
materials such as coins, cork, rubber,
glass, keys, pins, plastic scale, wooden
block, pencil lead, aluminium foil,
candle, sewing needle, thermo Col, paper
and pencil lead
...
12
...
Make
sure that the two wires do not touch
each other while you are doing so
...
12
...

Table 12
...
This means that these
materials do not allow the electric current
to pass through them
...
Materials which
allow electric current to pass through
them are conductors of electricity
...
With the help of
Table 12
...

Conductors ______, ______, _________
Insulator _________, _______, ________
What do you conclude? Which
materials are conductors and which are
insulators? Recall the objects that we
grouped as those having lustre, in
Chapter 4
...

Let us recall Activity 4 in which we
made an electric circuit with a switch
(Fig
...
9)
...

What about the air between the gap?
Since the bulb does not glow when there
is only air in the gap between the drawing
pins in your switch, it means that air is
also an insulator
...
Switches,
electrical plugs and sockets are made of
conductors
...

Caution: Your body is a conductor of
electricity
...

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An electric cell has two terminals; one is called positive (+ ve) while the
other is negative (– ve)
...

An electric bulb glows when electric current passes through it
...

Switch is a simple device that is used to either break the electric circuit or
to complete it
...

Materials that do not allow electric current to pass through them are called
insulators
...


Fill in the blanks :
(a) A device that is used to break an electric circuit is called _______________
...


2
...

(b) Instead of metal wires, a jute string can be
used to make a circuit
...


3
...
12
...

Fig
...
13

ELECTRICITY AND CIRCUITS

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Complete the drawing shown in Fig 12
...


5
...


6
...
12
...


Fig
...
14

Would the bulb glow in the circuit shown in Fig
...
15?

Fig
...
15
8
...
Is that object a conductor or an insulator? Explain
...


Why should an electrician use rubber gloves while repairing an electric switch
at your home? Explain
...
The handles of the tools like screwdrivers and pliers used by electricians for
repair work usually have plastic or rubber covers on them
...
Imagine there were no electric supply for a month
...
If possible stage the play written by you or your
friends in school
...
For your friends, you may set up a game "How steady is your hand?"
...
Fix two nails nearly one metre
apart on a wooden board so that these can be used as a hook
...
Connect one
end of this wire to a bulb and a cell
...
Ask your friend to move the loop along the straight wire
without touching it
...

3
...
You
may also find out about Thomas Alva Edison who invented the electric bulb
...
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13

Fun with Magnets

P

aheli and Boojho went to a place
where a lot of waste material was
piled into huge heaps
...
The
long hand of the crane lowered a block
over a heap
...

Guess, what? Many pieces of iron junk
were sticking to the block, as it moved
away (Fig
...
1)!

sticking to the holder
...

Such stickers, pin holders and pencil
boxes have magnets fitted inside
(Fig
...
2)
...


Fig
...
2 Some common items that have
magnets inside them
Fig
...
1 Picking up pieces of iron from waste

They had just read a very interesting
book on magnets and knew immediately
that there must be a magnet attached
to the end of the crane that was picking
up iron from the junk yard
...

Have you seen stickers that remain
attached to iron surfaces like almirahs
or the doors of refrigerators? In some
pin holders, the pins seem to be

How Magnets Were Discovered
It is said that, there was a shepherd
named Magnes, who lived in ancient
Greece
...
He would take
a stick with him to control his herd
...
One day he was surprised
to find that he had to pull hard to
free his stick from a rock on the

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13
...
13
...
13
...
It seemed as
if the stick was being attracted by the
rock
...
It is said that this is
how natural magnets was discovered
...
Magnetite contains iron
...
The substances having the
property of attracting iron are now known
as magnets
...

In any case, people now have
discovered that certain rocks have the
property of attracting pieces of iron
...

They named these naturally occurring
materials magnets
...
These are known as
artificial magnets
...
For example, bar magnet,
horse-shoe magnet, cylindrical or a ballended magnet
...
13
...


Activity 1
Take a plastic or a paper cup
...
13
...
Place a magnet
inside the cup and cover it with a paper
so that the magnet is not visible
...
Fix the
other end of the thread at the base of
the stand
...
) Bring the clip near
the base of the cup
...


Fig
...
5 Effect of magnet - a paper clip
hanging in air!
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1 MAGNETIC
MATERIALS

AND

NON-MAGNETIC

Activity 2
Let us walk in the footsteps of Magnes
...

There will be a magnet at the end of our
shepherd's stick
...
Let us now go out on a "Magnes
walk" through the school playground
...
Test these
with the "Magnes stick"
...
Prepare a table in your
notebook as shown in Table 13
...
and
record your observations
...
1
and note the objects that are attracted
by a magnet
...
Is there any material common in
all the objects that were attracted by
the magnet?
We understand that magnet attracts
certain materials whereas some do not
get attracted towards magnet
...
The materials
which are not attracted towards a
magnet are non-magnetic
...
1? Is soil a
magnetic or a non-magnetic material?

Boojho has this question for you
...
The needle has slipped
from his hand on to the floor
...
1 Finding the objects attracted by magnet
Material which the object is made of
(Cloth/plastic/ aluminium/ wood/
glass/ iron/ any other

Attracted by Magnes
stick/ magnet
(Yes/No)

Iron ball

Iron

Yes

Scale

Plastic

No

Shoe

Leather

?

Name of
the object

FUN WITH MAGNETS

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Pull
out the magnet
...
Are some
particles still sticking to it? These might
be small pieces of iron (iron filings)
picked up from the soil
...
Try this activity near your home,
school or the places you visit on your
holidays
...
13
...

(a)

If you fill this table and send it to
Paheli and Boojho, they can compare
the amount of iron filings found in soil
from different parts of the country
...


13
...
Did you observe anything special
about the way they stick to the magnet?

Activity 4
Spread some iron filings on a sheet of
paper
...
What do you observe? Do the iron
filings stick all over the magnet? Do you
observe that more iron filings get attracted
to some parts of the magnet than others
(Fig
...
7)? Remove the iron filings
sticking to the magnet and repeat the

(b)

(c)
Fig
...
6 Magnet with (a) many iron filings
(b) few iron filings and
(c) no iron filings sticking to it
...
2 Magnet rubbed in sand
...
13
...
Do you observe any change in
the pattern with which the iron filings
get attracted by different parts of the
magnet? You can do this activity using
pins or iron nails in place of iron filings
and also with magnets of different shapes
...
Is your drawing
similar to that shown in Fig
...
6 (a)?
We find that most of the iron filings
are attracted towards the two ends of a
SCIENCE

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You are given two identical bars
which look as if they might be
made of iron
...
How will
you find out, which one
is a magnet?

bar magnet
...
Try and bring a few magnets
of different shapes to the classroom
...
Can you now
mark the location of poles in the kind of
magnets shown in Fig
...
4?

13
...
Many properties of
magnets were also known to them
...
One
such story is about an emperor in China
named Hoang Ti
...
It had an
extended arm as if it was showing the
way (Fig
...
8)
...
It would rest in
such a position that its extended arm
always pointed towards South
...

FUN WITH MAGNETS

Fig
...
8 The chariot with direction finding statue

Let us make such a direction finder
for ourselves
...
Put a mark on one
of its ends for identification
...
13
...
Make sure that the
magnet can rotate freely
...
Mark two points on the ground to
show the position of the ends of the
magnet when it comes to rest
...
13
...
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line joining the two points
...
Now,
rotate the magnet by gently pushing one
end in any direction and let it come to
rest
...
Does the
magnet now point in a different
direction? Rotate the magnet in other
directions and note the final direction
in which it comes to rest
...
Do not use light objects for
this activity and avoid doing it where
there are currents of air
...
Use the direction of the
rising sun in the morning to find out
the rough direction towards east, where
you are doing this experiment
...
Using the Sun for finding
directions may not be very exact, but, it
will help to make out the direction
North from the South, on your line
...

The end of the magnet that points
towards North is called its North seeking
130

In which direction is the main
gate of your school situated from
your classroom?

end or the North pole of the magnet
...
All magnets have two
poles whatever their shape may be
...

This property of the magnet is very
useful for us
...
It is said
that in olden days, travellers used to find
directions by suspending natural
magnets with a thread, which they
always carried with them
...
It is
known as the compass
...
A magnetised needle is pivoted
inside the box, which can rotate freely
(Fig
...
10)
...
13
...
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with directions marked on it
...
Its needle
indicates the north-south direction
when it comes to rest
...
To identify the north-pole
of the magnetic needle, it is usually
painted in a different colour
...
4 MAKE YOUR OWN MAGNET
There are several methods of making
magnets
...

Take a rectangular piece of iron
...
Now take a bar magnet
and place one of its poles near one edge
of the bar of iron
...

Now, lift the magnet and bring the pole
(the same pole you started with) to the
same point of the iron bar from which
you began (Fig
...
11)
...
Repeat this
process about 30-40 times
...

If not, continue the process for some

more time
...
You can
also use an iron nail, a needle or a blade
and convert them into a magnet
...
Would you like to make your
own compass?

Activity 6
Magnetise an iron
needle using a bar
magnet
...
Let the cork
float in water in a
Fig
...
12 A
bowl or a tub
...
13
...

Your compass is now ready to work
...
Rotate the cork, with the needle
fixed in it, in different directions
...
Does the needle always
point in the same direction, when the
cork stops rotating?

13
...
13
...
Take two small toy cars
and label them A and B
...
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Fig
...
13 Do opposite poles attract each other?

Fig
...
14 Repulsion between similar poles?

(Fig
...
13)
...

Place the magnet in opposite direction
in car B
...
13
...
What do you
observe? Do the cars remain at their
places? Do the cars run away from each
other? Do they move towards each other
and collide? Record your observations
in a table as shown in Table 13
...
Now,
place the toy cars close to each other
such that the rear side of car A faces
the front side of car B
...
Next, place the car
A behind car B and note the direction
in which they move in each case
(Fig 13
...
Repeat the activity by
placing cars with their rear sides facing

each other
...

What do we find from this activity?
Do two similar poles attract or repel each
other? What about opposite poles — do
they attract or repel each other?
This property of the magnets can also
be observed by suspending a magnet
and bringing one by one the poles of
another magnet near it
...
3

Magnets loose their properties if they
are heated, hammered or dropped from
some height (Fig
...
15)
...
To keep them safe, bar

How do the
cars move?
wa
Position of the cars Moveatofrords/
aw y
m
each other/
not move at all

Boojho has this question for you
...
13
...
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Fig
...
16 Store your magnets safely

magnets should be kept in pairs with
their unlike poles on the same side
...
13
...


For horse-shoe magnet, one should keep
a piece of iron across the poles
...


Compass
Magnet
Magnetite
North pole
South pole

Magnetite is a natural magnet
...
These are called magnetic
materials
...

Each magnet has two magnetic poles—North and South
...

Opposite poles of two magnets attract each other whereas similar poles
repel one another
...
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1
...

(ii) The Materials which are attracted towards a magnet are called________
...

(iv) In olden days, sailors used to find direction by suspending a piece of
___________
...


2
...

(ii) Artificial magnets were discovered in Greece
...

(iv) Maximum iron filings stick in the middle of a bar magnet when it is brought
near them
...

(vi) A compass can be used to find East-West direction at any place
...


3
...
Name a material that might have
been used to make some part of it
...


Column I shows different positions in which one pole of a magnet is placed near
that of the other
...
Fill in the blanks
...


Write any two properties of a magnet
...


Where are poles of a bar magnet located?

7
...
How would you find out
near which end is its north pole located?

8
...
How will you make it into a magnet?

9
...
A magnet was brought from different directions towards a toy boat that has
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Affect observed in each case is stated in
Column I
...
Match the statements given in Column I with those in Column II
...


Using a compass, find the direction in which windows and entrance to your
house or class room open
...


Try to place two equal sized bar magnets one above the other such that their
north poles are on the same side
...


3
...
How can you help him in getting the nails
and screws back from the scrap without wasting his time in searching with
his hands?

4
...

13
...
Take a doll and attach a small magnet in one of its hands
...
Now, your intelligent
doll is ready
...

Knowing the material of the object you can tell in advance whether the doll
would catch it or not
...
13
...
Could magnets be involved?
FUN WITH MAGNETS

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Imagine what would happen? Would you
be able to cook, clean utensils, wash
clothes or bathe? What are the other
activities you would not be able to do?
What would happen if we do not have
easy access to water for a long period
of time?
Apart from drinking, there are
so many activities for which we use
water (Fig
...
1)
...
You may use a mug, a glass,
a bucket or any other container to
measure the amount of water used
...
1 Estimation of the
amount of water used by a
family in a day
Activity

Amount of
water used

Drinking
Brushing
Bathing
Washing utensils
Washing clothes
Toilets
Cleaning floor
Any other
Total water used in
a day by a family

Fig
...
1 Uses of water

14
...
Some activities are listed
in Table 14
...
Make a similar table in
your notebook
...

Using this information, calculate the
amount of water needed by your family
in a year
...

This will give an idea of the amount of
water needed by one member of your
family in a year
...

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Boojho wonders whether people
living in different regions of our
country get the same amount of
water
...
Do you think,
our water requirement is limited to
activities like these? We use wheat, rice,
pulses, vegetables and many other food
items everyday
...
Is water not needed
to grow these? Can you think of some
more uses of water? Water is used in
industries for producing almost all the
things that we use
...


Paheli wants to tell you that
about two glasses of water
are required to produce
each page of a book
...
2 WHERE DO WE GET WATER
FROM?
Where do you get the water that you
use? Some of you may say, “We draw
WATER

water from a river, spring, pond, well or
a hand pump”
...
Have you ever
wondered where water in the taps comes
from? Water that we get from taps is also
drawn from a lake or a river or a well
(Fig
...
2)
...


Fig
...
2 Water in taps comes from rivers, lakes
or wells

Each of us may be getting water into
our homes in different ways
...

We have discussed some of the
sources of water
...
So,
you have to fetch it yourself from
a far away place
...
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That is where the water cycle
comes in!

14
...
14
...
14
...

The water in the oceans and seas has
many salts dissolved in it — the water
is saline
...
You might have heard
the famous lines of the poem “Rime of
the Ancient Mariner” written by S
...

Coleridge in 1798:

How many times have you noticed that
water spilled on a floor dries up after
some time? The water seems to disappear
...
14
...
Water
from wet roads, rooftops and a few other
places also disappears after the rains
...
14
...

Yet, oceans play an important role
in supplying the water that we use
...
Many of
us live in places far away from the
oceans
...
This activity gives us
an idea that, on heating, water changes
into its vapour
...
Water vapours so
formed become a part of the air and
cannot usually be seen
...
However, we have seen
that water changes into its vapour also

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We also discussed in
Chapter 5 that to obtain salt, water from
the sea is left in shallow pits to let the
water evaporate
...


Activity 2
Take two similar plates
...
Now, pour equal amount
of water in each of the plates (Fig
...
5)
...
Make sure that water does not
spill over
...
Does the water seem
to disappear? From which plate does it
disappear first? What is the source of
heat for this evaporation?
During the daytime, sunlight falls on
the water in oceans, rivers, lakes and
ponds
...
As a result, water
from all these places continuously
changes into vapour
...

In Activity 2, did you find that water
also disappeared from the plate kept in

the shade, though it could have taken
more time? Does the heat from the
sunlight reach here? Yes, during the
daytime all the air surrounding us gets
heated
...
Thus,
evaporation takes place from all open
surfaces of water
...

However, evaporation of water is a slow
process
...
In
sunlight, evaporation takes place faster
...
Is
there any other process through which
water vapour gets transferred into air?

Loss of Water by Plants
You have learnt in Chapter 7 that plants
need water to grow
...
He asked himself how much water is lost through
transpiration by wheat plants
that give us one kilogram of
wheat? He found out that this is
nearly 500 litres, that is, roughly
25 large sized buckets full of
water
...
14
...
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retain some of it in their different parts
...
Do
you remember observing transpiration
of water by plants in Activity 4 in
Chapter 7?
Water vapour enters the air through
the processes of evaporation and
transpiration
...


Paheli has noticed dew on leaves of
grass on winter mornings
...
Wipe
the glass from the outside with a clean
piece of cloth
...
Wait for one or two minutes
...
14
...

From where do water drops appear
on the outer side of the glass? The cold
surface of the glass containing iced water,
cools the air around it, and the water
vapour of the air condenses on the
surface of the glass
...


Fig
...
6 Drops of water appear on outer
surface of the glass containing water with ice
140

The process of condensation plays an
important role in bringing water back
to the surface of earth
...
When
the air moves up, it gets cooler and
cooler
...
It is these
tiny droplets that remain floating in air
and appear to us as clouds (Fig
...
7)
...
14
...
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Boojho has noticed fog near the
ground in winter mornings
...
What do you
think?

drops of water
...

These falling water-drops are, what we
call rain
...

Thus, water in the form of vapour
goes into air by evaporation and
transpiration, forms clouds, and then
comes back to the ground as rain, hail
or snow
...
4 BACK

TO THE

OCEANS

What happens to the water that rain and
snow bring to different regions of earth?
Almost all land surfaces are above the
level of oceans
...

This happens in many ways
...
This water flows down the
mountains in the form of streams and
rivers (Fig
...
8)
...
Most of the
rivers cover long distances on land and
ultimately fall into a sea or an ocean
...

WATER

Fig
...
8 Rain water flows down in the form of
streams and rivers

The rainwater also fills up the lakes
and ponds
...
Some of this water
is brought back to the air by the process
of evaporation and transpiration
...
Most of this
water becomes available to us as ground
water
...
Ground water is the source for
many lakes as well
...
The more handpumps or
tubewells that are used in an area, the
deeper we need to dig to find this ground
water
...

Paheli wants to share a concern with
you
...
Flowing rainwater also
takes the top layer of the soil away with
it
...
This
reduces the seepage of rainwater into the
ground which ultimately affects the
availability of ground water
...
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We now know that water brought
back to the surface of the earth by rain,
hail or snow, goes back to oceans
...
The circulation of
water in this manner is known as the
water cycle (Fig
...
9)
...
This maintains the
supply of water on land
...
5 WHAT

IF IT

RAINS HEAVILY?

The time, duration and the amount of
rainfall varies from place to place
...


Fig
...
10 A scene after heavy rains

In our country, most of the rainfall
occurs during the monsoon season
...
The sowing of many crops
depends on the arrival of monsoon
...
14
...
Heavy

Fig
...
9 Water cycle
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14
...
The water
may then spread over large areas causing
floods
...
14
...
In our country, floods cause
extensive damage to crops, domestic
animals, property and human life
...
They often get trapped on land
areas and die when floodwater recedes
...


14
...
Since
it is not being brought back by rain,
the soil becomes dry
...
The ground water may also become
scarce
...

In drought conditions, it is difficult
to get food and fodder
...
Are
you aware of the difficulties faced by
the people living in these areas? What
happens to the animals and the
vegetation in these conditions? Try and
find out about this by talking to your
parents and neighbours and by
reading about it from newspapers
and magazines
...
7 HOW CAN WE CONSERVE WATER?
Only a small fraction of water available
on the Earth is fit for use of plants,
animals and humans
...
When the level of the ground
water decreases drastically, this can not
be used any more
...

The demand for water is increasing
day-by-day
...
In many cities, long queues
for collection of water are a common site
(Fig
...
12)
...
These factors are leading

Fig
...
12 A queue for collecting water
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Hence, it is very important
that water is used carefully
...


14
...
Collecting rainwater in
this way is called rainwater harvesting
...

What happens to the rainwater that
falls in places that are mostly covered
with concrete roads and buildings? It
flows into the drains, isn't it? From there
water goes to rivers or lakes, which could
be far away
...

Discussed here are two techniques
of rainwater harvesting:
1
...
14
...
This water may contain soil
from the roof and need filtering
before it is used
...
This then seeps into the
soil to recharge or refill the ground
water (Fig
...
13)
...
Another option is to allow water
to go into the ground directly
from the roadside drains that
collect rainwater
...
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Water is essential for life
...

The water vapour in the air condenses to form tiny droplets of water, which
appear as clouds
...

Rain, hail and snow replenish water in rivers, lakes, ponds, wells and soil
...

Excessive rains may cause floods while lack of it for long periods may
cause droughts
...


1
...

(b) The process of changing water vapour into water is called _________________
...

(d) Excessive rains may cause _________________
...


State for each of the following whether it is due to evaporation or condensation:
(a) Water drops appear on the outer surface of a glass containing cold water
...

(c) Fog appearing on a cold winter morning
...

(e) Steam rising from a hot girdle when water is sprinkled on it
...


Which of the following statements are “true” ?
(a) Water vapour is present in air only during the monsoon
...
( )
(c) The process of water changing into its vapour, is called evaporation
...
(

)

)

(e) Water vapour condenses to form tiny droplets of water in the upper layers of
air where it is cooler
...
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4
...
Would spreading it near
an anghiti or heater help? If yes, how?

5
...
After
some time you notice a puddle of water around it
...


To clean their spectacles, people often breathe out on glasses to make them
wet
...


7
...


When does a drought occur?

SUGGESTED PROJECTS AND ACTIVITIES
1
...


Collect pictures relating to floods or droughts from old magazines or
newspapers
...


3
...


4
...
For each activity describe
how you would do it
...


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But, have you ever seen air?
You might not have seen air, but, surely
you must have felt its presence in so
many ways
...
Pages
of an open book begin fluttering
when the fan is switched on
...
Do you remember Activity 3 in
Chapter 5 in which you separated the
sand and sawdust by winnowing?
Winnowing is more effective in moving
air
...
It may even uproot trees and blow
off the rooftops
...
15
...
15
...
Observe, what happens
...
15
...


Fig
...
3 A weather cock

15
...
15
...


Activity 1

Activity 2

Let us make a firki of our own, following
the instructions shown in Fig
...
2
...


Take an empty glass bottle
...
Is something
inside it, now?

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...
15
...


Now, dip the open mouth of the bottle
into the bucket filled with water as
shown in Fig
...
4
...

Does water enter the bottle? Now tilt the
bottle slightly
...
It is “air”, that was
present in the bottle
...
In fact, it was filled
completely with air even when you
turned it upside down
...

When the bottle was tilted, the air was
able to come out in the form of bubbles,
and water filled up the empty space that
the air has occupied
...
It fills all the space in the bottle
...
Air
has no colour and one can see through
it
...

Our earth is surrounded by a thin
layer of air
...

Why do you think, mountaineers
carry oxygen cylinders with them, while
climbing high mountains (Fig
...
5)?
148

Fig
...
5 Mountaineers carry oxygen cylinders
with them

15
...

Experiments have proved that it is really
not so
...

What kind of a mixture is it? Let us find
out about some of the major
components of this mixture, one by one
...
We also saw that, when
air comes in contact with a cool surface,
it condenses and drops of water appear
on the cooled surfaces
...


Oxygen
Activity 3
In the presence of your teacher, fix two
small candles of the same size in the
middle of two shallow containers
...
Light
the candles and then cover each one of
them with an inverted glass (one much
SCIENCE

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The major part of air
(which does not support burning candle)
is nitrogen
...


Carbon dioxide
Fig
...
6 Air has oxygen

taller than the other) as shown in Fig
...
6
...

Do the candles continue to burn or
go off? Does the level of water inside
glasses remain the same?
The burning of the candle must be
due to presence of some component of
air, isn’t it? Do you find any difference
in your observation with the two glasses
of different heights? What can be the
reason for this?
Burning can occur only in the
presence of oxygen
...
Now, the
amount of air and hence its oxygen
component inside each glass in our
experiment, is limited
...
Also, some of the space occupied
by the oxygen inside the glass becomes
empty and the water rises up to fill or
occupy this space
...
This is due to
excess of carbon dioxide that may be
accumulating in the room, as the
burning continues
...
Plants and animals consume
oxygen for respiration and produce
carbon dioxide
...


Dust and smoke
The burning of fuel also produces
smoke
...

That is why you see long chimneys in
factories
...


Activity 4
Find a sunny room in your school/
home
...
Now, open the door or a
window facing the sun, just a little, in
such a way that it allows sunlight to
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15
...
15
...

Look carefully at the incoming beam
of sunlight
...
15
...
The presence of dust
particles in air varies from time to time,
and from place to place
...
Fine hair and
mucus are present inside the nose to
prevent dust particles from getting into
the respiratory system
...

We may conclude, then, that air
contains some gases, water vapour and
dust particles
...
However, there may be some
variations in the composition of air from
place to place
...
15
...


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15
...
In fact,
these two gases together make up 99%
of the air
...
15
...


15
...
Heat it slowly on a tripod stand
...
15
...


vessel
...
15
...
When you heat the
water, to begin with, the air dissolved in
it escapes
...
We learnt in Chapters 8
and 9, that the animals living in water
use the dissolved oxygen in water
...
Add water to it and note what
happens (Fig
...
11)
...

When the water is poured on the
lump of soil, it displaces the air which
is seen in the form of bubbles
...
A lot
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15
...

These burrows also make spaces
available for air to move in and out of
the soil
...
In this situation,
animals living in the soil have to come
out for respiration
...
4 HOW IS THE OXYGEN IN THE
ATMOSPHERE REPLACED?
In Chapter 7, we read about
photosynthesis
...
Plants also
consume oxygen for respiration, but
they produce more of it than they
consume
...

It is obvious that animals cannot live
without plants
...
They
would consume all the carbon dioxide
in the atmosphere
...
This
shows the interdependence of plants
and animals
...
Are there any other
uses of air? Have you heard about a
windmill? Look at Fig
...
12
...
15
...
The windmill is used to draw
water from tubewells and to run flour
mills
...
Air helps in the
movements of sailing yachts, gliders,
parachutes and aeroplanes
...
Air also helps in the
dispersal of seeds and pollen of
flowers of several plants
...

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We cannot see air, but we can feel it
...

Air occupies space
...

Air is a mixture of nitrogen, oxygen, carbon dioxide, water vapour and a few
other gases
...

Oxygen supports burning and is necessary for living organisms
...

Atmosphere is essential for life on earth
...

Plants and animals depend on each other for exchange of oxygen and carbon
dioxide from air
...


What is the composition of air?

2
...


How will you prove that air supports burning?

4
...


Why does a lump of cotton wool shrink in water?

AIR AROUND US

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


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


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


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

SUGGESTED PROJECTS AND ACTIVITIES
1
...


154

On a clear glass window facing towards an open area, fix a small rectangular
strip of paper
...
Do you notice a difference
between the rectangular section that was left covered with paper and the
rest of the glass window? By repeating this exercise every month, you can
have an idea about the amount of dust present in air around you at different
times of the year
...
Note
whether their leaves have some dust or soot deposited over them
...

Is there any difference in deposition of soot on leaves of trees near the roadside?
What could be the possible reasons for this difference? Take a map of your
city or town and try to identify regions in the map where you have noticed
very thick layer of soot on the plants by the roadside
...
Perhaps
the results from all the students could be summarised and reported in
newspapers
...
GOALias
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16

Garbage in, Garbage out

W

e throw out so much rubbish
or garbage everyday from our
homes, schools, shops and
offices
...
All these
wrapping material go out as garbage
...

We generate so much garbage in our
day-to-day activities! We often throw
groundnut shells on public places, in
buses or trains, after eating the nuts
...
A child might go on
sharpening pencils just for fun
...
And we also throw away
many domestic wastes such as broken
toys, old clothes, shoes and slippers
...


Children from Paheli and Boojho’s
school did a project called ‘Dealing with
Garbage’
...


16
...
16
...

There the part of the garbage that
can be reused is separated out from the
one that cannot be used as such
...
16
...
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the garbage has both useful and nonuseful components
...
It is then
spread over the landfill and then
covered with a layer of soil
...

For the next 20 years or so, no building
is constructed on it
...
What is
compost? Let us learn about it, from the
following activity
...

Separate it into two groups, so that
they have:
Group 1: Garbage from the kitchen —
like fruit and vegetable peels, egg shells,
waste food, tea leaves
...

Group 2: Pieces of cloth, polythene
bags, broken glass, aluminium wrappers,
nails, old shoes and broken toys
...
Label them
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Fig
...
2 Putting garbage heaps in pits

as A, B, C and D
...
Tie the
mouth of these two bags tightly
...
16
...
You
can also use four pots to bury these
garbage heaps
...
A
black colour and no foul smell indicates
that rotting of garbage is complete
...
Observe again after every
two days and note your observations as
suggested
...

(i) rot completely and not smell?
(ii) rot only partially?
(iii) rot almost completely, but still
smells bad?
(iv) not change at all?
Garbage in which heap was seen to
rot and which did not?
Enter options (i), (ii), (iii) or (iv) in
the columns of Table 16
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Table 16
...
If you make any other
observations, do not forget to write all
these down in your notebook
...

If the garbage was found to rot
completely and did not smell, mix it in
the soil where you sow your favourite
plants
...

You must have observed from this
activity that some things in the garbage
rot
...
The rotting and
conversion of some materials into
manure is called ‘composting’
...

Usually one is coloured blue and the
other green
...
Did you
notice that these are the materials that
do not rot in the garbage heaps? The
green bins are for collecting kitchen and
other plant or animal wastes
...
Do
GARBAGE IN, GARBAGE OUT

you see why it is necessary for
us to separate waste into two
groups as we did in Activity 1,
After 4
before we throw it?
weeks
Have you noticed garbage
heaps of dried leaves on the
roadside? Most of the time
these are burnt (Fig
...
3)
...
Burning of these, produces
smoke and gases that are harmful to
our health
...
These wastes could be
converted into useful compost
...
16
...

Boojho noted in his notebook: Do
not burn leaves! You will not be
able to tolerate the fumes!

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She must have
meant “illegal”
...


16
...
We will also be very
good friends to ourselves by making
compost
...

This method of preparing compost
with the help of redworms is called
vermicomposting
...


vegetable wastes including peels of fruits
over this layer of sand
...
However, shiny or
plastic coated paper should not be used
for this purpose
...

Sprinkle some water to make this
layer wet
...
Do not press the layer of waste
...

Now, your pit is ready to welcome the
redworms
...
16
...
Cover them
loosely with a gunny bag or an old sheet
of cloth or a layer of grass
...
What about
a place which does not get direct
sunlight? Let us now make a
comfortable home for our redworms in
the pit or the box
...
You can
also spread 1 or 2 cm thick layer of sand
as an alternative
...
16
...
You can give
them vegetable and fruit wastes, coffee
and tea remains and weeds from the
fields or garden (Fig
...
5)
...
Do not use wastes
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16
...
If you put these
things in the pit, disease-causing small
organisms start growing in the pit
...

Redworms do not have teeth
...

Powdered egg shells or sea shells could
be mixed with the wastes
...
A
redworm can eat food equal to its own
weight, in a day
...
They also
need moisture around them
...

Observe the contents of the pit
carefully after 3-4 weeks
...
16
...

Put some wastes as food in one corner
of the pit
...
16
...
Remove the compost from
the vacated part and dry it in the sun
for a few hours
...
You can use these for
preparing more compost or share them
with another user
...
Is this not
like getting the ‘best out of waste’? Those
of you who have agricultural fields can
try vermicomposting in large pits
...


16
...
Use a 5-10 litre bucket to
collect the garbage from your home for
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16
...
In how many days does the
bucket become full? You know the
number of members in your family
...
16
...
Nanu studies in Class VI
...
His
mother is very annoyed when he tears
off sheets from new notebooks to make
aeroplanes, but Nanu does not care
...
He was amazed
at the variety of things his cousin Shyam
had made
...
Shyam had even made a
diary from invitation cards!
160

One morning Nanu went looking for
his grandmother (Nani)
...

Nanu asked, “Nani, What are you doing?
What is this paste?”
“This is papier-mâchè, a paste made
of clay and paper in which I have also
mixed some rice husk”, replied Nani
...

“To make it stronger”, said Nani and
added “would you like to learn this from
me?” Nanu was not very keen and ran
outside to play
...
In
fact he also started tearing up papers
from Shyam’s files!
Shyam collected all the pieces of
paper Nanu had used, wondering what
to do about him! He just did not listen
to anyone!
It was Nanu’s birthday in a few days
...

Nanu took out money from his mud pot
and went to the market
...
He asked the
shopkeeper for a polythene bag to keep
the hats, who gave him a paper bag
instead of polythene
...
He found it difficult to carry all
of these things as no shopkeeper was
ready to give a polythene bag
...
Somehow, he managed to reach
home with all his purchases (Fig
...
8)
...

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16
...
He had
a special gift for Nanu as well
...
All his friends went
home with their masks
...

Nanu returned home, after his
holidays were over
...
But now he stopped
making faces when he saw the rag
picking children near his house
...
Observe the children at
work and find out how they separate
usefull material from the garbage
...

GARBAGE IN, GARBAGE OUT

Talk to one such child and find out:
What do they do with the rubbish
they collect? Where do they take it?
Does he/she go to school? What
about his/her friends?
If they do not go to school, find out
the possible reasons
...

Would you like to make paper from
old and discarded paper like Shyam?
Let us learn to do this
...
4 RECYCLING

OF

PAPER

You will require pieces of old newspapers,
magazines, used envelopes, notebooks,
or any other paper
...
You will also need
a frame fitted with a wire mesh or a net
...

Tear the paper into small pieces
...
Let the pieces of paper remain
submerged in water for a day
...

Now, spread the wet paste on the wire
mesh fixed to the frame
...
Wait till water
drains off
...

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Keep the
corners of the newspaper sheet pressed
by putting some weights so that these
do not curl up
...
It would help you to get a
recycled paper with beautiful patterns
on it
...
5 PLASTICS – BOON

OR A

CURSE?

Some kind of plastics can be recycled,
but, not all of them
...

It may be a little difficult to imagine
our life without plastics
...

Can you name a few parts of a bus, car,
radio, television, refrigerator and a
scooter that are made of plastics?
The use of plastics in itself might not
create so much of a problem
...
This is what is
happening all around us! We might even
be acting irresponsibly, knowing well
about its harmful effects
...
Sometimes these bags
may not be suitable for keeping eatables
...

Many a time shopkeepers use plastic
bags that have been used earlier for
some other purpose
...
Use of such recycled
plastic bags to keep food items could be
harmfull for our health
...

All kind of plastics give out harmful
gases, upon heating or burning
...
The
government has also laid down
guidelines for recycling of plastics
...

You must have noticed that people
often fill garbage in plastic bags and
then throw it away
...
Sometimes, they die
due to this
...
As a
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During heavy rains,
it might even create a flood like situation
...
We make a minimum use of plastic
bags
...

2
...
We carry a cloth or a jute bag
when we go out for shopping
...
We do not use plastic bags to store
eatables
...
We do not throw plastic bags here
and there, after use
...
We never burn plastic bags and other
plastic items
...
We do not put garbage in plastic bags
and throw it away
...
We use vermicomposting at home and
deal with our kitchen waste usefully
...
We recycle paper
...
We use both sides of the paper to
write
...

We use blank sheets of paper left in
our notebooks for rough work
...
We make our family, friends and
others to follow proper practices for
disposing different kinds of wastes
...


Waste
Garbage
Landfill
Compost
Ver micomposting
Recycling

Landfill is an area where the garbage collected from a city or town is
dumped
...

Converting plant and animal waste including that from kitchen, into
manure, is called composting
...
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The method of making compost from kitchen garbage using redworms is
called vermicomposting
...

Plastics cannot be converted into less harmful substances by the process
of composting
...


1
...
Draw pictures of these
...


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

3
...


(a) Collect pieces of different kinds of paper
...

(b) With the help of a lens look at the pieces of paper you collected for the above
question
...


(a) Collect different kinds of packaging material
...

(b) Give an example in which packaging could have been reduced?
(c) Write a story on how packaging increases the amount of garbage
...


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

ACTIVITIES FOR DEALING WITH GARBAGE
1
...


164

Collect old and discarded objects and material like glass bottles, plastic bottles,
coconut husk, wool, bed sheets, greeting cards and any other thing
...

Prepare a detailed project report on compost making activity you did in school
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A MATTER OF CONCERN!
In autumn lots of leaves are burnt in cities like Delhi
...

Instead of burning, if we make compost from these leaves, we can reduce the
use of chemical fertilizers
...

If you find any one is burning the leaves bring it to notice of municipal authorities
or write to newspapers about it
...
Ensure that fallen leaves
are not burnt but used for making compost
...


GARBAGE IN, GARBAGE OUT

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