science class -3- 2077 press

4. Answer the following questions.
a. What is information? Write down any three sources of
information.
b. What are means of information? Write down any three
importance of information and communication.
c. What is communication? Make a list of any three means
of each of one - way and two way communication.
d. A library is a good source of information, why?
e. Write the main difference between radio and television.
f. How can we use computer network as means of
communication?

Reference Video Use and Function of compound microscope

Scan for practical experiment

URl: csp.codes/c04e01

Blooming Science, Health and Physical Education Book 4 151

Lesson Local Technology

14

Learning outcomes

At the end of this lesson, the students will be able to:

 define local technology.

 introduce some local technologies like water mill, turbine and pump set.

 tell the advantages of water mill, turbine and pump set.

Scan for practical experiment

Boost Up

URl: csp.codes/c04e25

1. Mention the name and one use of following devices.

.......................... .......................... .......................... .......................
.......................... .......................... .......................... .......................

2. Are these technologies imported from other countries or
indigenous? ..............................

152 Blooming Science, Health and Physical Education Book 4

Human beings have developed different technologies from
ancient time. They have made their works easy and fast by using
locally available tools and technologies. Such technologies
are called local technologies. Technology developed by the
local people using their skill and resources to make their
work easier is called local technology. These are indigenous
in which technologies are not imported from other countries.
Local technologies are made by people without the proper
knowledge of their scientific way of working. The people have
been using such technologies to make their lives easier.

In the remote areas, people have been using different
technologies since many years. Local people use stone grinder
(Janto), Dhiki, water - mills (pani ghatta) for grinding food
grains to flour. People of different communities make their
traditional clothes, mats, carpets, ropes, etc using their own
technologies. They plough their field by using wooden plough
with oxen or buffaloes. They grind the spices with mortar
(Okhal). Similarly, people use their technologies to generate
electricity and draw out underground water. These all are the
examples of local technology.

You have studied about compost manure, biogas,
sharpening tools and cold stores in class three. In this lesson,
we are going to discuss three instruments which are used with
local technology. They are water mill (pani ghatta), turbine to
generate electricity and water pump (hand pump).

Blooming Science, Health and Physical Education Book 4 153

Some Local technologies

Water - Mill (Pani ghatta)

Water mill or pani ghatta is one
of the old local technologies in the
rural areas. People have been using
this technology to grind grains like
wheat, maize, millet, rice, barley,
etc. This technology is run by water.
Therefore, it is called pani mill or
panighatta.

This technology is based on the principle that moving
water can bring a still object into motion. Water mill has a
rotating blade made of wooden flakes or iron plates. It also
consists of stone grinder (Jaanto) and water supply with a force
by using wooden canal or plastic pipe. The upper part of stone
grinder is fixed with the rotating blade tightly whereas lower

154 Blooming Science, Health and Physical Education Book 4

grinding stone is fixed
in a position. When
the water falling from
a height strikes the
rotating blades with a
greater force, the stone
grinder moves round
and grinds the grains
kept inside the grinder.
The flour obtained by
grinding the grains in water mill is good for health as it is the
whole meal flour and rich with fibre.

Turbine

Turbine is the improved form of pani ghatta. Now a days,
a modern technology is developed in the form of turbine.
Principle of water mill and turbine is same. The rotating
blades made up of iron or steel and connected to the dynamo
to produce electricity is called turbine. Turbine is made up
of steel or iron blades. The blades are fixed with the core of
dynamo (generator). When the fast flowing water falls on the
blades, the turbine rotates. The rotating turbine is used to spin a
generator which produces electricity. The electricity generated
in the power house is distributed to our houses with electric
wires. Turbine can also be rotated with wind power.

Blooming Science, Health and Physical Education Book 4 155

Pump set

Pumpset is a device which is

used to pump out the underground

water for different purposes.

Underground water is the main

source of water in Terai region. It is

lifted out in many ways. One of the

easiest way of lifting underground

water out is by the use of pump set.

The pump sets can be driven

by fuels like diesel, petrol;

animals and electricity also. Water Force rod
The simple form of pump set outlet Piston rod
to lift underground water is Water
the hand pump. It is also called suction line Cylinder
as 'Chapakal’ in Nepali as it is Piston
based on the pressure. Check valve

Check valve

The hand pump is simple Water

in structure. It consists of a

handle connected with long

iron or plastic pipe dipped into

the ground to reach the water level. The handle of the pump

set is connected with valve inside the pipe. When the handle

of pump set is moved up and down, the underground water is

pulled through the pipe and come out from the spout.

Key words

Grind – reduce to small particles by crushing it.
Flakes – a small, flat, very thin piece of something.
Generator – a device used to generate electricity.
Underground – found below the earth’s surface.

156 Blooming Science, Health and Physical Education Book 4

Main Points to Remember

 Technology developed by the local people by using their skill and resources is
called local technology.

 Human beings have been adopting various local technologies to make their lives
easier.

 Water mill is a device that converts the power of running water into energy.
 Turbine is the developed form of water mill which can be used to generate

electricity by connecting with dynamo or generator.
 The turbine can rotate with the help of running water or wind.
 Pump set is a device that pumps out the underground water with the help of

pressure.

Project work

1. Making paper fan to show water has energy to bring an
object into motion:

– Take a cardboard and cut it in a circular shape.

– Divide the circular piece into four equal parts by
drawling lines and cut the cardboard along the lines
up to the centre.

– Fold its edges to make a fan.

– Fix an iron nail at the centre of the fan.

– Pour water in one side of the fan.

– Observecarefullywhathappens.Drawtheconclusion
and discuss with your friends and teacher.

2. Observe the local technologies that are used in your
locality. Make a list with their uses also. Discuss it with
your friends and teacher in your class.

Blooming Science, Health and Physical Education Book 4 157

Exercise

1. Fill in the blanks with suitable words.
a. Local technologies are simple and have been used
since ........................ time.
b. Pani ghatta runs with the help of ........................
c. Pani ghatta is used to ........................ the grains.
d. ........................ is improved form of water mill.
e. ........................ is used to lift underground water.
f. Turbine is used to generate ........................

2. Write ‘True’ for correct sentences and ‘False’ for wrong
ones.

a. The local technology is used in rural areas.

B. Water mill is used to lift underground water.

c. Turbine works on the principle of pressure.

d. Turbine converts the power of moving water
or wind into energy.

e. Hand pumps are used to lift underground
water in hilly region.

3. Match the following:

Water mill Indigenous technology
Turbine Lifts underground water
Pump set Grinds food grains
Generates electricity
Local technology

158 Blooming Science, Health and Physical Education Book 4

4. Answer the following questions.
a. What is local technology? Give any three examples of
local technology.
b. How do the people make traditional clothes?
c. What is water mill? On which principle does it work?
d. What is the use of turbine?
e. Write down any two advantages of local technology
over modern technology.
f. What is hand pump? What is its use?
g. Write down the main difference between water mill
and turbine.

5. Draw the diagram of a hand pump.

Blooming Science, Health and Physical Education Book 4 159

(A sample work sheet to be given to the students in practical classes.)

Name: ....................................... Section: ....... Roll: .......

Aim: To demonstrate that air has weight.

Required: balloons, small sticks, thread, pin, etc.

Theroy: ...........................................................................

Method:

1. Take two equal sized balloons and inflate both of them
with equal amount of air.

2. Hang them on a stick to balance them on it.

3. Prick one of the balloons and observe the weight of
the balloons on the balance.

Observation:
1. What happens when a balloon is pricked?

............................................................................................

............................................................................................

............................................................................................

160 Blooming Science, Health and Physical Education Book 4

Result:
The balloon which is pricked moves up and the other

balloon moves down due to the weight of air in the
balloon.
Conclusion:
Air has weight.
Diagram:

Questions:
Q.No. 1. Write any two properties of air.
Ans: ............................................................................................
............................................................................................
............................................................................................
............................................................................................

Blooming Science, Health and Physical Education Book 4 161

Model Questions

1. Fill in the blanks:
a. Sudden shaking of the earth is called ...................
b. Liquids take the shapes of ...................
c. The process of changing a gas into liquid on cooling
is called ...................
d. The increase in the size of an object on heating is
...................
e. .................. is the longest day of the year in Northern
Hemisphere.
f. The season between winter and summer is .................
g. A bright star like object with a tail, in the solar
system is a ...................
h. The outermost solid layer of the earth is called
...................
i. The dry outer covering of grain, nut, etc is called
...................
j. .................. is a device to lift water from under the
ground.

2. Write ‘T’ for true and ‘F’ for false statements:
a. Herbivores eat other animals for food.
b. Desert plants have broad leaves.
c. The seedling that lies inside a seed is called embryo.
d. When food burns, it produces oxygen.
e. Camels have narrow feet.
f. Thick layers of fat inside the skin helps a polar bear
to stay warm.
g. Earthworm is a parasite.

162 Blooming Science, Health and Physical Education Book 4

h. Dolphin is a fish.
i. Backbones in our body helps us to stand.
j. Long thin animals with backbone are worms.

3. Encircle the correct answer from the given options:

a. Which is not the means of communication?

(i) Radio (ii) Newspaper

(iii) Reporter (iv) Letters

b. The smallest planet of the solar system is

(i) Venus (ii) Neptune

(iii) Mars (iv) Mercury

c. The land part of the earth is called

(i) Atmosphere (ii) hydrosphere

(iii) Troposphere (iv) Lithosphere

d. Longest day in the northern hemisphere is:

(i) March 21 (ii) June 21

(iii) December 22 (iv) September 23

e. Biogas is one of the sources of energy which is also
called as

(i) Liquefied petroleum gas (iii) Gobar gas

(ii) Carbondioxide gas (iv) All of the above

f. Which of the following doesn’t belong to floating
plants?

(i) Water lily (ii) Duckweed

(iii) Pistia (iv) Water hyacinth

4. The table shows the different layers of earth and their
thickness. Match the appropriate options on either side:

Blooming Science, Health and Physical Education Book 4 163

Outer core of the earth 2100 km
Inner core of the earth 16 – 35 km
Mantle layer of the earth 1300 km
Earth crust 2900 km

5. Define the following:
a. Information
b. Thermometer
c. Volume
d. Satellite
e. Photosynthesis
f. Camouflage

6. Answer the following questions:
a. What are the different factors of weather?
b. What causes the change of seasons on earth?
c. Write the different forms of energy.
d. How does rainfall occur?
e. Write any two characteristics of floating plants.
f. Write importance of information in two points.
g. Write the name of eight planets of the solar system.

7. Give reasons:
a. TV is a better source of information than a radio.
b. We can open a tight cap of a bottle by dipping it into
hot water.
c. The roots of desert plants grow deep into the soil.
d. Living organisms are found only in the earth.

164 Blooming Science, Health and Physical Education Book 4

8. Write any 2 points of difference between the following:
a. Sun and moon.
b. Renewable and nonrenewable sources of energy.
c. Solid state and liquid state.
d. Vertebrates and invertebrates.

9. Observe the following diagram and answer the following
questions:

a. What is the figure showing?

b. Label A, B.

c. How can we

increase the speed of

doing work in this A
instrument?

d. For what work it is
being used?

10. Draw a diagram showing B
the change of seasons
and label any 4 different
seasons.

11. Observe the following diagram and answer the following
questions:
a. Label A, B, C & D.
b. In which stage butterfly does not eat food?
c. What is the food of stage B and stage D.
d. Which stage is called voracious eater?

Blooming Science, Health and Physical Education Book 4 165

AC

D
B

12. Write a practical activity which proves that air expands on
heating by taking help of following points.
(Aim, Materials Required, Method, Observation,
Conclusion and Diagram)
The End

166 Blooming Science, Health and Physical Education Book 4

Part

2

Health Education

Blooming Science, Health and Physical Education Book 4 167

Lesson

15 Personal Hygiene

Learning outcomes

At the end of this lesson, the students will be able to:
 explain the advantages of regular cleanliness of various body organs.
 develop the concept of being healthy and disease free by maintaining personal

hygiene.
 practice various methods to maintain personal hygiene.

The practice of keeping our body and body parts clean and
promoting healthy habit is called personal hygiene. It includes
cleanliness of different body parts, wearing clean clothes and
adapting healthy habits like proper exercise and rest. It is an
essential process of life. If we do not take care of different body
organs of our body, then we become sick and suffer from many
diseases. So, we should take care of different body organs and
adopt the healthy habit.
Our body consists of various systems, organs, tissues and
cells. Our body can be divided into three major parts. They
are head, trunk and limbs. These parts combine together to
provide a fixed framework to our body in which many other
organs are present.

168 Blooming Science, Health and Physical Education Book 4

eyes head
mouth ears
nose
chest teech
arm
stomach elbow
hand

fingers

knee
leg

foot

Human body

Head

Head is the uppermost part of our body. It is the most
important part of our body because it consists of vital organs like
eyes, ears, nose and mouth. The uppermost part of the head is
covered with hair. The facial part includes eyes, nose, and mouth.
If we clean those organs regularly, we will look clean and smart.

Trunk

The part of our body below the head is called trunk. It
is the biggest part of our body. It includes chest, abdomen,
back and backbone. The lowermost part of the trunk consists
of anus and genital organs. We pass out stool through anus
and urine through genital organs. Genital organ (penis in male
and vagina in female) is found in front part and anus is found
at the back part of the trunk. We should clean our trunk, anus
and genital organs regularly to be healthy.

Blooming Science, Health and Physical Education Book 4 169

Limbs

Two hands connected to upper part of the trunk and two
legs connected to lower part of the trunk are called limbs. We
move hands and legs a lot. We walk with the help of legs and
do various works by hands. Each hand consists of five fingers
and nail in each finger. Similarly, each leg consists of five toes
and nail in each toe. We should clean our limbs and trim our
nails regularly.

Personal Hygiene

The person who is physically strong and mentally fit is
called a healthy person. Good health makes us happy and
cheerful. The science of health is called hygiene. The activities
which we perform to maintain a good health is personal
hygiene. To maintain the personal hygiene, we need to keep
all of our body organs clean. We should take care of our body
organs to be smart and healthy.

Taking care and cleanliness of different parts of our body

Taking care of head

Eyes, nose, ears, mouth and hairs are continuously exposed
to the outer environment. So, they easily get dirty. We have to
maintain the cleanliness and regular care of these parts of the body.

Care of eyes

We have two eyes in our face. They help us to see. We
can see properly when they are healthy. We can maintain the
cleanliness of our eyes by doing the following things.

170 Blooming Science, Health and Physical Education Book 4

i. We should wash our eyes with clean
and cold water in the morning and in
the evening before going to the bed.

ii. We should not rub our eyes. Dust and
dirt should be removed by splashing
with clean water.

iii. We should not see in a very bright
light or a dim light.

iv. We should not sit too close while
watching TV and we should not watch TV and computer
for a long time.

Care of ears
We have a pair of ears on the either side
of our head. We hear through our ears. We
can maintain the cleanliness of the ears by
following ways.
i. We should be away from loud music

and very noisy places.
ii. We should not put anything into the

ears.
iii. We should wipe our ears with a clean

towel after taking bath.
iv. We should clean the inner parts of the ears using ear buds

carefully.

Blooming Science, Health and Physical Education Book 4 171

Care of nose

We have a single nose. It has two nostrils.
We smell and breathe through nose. It must
be clean and healthy to smell and breathe
properly.

i. We should remove the dirt with a soft
tissue or soft piece of clothes. We should
not pick our nose.

ii. We should use a mask or clean
handkerchief to cover our nose in dusty
places.

iii. We should not blow our nose hard.

iv. We should cover our nose with a handkerchief while
blowing and sneezing.

Care of mouth

We eat with our mouth. It also helps us to speak. When we
take food in our mouth, teeth grind the food into small pieces. The
salivary glands produce saliva and makes the food slippery which
is swallowed by the tongue. Tongue also helps to find the taste
and speak. Basically in the mouth, teeth becomes dirty everyday.
The dirty teeth may cause various diseases. We can maintain the
cleanliness of our mouth and teeth by following ways.

i. We should brush our teeth twice a day; in the morning
and in the evening after meals.

ii. We should not eat sugary food too much. Such foods
are harmful to the teeth. We should brush our teeth
after eating sweets and chocolates.

172 Blooming Science, Health and Physical Education Book 4

iii. We should not have a habit of
drinking alcohol, smoking and
chewing Tobacco. These are
harmful to our mouth also.

iv. We should use soft tooth brush and
fluoride containing toothpaste to
keep our teeth and gums healthy.

v. We should clean our tongue by
tongue cleaner.

Care of hair

We have thick hair on our head. It
protects our skin from cold. When we play
and do work, it becomes dirty. Lice grow
on dirty hair and make the skin of our head
irritating and dirty. Dandruff also makes our
hair unhealthy. We can keep our hair clean by
following ways.

i. We should wash our hair regularly
with clean water and shampoo.

ii. We should wipe our hair by clean and soft towel after
washing it.

iii. We should apply the oil and comb it properly.

iv. We should get our hair cut with good hair style. It
gives us good look.

Care of body and skin

Our body produces sweat while doing work and playing.
The sweat gets mixed with dirt and dust and makes our body

Blooming Science, Health and Physical Education Book 4 173

dirty. Due to this, our body smells bad and becomes unhealthy.
Many skin diseases can occur in a dirty body. We can maintain
the cleanliness of our body by following ways.

i. We should bathe regularly with clean water and soap.
ii. We should wipe our body with clean and soft towel

after taking bath.
iii. We should not leave our skin dry in cold season. We

can apply oil or moisturizer to make the skin soft and
smooth.
iv. We should clean genital organs properly while taking
bath.
v. The anus should be washed with clean water and
wiped with soft tissue paper. We should never use
hard solids or weeds for this purpose.
vi. We should wear clean clothes.
vii. We should wash our clothes with soap and clean water.
Then we should dry them in sunlight which kills the
germs.

174 Blooming Science, Health and Physical Education Book 4

Care of hands and legs

We have a pair of hands and legs. Hands are used for doing
work and eating. Legs are used for walking. It is important to
clean and take care of hands and legs. We can clean our hands
and legs by following ways.

i. We should wash our hands and legs with soap and
clean water after doing any work or playing.

ii. We should wash our hands with soap and water before
and after each meal.

iii. We should wash our hands properly with soap and
water after using the toilet.

iv. We should trim our nails with a nail trimmer and we
should clean the dirt from the nails.

When we take care of all the body organs, we can maintain
our personal hygiene. Personal hygiene plays a very important
role to be healthy. A healthy person is fit in all respect. A
healthy person is physically strong and mentally fit. Along
with personal hygiene, we need to do regular exercise and take
enough rest to be healthy. Hygienic food and enough sound
sleep also play an important role in human health. The children
should be vaccinated to prevent from different communicable
diseases as well.

Key words

Adopt – to choose as one’s own.

Framework – a frame or structure composed of parts fitted
and joined together.
Dandruff –
a scurf that forms on the scalp and comes off
Vaccinate – in small scales.

to give a person a vaccine by injecting it.

Blooming Science, Health and Physical Education Book 4 175

Main Points to Remember

 The practice of keeping the body and body parts clean is called personal hygiene.
 One can be healthy by maintaining the personal hygiene.
 We should care various organs of our body and keep them clean to be healthy.
 A healthy person is physically strong and mentally fit.
 We should do regular exercise and take enough rest and hygienic food to be healthy.
 The children should be vaccinated to prevent from various diseases.

Project work

1. Make a list of activities that you perform for your personal
cleanliness and show it to your teacher.

2. Divide the students of your class into different groups
So that there will be four students in each group. Name
them as A, B, C and D. Check the personal hygiene of
your friends with each other as follow:
A – mouth and teeth
B – skin (neck, hand and leg)
C – Hair and nail
D – Clothing and shoes.

Check the personal hygiene with each other in presence of
your teacher at least once in a week. Clap to encourage clean and
tidy friends and suggest to be clean for those who are untidy.

Exercise

1. Fill in the blanks with suitable words.

a. A ........... person is physically strong and mentally fit.

b. Dust and dirt from eyes should be removed by .............
water.

176 Blooming Science, Health and Physical Education Book 4

c. Teeth helps to ..................... our food.
d. We should wash our hair with clean water and ...............
e. We should brush our teeth ..................... a day.
f. Vaccination of children prevents from ............ diseases.

2. Write ‘True’ for correct sentences and ‘False’ for wrong ones.
a. We should watch television from a far distance.
b. We can pick the nose with fingers.
c. We must enjoy the loud sound coming from
speaker.
d. We should use soft tooth brush and fluoride
containing tooth paste.
e. Dandruff makes our hair clean and healthy.
f. We must do regular exercises and take enough
rest to be healthy.

3. Answer the following questions.
a. What is personal hygiene? Write any two advantages
of personal hygiene.
b. How should we remove dirt and dust from our eyes?
c. Write down any three points by which we can care for
our ears.
d. Write down any two advantages of regular brushing
of teeth.
e. How can we care our skin? Write down any three points.
f. Why should we trim our long nails?

Blooming Science, Health and Physical Education Book 4 177

Lesson Environmental
Sanitation
16

Learning outcomes

At the end of this lesson, the students will be able to:
 introduce environment and state various causes of environmental pollution.
 make a list and classify waste materials.
 tell others that we should stay in a clean environment to be healthy.
 motivate friends, parents, brothers and sisters to keep their environment clean.

There are different living beings and non-living things
around us. Environment is the natural world around us which
is made by living beings and non-living things. It includes
all the living things like plants and animals and all the non-
living things like soil, rocks, etc. Human beings get food,
air, water, warmth, etc from the environment. We can not be
healthy simply by keeping ourselves clean. We need fresh air,
hygienic food and clean water to survive, So, we need to keep
our environment clean to lead a healthy life. Human activities
play an important role in maintaining a clean environment.
Now-a-days, our environment is being polluted day by day
due to human activities. Some bad habits of human beings like
throwing waste materials anywhere, defecating and urinating
in open places, mixing sewage into the water resources, etc

178 Blooming Science, Health and Physical Education Book 4

cause air, water and
soil pollution. When
various components
of our environment
are polluted, we will
suffer from various
diseases and our
environment does
not become suitable
to live a healthy life.

Causes of environmental pollution

The degradation of the quality of environment by mixing
of various harmful wastes is called environmental pollution.
Various components of environment are being polluted
by different human activities. Throwing untreated sewage
into the rivers causes water pollution. Smokes emitted from
vehicles, industries and houses causes air pollution, dumping
of garbages from house and school and disposal of industrial
wastes cause soil pollution. An environment is polluted because
of the following activities.

i. by disposing the household wastes everywhere.

ii. by throwing wastes near by the source of water.

iii. by not disposing the garbage collected at the sides of road.

iv. by defecating and urinating near the source of water.

v. by burning down the plastics.

vi. by mixing sewage from cities and factories directly into
the river.

vii. by producing more smoke from vehicles and industries.

Blooming Science, Health and Physical Education Book 4 179

Sources of wastes

The wastes are produced by many different human
activities. We use many things in our house and all the things
are not used up. Similarly, many waste materials are produced
in our kitchen. The wastes are produced not only in the houses,
these are produced in industries, schools, public places, etc.
The wastes come in the environment from different places.
Some of them are given below.

From our houses

We live in our house. We use many things in our house.
Among many things, some are produced as garbage. Peels of
vegetables and fruits, leftover food, plastic bags, waste water,
husk of grains, etc are produced as garbage in the kitchen.
Similarly, shopping bags and plastics, broomed wastes (dust),
used books and copies of children, broken utensils, etc also
come from the house. In this way a lot of garbage and sewage
is produced in houses. If they are not managed properly, they
cause environmental pollution.

180 Blooming Science, Health and Physical Education Book 4

From schools

We read in our school.
We produce different types
of wastes in our school.
The torn out pages of
books and copies, leftover
khaja, spilled ink, chalk
dust, broomed dust, etc
are produced as waste in
school. Such garbage makes our school’s environment polluted
and unhealthy.

From industries, laboratories, hospitals and
vehicles

Vehicles and industries
are run by fuels. They give out
smoke, liquid and harmful
gases. Chemicals, broken glasses,
harmful gases and sewage are
produced from laboratories and
hospitals. These waste materials
make our environment polluted.

From farms and other agricultural work

Peoples keep different types of animals and birds in their
farms for wool, egg, meat, etc. The excreta of such animals make
our environment dirty. Chemical fertilizers and insecticides
used in agriculture and remaining materials after separating
grains from plants also make the environment polluted.

Blooming Science, Health and Physical Education Book 4 181

From public places

There are different public
places like cinema hall, bus parks,
airports, parks, etc. Garbage
comes in large scale from these
places also.

Types of waste

We know that different types of wastes come out from
different sources. All the wastes are not of same nature. Some
wastes decay in a short period while others need a very long
period of time to decay. The wastes can be divided into two
types. They are biodegradable wastes and non-biodegradable
waste.

Biodegradable wastes

The wastes which decay easily in short time and get mixed
in the soil are called biodegradable wastes. Weeds, leaves,
leftover food, unused parts of fruits and vegetables, etc are the
biodegradable wastes. Such types of wastes can be collected
separately so that they can be changed into manure.

182 Blooming Science, Health and Physical Education Book 4

Non-biodegradable wastes

The wastes that do not decay for a long time are called
non-biodegradable wastes. The wastes such as plastics,
glass, metal, bone of dead animals, etc are the examples of
non-biodegradable wastes. These wastes need thousands of
years to decay. These wastes must be managed in a proper and
scientific way.

Waste management

In our daily life, a large amount of waste is produced
everyday. There are different types of wastes. Some wastes
are harmful to us and some are even useful also. The safe
method of waste disposal is called waste management. For
the waste management, primarily the biodegradable and non-
biodegradable wastes have to be collected separately. After
collection, biodegradable wastes should be kept in a compost
pit so that the waste materials are changed into compost
manure. This can be used in agriculture. Such wastes can also
be used to produce biogas.

The non-biodegradable wastes contain various types of
materials that do not decay. They pollute the environment when
burnt or left open in some places. Some of the non-biodegradable
wastes can be reused and recycled which minimizes the wastes.
More harmful chemicals should be changed into less harmful
chemicals by various chemical processes. Then only such materials
should be disposed in water or air.

For the waste management in city areas, municipalities
should develop the scientific system to collect and manage the
waste. In rural areas, the people should be aware of making
compost manure by biodegradable wastes and harmful effects
of disposing other wastes in unplanned way.

Blooming Science, Health and Physical Education Book 4 183

3 ‘R’ method of waste management

Now a days, 3’R’ concept of waste
management is used effectively. The
meaning of 3’R’ is Reduce, Reuse and
Recycle.

Reduce means as far as possible we
should reduce the amount of wastes. It
helps to keep our environment clean.

Reuse means some of the waste materials can be used for
other purposes. For example, we can use glass bottles, plastic
bottles, etc again and some wastes can be used to make craft
materials.

Recycle means some wastes like plastic, glass, paper,
metals can be used to make new articles from the materials.
So, we can recycle these to produce the less amount of waste in
our environment.

Key words

Garbage – discarded animals and vegetable matter.

Sewage – waste materials that passes the sewers water.

Husk – the dry external covering of certain fruits or seeds.

Excreta – excretory products of animals.

184 Blooming Science, Health and Physical Education Book 4

Main Points to Remember

 Environment is the natural world around us which is made by living beings and
non-living things.

 Environment gets polluted by various human activities. A polluted environment
is not good to lead a healthy.

 The disposal of various types of wastes in an unplanned way causes the
environmental pollution.

 The wastes are produced from our houses, schools, industries, laboratories,
hospitals and public places

 There are two types of wastes. They are biodegradable wastes and non-
biodegradable wastes

 Biodegradable wastes should be collected separately and used for making manure
and producing biogas.

 The non- biodegradable wastes should be collected separately and managed in a
scientific way.

 The best way of managing non-biodegradable wastes is 3’R’ method of waste
management.

 3’R’ refers Reduce, Reuse and Recycle.

Project work

1. Collect the waste materials produced in your house for a
week. Keep these in two different dust bins, degradable
in one dust bin and non-degradable in another dust bin.
Make a list of these materials. Dispose the degradable
wastes into compost pit and separate recyclable and
reusable from the non-degradable wastes.

2. Organise the cleaning compaign of your school’s
surrounding by class four students in the leadership
of your class monitor and with the help of your health
teacher.

Blooming Science, Health and Physical Education Book 4 185

Exercise

1. Fill in the blanks with suitable words.
a. Human activities play an important role to maintain a
clean ......................
b. Defecating and urinating near water source causes
......................
c. Burning plastics causes ......................
d. Left over food, weeds and fruit peels are ......................
wastes.
e. 3 ‘R’ management of wastes includes ......................

2. Write ‘True’ for correct sentences and ‘False’ for wrong
ones.
a. Air, water and soil are the non- living
components of an environment.
b. Human activities are the main causes of
environmental pollution.
c. We can dispose all type of wastes in same place.
d. Plastic is a degradable waste.
e. Glass bottles and shopping bags are reusable
wastes.
f. Animals' excreta do not cause any type of
pollution.

186 Blooming Science, Health and Physical Education Book 4

3. Answer the following questions.
a. What is environment? What is it made up of?
b. What is environmental pollution?
c. Make of list of any three degradable and any three
non-degradable wastes produced from our house.
d. Write down any three activities that cause
environmental pollution.
e. Writedownanytwodifferencesbetweenbiodegradable
and non-biodegradable wastes.
f. What are reusable wastes? Give any three examples.
g. What are recyclable wastes? Give any three examples.
h. Write down any three ways by which we can utilize
our household wastes for our benefit.

Blooming Science, Health and Physical Education Book 4 187

Lesson

17 Food and Nutrition

Learning outcomes

At the end of this lesson, the students will be able to:
 tell the name of food that they eat everyday.
 group the food items according to their nutrients.
 develop the concept of importance of nutritious food.
 tell the disadvantages of junk foods found in market.
 preserve iodine in iodized salt.

All the living beings need food to be alive and to grow.
Plants can prepare their food by themselves whereas animals
depend upon other animals and plants for their food. Human
beings need food as one of the basic needs of their life. We
need food to get energy to do work and play. Food is required
for the growth and to protect body from various diseases.
Everyday we eat varities of foods like rice, pulses, vegetables,
milk, meat, egg, bread, etc. These food materials contain many
useful substances for our body.
Our main food is made by rice, maize, wheat, potato, oat,
etc. We eat some other things like egg, meat, milk, pulses, green
vegetables, fruits, etc with the main food. The types of food
depends on the place where people live in. People in the terai,

188 Blooming Science, Health and Physical Education Book 4

hilly and himalayan region eat different types of food. People
in the himalayan region grow potato, oat and buckwheat. So,
they eat different dishes. In the hilly region, people mostly
grow rice, wheat, maize, millet and potato. So, their food are
made by such food items. In terai region, people mostly eat rice
or chapati (roti) as they produce rice and wheat. We should
eat other food items with the main food to get all the required
nutrients. The food items must be safe, clean and fresh.

We have to eat different types of food in an appropriate
amount. The food provides us nutrients. A substance
that provides essential nourishment for the growth and
development is called nutrient. The process of obtaining the
food for health and growth is called nutrition. Eating only
one kind of food does not provide enough nutrients needed
for our body. So, we include varieties of food to set essential
nutrients.

The nutrients required for our body are carbohydrates,
proteins, fats and oils, minerals, vitamins and water.

rice millet oat potato

Carbohydrates

Carbohydrates are energy giving nutrients. Most of the
foods that we eat everyday contain carbohydrates. They are
our main food. We use energy given by these foods for various
purposes. The foods rich in carbohydrates are rice, maize,
wheat, millet, buckwheat, potato, sweet potato, sugarcane, etc.

Blooming Science, Health and Physical Education Book 4 189

Some food items rich in carbohydrates

Proteins

Proteins are body building nutrients. Proteins help the
body to grow and to repair the body cells. Growing children
and pregnant women need more protein containing foods. The
foods rich in protein are milk, meat, fish, eggs, beans, peanuts,
pulses, cheese, etc.

Some food items rich in proteins

Fats and oils

Fats and oils are simply called as ‘fat’. Fats are nutrients
that give us energy. They give more energy than carbohydrates.
They also help to keep our body warm. Excess fat stored in our
body is harmful. We get fat from plants and animals. The foods
rich in fat are oils, butter, ghee, nuts, cheese, meat egg, etc.

190 Blooming Science, Health and Physical Education Book 4

Some food items rich in fats

Minerals

Minerals are the nutrients that helps to make our teeth and
bones strong. Minerals also helps in the growth of our body
and formation of blood cells. Calcium, phosphorus, iodine,
iron, magnesium, etc are the minerals that are needed for our
body. We get minerals from fruits, green leafy vegetables, milk,
beans, fish, liver, etc.

Some food items rich in minerals

Vitamins

Vitamins are the nutrients that protect our body from
diseases and keeps us healthy. There are different types of
vitamins. They are vitamins A, B, C, D, E and K. They are found
in green vegetables, fruits, milk, meat, fish, etc.
The vitamins, their function and important sources are
given below in the table.

Blooming Science, Health and Physical Education Book 4 191

S. No Vitamins Main function Sources

Leafy vegetables,

1. A Good eye sight carrot, yellow

pumpkin, mango

Functioning of body Fruits egg, meat,

2. B parts, skin and broccoli, leafy veg,

muscle liver, nut

3. C To keep teeth and Fruits and
gums healthy vegetables

4. D Formation of bone Mushroom, fish,
and growth of body. egg, liver

5. E Reproduction Nuts and seeds

6. K Clotting of blood Green vegetables,
citrus fruits

Water

Water is very essential nutrient for our body. Our body
needs proper amount of water to remain healthy. It is required
to conduct various life processes like digestion and excretion.
We should drink enough water everyday. Some amount of

192 Blooming Science, Health and Physical Education Book 4

water is supplied to our body from different types of food that
we eat daily.

Balanced diet

A single food does not contain all the nutrients required
for our body. We should include different food items in our
diet. The food which contains proper amount of all the essential
nutrients is called a balanced diet. A balanced diet contains
proper amount of carbohydrate, protein, fat and oil, minerals,
vitamin and water.

Different food items of a
balanced diet

Food pyramid

Safe and unsafe food

We should eat clean, fresh and safe food. We should not
eat stale, rotten and fly-blown food. Such types of food may
cause many different diseases. We should not eat canned and
packet food, spicy and oily foods, fizzy drinks and too much
sugary foods as these foods are not good for our health.

Blooming Science, Health and Physical Education Book 4 193

Now-a-days, many types of ready made food (Junk
foods) are available in the market. They are tasty and packed
in attractive packets. But most of them do not contain enough
nutrients. These foods contain some chemicals which are not
good for our health. Some foods like sweets are made by using
colours to make them attractive. The colours mixed in food
items may be non- edible. Similarly, some preservatives are
used in some foods to preserve them for a long time. The ready
made foods contain more spices, fats, salts and non-edible
colour and preservatives which are not good for our health.
We should avoid such food. Instead of them, it is better to eat
home made foods like beaten rice, roti, fried rice, paratha, etc.

Preserving iodine in iodized salt

Iodine is essential mineral for our body.
Iodine is needed for the physical and mental
growth of our body. Iodine is required in
very small quantity. We get iodine from
iodized salt. Iodine is a chemical substance
added in common salt. It is easily lost from
salt. We should not keep the salt in open
places. Iodine evaporates and moves away
if it is kept open. Iodized salt is packed in
a packet. It must be kept in a vessel with lid after opening the
packet. The lid of the vessel must be kept air tight.

Key words

Stale – a food which is no longer fresh and unpleasant to
eat.
Rotten
Canned – foul, bad smelling.
Preservative – kept in a can.
– a chemical substance used to preserve foods.

194 Blooming Science, Health and Physical Education Book 4

Main Points to Remember

 Food is one of the basic needs of our life.

 Food items of different regions are different.
 The useful substances for our body that are present in the food are called nutrients.
 Carbohydrates are energy giving foods. We get energy for various purposes from

these foods.
 Proteins are body building foods. It helps for the growth and development of our body.
 Fats and oils also provide energy and these also make our body warm.
 Vitamins and minerals are protective foods. They help for the development of

body and protect us from diseases.
 We must drink enough water as it helps in the digestion and excretion of food.
 The food which contains proper amount of all essential nutrients is called

balanced diet.
 We should eat varieties of food to get balanced diet.
 We should not eat junk foods as these are not good for our health.
 Iodine is an important mineral found in iodized salt. To preserve iodine in salt,

it must be stored in a closed vessel.

Project work

1. Collect some dried food items of each category. Keep
these in a small plastic packet. Now fix these packets in
a chart paper. Write the name of food item and nutrient
present in each. Show collection to your teacher and fix it
some where in your classroom. (You can do this activity
in your group also.

2. Make a list of food items that you eat in a seek time and
write these in suitable column of the table prepared-in
your project work copy.

Carbohydrates Proteins Fats and Vitamins and
oils minerals

Blooming Science, Health and Physical Education Book 4 195

Exercise

1. Fill in the blanks with suitable words.

a. ................... is the basic requirement of living beings.

b. The food provides ......................... to us.

c. ............................ is required for growth and to repair
the body cells.

d. ............................. protect us from diseases.

e. The chemicals used as .................. may not be edible.

f. Iodine present in salt ...................... when kept open.

2. Write ‘True’ for correct sentences and ‘False’ for wrong
ones.
a. We need food for getting energy and for
growth of our body.
b. A single food does not provide all essential
nutrients to our body.
c. Carbohydrates are body building foods.
d. Minerals protect our body from diseases and
makes us healthy.
e. Iodine is needed for the physical and mental
development.
f. Fat and oil give less energy than carbohydrate.

196 Blooming Science, Health and Physical Education Book 4

3. Match the following: Yellow fruits
Carbohydrates Iodized salt
Proteins Junk food
Fat Rice
Vitamins Pulses
Minerals Ghee
Noodles

4. Answer the following questions:
a. Why do we need food ?
b. What are nutrients ? Give examples.
c. What is the main function of minerals in our body?
d. Define balanced diet?
e. What are carbohydrates? Name any four sources of
carbohydrates.
f. What are proteins? Name any four sources of proteins.
h. Why are junk foods not good for our health?
i. How can we preserve iodine in salt?

Blooming Science, Health and Physical Education Book 4 197

Lesson Diseases and Health
Services
18

Learning outcomes

At the end of this lesson, the students will be able to:
 define communicable and non-communicable diseases with examples.
 tell the causes, symptoms and preventive measures of some communicable and

non- communicable diseases.
 help the sick (diseased) people.

 take the health services when he/she become sick.

 help others to get health service facilities whenever required.

When we are healthy, we feel good and comfortable.
Health is the state of physical, mental and social well being.
But sometimes we do not feel well and are not active to do our
daily activities. At that condition, we get disease and feel sick.
Any disorder in the normal functioning of the body is called a
disease. When all or a part of body does not work properly, a
person may suffer from disease or sickness. It makes a person
unwell and weak. The diseases are caused by germs and
bacteria, lack of balanced diet, injury or addiction to some bad
habits like drinking alcohol and using drugs.

There are many types of diseases. Mainly they are kept in
two groups. They are:

1. Communicable diseases.

2. Non- communicable diseases.

198 Blooming Science, Health and Physical Education Book 4

Communicable diseases

The diseases which are transmitted from one person
to another person are called communicable diseases. These
diseases are mainly caused due to contaminated air, polluted
water and eating stale food. The diseases like dysentery,
tuberculosis, typhoid, measles, mumps, leprosy, polio, cholera,
etc are some examples of communicable diseases.

Communicable diseases are caused by microbes. The
disease causing microbes are called germs. When these
germs attack our body, we are caught with diseases. These
germs spread from sick person to others through air, water,
contaminated food, direct contact or animal bite. The disease
causing germs are bacteria, fungi, viruses and protozoa.

Non-communicable diseases

The diseases which are not transmitted from one person
to another person are called non-communicable diseases.
Diabetes, cancer, heart diseases, goiter, anaemia, etc are some
examples of non- communicable diseases. Non- communicable
diseases are not caused by germs and bacteria. These diseases
are caused due to lack of nutrition or due to malfunctioning of
different body organs. The main causes of non-communicable
diseases are;

1. Addiction of some bad habits like drinking alcohol,
smoking and taking drugs.

2. Taking excess of fatty and spicy food items.

3. Lack of proper physical exercises and rest.

4. Hereditary causes.

5. Mental tension or hypertension due to various causes.

Blooming Science, Health and Physical Education Book 4 199

Some communicable diseases

Dysentery

Dysentery is caused by amoeba
(Protozoa) or bacteria. It is transmitted
through food and contaminated water.

Symptoms
i. Frequent passing out of loose stool.
ii. Abdominal pain and appearance of mucus and blood in

the stool.
iii. The patient feels weak and thirsty.
iv. Loss of appetite.
v. The eyes seem sunken and cheeks look hollow.
vi. Dehydration, fever and pain in the body.

Prevention
i. Oral rehydration solution i.e. Jeevan jal or ‘Noon chini

pani’ should be given to the patient.
ii. We should drink boiled and filtered water.
iii. Stale and fly-blown food should not be eaten.
iv. Hands should be washed properly before having meal

and after using toilet.
v. Vegetables and fruits should be washed properly before eating.
vi. Open fields should not be used to defecate.

200 Blooming Science, Health and Physical Education Book 4