Green Science 4 Final

Solar System unit

15

Weighting Distribution (Approximate)
Teaching periods : 11 Marks (in %): 9

Before You Begin

The sun is the brightest object in the sky. It is a medium-sized
star closest to the earth. It is an extremely hot ball of burning gas.
The sun is the most important heavenly body for all plants and
animals. The sun is the ultimate source of energy. The sun occupies
the central portion of the solar system. The family of the sun which
consists of eight planets, satellites, comets, asteroids, meteors, etc.
is called the solar system.

Learning objectives

After completing the study of this unit, students will be able to:
(i) define the solar system and name the planets of the solar

system in the order of increasing distance from the sun.
(ii) introduce planets, stars, satellites and comets.

Glossary: A dictionary of scientific/technical terms

solar : related to the sun or of the sun
planet : the heavenly body that revolves around the sun
satellite : the heavenly body that revolves around the planet
comet : a mass of ice and dust which looks like a bright star with a tail
elliptical : oval shaped
orbit : a curved path followed by a planet
twinkle : to shine with a light that keeps changing from bright to faint to bright

again

Science, Health and Physical Education Book-4 GREEN BOOK 101

Solar System

The solar system is the family of the sun which consists of eight planets and
their satellites, comets, asteroids, meteors, meteorites, etc. The sun occupies
the central position of the solar system. All the planets and other members of
the solar system revolve around the sun in fixed paths called orbits.

Project work Do You Know

Take a chart paper and draw a neat The sun is the brightest
and labelled figure of the solar system. heavenly body that we see
from the earth.
Put suitable colour on the picture and
demonstrate it in your classroom Animals and plants cannot
survive on the earth due to
the absence of the sun.

Planets

Planets are the heavenly bodies that revolve around the sun in elliptical paths
called orbits. Planets do not have their own source of light for shining.

There are eight planets in the solar system. The eight planets of the solar system
in the order of increasing distance from the sun are given below:

(i) Mercury (ii) Venus

(iii) Earth (iv) Mars

(v) Jupiter (vi) Saturn

(vii) Uranus (viii) Neptune

A brief description of all the planets of the solar system is given below:

1. Mercury Fig.

Mercury is the nearest planet to the sun. Mercury
It is the smallest planet of the solar system.
Life cannot exist on Mercury as it has no
atmosphere. The part of Mercury that faces
the sun is extremely hot and the other part is 15.1
extremely cold. Mercury has no satellites.

102 GREEN BOOK Science, Health and Physical Education Book-4

Activity 1 Do You Know

Mercury can be seen just before the Mercury is the smallest
sunrise in September and October. It planet of the solar system.
can also be seen just after the sun set in
March and April. Venus is the hottest and
brightest planet of the
Observe Mercury in the sky and write solar system.
its three features after your observation.

2. Venus

Venus is the nearest planet to the earth. It is Fig. Fig. Fig. Venus
the brightest and hottest planet of the solar
system. Life cannot exist on Venus. This 15.2
planet also has no statellites.

Activity 2 Do You Know

Venus can be seen just before the Mars is called the red
sunrise and just after the sunset. planet.

Observe Venus and write its three Jupiter is the largest planet
salient features. of the solar system.

3. Earth The earth

The earth is our home planet. It is the third
nearest planet from the sun. The earth has
plenty of water, suitable temperature and life
supporting gases. Therefore, life can exist on
the earth. The earth takes 24 hours to complete
one rotation in its own axis. Similarly, the
earth takes 365.25 days to complete one 15.3
revolution around the earth. The earth has
only one satellite, i.e. the moon.

4. Mars

Mars is commonly known as the red planet. It
is the fourth distant planet from the sun. It is
nearly half size of the earth. Mars can be seen
with our naked eyes and it looks like a bright

15.4
Mars

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orange red star. Mars has two satellites. Fig. Fig. Jupiter
Saturn
5. Jupiter Fig. Fig. Uranus
Jupiter is the largest planet of the solar system. Neptune
It looks like a bright star when we see with
our naked eyes. Jupiter is the third brightest
object in the night sky after the moon and
Venus. This planet has 63 known satellites.

15.5

6. Saturn
Saturn is the second largest planet of the solar
system. It is the third farthest planet from the
sun. Saturn is surrounded by rings of dust
and rocks. This planet has 60 known satellites.

15.6

7. Uranus
Uranus is the second farthest planet from
the sun. It is a very cold planet. It has rings
around it like Saturn. This planet has 27
known satellites.

15.7

8. Neptune
Neptune is the coldest planet of the solar
system. It cannot be seen with our naked eyes.
This is the farthest planet of the solar system.
Neptune has 13 known satellites.

15.8

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Stars

Stars are extremely large burning balls of Fig. Fig. Fig. Stars
gases. We can observe millions of stars when
we see at a dark and clear night sky. Stars
twinkle at night. The extremely large and hot
ball of gases that twinkle at night are called
stars. Stars have their own source of light for 15.9
shining. So they are called luminous bodies.

Stars appear very small from the earth as they are very far from us. The sun is
a medium sized yellow star.

Activity 3
Look at a dark and clear night sky.
Observe numerous stars, planets, moon, etc.

Satellites Moon

Satellites are the heavenly bodies that revolve
around the planets. Examples: moon, titan,
phobos, etc. The moon is the natural satellite
of the earth. Titan is the natural satellite of
Saturn and phobos is the natural satellite of
the mars. All the planets of the solar system 15.10
have satellites except Mercury and Venus.

Moon

The moon is the brightest object that can be seen in the clear night sky. It is the
natural satellite of the earth. Life cannot exist on the moon as it does not have
water and life supporting gases. The moon is about one-fourth of the size of
the earth. It revolves round the earth in its own orbit.

Comets

The heavenly bodies having a long tail that

revolve around the sun are called comets.

They are made of ice, dust and gases. The tail

of comet is seen when it comes near the sun. 15.11
Examples: Benet, Enke, Halley's comet, etc.
Comet

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Key concepts

1. The family of the sun which consists of eight planets, satellites, comets,
etc. is called the solar system.

2. All the planets and other members of the solar system revolve around
the sun in fixed paths called orbits.

3. Planets are the heavenly bodies that revolve around the sun. There are
eight planets in the solar system.

4. The earth has plenty of water, suitable temperature and life supporting
gases. Therefore, life can exist on the earth.

5. The extremely large and hot ball of gases that twinkle at night are called
stars.

6. Satellites are the heavenly bodies that revolve around the planets.

7. The moon is the brightest object that can be seen in the clear night sky.

Exercise

1. Tick (√) the best answer from the given alternatives.
a. The solar system consists of ........................ planets.

nine eight seven

b. Which of the following is the largest planet?

Venus Jupiter Mars

c. Which of the following is the brightest planet?

Mars Venus Neptune

d. Which of the following objects twinkle at night?

planets stars comets

2. Put a (√) for the correct statement and a cross (×) for the incorrect one.
a. The sun occupies the central portion in the solar system.
b. Jupiter is the smallest planet.

106 GREEN BOOK Science, Health and Physical Education Book-4

c. Neptune is the coldest planet.
d. Satellites revolve around the planets.

3. Fill in the blanks using appropriate words.
a. ............................ is the nearest planet to the earth.
b. ............................ is also known as the red planet.
c. ............................ is the farthest planet to the sun.
d. ............................ is the nearest planet to the sun.

4. Match the following. Largest planet
a. Mercury Smallest planet
b. Venus Hottest planet
c. Earth Our home planet
d. Jupiter Coldest planet
e. Neptune

5. Answer the following questions.

a. What is the solar system?

b. What are planets? How many planets are there in the solar system?

c. Name the following:

(i) nearest planet to the sun (ii) smallest planet

(iii) nearest planet to the earth (iv) largest planet

(v) coldest planet (vi) farthest planet

(vii) natural satellites of the earth

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d. Write any two features each of the following planets.

(i) Mercury (ii) Earth

(iii) Juptier (iv) Neptune

e. What are stars? Why do stars appear small when viewed from the
earth?

f. Write any two features of the stars.

g. What are satellites? Give any two examples.

h. Write any two features of the moon.

i. What are comets? Give any two examples.

6. Identify the given heavenly bodies.

(a) (b) (c) (d)

7. Differentiate between:
a. Venus and Earth
b. Mercury and Neptune
c. Planets and Stars

8. Give suitable reasons.
a. The earth is called a planet.
b. Moon is called a satellite.
c. Life exists on the earth but not on the moon.

108 GREEN BOOK Science, Health and Physical Education Book-4

Means of Information unit

and Communication 16

Weighting Distribution (Approximate)

Teaching periods : 10 Marks (in %): 8

Before You Begin

Information is the accumulated knowledge or details about
somebody or something. We read books and newspapers, watch
television and listen to the radio to get information on different
things. Similarly, we browse the Internet to collect information of
various fields. Books, newspapers, television , radio, Internet, etc.
are the sources of information. Communication is the process of
expressing ideas and feelings or giving people information. Means
of communication play a vital role to disseminate information to
make people aware and well informed. In this unit, we will study
various means of information and communication with their
importance.

Learning Objectives

After completing the study of this unit, students will be able to:
(i) introduce sources of information with examples.
(ii) introduce means of information and communication with

examples.
(iii) define one-way communication and two-way communication.
(iv) explain the importance of information and communication.

Glossary: A dictionary of scientific/technical terms

information : the accumulated knowledge or details about something/somebody
communication : the activity or process of expressing ideas and feelings or giving people

preserve information
forecast : to keep something safe
: a statement about what will happen in the future based on information
advertisement
wonder that is available now
pivotal : a notice, picture or film telling people about a product, service or job
disseminate : to think about something
: of great importance because other things depend on it
: to spread information, knowledge, etc. so that it reaches many people

Science, Health and Physical Education Book-4 GREEN BOOK 109

Sources of Information

Information can be defined as the collected knowledge or data on any subject.
The materials that provide knowledge on somebody/something are called
sources of information. Books, newspapers, hoarding boards, posters, radios,
television and Internet are some main sources of information.

Fig. Fig.16.1

Reading newspaper Watching TV Using Internet

We read books to get information on various things. Some books are on

particular subject such as science book, mathematics book, etc. while others on

various subjects such as GK book, encyclopedia, etc. We read newspapers to get

information related to different subjects or fields. In newspapers, information

on national and international current affairs is collected and published. We

can go to a library to read books and newspapers to get information on

various things. Therefore, books, newspapers and libraries are the sources of

information.

We listen to the radio and watch television to get information on various
subjects or fields such as national and international current affairs, weather
forecasting, sports, advertisements, etc. Therefore, radio and television are
also the sources of information.

16.2

Poster Hoarding board

We see posters or hoarding boards placed on the poles, walls, rooftops or on

the side of roads. These materials contain advertisement of some products,

companies or institutions to market their goods or services. We get information

about goods or services through these advertisements. Therefore, posters and

hoarding boards are also the sources of information.

110 GREEN BOOK Science, Health and Physical Education Book-4

Activity 1

Listen to the radio or watch television at 7:00 pm in the evening.

Write the news that you have listened or watched and submit to your
teacher.

Read a newspaper and copy a piece of news in your note book and submit
it to your teacher.

Means of Information and Communication

We write and send letters to communicate with our relatives or friends when
they are far from home. The letter contains information what we write and our
friends or relatives get information through the letter. Therefore, letters are the
means of information and communication. Do you know how are letters sent
from one place to another?

We can send particular information to many people at the same time through
newspapers, radio, television, etc. Information published on newspapers
reaches different places and people get information reading those newspapers.
Similarly, we watch television or listen to the radio to get information about
different things. Now-a-days, we use telephone, mobilephone, facebook,
twitter, etc. to communicate with one another.

Fig.

16.3 Mobile Facebook Twitter
Telephone

Activity 2

Write a letter to you friend describing 'Earthquake of Nepal 2072'. Enclose the
letter in an envelope. Write the address on it and submit it to your teacher.

Activity 3

Prepare a list of any four sources and means of information and communication
and draw a neat figure of each.

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Activity 4

Prepare a list of any five programmes that you have listened on the radio.

Prepare a list of any five programmes that you have watched on television.

One-way Communication and Two-way Communication

The system of communication in which communication takes place in one-
sided manner is called one-way communication. Newspaper, radio, television,
etc. are means of one-way communication. We use them to send or broadcast
information but people cannot send their feelings or reactions at once through
the same medium.

Fig. Fig.16.4

Newspaper Radio Television

The system of communication in which we can send information and get

reaction at once is called two-way communication. Telephone, mobile phone,

messenger, etc. are the means of two-way communication.

16.5 Mobile Messenger
Telephone

Importance of information and communication

Collection of information does not have any significance if it is not
communicated. So, collecting information as well as its communication to
the right people are equally important. Information cannot be disseminated
in the absence of means of communication. What would happen if there
were no means of communication? Have you even wondered? If information
is not disseminated, it does not have any importance. Therefore, means of
communication play a significant role to disseminate information.

112 GREEN BOOK Science, Health and Physical Education Book-4

Information and its communication to the target group plays an important
role in the day to day activities of people. The information helps to make plans
according to the situation. For example, people get information about various
programmes, weather, diseases, accidents, etc. through television, radio,
newspapers, etc. Government generates awareness about different things
through the means of communication. Information dissemination plays a
great role in this modern world by expanding markets inside and outside the
country. Therefore, information and communication are very important in
modern era of science and technology.
Key concepts
1. Information is the accumulated knowledge or details about somebody or

something.
2. Communication is the process of expressing ideas and feelings or giving

people information.
3. We can send a particular information to many people at the same time

through newspapers, radio, television, etc.
4. The system of communication in which we can send information and get

reaction at once is called two-way communication.
5. Information and communication are very important in this modern era

of science and technology.

Exercise

1. Put a (√) for the correct statement and a cross (×) for the incorrect one.
a. Information is the accumulated knowledge or details about somebody/
something.

b. We cannot get information from newspapers.

c. Radio and television are the means of one-way communication.

d. In two-way communication, immediate reaction cannot be obtained.


Science, Health and Physical Education Book-4 GREEN BOOK 113

2. Fill in the blanks using appropriate words.
a. The accumulated knowledge or details about something is called
..............................
b. .............................. is the process of expressing ideas or giving
information.
c. The system in which communication takes place in one-sided manner
is called ..............................
d. Telephone and mobile are the means of ..............................

3. Answer the following questions.
a. Define information and communication.
b. What are sources of information? Give any three examples.
c. Define means of communication with any three examples.
d. What is meant by one-way communication? Write any two means of
one-way communication.
e. What is meant by two-way communication? Write any two means of
two-way communication.
f. Describe the importance of information and communication.

4. Identify the means of information communication and write the use of
each.
a. b. c.

5. List the means of information and communication that you have used so
far.

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Some Local unit
Technologies
17

Weighting Distribution (Approximate)
Teaching periods : 10 Marks (in %): 8

Before You Begin

Technology is the use of science in industry, engineering, etc. to
invent useful things or to solve problems. In rural areas, people
have been using various local technologies from ancient (pre-
historic) time to make their life easy and comfortable. The
technologies that are simple in structure, cheap in operation and
easy to use are called local technologies. There are various local
technologies prevalent in rural areas of Nepal. In this unit, we will
study water mill, turbine and pumpset in brief.

Learning Objectives

After completing the study of this unit, students will be able to:
(i) introduce local technologies with examples.
(ii) explain working mechanism and utility of water mill (pani

ghatta), turbine and pumpset.

Glossary: A dictionary of scientific/technical terms

technology : the use of science in industry, engineering, etc. to invent useful things
or solve problems
ancient
grind : belonging to a period of history in the past
turbine
: to crush something into very small pieces between two hard surfaces
pumpset
: an engine that has a part with blades that are caused to spin by pressure
from water, steam or air

: a device which is used to draw the underground water

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1. Water Mill or Pani Ghatta

Water mill or Pani Ghatta is

a very common technology

in rural areas of the hilly

region of Nepal. From

ancient time, local people

have been using water mills

to grind grains like wheat,

maize, barley, millet, rice,

etc. water mill is operated

with the help of force of

water. So, this technology is Fig.

known as water mill or Pani

Ghatta. Water mill
17.1

The technology of Pani
Ghatta is based on the theory

that running water generates motion in a body at rest. The major components

of a water mill are Jaanto, wooden or iron fan, wooden canal or plastic pipe

and Daali (grain container). Have you seen a water mill in your locality?

To construct a water mill, a wooden fan or iron fan is fixed to the ground and a
Jaanto is fixed to the axle of the fan. A Daali is fixed just above the centre of the
Jaanto and the Daali is connected to the Jaanto with the help of a wooden piece
called Ghodi in such a way that when the Jaanto rotates, the Ghodi shakes the
Daali.

The fan is rotated with the help of water current sent through the canal. The fan
rotates the Jaanto connected to the upper end of the fan. The grains are poured
into the Jaanto through the hole in the centre. The rotating Jaanto grinds the
grains and we get flour. In this way, Pani Ghatta produces flour by grinding
the grains.

Activity 1

Visit a nearby water mill or Pani Ghatta in your locality. Observe the
structure and working mechanism of the Pani Ghatta.

Draw a neat and labelled figure after your observation.

116 GREEN BOOK Science, Health and Physical Education Book-4

2. Turbine

A turbine is an engine that has a
part with blades that are caused
to spin by pressure from water,
air, etc. Turbine is the improved
form of a water mill.

A turbine is used to generate

hydroelectricity. A turbine has
Fig.
Fig.a fan which is rotated when

water strikes the fan with a high 17.2 Turbine
speed. Rotating turbine generates
electricity and the electricity is

supplied and distributed to houses and industries with the help of electric

wires.

3. Pumpset or Tubewell

A pumpset is used to draw underground water. It is a major means of drawing
underground water in the Terai region and the Kathmandu valley.

17.3

Shallow tube well Pumpset

In a pumpset, a long iron pipe is driven underground down to the level of

underground water. At the upper end of that pipe a pumpset with a valve is

fixed. When the handle fixed to the pumpset is moved up, underground water

comes up in the iron pipe and finally comes out through the pipe fixed to the
pumpset. In this way, underground water is drawn on the surface with the
help of pumpset. The water thus drawn is used for drinking, bathing, washing,
irrigating, etc.

Science, Health and Physical Education Book-4 GREEN BOOK 117

Activity 2
Observe the structure of a turbine and a pumpset in your locality.
Study their working mechanism and prepare a short report after your

study.

Key concepts
1. Technology is the use of science in industry, engineering, etc. to invent

useful things or to solve problems.
2. The technologies that are simple in structure, cheap in operation and

easy to use are called local technologies.
3. A water mill or Pani Ghatta is a very common technology in rural areas

of hilly region of Nepal.
4. A turbine is an engine that has a part with blades that are caused to spin

by pressure from water, air etc.
5. A pumpset is used to draw underground water. It is a major means of

drawing undergruond water in the Terai region and the Kathmandu
valley.

Exercise

1. Put a (√) for the correct statement and a cross (×) for the incorrect one.

a. Local technologies make our life easy and comfortable.

b. Local technologies are very expensive.

c. A water mill is used to grind grains.

d. A turbine is used to generate hydroelectricity.

2. Fill in the blanks using appropriate words.

a. The technologies that are simple in structure and easy to use are called
.......................................

b. ....................................... is used to obtain flour by grinding grains.
118 GREEN BOOK Science, Health and Physical Education Book-4

c. ....................................... is the improved form of a water mill.
d. ....................................... is used to draw the underground water.
3. Answer the following questions.
a. What are local technologies? Write with examples.
b. What is a water mill? Write down its utility.
c. Write any three components of a water mill.
d. What is a turbine? Write down its utility.
e. What is a pumpset? Write down its utility.
4. Name the local technologies shown in the given figures.
a. b. c.

5. List the local technologies that are prevalent in your locality.

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Sample Test Paper 2

Science and Environment

F.M. 60

Time: 1 hr. 50 min.

1. Tick (√) the best answer from the given alternatives. 5

a. Which of the given plants has thick and fleshy leaves?

orange cactus sugarcane

b. Which of the given plants is a fixed hydrophyte?

duckweed tapegrass waterlily

c. Molecules are closely packed in ........................

solids liquids gases

d. Snowfall generally occurs in ........................

terai hills mountains

e. Which of the following is the largest planet?

Mercury Jupiter Earth

2. Put a (√) for the correct statement and a cross (×) for the incorrect one. 5
a. Trees have hard, strong and woody stems.
b. Animals do not depend on plants for food.
c. Floods and landslides mainly occur in rainy season.
d. Heat cannot change the state of matter.
e. Radio and television are the means of two-way communication.

3. Fill in the blanks with appropriate words. 5
a. The scientist who studies weather is called ........................
b. ........................ is the part of land on the surface of the earth.
c. ........................ is also known as the red planet.
d. Telephone and mobile phones are the means of ........................
e. A ........................ is used to obtaian flour by grinding grains.

120 GREEN BOOK Science, Health and Physical Education Book-4

4. Answer the following questions. 15 × 2 = 30

a. What are xerophytes?

b. Write any two characteristics of submerged hydrophytes.

c. What is environment?

d. Why do human beings depend on environment?

e. What are natural disasters?

f. Write any two preventive measures of landslides.

g. Write any two properties of solids.

h. What are the sources of energy?

i. Write any two applications of heat in our daily life.

j. What is meteorology?

k. How are hailstones formed?

l. What is lithosphere?

m. What is the solar system?

n. What is meant by two-way communication?

o. What are local technologies?

5. Match the following. 4

a. Autotroph Lion

b. Herbivore Bear

c. Carnivore Grass

d. Omnivore Cow

6. Identify the means of information and communication and write the

use of each. 3

a. b. c.

Science, Health and Physical Education Book-4 GREEN BOOK 121

7. Give reasons. 3
a. The earth is called a planet. 5
b. Air and smoke are called gases.
c. Cactus and aloe are called xerophytes.

8. Draw a neat and labelled figure showing the water cycle.

Marks obtained: ...............................................

Student's grade: ...............................................

Teacher's remark: ............................................. Gardian's signature and

Teacher's signature: ......................................... remark

122 GREEN BOOK Science, Health and Physical Education Book-4

Health Education unit

Our Body and 18
Personal Hygiene

Weighting Distribution (Approximate)

Teaching periods : 11 Marks (in %): 17

Before You Begin

Various systems, organs and tissues form our body. It can be
divided into head, trunk and limbs. We should keep our body neat
and clean. We should maintain a high level of personal hygiene
to remain fit and fine. The person who is physically and mentally
fit in all respects is called a healthy person. Good health makes us
happy and cheerful. The science of health is called hygiene. The
activities which we do to maintain good health is called personal
hygiene. In this unit, we will study the various body parts and
various ways of maintaining personal hygiene.

Learning objectives

After completing the study of this unit, students will be able to:
(i) introduce various parts of our body.
(ii) develop confidence that personal hygiene keeps us healthy

and disease free.
(iii) practise various methods to maintain personal hygiene.

Glossary: A dictionary of scientific/technical terms

personal : belonging or relating to a particular person
hygiene : the science of health, the things that you do to keep yourself and your

vital surroundings clean to maintain good health
trunk : necessary or essential for something to exist
trim : the part of the body below the head except limbs
: to make neat by cutting it

Science, Health and Physical Education Book-4 GREEN BOOK 123

Our Body

Our body can be divided into three main parts. They are head, trunk and limbs.

1. Head

The head is the uppermost part of the body. It consists of vital organs like
brain, eyes, ears, nose, mouth, etc. The uppermost part of the head remains
covered with hair. We should wash our head and face every day.

Hair Head

Ear Forehead
Mouth Eye
Nose
Chin Neck
Shoulder Chest
Arm
Navel
Hand Abdomen
Fingers
Palm
Knee
Leg Thigh

Foot Toes

Fig.

18.1
Various parts of the human body

124 GREEN BOOK Science, Health and Physical Education Book-4

2. Trunk

The part of the body below the head except the limbs is called the trunk. it is
the biggest part of the body. It includes backbone, chest and abdomen. The
lowermost part of the trunk consists of genital organs and anus. We pass out
urine through the genital organs and stool through the anus. We should clean
our trunk, genital organs and anus regularly.

3. Limbs

Two pairs of limbs (two hands and two legs) are attached to the trunk. Two
hands are connected to the upper part of the trunk whereas two legs are
connected to the lower part of the trunk. Each hand consists of five fingers
with nails. Similarly, each leg consists of five toes with nails. We should clean
our limbs and trim nails regularly.

Personal Hygiene

Personal hygiene is the practice of keeping our body and belongings neat and
clean in order to live a healthy life. We should perform various activities to
maintain personal hygiene. These activities include regular bathing, wearing
clean clothes, brushing teeth regularly, washing hands before taking food and
after using the toilet, washing, trimming and combing hair regularly, eating
fresh and balanced diet, drinking pure water regularly, etc. Maintaining
personal hygiene helps to prevent from falling sick. The various methods of
maintaining personal hygiene are given below:

Fig.
Fig.

18.2 18.3
Brushing Bathing

1. We should take a bath regularly

We should take bath regularly to stay healthy. We should use clean water and
soap to take bath. Dirt particles get deposited on our body while working and

Science, Health and Physical Education Book-4 GREEN BOOK 125

playing. Therefore, we should take a bath regularly. After bathing, we should
wipe our body with a clean towel.

Fig.18.418.5
Fig.BathingWiping the body with a clean towel

Fig.
2. We should brush our teeth regularly

We should brush our teeth twice a day to keep

them clean. We should use good toothpaste

and a soft brush to clean our teeth. If we do

not clean our teeth regularly, food particles

get stuck between the cavities of teeth. These

food particles rot and inhance growth of

germs along with bad odour. Those germs

damage our teeth. Therefore, we should clean

our teeth regularly. 18.6

3. We should keep our hair clean Brushing

We should wash our hair regularly with clean water and shampoo or soap. We
should trim our hair regularly. Washing hair regularly helps to remove the dirt
from hair. It also prevents itching, growth of dandruffs, microbes and lice. We
should comb our hair regularly.

Fig.
Fig.

18.7 18.8
Washing hair
Combing hair

126 GREEN BOOK Science, Health and Physical Education Book-4

4. We should wear clean clothes

We should always wear clean and
comfortable clothes. We should change
under garments and shocks regularly.
We should wash and iron our clothes
regularly.

18.9
Washing clothes

5. We should take proper care of eyes, ears and nose

We should keep our eyes, ears and nose clean to remain healthy. We should
splash our eyes, with cold and clean water. We should not rub our eyes. We
should not read in too bright or too dim light and in a moving vehicle.
Fig.
Fig.

Fig.

Fig.

18.10 18.11 18.12

Cleaning eyes Cleaning ears Cleaning nose

We should clean our ears regularly with clean water and cotton buds or soft
cloth. We should clean our nose regularly. We should wipe our nose with a
soft and clean handerkechief. We should not insert sharp and pointed objects
inside the nose and ears.

6. We should trim and clean our nails regularly

We should trim our nails regularly

with a nail cutter. We should not use a

blade or knife to trim our nails. If we do

not trim our nails dust and dirt stick to

the nails which leads growth of germs. Fig.

Therefore, we should trim and clean

our finger nails regularly. 18.13

Trimming nails

Science, Health and Physical Education Book-4 GREEN BOOK 127

7. We should wash our hands properly before and after meal

We should wash our hands properly

with soap and water before taking

meal. If we do not wash hands, the

germs present in our dirty hands enter

the body along with food and make Fig. Fig.

us sick. Similarly, we should wash our

hands properly after taking meal. 18.14

Washing hands

8. We should wash our hands properly after using the toilet

After using the toilet, we should

wash our hands properly with soap

and water. We should not defecate on

open places. Harmful germs and flies

grow on the excreta and it may spread

dangerous diseases like typhoid,

cholera, dysentry, etc. 18.15

Washing hands after toilet

Key concepts
1. We should maintain a high level of personal hygiene to remain fit and fine.
2. The activities which we do to maintain good health is called personal

hygiene.
3. Personal hygiene is the practice of keeping our body and belongings neat

and clean in order to live a healthy life.
4. Maintaining personal hygiene helps to prevent us from falling sick.
5. We should wash our hands properly with soap and water before eating

food and after using the toilet.

128 GREEN BOOK Science, Health and Physical Education Book-4

Exercise

1. Put a (√) for the correct statement and a cross (×) for the incorrect one.
a. We should maintain a high level of personal hygiene.
b. Our body can be divided into head and trunk.
c. We should brush our teeth after two days.
d. We should not trim our nails.

2. Fill in the blanks using appropriate words.
a. We should use ........................... and ........................... to take a bath.
b. We should clean our eyes with ...........................
c. We should wear ........................... and ........................... clothes.
d. After using the toilet, we should wash our hands with ...........................
and ...........................

3. Answer the following questions.
a. What is meant by personal hygiene?
b. Why is personal hygiene important for us?
c. Why should we take a bath regularly?
d. How can we keep our eyes clean?
e. What happens if we do not trim our nails?
f. Why should we wash our hands with soap and water before taking
meal?
g. What should we use to trim our nails?
h. How can you take care of your eyes and ears?

4. Write any five ways to maintain personal hygiene.

5. Write down the importance of personal hygiene in two points.

Science, Health and Physical Education Book-4 GREEN BOOK 129

Healthy Environment unit
and Healthy Life
19

Weighting Distribution (Approximate)

Teaching periods : 10 Marks (in %): 15

Before You Begin

Environment is the natural world around us where plants and
animals live. Human beings depend on the environment to
fulfill basic needs. Various human activities are polluting the
environment day by day. Therefore, we should play an important
role to reduce environmental pollution. The environment which is
free from pollution is called a healthy environment. We can live a
healthy life if we live in a healthy environment.

Learning objectives

After completing the study of this unit, students will be able to:
(i) introduce environment and state the causes of environmental

pollution
(ii) explain how to inform others that we should stay in a healthy

environment to live a healthy life.
(iii) classify wastes into biodegradable and non-biodegradable

wastes.
(iv) explain some safe methods of waste disposal.

Glossary: A dictionary of scientific/technical terms

contaminate : to make a substance dirty by adding another thing
disposal : the act of getting rid of something
sewage : used water and waste substance that are produced by human bodies

recycle that are carried away from houses and factories through special pipes
: to treat things that have already been used so that they can be used
compost
biodegradable again
: a mixture of decayed plants, cow dung, etc.
wastes : a substance that can be changed to a harmless natural state by the
garbage
incineration action of bacteria and will therefore not damage the environment
landfill : materials that are no longer needed and are thrown away
: waste food, paper, etc. that we throw away
pit : the burning of waste materials at high temperature (above 1000°C)
recycle : an area of land where large amount of waste materials are buried under

the earth
: a large deep hole in the ground
: to treat things that have already been used so that they can be used again

130 GREEN BOOK Science, Health and Physical Education Book-4

Fig.Healthy Environment

The natural world around us is called the environment. A variety of animals
and plants are found in the environment. Human beings depend on the
environment to fulfill their basic needs. Human beings obtain food, shelter,
clothes, air, water, fertile land, timber, etc. from the environment.

:jR5
jftfj/0fsf] lrq

19.1
Healthy Environment

Various human activities are responsible for environmental pollution. Human
beings are damaging the environment in many ways. Improper disposal of
garbage, sewage, household wastes, animal dung, etc. cause environmental
pollution. Similarly, agricultural wastes and industrial wastes, smoke emitted
by vehicles, etc. also cause environmental pollution. Therefore, we should try
to maintain our environment healthy. The environment which is free from
pollution is called healthy environment. Proper disposal of household wastes,
industrial wastes and agricultural wastes is a key factor to maintain a healthy
environment.

Ways to maintain a healthy environment

1. Afforestation should be encouraged and deforestation should be
discouraged.

2. Garbage and sewage should be disposed properly.
3. Sewage, industrial wastes and wastes from hospitals should be treated

properly before their disposal.

Science, Health and Physical Education Book-4 GREEN BOOK 131

4. Mixing of sewage, garbage and other wastes in the sources of water should
be stopped.

5. The use of compost manure should be increased instead of chemical
fertilizers.

6. The use of solar energy, wind energy and hydroelectricity should be
increased and the use of petroleum products like coal, petrol, diesel, etc.
should be decreased.

7. The use of plastic bags should be banned. The bags of jute, paper, etc.
should be used instead of plastic bags.

Activity 1

Observe different types of waste materials in your surroundings.

Classify these waste materials into biodegradable and non-biodegradable
wastes.

Activity 2

Observe the condition of environmental sanitation in your locality and
prepare a short report on it.

Suggest any five ways to maintain environmental sanitation in your
locality.

Solid Wastes

The waste materials that exist in solid state

are called solid wastes. We produce a lot of

solid wastes from houses and industries.

Peel of fruits and vegetables, meat bones,

waste foods, plastics, waste papers, animal

dung, human excreta, pieces of leather Fig.

and clothes etc. are some examples of solid

wastes. 19.2

Classification of Solid Wastes Solid wastes

Some of the solid wastes decay due to the action of microbes but others don't.
On this basis, solid wastes are classified into following two groups:

1. Biodegradable wastes 2. Non-biodegradable wastes

132 GREEN BOOK Science, Health and Physical Education Book-4

1. Biodegradable wastes Fig. Fig. Biodegradable wastes
Non-biodegradable wastes
The solid wastes that decay easily are
called biodegradable wastes. Examples:
peel of fruits and vegetables, animal
dung, human excreta, used flowers,
parts of plants, dead bodies of plants and
animals, etc. All waste materials derived
from animals and plants get mixed
with soil. Therefore, the waste materials 19.3
derived from plants and animals are
called biodegradable wastes.

2. Non-biodegradable wastes

The solid wastes that do not decay easily

are called non-biodegradable wastes.

Examples: plastic bags, pieces of glass,
old bottles, cold drink bottles, metal cans,
light bulbs etc. These waste materials
remain in the soil for a long time and

cause environment pollution. Non- 19.4
biodegradable waste do not decay due to

the action of microbes.

Methods of Waste Disposal

Every household produces wastes or garbage everyday. In cities, a large amount
of waste is produced everyday. So it is very difficult to dispose it safely. Some
of the common methods of waste disposal are described below:

1. Recycling 2. Sanitary landfill 3. Incineration

1. Recycling

The process of treating things that have Fig.
already been used is called recycling.
We can recycle the solid wastes like Recycling
polythene bags, glass bottles, tin cans,
metals containers, used papers, etc. The
broken plastic materials like buckets,
troughs, jugs, bags, plates, etc. are sent to
plastic factories for recycling. Similarly,
glasses papers and metals can be sent to 19.5
respective factories for recycling.

Science, Health and Physical Education Book-4 GREEN BOOK 133

2. Sanitary landfill 19.6Fig. Fig.

Sanitary landfill is the process of burying Sanitary landfill
a large amount of waste materials under Incinerator
the earth. In this method, most of the
waste materials in urban areas are buried
in a low lying area. A landfill site is
constructed away from the residential
area, water resources and agricultural
land. The landfill should be covered with
soil, when full to prevent foul smell and
breeding of insects and micro-organisms.

3. Incineration 19.7

Incineration is the burning of waste
materials at very high temperature (above
1000°C). Incineration is carried out in
incinerators or furnaces. This method is
used to burn household wastes, industrial
wastes and wastes from hospitals. This
method should be carried out away from
residential areas as it causes air pollution.

Reduce, Reuse and Recycle

'Reduce, reuse and recycle' (The 3R's) is the most effective technique of waste
management. We should follow this technique to reduce environmental
pollution.

Reduce

To reduce environmental pollution,
we should reduce the amount and
number of wastes as far as possible.

Reuse Fig.

Some waste materials like old books, 19.8 The 3R's
old bottles, plastics bags, cartons, tin

cans, papers, etc. can be used again and again. Old books and papers can be

134 GREEN BOOK Science, Health and Physical Education Book-4

used by students, old plastic bags, old tin cans and bottles can be reused to
store things. This activity helps to reduce environment pollution.

Recycle

Some wastes like broken plastics materials, broken glasses, used papers, etc.
can be recycled to make new things. This process helps to reduce environmental
pollution.

Key concepts
1. Environment is the natural world around us where plants and animals

live.

2. The waste materials that exist in solid state are called solid wastes.

3. The solid wastes that decay easily are called biodegradable wastes.

4. The solid wastes that do not decay easily are called non-biodegradable
wastes.

5. The process of treating things that have already been used is called
recycling.

6. Sanitary landfill is the process of burying a large amount of waste
materials under the earth.

7. Incineration is the burning of waste materials at very high temperature
(above 1000°C).

Exercise

1. Put a (√) for the correct statement and a cross (×) for the incorrect one.
a. The wastes that exist in solid state are called solid wastes.

b. Solid wastes do not cause environment pollution.

c. Biodegradable wastes do not decay for a long time.

d. Sanitary landfill is the process of burning of waste materials.

Science, Health and Physical Education Book-4 GREEN BOOK 135

2. Fill in the blanks using appropriate words.
a. Most wastes exist in ....................... state.
b. The solid wastes can be divided into two groups. They are .......................
and .......................
c. ....................... is the process of burying of waste materials under the
earth.
d. Incineration is carried out in .......................

3. Answer the following questions.
a. What is environment?
b. What are solid wastes? Give any three examples.
c. How many types of solid wastes are there? Name them.
d. Define biodegradable wastes with any three examples.
e. Define non-biodegradable wastes with any three examples.
f. Name any three methods of waste disposal.
g. What is meant by recycling? Name any two wastes that can be recycled.
h. What is sanitary landfill?
i. What is incineration? Name the equipment in which this process is
carried out.

4. Differentiate between biodegradable and non-biodegradable wastes.
5. 'Reduce, reuse and recycle' of wastes is very important to reduce

environmental pollution. Justify this statement.

136 GREEN BOOK Science, Health and Physical Education Book-4

Our Food and unit
Nutrients
20

Weighting Distribution (Approximate)
Teaching periods : 10 Marks (in %): 15

Before You Begin

Everyday we eat different types of food items. We eat rice, bread,
meat, egg, pulse, milk, fruit, vegetables, chocolate, sweets, etc.
These food items contain a variety of nutrients. But all the food
items do not contain the same nutrients. The nutrients that our
body needs are carbohydrates, proteins, vitamins, fat, minerals and
water. The diet that contains all these nutrients is called balanced
diet. In this unit, we will study the different types of nutrients that
our body needs and the method of preparing balanced diet.

Learning objectives

After completing the study of this unit, students will be able to:
(i) introduce food and nutrients.
(ii) group the food items that we eat according to their nutrients.
(iii) explain how to inform people that they should eat nutritious/

balanced diet.
(iv) explain the disadvantages of junk food found in market.
(v) say how to preserve iodine in iodized salt.

Glossary: A dictionary of scientific/technical terms

nutrients : the materials in the food which help us to remain healthy
carbohydrates : the nutrients that give us energy
proteins : the nutrients that build our body, help the body to grow and repair

vitamins cells
minerals : the nutrients that protect our body from diseases
beri-beri : the nutrients which help to build strong bones and teeth
scurvy : a disease that affects heart and nerves
rickets : a disease caused by lack of vitamin C
: a disease of children that makes bones soft

Science, Health and Physical Education Book-4 GREEN BOOK 137

Our Food and Nutrients

We eat food to get energy and we need

energy to do work. We eat a variety of

food items every day. These food items

include rice, pulse, bread, meat, milk,

fruits, vegetables, eggs, etc. These food

items contain a variety of nutrients.

The materials in the food which help us
Fig.
Fig.to remain healthy are called nutrients.

These substances nourish our body and 20.1 Our food items
help to grow and remain healthy. Some
nutrients provide us energy, some help

to grow and others help to protect from diseases. Different food items contain

different nutrients.

The nutrients which are essential for our body are as follows:

1. Carbohydrates 2. Proteins 3. Fats

4. Vitamins 5. Minerals 6. Water

1. Carbohydrates

Carbohydrates are the nutrients that give energy to the body. These nutrients
are required by our body to get instant energy. The food items that are rich in
carbohydrates include rice, maize, wheat, barley, millet, potato, sweet potato,
banana, sugarcane, honey, etc.

20.2 rice bread potato maize banana

Foods rich in carbohydrates

2. Proteins

Proteins are the nutrients that build our body, help the body to grow and
repair the cells. In short, proteins are the body-building nutrients. They are
very essential for growing children. The food items rich in proteins include
meat, eggs, pulses, milk, fish, chicken, peanuts, curd, cheese, cashew nuts, etc.

138 GREEN BOOK Science, Health and Physical Education Book-4

Fig. Fig. Fig.meat chicken fish eggs milk
20.3

Foods rich in proteins

3. Fats

Fats are the nutrients that give us more energy than carbohydrates. They also
help to keep our body warm and our skin smooth. These nutrients can be
stored in our body for future use. The food items rich in fats are ghee, cheese,
egg yolk, oil, butter, nuts, meat, etc.

20.4 ghee butter cheese nuts oil

Foods rich in fats

4. Vitamins

The nutrients that protect our body from diseases and keep us healthy are
called vitamins. The food items rich in vitamins include green and leafy
vegetables, fruits, cereals, pulses, chicken, milk, etc.

20.5 fruits vegetables eggs milk
Foods rich in vitamins

5. Minerals

The nutrients which help to build strong bones and teeth are called minerals.
They help in proper growth of the body and formation of blood cells. The food
items rich in minerals include green and leafy vegetables, fruits, fish, meat,
liver, eggs, milk, etc.

Science, Health and Physical Education Book-4 GREEN BOOK 139

Fig.

20.6 leafy vegetables fruits milk fish meat

Foods rich in minerals

6. Water

Water is another essential nutrient required by our body. We should drink
plenty of pure water to remain healthy. Water helps the body to digest food,
get rid of waste materials and circulation and use of nutrients properly. We
should drink about two litres of water per day.

Methods of preparing a balanced diet

A single food item or a few food items do not contain all the nutrients required
for our body. So we should eat a variety of food items everyday to have a
balanced diet. Therefore, different food items have been divided into the
following four groups to make the composition of a balanced diet easier.

1. Cereal group
This group includes food items like, rice, bread, noodles, pastas, etc. These
foods are rich in carbohydrates and minerals.

2. Protein group
This group consists of food items like meat, eggs, pulses, nuts, fish, etc. These
food items are rich in proteins, fats and minerals.

3. Milk group
This group consists of milk and milk products like curd, cheese, icecream,
butter, etc. These food items are rich in proteins, fats and minerals.

4. Fruit and vegetables group
This group consists of different types of fruits and vegetables. These food items
are rich in vitamins and minerals.

A balanced diet should be made by keeping at least one food item from each
of the above groups. We should try to eat a balanced diet everyday. Such diet
helps us to keep fit, fine and healthy.

140 GREEN BOOK Science, Health and Physical Education Book-4

Activity 1
Prepare a list of food items that you eat everyday.
Find out whether your diet is balanced or not.

Activity 2
Prepare a list of food items that your friends have eaten this morning.
Name the nutrients found in each of these food items.
Now, divide these food items into four groups.

Disadvantages of ready-made food found in the market

A variety of ready-made food items such as noodles, chowmein, momo,
biscuits, cakes, etc. are found in the market. These food items are also called
junk food. Most children like to eat junk food.

Fig.

20.7 Chowmein Coke
Momo

Ready-made food items contain some chemicals which are harmful for our
body. In factories, some chemicals like MSG are added to make food tasty and
some chemicals are added to preserve food for a long time. Junk food also
contains inedible colours, fats, salts, spices, etc. These added substances affect
our health. Therefore, we should avoid junk food.

Methods of preserving iodine in iodized salt

Iodine is an important mineral required for our body. We suffer from goitre due
to lack of iodine. We consume iodized salt to supply iodine. It gets evaporated
when kept in an open container or heated. Therefore, the following methods
should be adopted to preserve iodine in iodized salt.

1. The iodized salt should be stored in an enclosed container.

2. We should mix iodized salt into foods just before serving.

Science, Health and Physical Education Book-4 GREEN BOOK 141

Fig. Do You Know

Iodine evaporates and goes away
when stored in an open container.

If we add iodized salt in our
food while cooking, iodine gets
evaporated and goes away. As a
result, our body cannot get iodine.

20.8
Iodized salt

Key concepts

1. The materials in the food which help us to remain healthy are called
nutrients.

2. Carbohydrates are the nutrients that give energy to the body.

3. Proteins are the nutrients that build our body, help the body to grow and
repair the cells.

4. Fats are the nutrients that give us more energy than carbohydrates.

5. The nutrients that protect our body from diseases and keep us healthy
are called vitamins.

6. The nutrients which help to build strong bones and teeth are called
minerals.

Exercise

1. Put a (√) for the correct statement and a cross (×) for the incorrect one.
a. Nutrients are the materials in the food which help us to remain
healthy.
b. A single food item contains all the nutrients required for the body.

c. Proteins are the nutrients that give energy to the body.
d. Ghee, cheese and butter are rich in fats.
e. Minerals help to build strong bones and teeth.

142 GREEN BOOK Science, Health and Physical Education Book-4

2. Fill in the blanks using appropriate words.
a. A ....................... contains required amount of all the nutrients.
b. Carbohydrates are the nutrients that give ....................... to the body.
c. Food items like meat, fish and eggs are rich in .......................
d. ....................... give us more energy than carbohydrates.
e. ....................... are the nutrients that protect our body from diseases.

3. Answer the following questions.
a. What are nutrients? Name the six types of nutrients essential for our
body.
b. What is a balanced diet?
c. What are carbohydrates? Name any three food items that are rich in
carbohydrates.
d. What are proteins? Name any three food items rich in proteins.
e. What are vitamins? Name any three food items that are rich in vitamins.
f. What are minerals? Prepare a list of food items rich in minerals.
g. What is the importance of water in our body?
h. What are junk foods? Give any three examples.
i. Why should we not eat junk food?
j. Write any two methods of preserving iodine in iodized salt.

4. Write down the methods of preparing a balanced diet in brief.

5. Name the four groups of food items on the basis of nutrients present in
them.

6. Name the nutrients found in each of the given food items.

potato bread meat milk fruits vegetables
ghee eggs cheese pulses fish curd

Science, Health and Physical Education Book-4 GREEN BOOK 143

Diseases unit

21

Weighting Distribution (Approximate)

Teaching periods : 2 Marks (in %): 3

Before You Begin

All the time we do not remain well/healthy. Sometimes we fall sick.
When we are healthy, we can do work and we feel comfortable.
But when we suffer from a disease, we cannot do work and we
feel uneasy. So a disease or illness is the disorder in the normal
functioning of the body or body parts. Most of the diseases
transmit from a sick person to a healthy person and some do
not. The diseases which are transmitted from a sick person to
another are called communicable diseases. For example, common
cold, typhoid, malaria, etc. There are two types of diseases, viz.
communicable diseases and non-communicable diseases.

Learning Objectives

After completing the study of this unit, students will be able to:
(i) introduce disease with examples.
(ii) define communicable and non-communicable diseases with

examples.
(ii) describe the methods of transmission of communicable

diseases.

Glossary: A dictionary of scientific/technical terms

disease : an illness or disorder in the normal function of the body or body parts

communicable : which can transmit from one person to another

non-communicable : which cannot transmit from one person to another

bacteria : the simplest parasites that cause diseases

viruses : sub-microscopic parasites that cause diseases

vector : the agent which carries germs from a sick person to a healthy person

curable : which can be treated, cured

adequate : good enough in quantity

144 GREEN BOOK Science, Health and Physical Education Book-4

Non-communicable Diseases

The diseases which do not transmit from a sick person to another are called
non-communicable diseases. Goitre, anaemia, heart disease, scurvy, marasmus
and kwasiorkor are some examples of non-communicable diseases. These
disease are not caused by microbes or germs. Non-communicable diseases are
caused due to lack of nutrients in the diet or disorder in the body organs.

Fig. Fig.21.1 Scurvy Marasmus
Goitre

Communicable Diseases

The diseases which transmit from a sick person to a healthy person are called
communicable diseases. Common cold, measles, rabies, polio, tuberculosis,
chicken pox, malaria, typhoid, cholera, dysentery, AIDS and mumps are some
examples of communicable diseases. These diseases are transmitted by various
methods.

21.2 Chicken pox Dysentry
Common cold

Communicable diseases are caused by bacteria, viruses, protozoa, etc. Typhoid,
tuberculosis, leprosy, cholera, whooping cough, etc. are the diseases caused
by bacteria. AIDS, rabies, common cold, mumps, polio, measles, chicken pox,
etc are the diseases caused by viruses. Similarly, dysentery, malaria, sleeping
sickness, etc. are the diseases caused by protozoa.

Science, Health and Physical Education Book-4 GREEN BOOK 145

Various agents like air, water, insects, contaminated food, etc. transmit
communicable diseases from one person to another. The living organisms like
mosquito, housefly, etc. that transmit diseases are called vectors. Mosquitoes
are the vectors of malaria, yellow fever, encephalitis, dengue, etc. Houseflies
are the vectors of dysentery, cholera, etc. Similarly, communicable diseases are
transmitted due to close contact with the patient and through the materials
used by the patient. The transmission of communicable diseases can be
prevented by maintaining personal hygiene and environmental sanitation.

If we visit a hospital, we can see hundreds of people suffering from various
types of communicable and non-communicable diseases. Any body can suffer
from a disease at any time. Have you suffered from any disease so far? We
should not hate a sick person. We should love and take care of a sick person.
We should take a sick person to a health post or hospital for treatment. In rural
areas, many people believe on Dhami, Jhakri, Tantrik, etc. and they do not
go to hospital for treatment. As a result many people die of various diseases
in rural areas due to lack of treatment. Therefore, we should not believe in
Dhami, Jhakri, Tantrik, etc. for treatment of diseases.

In rural areas, many people hide some curable diseases like leprosy, tuberculosis,
etc. due to fear of the society. We should not hate them. We should rather help
those people to go to hospital for treatment. However we should be careful
and maintain a high level of personal hygiene while taking care of sick people.
Consumption of nutritious diet, adequate rest, sleep and regular exercise are
the key factors to live a healthy life.

Key concepts

1. A disease or illness is the disorder in the normal functioning of the body
or body parts.

2. The diseases which do not transmit from a sick person to another are
called non-communicable diseases.

3. The diseases which transmit from a sick person to a healthy person are
called communicable diseases.

4. Communicable diseases are caused by bacteria, viruses, protozoa, etc.

5. Various agents like air, water, insects, contaminated food, etc. transmit
communicable diseases from one person to another.

6. The transmission of communicable diseases can be prevented by
maintaining personal hygiene and environmental sanitation.

146 GREEN BOOK Science, Health and Physical Education Book-4

Exercise

1. Put a (√) for the correct statement and a cross (×) for the incorrect one.
a. Goitre and scurvy are non-communicable diseases.
b. The diseases which do not transmit from one person to another are
called communicable diseases.
c. Common cold, typhoid and AIDS do not transmit from one person to
another.
d. We should go to Dhami and Jhakri for treatment.

2. Fill in the blanks using appropriate words.
a. Diseases are of two types, viz. ............................ and ............................
b. ............................ do not transmit from one person to another.
c. The diseases which transmit from one person to another are called
............................
d. Mosquitoes and houseflies are called ............................ of diseases.

3. Answer the following questions.
a. What is a disease? Give any two examples.
b. What are non-communicable diseases? Give any three examples.
c. Define communicable diseases with any three examples.
d. Why is common cold called a communicable disease?
e. Why do most people die in rural areas when they fall sick?

4. Write any two differences between non-communicable and
communicable diseases.

Science, Health and Physical Education Book-4 GREEN BOOK 147

Some Communicable unit
Diseases
22

Weighting Distribution (Approximate)

Before You Begin Teaching periods : 6 Marks (in %): 9

In unit 21, we studied diseases and their types. The diseases
which transmit from a sick person to a healthy person are called
communicable diseases. Common cold, typhoid, dysentry, cholera,
measles, AIDS and polio are some examples of communicable
diseases. Those disease are caused by different types of microbes
such as bacteria, protozoa, virus, fungi, worms, etc.

Communicable diseases are transmitted through direct contact
with the sick person, using personal articles of the sick person,
through contaminated food and drinks, through insect bite, etc. In
this unit, we will study some communicable diseases like dysentry,
polio, tuberculosis, measles, pneumonia, diptheria and trachoma.

Learning Objectives

After completing the study of this unit, students will be able to:
(i) introduce communicable diseases and state the symptoms of

some communicable diseases.
(ii) state the causative agents and modes of transmission of some

communicable diseases.
(iii) describe the preventive and control measures of

communicable diseases.

Glossary: A dictionary of scientific/technical terms

communicable : which can transmit from one person to another
diptheria : a serious disease of throat that causes difficulty in breathing
pneumonia : a serious disease that affects lungs
trachoma : an infection of eyes
mucus : a thick liquid produced inside the nose
sunken : hollow and deep as a result of disease
dehydration : loss of too much water from the body
appetite : physical desire for food
sputum : liquid from throat or lungs
antibiotics : substances that can destroy or prevent the growth of bacteria and

sterilize cure in infections
ulcer : to kill bacteria in or on something
scar : a sore area on the surface of skin which may be painful
nerves : a mark left on the skin after the wound has healed
: thread-like structures that carry messages between brain and body.

148 GREEN BOOK Science, Health and Physical Education Book-4

1. Dysentery

It is a water-borne or food borne disease caused by amoeba or bacteria.
Dysentery is of two types, viz. (i) amoebic dysentery, and (ii) bacterial dysentery.

Causative agents

Entamoeba histolytica causes amoebic dysentery whereas Shigella shiga causes
bacterial dysentery.

Modes of transmission

Dysentery is transmitted:
a. through contaminated water and food.
b. by means of flies through the stool of the infected person.

Symptoms of amoebic dysentery

a. Frequent passing out of loose stool more
than 3 times in a day

b. Appearance of mucus in the stool

c. Abdominal pain Fig.
Fig.
d. Weakness, thirst due to loss of water

e. Sunken eyes and hollow cheeks 22.1

Symptoms of bacterial dysentery Dysentery

a. Frequent passing out of loose stool more than 3 times in a day
b. Abdominal pain
c. Appearance of blood in the stool
d. Weakness, fever and dehydration
e. Thirst and dry tongue due to loss of water

Preventive and control measures

a. Oral rehydration solution (Jeeven Jal) should

be given to the patient. When Jeevan Jal is not

available, solution of salt, sugar and water can 22.2
be given.
Jeevan Jal

Science, Health and Physical Education Book-4 GREEN BOOK 149

b. Hands should be washed properly before having food and after using the
toilet.

c. Flies should be controlled.
d. Defecating on open fields and near the sources of water should be avoided.
e. Fruits and vegetables should be washed properly before eating.
f. We should drink filtered water and boiled water.

2. Polio

Polio is a serious disease common in
children below the age of five years. It
causes paralysis in the children.

Causative agent

Polio is caused by polio virus.

Modes of transmission Fig.

Polio is transmitted:

a. through nasal secretion and stool of the 22.3 Polio
patient.
Do You Know
b. by means of flies from contaminated
food and water. Polio can infect a person of
any age, but children five
c. through personal articles of the patient. and under are specially
d. through close contact with the patient. vulnerable and make
up roughly 50% of polio
Symptoms victims.

a. High fever, headache Jonas Salk produced the
b. Stiffness in the neck and muscles first polio vaccine in 1952
c. Paralysis of body parts AD, the best way to prevent
polio because there is no
cure for polio.

Preventive and control measures

a. Polio drops should be given to child before the age of one year.

b. The patient should be kept in a separate room.

c. Defecating on open field should be avoided.

150 GREEN BOOK Science, Health and Physical Education Book-4