Oasis Science and Technology 4

Step 3 : Then we should select the colour. It is available at the
bottom.

Step 4 : Left click at any part of the canvas, hold it and drag to draw
a line.

Step 5 : Releasing the left click button stops the drawing.

paint brush tool can be used to draw in the canvas

Activity
Draw a picture on Tux Paint and save the file.
Now let’s ttry to use ready-made photographic pictures from the
Rubber Stamp tool. It can be done in following ways:
Step 1 : Select the stamp tool.
Step 2 : Select the picture from the panel on the left side.
Step 3 : Left click on the canvas to enter the picture.

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rubber stamp tool allows to insert pictures

Now let's practise colouring.
We can insert ready-made pictures on the canvas and colour them
with the help of the Magic tool. We can do it in following ways:

magic tool allows to colour the available pictures

Step 1: Left click on the new tool. It is on the left side of the canvas.

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Step 2: Many pictures will pop up on the screen. Select one of them.

Step 3: Select the open icon and click it.

Step 4: Left click the Magic tool.

Step 5: You will see the Fill option in the magic tool panel. Select it.

Step 6: Here you can select the colour.

Step 7: Left click on the picture to colour it.

We have successfully drawn the lines, used photographic pictures
and filled colours, too. Now we should left-click the save tool. It saves
our pictures on the computer. When the image is successfully saved
notification appears at the bottom of Tux paint windows.

Summary

1. The software that helps us to practise typing is called typing
software.

2. The software that allows users to draw and colour pictures is
called paint software.

3. Paint tools can be used to draw lines, logos and clip arts.
4. The rubber stamp tool is used to insert ready-made photographic

images on the canvas.
5. We can insert ready-made pictures on the canvas and colour

them with the help of the Magic tool.
6. When the image is successfully saved notification appears at the

bottom of Tux Paint windows.

Model Questions with Their Answer

1. What does a paint tool do?
The Paint tool allows us to create and colour the pictures.

2. Which tool saves the image?
The Save tool saves the image.

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3. Differentiate between paint software and typing software.
The differences between paint software and typing software are:

SN Paint software SN Typing software

1 The software that allows 1 The software that helps us

users to draw and colour to practise typing is called

pictures is called paint typing software.

software.

2 It helps to make digital 2 It helps to increase our

paintings. typing speed.

4. How do you use Rubber tools?
We can use Rubber tools in the following ways:
Step 1: Select the Stamp tool.
Step 2: Select the picture from the panel on the left side.
Step 3: Left click in the canvas to enter the picture.

5. Why is digital painting growing popular?
Digital painting is growing popular because of the following

reasons:
i. We do not need paper and colour.
ii. It is easy to erase and edit.
iii. It is cheap.

Exercise

1. Fill in the blanks with an appropriate word.

typeshala pictures rubber eraser paint
stamp tool

a. Some common typing software used in Nepal are ………….

b. People draw ………….on the canvas.

c. We can draw and paint the picture in …………. software.

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d. Ready-made photographic images is inserted in the canvas
by …………. tool.

e. Unwanted parts of an image is deleted by …………

2. Write true for the correct and false for the incorrect statements.
a. We need to type while writing books and essays, chatting
and filling forms.

b. The Shape tool is used to create different geometric shapes.
c. Save tool is used to store images on the hard disk.
d. We can practise typing using rubber tools.
e. Microsoft Paint, Tux Paint etc. are popular typing software.

3. Choose the best answer from the given alternatives.
a. What is typing software?

tux paint typeshala MS Paint all of them
b. What is paint software?

MS Paint typing tutor MS word typeshala
c. Which tool of tux paint helps to draw dotted lines?

lines tool eraser tool paint tool save tool

d. Which tool of tux paint saves the image?

text tool lines tool save tool magic tool

e. Which tool of tux paint allows entering text in the canvas?

lines tool save tool text tool all of them

4. Match the following. colour the image
Typeshala helps to enter the letters in canvas
The paint tool make clip art
Eraser tool delete some part of the picture
Magic tool typing software
Text tool

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5. Answer the following questions in a word each.
a. Give an example of typing software.
b. Write down an example of paint software.
c. Which tool helps to draw lines in the canvas?
d. Which tool helps to use photographic images?
e. Which tool saves images?

6. Write any two differences between:
a. Tux Paint and Typeshala
b. Typing software and paint software

7. Give reason.
a. Paint software is growing popular.
b. People should use typing software.

8. Study the given diagram and answer the following questions.
i. Which software is shown in the
diagram?
ii. What is the advantage of using this
type of software?

9. Answer the following questions.
a. Define paint software.
b. What is typing software?
c. What do you know about a paint tool?
d. How do you use a Magic tool?
e. Write down the steps to draw a line in Tux Paint.

10. Project work.
Collect five pieces of information on digital painting.

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Unit

2.4 The internet

Key terms and terminologies

1. Internet: The Internet is the network where computers all over the world
are connected for communication..

2. Internet service providers: The companies that can connect our computers
to the internet are called internet service providers.

3. Web browsers: The application that allows us to access the website is called
a web browser.

4. Search engines: The application that helps to search the information is
called a search engine.

5. Omni bar: Omni bar is a region where we should type the topic to be
searched.

Introduction

There are billions of computers worldwide. If these computers are
connected, they form the internet. The Internet is the network where
computers all over the world are connected for communication. The
internet is a modern means of communication. It was invented by
Vint Cerf. He is called the father of the internet. Computers work
with information. Therefore, the internet also works with information.
A vast amount of information is stored in supercomputers. The
internet can be used to share information with anyone in any corner
of the world.

Fact file
Google is the most powerful website in the world
followed by YouTube.

local networks super computer satellites

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Uses of the internet
Some of the uses of the internet are listed below:
i. We can watch movies, games and music videos online.
ii. We can download and install useful software.
iii. We can learn about the weather and climate.
iv. We can take part in an online class.
v. We can use it for sending emails, chatting, audio and video calls.
vi. It can be used to learn about the culture, geography, history,

literature of a particular place and people.

watching YouTube sending email searching in google

Activity
Turn on the computer. How can you tell if your
computer is connected to the internet or not? Discuss
with your friends and teacher.

Resonable facts
Why should we not use the internet carelessly?
We should not use the internet carelessly because
computer viruses may destroy our computers.

Internet service providers

Computers can be used to access information but they must be
connected to the internet. The companies that can connect our
computers to the internet are called internet service providers.

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Fact file
There are 5 billion Google searches each day.

Web browser

When the computer is connected to the internet, we can use web
browsers to access information. The application that allows us to
access the website is called a web browser. There are many web
browsers. Microsoft Edge is a default browser on the computer. Some
of the other web browsers are Google Chrome, Firefox, Chromium,
Opera Mini, etc.

Microsoft edge Google chrome Firefox Chromium Opera Mini

fig: some popular web browsers

Google search and Bing are search engines. These applications help
us search for information. We can use search engines to look for
information on any topic.

Activity
Launch a web browser. Search for five pieces of
information about your favourite scientist.

Resonable facts
Why do we need a browser?
We need a browser to access websites.

A web browser has an Omni bar. We should type the topic in the
Omni bar and press enter. Below the Omni bar, we can see some
options such as All, Videos, Images, Books, maps and more. We can
select any one of them and launch a search accordingly.

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Summary

1. The network of many computers is called the internet.
2. The internet can be used to share information with anyone in any

corner of the world.
3. It can be used to learn the culture, geography, history and

literature of a particular place and people.
4. The application that allows us to access the website is called a

web browser.
5. Some of the web browsers are Google Chrome, Firefox, Chromium,

Opera Mini, etc.
6. Google Search and Bing are search engines.

Model Questions with Their Answer

1. What is the internet?

The Internet is the network where computers all over the world
are connected for communication.

2. Why is a web browser important?

The web browser is important because it helps to access websites
to search for information.

3. The internet makes communication easier. How?

The internet makes communication easier by:

i. Connecting our computer to the world.

ii. Helping to do audio calls and video calls.

iii. Helping to take online classes.

4. Write any three uses of the internet.

The uses of the internet are listed below:

i. We can learn about weather and the climate.

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ii. We can take part in online classes.

iii. We can use it for sending emails.

5. How do you search for information on the internet?
We can search for information on the internet in the following

ways:

i. Open a web browser.

ii. A web browser has an Omni bar. We should type the topic in
the Omni bar and press enter.

iii. Below the Omni bar, we can see some options, such as All,
Videos, Images, Books, maps and more. We can press any
one of them for accuracy.

iv. Click the link we want to open.

Exercise

1. Fill in the blanks with an appropriate word.

omni bar microsoft edge internet super vint cerf

computers

a. The network of many computers is called ………..
b. A vast amount of information is stored in ………….
c. Internet was invented by …………….
d. Default browser in the computer is ………….
e. A web browser has ……….

2. Write true for the correct and false for the incorrect statement.
a. We can watch movies, football matches and music videos

online.

b. The companies that can connect our computers to the internet
are called internet service providers.

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c. Computers can be used to access information without the
internet.

d. The application that allows you to access the website is called
a web browser.

e. Google Search and Bing are search engines.

3. Choose the best answer from the given alternatives.
a. What is the internet?

network of selling of brain of all of them
computer computer computer

b. What does ISP do?

provide internet sell download none

service computers applications

c. Which one is an example of a web browser?

Google Chrome Bing Zoom Facebook

d. What is an example of a search engine?

Microsoft Edge Google Google Facebook
Chrome Search

e. Where do we type to search for information in web browsers?

omni bar webpage nowhere images

4. Match the following.
Network of computer search engine

ISP type topic to search

Omni bar web browser

Google Search Internet Service Provider

Opera mini internet
5. Answer the following questions in a word each.
a. What is the network of computers called?
b. What did Vint Cerf invent?
c. Where do we type the topic in the web browser?

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d. Give an example of a web browser.
e. Give an example of a Search Engine.
6. Write any two differences between:
a. Web browser and search engine
7. Give reason.
a. Internet is growing very popular.
b. Web browser is important software.

8. Study the given diagram and answer the following questions.
i. What is shown in the diagram?
ii. What is it used for?

9. Answer the following questions.
a. Define internet with its importance.
b. What is a web browser?
c. What is an Omni bar?

d. How do you search for information in the web browser?
Explain.

10. Project work.
Internet is a very important modern means of communication.

Explain.

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UNIT Organism and

3 Environment

Introduction

We live on the earth. On the earth there are living and nonliving

things. Both the living and non-living things around us make up our

environment. Plants and animals are living things around us, whereas

air, water, soil, heat and light are

non-living things. Non-living

things do not have life in them.

They cannot eat or breathe. Living

things have life in them. They

need to eat food and breathe. A

plant is a living thing because it

needs to eat and breathe. It has

life in it. Green leaves of the plant

can make food. The process in

which plants can make food by

using carbon dioxide, water and

sunlight is called photosynthesis. photosynthesis

It produces food and oxygen.

Fact file
All living things are made up of cells.

Resonable facts
Why are plants called producers?
The plants are called producers because they produce
food with the help of sunlight, water and carbon dioxide.

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Unit The Environment
3.1

Key terms and terminologies

1. Environment: The group of living things and non-living things around us
makes our environment.

2. Non-living things: The things that do not have life in them are called non-
living things.

3. Living things: The things that have life in them are called living things.
4. Photosynthesis: The process in which plants can make food by using carbon

dioxide, water and sunlight is called photosynthesis.
5. Air: The mixture of various gases is called air.
6. Soil: Soil is a powdered rock that contains humus.
7. Solar energy: The heat energy and light energy obtained from the sun is

called solar energy.

Introduction

Air, water, water vapour,

cloud, soil, rocks, etc. are

present in our surroundings.

Minerals are found in the soil.

The sun gives a large amount

of heat energy and light

energy. These are non-living

things found in the

environment. Green plants, Environment
aquatic animals, land animals,

insects, birds, bacteria, etc. are living things found in the environment.

Both the living and non-living things around us make up the

environment.

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Activity
Visit a nearby botanical garden with your parents. Make a list of
living things and non-living things you find there.

Living things Non-living things

Fact file
All living things reproduce their own kind.

Resonable facts
Why do we live in an environment?
We live in an environment because it gives us food, cloth
and shelter.

Green plants produce food by photosynthesis. Animals feed upon
them. Birds, insects and animals help in pollination. When living
things die, minerals present in their body return to the earth.

animals grazing pollination mushroom decaying organic matter

Some of the important non-living factors that affect living things are
air, water, soil and solar energy.

Solar energy

The sun is a star. It produces a tremendous amount of heat energy
and light energy. It is the ultimate source of energy for the earth. Heat

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energy from the sun keeps the earth warm. It runs the water cycle on

the earth. It helps in the germination of seeds as well.

Sunlight helps plants in photosynthesis. It gives us a

sense of vision. Sunlight has a huge effect on the life

of organisms. Sun
Activity

Heat and light energy that comes from the sun is called

solar energy. Observe your surroundings and note

what the solar energy is used for?

Heat energy from the sun Light energy from the sun

Air

Air is a very useful component of the environment. A mixture of
oxygen, nitrogen, carbon dioxide, water vapour, dust and many other
gases makes air. The mixture of various gases is called air. Oxygen is
necessary for plants and animals for respiration. Plants use carbon
dioxide gas for photosynthesis. Wind pollinates the flower. The breeze
carries away the seeds of plants from one place to another. Nitrogen
is used by bacteria. Bacteria make the soil fertile.

air is necessary for breathing the dispersal of seed through the air
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Water

Water is a very useful natural resource. Rainfall brings water to land.
Many plants and animals live in water. They are called aquatic plants
and aquatic animals. Animals drink water from lakes, ponds and
rivers. We also obtain drinking water from springs, taps and
watersheds. We must drink plenty of water every day to be healthy.
The plants absorb underground water. Roots help them to absorb
water and minerals from the soil. The plant uses the water for
photosynthesis.

many animals live in water animals drink water from pond

Resonable facts
Why should we drink water every day?
We should drink water every day to be fit and healthy.

Soil

Soil is a powdered rock. It is a solid surface. We live on land. Fertile
soil is dark black or brown. Plants grow well on fertile land. It provides
sufficient minerals and water for plants. Many animals live in the soil.
Rabbits live in burrows. Snakes live in holes. The earthworm is a
friend of the farmer. It lives in the soil and makes it fertile. Farmers
love to have earthworms in their fields.

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some animals live in burrow earthworm makes soil fertile plants grow in the soil

Activity

It is said that if honey bees go extinct from the earth,
human beings will also go extinct. What might be the
reason? Collect information about the topic from a Google
search.

Fact file
27000 trees are cut each day to make the toilet paper.

Interrelationship between organisms and environment

Organisms depend upon their environment to survive. All of the
living things and non-living things help each other and continue
living.

The following statements help to clarify the relationship between
organisms and the environment.
i. Animals take oxygen from plants for respiration and give carbon

dioxide in return for photosynthesis.
ii. Plants give us fruits and we help in the dispersal of their seeds.
iii. Plants give grass for animals and animals help in the dispersal of

grass seeds.
iv. The honey bee eats nectar from the flower and helps in pollination.
v. Humans grow flowers for honey bees and bees give us honey

and wax.

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vi. Plants prevent the soil erosion and landslide. At the same time
the soil gives water and minerals to the plant.

Summary

1. Earth has air, water, soil, plants and animals in it.
2. Both the living and non-living things around us make up our

environment.
3. Non-living things do not have life in them.
4. The plant is a living thing because it needs to eat and breathe.
5. The process in which plants can make food by using air, water

and sunlight is called photosynthesis.
6. Air, water, water vapour, cloud, soil, rocks, etc. are present in our

surroundings.
7. Some of the important non-living things that affect living things

are air, water, soil, solar energy, etc.
8. The sun is the ultimate source of energy on the earth.
9. Oxygen is necessary for plants and animals for respiration.
10. Plants use carbon dioxide for photosynthesis.
11. Animals drink water from lakes, ponds, rivers, etc.
12. Roots of plants help them to absorb water and minerals from the soil.
13. Soil is a powdered rock.
14. Farmers love to have earthworms in their fields.
15. All of the living things and non-living things help each other and

continue living in the environment.
16. Humans grow flowers for honey bees and bees give us honey and

wax.

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Model Questions with Their Answer

1. Define photosynthesis.
The process in which plants can make food by using carbon

dioxide, water and sunlight is called photosynthesis.

2. What helps in the pollination of the flower?
The wind, insects and various animals help in the pollination of

the flowers.
3. The earthworm is called a friend of a farmer. Why?
The earthworm is called a friend of a farmer because the

earthworm makes the soil fertile.
4. Write the importance of air.
The importance of air is noted below:
i. Air helps in the pollination of the flower.
ii. The wind brings clouds.
iii. Air gives us oxygen to live.
d. Air gives carbon dioxide for plants to make food.
5. Describe the relationship between organisms and the

environment.
There is a very important relationship between organisms and

the environment. Some of the relationships are given below:
i. Animals take oxygen from plants for respiration and give

carbon dioxide in return for photosynthesis.
ii. Plants give grass for animals and animals help in the

dispersal of grass seeds.
iii. The honey bee eats nectar from the flower and helps in its

pollination.

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Exercise

1. Fill in the blanks with an appropriate word.

earth pollinates photosynthesis environment food

a. Air, water, soil and living things are present in …………

b. All living and non-living things around us is called …….

c. Green leaves of the plant can make …………

d. Sunlight helps the plant in ……….

e. Wind ………. the flower.

2. Write true for the correct and false for the incorrect statement.

a. The mixture of various gases is called air.

b. We also obtain drinking water from springs, taps and
watersheds.

c. Farmers hate to have earthworms in their fields.

d. Plants give us fruits and we help in the dispersal of their
seeds.

e. Honey bees eat fruits.

3. Choose the best answer from the given alternatives.

a. What are all the living and non-living things together around
us called?

environment earth natural resources minerals

b. What is the process of making food by the green plants
called?

germination pollination photosynthesis dispersal of
seed

c. What are the raw materials necessary for photosynthesis?

air water sunlight all of them

d. Where does the earthworm live?

air water land snow

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e. Which gas is used by the plant for photosynthesis?

oxygen carbon dioxide nitrogen hydrogen

4. Match the following.

Green leaves earthworms

Solar heat energy photosynthesis

Respiration absorb water

Roots oxygen

Farmer's friend germination

5. Answer the following questions in a word each.

a. What is the mixture of various gasses called?

b. Where do the animals get drinking water from?

c. Where do the plants get water and minerals from?

d. Where do snakes live?

e. Which gas is changed into fertiliser by bacteria?

6. Write any two differences between:

a. Air and water

7. Give reason.

a. Animals live in the forest.

b. A plant needs air, water and sunlight.

c. The earthworm is called a friend of a farmer.

d. The honey bee is tiny but very important.

8. Study the given diagram and answer
the following questions.

i. Write the name of the process shown
in the diagram.

ii. What is produced by the above
process?

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9. Answer the following questions.
a. What are living things? Write with examples.

b. Define non-living things with examples.

c. What is the environment?

d. What are the main non-living factors of the environment?

e. How does water help living things?

f. List the uses of solar energy in nature.

g. Write a short note on the importance of soil.

h. Describe the interrelationship between living things and
non-living things.

10. Project work.
Farmers used chemicals to kill insects in the mustard field. All

the honey bees also died. The mustard plants did not produce
enough mustard seeds that year. What might be the reason?
Discuss with your friends.

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Unit
The Interrelationship between Organisms

3.2 and the Environment

Key terms and terminologies

1. Forest: The large area covered by the plants is called a forest.
2. Deforestation: The act of cutting down large numbers of trees from a place

is called deforestation.
3. Environmental pollution: The decrease in the quality of the environment is

called environmental pollution.
4. Afforestation: The act of planting trees is called afforestation.
5. Air pollution: The decrease in the quality of air due to smoke and dust is

called air pollution.
6. Water pollution: The decrease in the quality of water due to sewage is called

water pollution.
7. Land pollution: The decrease in the quality of land due to garbage is called

land pollution.

Introduction

Living things need oxygen to

breathe. We get energy from

food. We need to drink water

to be alive. We need cloth and

shelter too. Where do we get

these things from? We get

them from the environment

where we live in. Wild animals in the forest
animals get their basic needs

from the forest. All life forms depend upon the environment to

survive. There is a very important relationship between living things

and their environment.

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Human beings and environment

Humans depend upon the environment for food, clothes and shelter.
We use natural resources. Those resources regenerate over time.
However, human population is growing very fast and consuming
resources beyond the rate of regeneration. The quality and quantity
of the environment is decreasing. Some of the harmful effects of

population growth on the environment are listed below:

i. Change in climate
ii. Increasing temperature of the earth.
iii. Irregular rainfall
iv. Deforestation
v. Environmental pollution
vi. Decrease in the population of wild animals

vii. Drying of water sources

drying river deforestation environmental pollution
fig: causes of deforestation

Resonable facts
Why is overpopulation harmful to the environment?

Overpopulation is harmful to the environment because it
destroys air, water, land and forest.

Fact file
Rainforests are being cut 100 acres per minute.

Activity

Observe your surroundings. Was it the same 5 years ago?

Ask your parents. Was it same 15 years ago? Why is your

environment changing slowly? Think about it.

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Deforestation

A large area covered by plants is called a forest. A forest is very useful
for us. It gives us fresh air and water. It gives food and shelter to wild
animals. We get medicinal plants, timber and fodder from the forest.
However, people are using forest resources beyond the capacity of
the forest to regenerate them. This has increased the rate of
deforestation. The act of cutting down large numbers of trees from a
place is called deforestation.

cutting trees forest fires overgrazing

Causes of deforestation

Population growth is the main cause of deforestation. Some of the
major causes of deforestation are listed below:

i. Agriculture

Since there are more people, they need more food. People clear the
forest and make lands to grow crops.

ii. Urbanization

More people need more houses to live in. They cut down trees and
make human settlements. Construction of roads, football grounds
etc. also destroy the forest.

iii. Forest fire

People start fire in the forest so that they can cut wood from there
later.

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iv. Illegal selling of raw materials

People illegally cut down trees, medicinal herbs and kill wild
animals.

v. Overgrazing

When domestic animals graze on hills, they eat all new seedlings.
No new plant grows on the hills.

Fact file
Forest is home to 80% of land animals.

Activity

The number of wild animals and birds are decreasing
every year. What might be the reason? Discuss in a group.

Resonable facts
Why is deforestation bad for air?
Deforestation is bad for air because it increases the amount
of carbon dioxide and decreases the amount of oxygen.
Effects of deforestation on the environment

The loss of forests is not good for the environment. Some of the
harmful effects of deforestation are:
i. Wild animals will lose food and shelter.
ii. Medicinal herbs will be lost.
iii. The amount of carbon dioxide will increase and oxygen will

decrease in the air.
iv. Rainfall will be irregular.
v. Water sources will dry up.
vi. Soil erosion, flood and landslide will occur.

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Environmental pollution

Overpopulation causes environmental pollution. More people need
more food, shelter and other products. Forests will be lost to agriculture
and housing. Cities are formed. Industries and factories produce
waste materials. Vehicles and machines mix smoke in the air. All this
decreases the quality of the environment. The decrease in the quality
of the environment is called environmental pollution.

Air pollution

The loss of trees pollutes air. When trees are lost, there will be less
oxygen but more carbon dioxide in air. Air won’t be fresh anymore.
The surrounding temperature will rise. Climate will change. Smoke
from industries and vehicles mix in the air. Germs and dust are found
in polluted air. People living in polluted air become sick. Villages
have fresher air than cities.

smoke from factory smoke from chimney smoke from vehicle

Land and Water pollution

Cities have factories. Factories produce waste materials. There are
more people in the city. They produce tons of waste. These waste
materials pollute land and water. Sewage from hospitals, industries
and cities directly pollute water. Loss of trees makes land dry. There
will be less rainfall. Water sources will go dry.

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Activity
Visit a river with your parents. Is it clean? Can you
drink that water? What are human beings doing that
has decreased the quality of the river water? Discuss
with your parents.

Fact file
Children are mostly affected by air pollution.

Resonable facts
Why should we wear a mask while going out of the house?
We should wear a mask while going out of our homes
because it protects us from germs, smoke and dust.

land pollution Soil pollution Sewage pollutes water
resources
Effects of the pollution

i. Breathing in dirty air makes us sick.

ii. Dirty drinking water is bad for health.

iii. Plants and animals get sick and die.

children are more affected by pollution plants get sick because of pollution
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Conservation of environment
We must live in a healthy environment for good health. We can

conserve the environment in many ways. Some of the ways that help
us conserve the environment are given below:

i. Do not cut trees.
ii. Plant more trees in a barren land.
iii. Produce fewer waste materials.
iv. Reuse and recycle waste if possible.

v. If there is degradable waste, use it to make compost.

Composting the degradable waste

We can dig a pit. Degradable waste such as composting
decaying food, waste food, vegetable peels,
grass etc. can be collected there. The degradable
waste dumped in the pit will change into
compost fertiliser after a few months.

Summary

1. We get energy from food.

2. Wild animals get their basic needs from the forest.
3. Humans depend upon the environment for food, clothes and

shelter.
4. A large area covered by plants is called a forest.
5. We get medicinal plants, timber and fodder from the forest.
6. The act of cutting down a large number of trees in a place is called

deforestation.
7. Population growth is the main cause of deforestation.
8. Since there are more people, they need more food. People cut the

forest and make lands to grow crops.
9. The decrease in the quality of the environment is called

environmental pollution.
10. Germs and dust are found in polluted air.
11. Sewage from hospitals, industries and cities directly pollute

water.

12. We must live in a healthy environment for good health.

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Model Questions with Their Answer

1. Define forest.
A large area covered by plants is called a forest.
2. Deforestation is bad for the environment. Explain.
Deforestation is bad for the environment because:
i. Wild animals will lose food and shelter.

ii. The amount of carbon dioxide will increase and oxygen will
decrease in air.

iii. Water sources will go dry.
3. Why should we protect the forest?
We should protect the forest because:
i. It gives shelter to wild animals.
ii. It gives us oxygen.
iii. It protects water resources.
4. How does deforestation cause air pollution?
Deforestation is the cause of air pollution. When trees are lost,

there will be less oxygen and more carbon dioxide in air. Air
won’t be fresh anymore. It will be polluted.
5. How can we protect the environment?
We can protect the environment in the following ways:
i. Not cutting down trees
ii. Planting more trees on barren lands
iii. Producing fewer waste materials
iv. Reusing and recycling waste if possible

Exercise

1. Fill in the blanks with an appropriate word. seedling
waste materials oxygen forest deforestation

a. Living things need ………..to breathe.
b. A large area covered by plants is called ……...

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c. Population growth is the main cause of …………..
d. Industries and factories produce ……………

e. When domestic animals graze on hills, they eat all new …….
2. Write true for the correct and false for the incorrect statement.

a. There is a very important relationship between living things
and their environment.

b. We use natural resources found in the environment to live.
c. The act of cutting down a large number of trees in a place is
called afforestation.

d. Loss of forest is good for the environment.

e. Vehicles and machines mix smoke in the air.

3. Choose the best answer from the given alternatives.
a. What is the cause of deforestation?

agriculture urbanization population growth all of them

b. What is the main effect of population growth on the
environment?

fresh air deforestation afforestation all of them

c. What is the act of cutting down of trees called?

afforestation deforestation pollution none

d. What causes air pollution?

heavy rainfall smoke afforestation all of them
none
e. What causes water pollution?

smoke afforestation sewage

4. Match the following. cutting down of trees
Afforestation planting trees
Deforestation sewage
Air pollution kill wild animals
Water pollution climate change
Forest fire

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5. Answer the following questions in a word each.
a. What is the main cause of environmental pollution?
b. What is the term used to describe the loss of forest?
c. What is the act of planting trees called?

d. What is the term used to describe the decrease in the quality
and quantity of the environment?

e. What is the main chemical that pollutes air?
6. Write any two differences between:
a. Air pollution and water pollution
b. Afforestation and deforestation

7. Give reason.
a. The number of wild animals is decreasing nowadays.
b. People destroy the forest.
c. We should plant trees on barren lands.

8. Study the given diagram and answer the following questions.
i. What is showing in the diagram?
ii. How is it harmful to us?

9. Answer the following questions.
a. What is a forest? What do we get
form it?

b. Define deforestation. Write down its effects.
c. Define environmental pollution.
d. Whataretheeffectsofpopulationgrowthontheenvironment?
e. List any two harmful effects of pollution on human beings.

f. Mention any three things that we can do to save the
environment.

10. Project work.

How does deforestation increase the temperature of the
surrounding places? Discuss in a group.

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UNIT Classification of

4 Living Things

Introduction

Plants and animals have life. So they are called living things. Among
them, some organisms live in water and some live on land. Some are
very small such as amoeba and some are very big such as blue whales.
Some have bones such as humans and some do not have bones such
as earthworms.

amoeba humans deer mushroom fern rose

fig: living things around us

There are billions of species of living things on earth. Each species has
its characteristics. It will be very difficult to study them individually.
These organisms must be divided into different groups. Thus, the
process of dividing organisms into different groups based on their
characteristics is called the classification of living things. Broadly,
living things are divided into two groups. They are plants and animals.

Fact file
A blue whale is 3 times heavier than an elephant.

Resonable facts
Why are living things classified into different groups?
Living things are classified into different groups
because the grouping makes it easier to study them.

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Unit Animals around us
4.1

Key terms and terminologies

1. Classification of living things: The process of dividing organisms into
different groups based on their characteristics is called the classification of
living things.

2. Animals: The organisms which usually eat other living things and do not
have chlorophyll in their cells are called animals.

3. Vertebrates: The animals which have a backbone in their body are called
vertebrates.

4. Invertebrates: The animals which lack the backbone in their body are called
invertebrates.

5. Viviparous animal: The animal in which a baby is developed in the mother’s
womb is called a viviparous animal.

6. Oviparous animal: The animal which lays eggs and a baby is developed
inside the egg is called an oviparous animal.

7. Aquatic animal: The animal that spends most of its time in water is called
an aquatic animal.

8. Terrestrial animal: The animal that spends most of its time on land is called

a terrestrial animal.

Introduction

There are many animals around us. Humans also belong to the animal
kingdom. Every animals are different and unique. Paramecium is a
unicellular animal. The elephant is a multicellular animal. Rats, cats,
lizards, spiders, etc. are small animals. Elephants, tigers, rhinoceros,
etc. are big animals. The goat is a plant-eating animal. The lion is a
flesh-eating animal. We eat grains, leaves, meat, milk, eggs, etc.
Sharks live in seawater. Trout fish live in freshwater. Humans live on
land. Therefore the animal kingdom is vast.

tiger goat frog fish

fig: animals around us

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The organisms which usually eat other living things and do not have
chlorophyll in their cells are called animals. The animal kingdom is
mainly divided into two groups. They are vertebrates and invertebrates.

Activity

What are common animals in your surroundings? Make a list of

vertebrates and invertebrates found there.

Vertebrates Invertebrates

Fact file
An adult human body has 206 bones.

Vertebrates human vertebral column

Some animals have bones and backbone
in their body. For example, humans, cow,
goat, elephant, etc. The animals which
have a backbone in their body are called
vertebrates. They are more developed
organisms than invertebrates. Pieces,
amphibians, reptiles, birds and mammals
are vertebrates.

fish frog snake cow bird

fig: five types of vertebrates

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Characteristics of vertebrates

Special characteristics of the vertebrates are listed below:
i. They have bones and a backbone in their body.
ii. Blood is produced inside the bone.
iii. Important organs such as the heart, liver, lungs, etc. are protected

by bones.
iv. Vertebrates usually have a tail.

Resonable facts
Why do animals have bones?
Animals have bones because bones make the body
stronger and protect vital organs as well.

Invertebrates

If we observe very carefully, amoeba sycon hydra
we will notice that butterflies,
houseflies, earthworms, etc. do roundworm leech tapeworm
not have backbone. Similarly
many animals around us do insects octopus starfish
not have backbones in them.
The animals which lack bones fig: nine types of invertebrates
and backbone are called
invertebrates. Amoeba, sycon,
hydra, roundworm, leech,
tapeworm, insects, octopus,
starfish, etc. do not have bones
and backbones in them.

Characteristics of invertebrates

Special characteristics of the invertebrates are listed below:

i. They lack backbones.

ii. They do not have blood.

iii. They have a soft body.

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iv. Their bodies are made up of muscles only.

Fact file
97% of the animal species are invertebrates.

Reproduction in animals

Reproduction is one of the important characteristics of the living
things. Animals give birth to young ones. Some of the animals give
birth to young ones directly while others lay eggs. Eggs hatch into
young ones. On the basis of way of giving birth to young ones, animals
are divided into two groups. They are oviparous animals and
viviparous animals.

Viviparous animals

Human beings give birth directly. Goats, buffaloes and horses also
give birth directly. The animal in which a baby is developed in the
mother’s womb is called a viviparous animal. Mammals are viviparous
animals.

Cow and the calf Goat and kid bat and pups
fig: viviparous animals

Resonable facts
Why does the cow belong to the group of viviparous
animal?
The cow belongs to the group of viviparous animals
because it gives birth to the calf directly.

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Oviparous animal

Mosquitos lay eggs on water. Eggs hatch into larvae. Turtles, snakes
and crocodiles also lay eggs. Their babies grow inside the eggs. The
animal whose baby is developed inside the egg is called an oviparous
animal. Insects, pieces, amphibians, reptiles and birds are oviparous
animals.

frogs and egg of frogs pigeon and the eggs fish and its eggs

fig: oviparous animals

Classification of animals on the basis of habitat

Activity

Do all animals reproduce in the same way? There may be many
animals, birds and insects in your surroundings. Make a list of those
organisms. Classify them as oviparous and viviparous animals.

Oviparous animals Viviparous animals

Human beings live on land. Fish live in water. Birds fly in the air.
Based on the place where they live, animals are divided into two
groups. They are aquatic animals and terrestrial animals.

Aquatic animals

Frogs are found in pond as well as land. Ducks swim in the pond to
catch fish. Similarly, octopus, starfish, whales, dolphins, etc. are found

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in the ocean. The natural home of these animals is water. The animals
that spend most of their time in water are called aquatic animals.

octopus starfish whales dolphin

fig: aquatic animals

Characteristics of aquatic animals

Special characteristics of the aquatic animal are listed below:
i. Most of them have boat-shaped body.
ii. They have waterproof scales.
iii. Some of them breathe by gills and others breathe by moist skin.
iv. They have air bubbles inside their bodies.

Activity

Observe a fish very carefully. Make a list of
characteristics you find in it.

Fact file
Male seahorses gives birth to babies.

Resonable facts
Why does a fish have a boat-shaped body?
A fish has a boat-shaped body to help it swim in water
with ease.

Terrestrial animals

A camel lives in the desert. A leopard lives in grassland. The monkey
spends most of its time on trees. So, the animals that spend most of

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their time on land are called terrestrial animals. The body of the
animal is always modified so that it can live easily in its environment.

camel lives in desert lion lives in open land rat lives in hole pigeon flies in air monkey lives in tree

fig: five types of terrestrial animals

Characteristics of terrestrial animals

Special characteristics of terrestrial animals are listed below:
i. Terrestrial animals live on land.
ii. They do not have gills. They breathe by lungs.
iii. They travel from one place to another with legs or wings.
iv. They have fur or feather.

Summary

1. Plants and animals are living things as they have life in them.

2. The process of dividing organisms into different groups based on
their characteristics is called the classification of living things.

3. The organisms which do not make their own food and eat other
living things are called animals.

4. The animal which has a backbone in its body is called a vertebrate.

5. Important organs such as the heart, liver, lungs, etc. are protected
by bones in vertebrates.

6. The animals which lack bone and the backbones are called
invertebrates.

7. The animals which give direct birth to the young ones are called
viviparous animals.

8. The animals which lay eggs are called oviparous animals.

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9. The animals that spend most of their time in water are called
aquatic animals.

10. The animals that spend most of their time on land are called
terrestrial animals.

Model Questions with Their Answer

1. What type of organisms are called animals?
The organisms which do not make their own food and usually

eat other living things are called animals.

2. A goat is called a vertebrate. Why?
A goat is called a vertebrate because it has a backbone in its body.

3. Why does the octopus have a soft body?
The octopus has a soft body because it does not have bones and a

backbone. It is made up of muscles only.

4. List the characteristics of aquatic animals.
Special characteristics of aquatic animals are listed below:

i. Most of them have a boat-shaped body.
ii. They have waterproof scales.
iii. They have air bubbles inside their body.

5. Write any four special characteristics of the terrestrial animals.
The special characteristics of the terrestrial animal are listed

below:
i. They live on land.
ii. They do not have gills and breathe through lungs.
iii. They travel from one place to another by using legs or wings.
iv. They have fur or feather.

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Exercise

1. Fill in the blanks with an appropriate word.

bones vertebrate classification of animals microscopic
living things

a. There are ……. organisms such as amoeba, paramecium, etc.

b. The process of dividing organisms into different groups
based on their characteristics is called ……….

c. The organisms which usually eat other living things are
called …......

d. The animal which has a backbone in its body is called
………….

e. Important organs such as heart, liver, lungs, etc. are protected
by ………………

2. Write true for the correct and false for the incorrect statement.
a. The animals which lack the backbone are called invertebrates.
b. Human beings give birth directly.
c. Insects, pieces, amphibians, reptiles and birds are oviparous
animals.
d. The animal that spends most of its time on land is called an
aquatic animal.
e. The monkey spends most of its time in the desert.

3. Choose the best answer from the given alternatives.

a. Which one is a vertebrate animal?

earthworm starfish snake mosquito

b. Which one does not have a backbone?

snake earthworm turtle hen

c. Identify viviparous animal.

goat fish frog butterfly

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d. Which one is an aquatic animal? maize
goat fish cow

e. Which animal has gills to breathe?

goat fish star fish elephant
4. Match the following.
Terrestrial direct birth
Oviparous land animals
Aquatic water living
Lung egg laying
Viviparous living on land

5. Answer the following questions in a word each.

a. Give an example of an oviparous insect.

b. What do land animals use to breathe?

c. What does a frog use to breathe underwater?

d. What kind of animal has a backbone in its body?

e. What kind of animal has waterproof scales in its body?

6. Write any two differences between:

a. Vertebrates and invertebrates

b. Oviparous and viviparous

c. Aquatic and terrestrial animals

7. Give reason.

a. Human beings are called vertebrates.

b. The butterfly is an invertebrate.

c. The hen is called an oviparous animal.

d. A goat is an example of a viviparous animal.

e. Fish have a boat-shaped body.

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8. Study the given diagram and answer the following questions.

i. What part of the fish is shown in the diagram?

ii. What is the function of this part?

9. Answer the following questions.

a. Write any three characteristics of the
vertebrates.

b. List any three characteristics of the invertebrates.

c. What are oviparous and viviparous animals? Write with
examples.

d. List any three characteristics of land animals.

e. Mention any three characteristics each for fish and lion.

10. Project work.

Complete the table given below:

Name of the animal Special characteristics
Fish Gills

Frog Lives on land and in water

Camel

Monkey

Pigeon

Lion

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Unit Plants around us
4.2

Key terms and terminologies

1. Plants: The organisms that contain chlorophyll and produce their own food
by the process of photosynthesis are called plants.

2. Non-flowering plants: The plants that do not bear flowers and seeds are
called non-flowering plants.

3. Flowering plants: The plants that bear flowers and produce seeds are called
flowering plants.

4. Herbs: Small plants with weak fleshy stems are called herbs.

5. Shrubs: The medium-sized plants with woody stems are called shrubs.

6. Tree: The tall and big plant with a woody stem is called a tree.

7. Aquatic plants: The plants that complete their lifecycle in water are called
aquatic plants.

8. Terrestrial plants: The plants that complete their lifecycle in the land are
called terrestrial plants.

9. Root system: The underground part of the plant is called the root system.

10. Root: The part of a root system that absorbs water and minerals from the
soil is called root.

11. Shoot system: A shoot system is the part of the plant that grows above the
soil.

12. Stem: The stem is a strong woody part of the plant.

13. Leaves: Leaves are the green part of the plant that make food.

14. Flower: The colourful part of the shoot system is called a flower.

Introduction

The plant kingdom includes those organisms which have green
leaves. Some of the characteristics of plants are:

i. They cannot move from one place to another.

ii. They are green due to the presence of chlorophyll.

iii. Their leaves make food by the process of photosynthesis.

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iv. Their cells have clell wall.
v. They produce oxygen during photosynthesis.

Chlamydomonas Bryophyta fern

radish jasmine banyan
fig: plants around us

The organisms that contain chlorophyll and produce their own food
by the process of photosynthesis are called plants. The plant kingdom
is divided into two groups. These are flowering plants and non-
flowering plants.

Fact file
One strawberry has more than 200 seeds.

Resonable facts
Why can plants make food?
Plants can make food because they have chlorophyll.

Non-flowering plants

Have you seen flowers? Do all plants bear flowers? No, they don’t.
Fern, mushroom and moss are a few examples of non-flowering
plants. They neither bear flowers nor have seeds. The plants that do
not bear flowers and seeds are called non-flowering plants. They
reproduce by spores.

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Activity

Put moist bread in a dark place for a few days. What will
grow in it? Discuss with your teacher.

mushroom moss mucor fern

fig: non-flowering plants

Flowering plants

Have you seen any flower in a pine tree? Pine trees do not bear flowers
but they produce seeds. Paddy plant, rose bush and apple tree bear
flowers. They produce seeds as well. The plants that bear flowers and
produce seeds are called flowering plants. They reproduce by seeds.

paddy banana lotus pine

fig: flowering plants

Plants are available in various sizes. They are broadly divided into
three groups: herbs, shrubs and trees.

Fact file
85% of plant species are aquatic.

Resonable facts
Why do flowering plants produce seeds?
Flowering plants produce seeds because seeds can
produce new plants.

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Herbs

Herbs are small plants. They have bushy roots. They have weak fleshy
stems. The small plants with weak fleshy stems are herbs. Grass,
wheat, tomato, onion, ginger, etc. are some herbs.

grass onion ginger

fig: herbs

Some special characteristics of herbs are listed below
i. Herbs are very small in size.
ii. Herbs grow in a particular season only. They are seasonal plants.
iii. They germinate, grow, produce seeds and die within a single

year. So, they are annual plants.
iv. Their stem is soft and weak.

v. They do not have branches.

Activity

Collect a herb and a shrub. Compare the physical properties of the
two plants.

Herb Shrub

Root
Stem
Branch

Shrubs

Shrubs are medium-sized plants. They have a woody stem. The

medium-sized plants with woody stems are called shrubs. Rosebush,

jasmine and marigold etc. are shrubs.
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