science class -3- 2077 press

Lesson

5 Reproduction in Plants

Learning outcomes

At the end of this lesson, the students will be able to:
 explain reproduction in flowering plants by seeds.
 define germination and list the condition needed for germination.
 observe various stages of plant development.
 state some other parts that can develop into the new plants.

Boost Up

1. Which parts of plants are shown in the given diagram.

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

................................. ...............................
2. Name any four plants that develop from their seeds.
.................. .................. .................. ..................

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Reproduction is one of the life processes through which
every living being produces their young ones. Like animals,
plants also produce young ones of their own kind. We can see
many small plants of same kind growing around a big tree.
Plants and animals reproduce in many ways. There are two
types of plants found in nature. They are non-flowering plants
and flowering plants. Non-flowering plants like mushroom,
fern, moss, etc do not bear flowers in them and reproduce by
tiny spores. Flowering plants like pea, rice, maize, mango,
apple, etc. bear flowers in them. The flowers give rise to fruits
and seeds. Such flowering plants like potato, rose, sugar cane,
etc reproduce from different parts such as stems, roots and
leaves.

Reproduction in flowering plants

A fully grown or matured plant has roots, stem, branches,
leaves, flowers and fruits. The roots lie under the ground and
other parts lie above the ground. The roots, stem, branches and
leaves do not have any role in reproduction whereas flowers
are the reproductive parts.

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Scan for practical experiment flower

URl: csp.codes/c04e09 fruit
leaves

stem
branch

root

A flowering plant

Flower is the most attractive and colourful part of the
flowering plants. Flowers help in the reproduction of the plant.
A complete flower has four parts. They are sepals, petals,
stamens and pistils. Stamens are the male parts and pistil is the
female reproductive part of a flower. Stamen produces pollen
grains which contain male cells and pistil produces ovules
which contain female cells.

When matured, stamens burst and pollen grains are
transfered from stamen to pistil. This process is called
pollination. After pollination, male cell and female cell fuse
to form a zygote. The flower then develops into a fruit which
contains seeds in it.

A seed is a small hard part produced in a fruit from which
a new plant grows. Seeds are found inside the fruit. Some fruits

Blooming Science, Health and Physical Education Book 4 53

like mango, plum, peach, etc contain only one seed whereas
fruits like orange, pumpkin, tomato, pea, etc. contain many
seeds. The seeds of different plants are different in shape, size
and appearance.

Some fruits with seeds

A seed is covered externally by a hard covering called
as seed coat. It protects the inner parts of the seed. There is a
rough mark in the seed by which the seed is connected to the
fruit called as scar. There is a hole from where water gets inside
the seed during germination.

Scan for practical experiment

Rajma seeds Maize seeds URl: csp.codes/c04e10

The seeds like beans, peas, oranges, etc have two parts in
them. We can see these when we remove the seed coat. These
are called cotyledons. The cotyledons store food for the baby
plant to grow until its can make it food itself.

The seeds like maize, rice, etc have only one part in them.
These seeds contain a soft part in them at a side which develops
into new plant. The soft part is called cotyledon. It has a hard
bigger part called endosperm. Endosperm provides the food
for the baby plant.

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Bean seed (dicot) Maize seed (monocot)

Activity: 1

To observe outer parts of a seed

Collect some seeds like beans, peas, rice, maize, peanut, etc. Observe them closely and
find the different parts you can see from outside. Draw the diagrams of the seeds and
label the parts.

Activity: 2

To observe inner parts of a seed

Soak few bean or pea seeds and observe the outer parts of it.
Does the size of the seed remain the same? Why does the size of seed changes?
Observe the seed by pressing it gently. What do you observe?
From where does the seed get water for it?
Peel off outer coat of the seed. You will see two cotyledons in it.
Now gently open the cotyledons and observe. You will be able to see a tiny baby plant.
Draw a diagram to show your observation.

Cotyledon Plumule
Scar Radicle

Hole
Seed coat

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Growing a plant from seed

When a seed gets favourable conditions, it gives rise to a
tiny baby plant. This process is called germination of seed. The
baby plant produced from a seed is called seedling or sapling.
For germination, seeds need enough water, air and warmth.

During germination,

the seed absorbs water and

then the seed coat breaks

open. First, the root grows

towards the soil and the

shoot grows upwards and

develops into stem and

leaves. The seedling are Stages of germination of seed

young and small. The leaves and stem are very soft. They can

be easily damaged by insects, extreme heat and cold. They

need proper care to develop into matured plant.

A seed can germinate only when there is moisture, suitable
warmth and air. It also needs sunlight for the growth of the
saplings.

Activity: 3

Take some cotton and wet it with water. Put the wet cotton in a plate and keep a few
bean seeds on it. Keep the plate in a safe place. Observe and record the changes you
see daily.

What can you see on first day?
When do you see a baby plant growing from it?
What happens to the cotyledons after a week?
Can you see roots developing from the seed? In which direction does it grow.

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Conditions necessary for the germination of seeds

All the seeds can
not germinate into new
plants. A seed germinates
only when it gets enough
water, air and warmth.

When a seed gets

favourable conditions, it

grows into seedling. The

seedling grows gradually

and develops branches and

sub-branches in the shoot.

With maturity, the plant Life cycle of a bean plant.

develops buds. Those buds finally develop into flowers that gives

rise to fruits seeds. When the seeds are dried and get favourable

conditions they again germinate to give rise to the young ones.

Activity: 4

To observe conditions necessary for germination of seeds.

Take three bean seeds, a jam bottle (or any other vessel), a bamboo strip or a short
ruler and thread or rubber bands. Tie the seeds on three different parts of the ruler.
Fill half of the bottle with water. Now, put the ruler in such a way that the middle
seed just touches the water level. The lower seed lies inside the water and upper seed
lies in air. Maintain the water level until the seed germinates. Observe after 3 - 4
days.

 Which seed germinates?

 Why do the other two seeds not germinate?

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Development of plants by other parts

Most of the flowering plants reproduce by the means of
seeds. However, there are some flowering plants like rose,
potato, sugarcane, ginger, etc that can reproduce by means of
other parts. These plants do not produce good seeds. So, they
reproduce by their roots, stem or leaves.

Some flowering plants like sweet potato and dahlia can
reproduce by the means of roots. The roots of these plants
contain buds. The buds develop into the new plants in suitable
condition.

Sweet potato Dahlia

The plants like sugarcane, rose, potato, ginger, yam,
cocoyam, etc reproduce by their stem. The stem with tiny buds
of sugarcane and rose are kept in soil and the new plants grow
from these buds. The underground stem of potato, ginger, yam,
cocoyam, etc develop into new plants in favourable conditions.

Ginger Potato plant

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Potato Potato plant Sugarcane plant

The plants like bryophyllum
and begonia can grow new plants
from their leaves. When these
leaves fall on the ground, new
plants develop from the buds.

Bryophyllum

Key words

Sepal – the outermost green part of a flower
the coloured part of a flower inner to sepal
Petal – the male part of a flower
the female part of a flower
Stamen – Tarul
Pindalu
Pistil –

Yam –

Cocoyam –

Main Points to Remember

 Like animals, plants also reproduce to produce their ownkinds to continue their
races.

 Non-flowering plants reproduce by the means of spores and flowering plants
reproduce by the means of seeds.

 A seed is covered by a seed coat. A seed is attached to the fruits with scar and a
prominent hole is present through which water enters in it.

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 A seed contains cotyledons and embryo in between the cotyledons.

 The process of sprouting a seed into seedlings is called germination.

 Enough water, air and warmth are needed for the germination of seed.

 A germinating seed first gives root from the embryo, then it gives shoot.

 Some flowering plants which do not produce good seeds reproduce by other parts
like roots, stem and leaves.

 Plants like dahlia and sweet potato reproduce by the means of roots; plants like
sugarcane, potato, yam, etc reproduce by the means of stem and plants like
bryophyllum, begonia, etc reproduce by the means of leaves.

Project work

Take a tin can or any other vessel to sow some seeds.
Make some small holes around and fill soil in it. Take 3-4
soaked seeds of pea, gram or bean and keep them in the
soil. Write down the date, keep it on sunlight and pour
water regularly so that the seeds germinate and grow.
Now observe the following points of germinating seeds:

a. In how many days the seedlings are seen?

b. How many leaves are seen first?

c. What is the change in the number of leaves?

d. What is the change in the height of plant?

e. What is the change in the thickness of plants?

You can fix a stick with plant to measure height and you
can measure thickness by thread.

Now observe the changes in your plant weekly for four
weeks and note down the records as follows:

Week Height of Thickness of No. of
First plant (cm) plant (mm/cm) leaves

Second

Third
Fourth

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Exercise

1. Fill in the blanks with suitable words.
a. Non-flowering plants mostly reproduce by
.............................
b. Flower is the ............................. part of a plant.
c. Stamens are male parts of a flower which produce
.............................
d. A peanut seed has two .............................
e. Potato produces new plants by underground
.............................

2 Write ‘True’ for the correct sentences and ‘False’ for the
wrong ones.
a. The part of a seed through which water
enters in it is scar.
b. Pistil is the female part of a flower.
c. A fruit of a peach contains many seeds in it.
d. It is easy to peel the seed coat of a dry seed.
e. All seeds can germinate and grow into
young plants.
f. The baby plant growing from a seed is called
seedling.

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3. Match the following: Leaf
Sugarcane Underground stem
Maize Roots
Dahlia Seeds
Cocoyam Stem with buds.
Begonia

4. Arrange the following diagrams in the sequential order of
growth.

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5. Label A, B and C in the following diagram.
A - scar
B - hole
C - coat

6. Draw a diagram of a seed splitted open and label its
cotyledons and embryo.

7. Answer the following questions:
a. What is pollination? Write down four parts of a
complete flower.
b. What is germination of seed? What conditions are
needed for germination?
c. What is seedling? Which part grows first in a seedling?
d. Which plants reproduce by parts other then seeds?
e. Name any two plants that reproduce by;
i. leaves ii. stem iii. roots

Blooming Science, Health and Physical Education Book 4 63

Lesson Life Processes

6

Learning outcomes

At the end of this lesson, the students will be able to:
 define life processes.
 explain various life processes that take place in the body of living organisms in

brief.
 state the importance of nutrition, respiration, transportation and excretion in

living beings.

Boost Up

Which life process is carried out by the following.

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

Mouth Food pipe
Tongue

Pancreas Stomach
Liver

Gallbladder
Small intestine

Large intestine

Appendix

Anus

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

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There are some processes which occur only in living things.
Non-living things do not have the characteristics of living
beings. Living beings have some common characteristics. All of
them need food, breathe in air and transport various necessary
materials in different parts of the body. All living beings can
feel, can move, can excrete and reproduce their young ones of
their own kind. The activities which are performed by living
beings for their survival are called life processes.

Although the animals and plants have common
characteristics, the way of life processes are different. For
example, plants prepare their food materials themselves
whereas animals depend upon plants and other animals for
their food. In this lesson, you will learn various common life
processes of living beings.

Nutrition

All living organisms need food to survive. Food provides
energy for their growth and for performing various activities
in their body. Food is also needed to repair the cells and for
protecting the body from diseases. The process by which
living beings obtain food and utilize nutrients present in them
is called nutrition. There are two types of nutrition in living
beings. They are autotrophic nutrition and heterotrophic
nutrition.

Autotrophic nutrition

All green plants can prepare their own food. The leaves
of plants are green due to the presence of chlorophyll in them.
Green leaves prepare the food in the presence of sunlight
by using carbon dioxide and water. Such nutrition is called

Blooming Science, Health and Physical Education Book 4 65

autotrophic nutrition. The process light energy
of making food by green plants oxygen
using carbon dioxide and water in
the presence of sunlight is called crbohydrates carbon dioxide
photosynthesis. Plants take carbon
dioxide from air, water from soil and water
energy is absorbed by chlorophyll to
prepare the food in green leaves.

Heterotrophic nutrition

Animals can not prepare their own food. They depend upon
other animals or plants for their food. Such type of nutrition is
called heterotrophic nutrition. Animals take various materials
as food. The food materials are changed into soluble form to get
energy by different ways. The process by which food materials
change into soluble form is called digestion. Digestion takes
place in various higher animals.

Food and digestion in human beings

We need food for growth, development and to get energy.
We eat different types of food and they provide different types
of nutrients. The food provides the nutrition after its digestion.

The food we eat is chewed properly and converted to small
fine pieces. The chewed food mixes with saliva which makes
food soft and easy to swallow. The saliva mixed food passes to
stomach and then to intestine where it is mixed with different
juices. The food is separated into useful and non-useful things
in the stomach and intestine. The useful things are absorbed
through the walls of intestine. The non-useful things are passed

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away as faeces. This Mouth Food pipe
process of separating Tongue
useful and non-useful
things of the food in
the alimentary canal
is called digestion.

Pancreas Stomach

Liver
Gallbladder
Small intestine

Appendix Large intestine
Anus

Respiration Digestive system

Living beings need energy to grow, move, work and to
perform various other activities in the body. They get energy
by the burning of food with the help of oxygen. This process is
called respiration. Respiration is the process in which digested
food combines with oxygen to release energy. This energy
is used by the organism for various purposes. The process
of respiration in animals and plants is different. Respiration
takes place in two steps, breathing and internal respiration. In
breathing, oxygen is inhaled with air through various organs
and carbon dioxide is exhaled. In internal respiration, the
inhaled oxygen combines with food to form energy and carbon
dioxide is produced.

In animals, breathing takes place from various organs like
nose, skin, gills, etc and plants breathe through stomata.

We breathe in air through the nose. The hair inside the
nose filters out the dust particles and air gets warm. The warm

Blooming Science, Health and Physical Education Book 4 67

air reaches to the lungs through the wind pipe. Oxygen present
in the air is exchanged with carbon dioxide in lungs. Carbon
dioxide is breathed out from the lungs and oxygen reaches to
the cells through blood. This oxygen combines with digested
food in the cells and release energy which is stored in the cell.
The stored energy can be utilized by the body and thus formed
carbon dioxide again reaches to the lungs through blood.

In plants, respiration takes place throughout the day and
night. They utilize oxygen formed by photosynthesis during
the day and take oxygen from atmosphere at night.

Lungs Gills Stomata
Heart
Internal transport

Living organisms

carry various substances

from one part of the

body to another. This

process is called internal

transport. Living beings

transport food materials,

oxygen, water and other

useful substances from

one part to another. They Blood circulatory

also transport excretory system

products to the excretory organs.

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In developed animals and human beings, internal
transportation is carried out by the blood circulatory system.
Circulatory system consists of heart, blood and blood vessels.
The heart is the blood pumping organ which collects blood
from all parts of the body and sends to lungs for purification.
It supplies the pure blood to all parts of the body. The blood
moves throughout the body by means of blood vessels.

In plants, internal transportation

is carried out by some special tissues

present in the stem. They transport

water and minerals from roots to the

leaves and prepared food from leaves to

other parts of the body. Scan for practical experiment

Transportation in plant

Excretion URl: csp.codes/c04e11

Living organisms produce various waste materials in their
bodies during various life processes. These may be harmful if
they remain in the body. Therefore, these materials should be
removed from body. The removal of waste materials from the
body of living organisms is called excretion.

In animals, the excretory materials are carbon dioxide,
urea, faeces and excess water. Animals exhale carbon dioxide
through breathing organs like nose. They release urea, excess
water and sweat from kidneys and skin. Similarly, solid wastes
are removed in the form of faeces through anus.

Plants excrete waste materials like oxygen and water
vapour through small pores on the leaves known as stomata.

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Plants do not have developed excretory system as very little
waste products are formed in them.

Lungs excrete carbon dioxide Kidneys excrete urine

Rectum excretes solid waste Skin excretes sweat

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Key words

Saliva – watery substance formed in the mouth.
produce, allow to move.
Release – nitrogen containing waste in animals.
green pigment present in leaves.
Urea – movement of blood throughout the body.

Chlorophyll –

Circulation –

Main Points to Remember

 The activities which are performed by living beings for survival are called life
processes.

 The animals and plants have common characteristics and common life processes
but the ways of conducting life processes are different.

 Nutrition, respiration, internal transport and excretion are the main life
processes in the living beings.

 In human beings, digestion helps to separate the useful things from the food,
food gives energy by respiration and various things are transported by the blood
circulatory system. The metabolic wastes are excreted by excretory system.

 Such common life processes take place in other developed animals also.

 In plants, the life processes take place in different way.

 Plants prepare their food by the process of photosynthesis in green leaves. Water
and food are transported by some tissues.

 Plants also get energy by the burning of food with oxygen but no definite
excretory system is developed as they have very less excretory products.

Project work

Draw the diagram of human alimentary canal in your project
work copy and colour it. Write down the changes that take
place in various parts of alimentary canal with the help of
your teacher.

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Exercise

1. Fill in the blanks with suitable words.
a. Living beings need ................... to get energy.
b. The process by which food materials are separated into
useful and non-useful materials is called ...................
c. The chewed food is mixed with ................... in mouth.
d. We breathe in ................... and breathe out ...................
e. We excrete urea in the form of ...................
f. ................... is the pumping organ of blood.

2 Write ‘True’ for the correct sentences and ‘False’ for the
wrong ones.
a. Different life processes take place only in the
animals.
b. The plants have autotrophic nutrition.
c. The useful food materials are absorbed in the
intestine.
d. Plants do not need oxygen for respiration.
e. There are definite excretory organs in plants.
f. Energy is released by the combination of
food and oxygen in the cells.

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3. Write down one function of the following.
a. b. c.

d. e. f.

4. Answer the following questions:
a. What is meant by life processes?
b. What is the difference between nutrition in plants and
nutrition in animals?
c. Define photosynthesis. Does photosynthesis take
place at night? Why?
d. What is respiration? Name any two breathing organs
of animals.
e. What is excretion ? Name any two excretory organs of
animals.
f. Waste materials should be removed from the body,
why?
g. What is the function of heart in human body?
h. How does digestion take place in human body?
Explain in brief.

5. Draw the diagram of human lungs.

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Lesson Interrelationship

7

Learning outcomes

At the end of this lesson, the students will be able to:
 describe the relation between living beings and environment.
 explain the relation between plants and animals.
 explain food chain of various environment.

Boost Up

Write down the sources of food of following organisms.

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

The natural world around us in which plants and animals live
is called environment. Environment is everything which makes
up the surroundings of a living being. There are different types
of living beings and non-living things in the environment.

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Plants, animals,

bacteria, etc. are

living things.

Air, water, soil,

minerals, sunlight,

etc are non-living

things. Living

things present in

the environment

are called biological

components or

biotic components

and non-living Inter dependence in oxygen and
carbon dioxide
things are
called physical

components or

abiotic components. All organisms including human beings

depend on the environment for different things like heat,

water, air, etc. We use oxygen from air for respiration, water

for drinking and for many other purposes. We make shelter

by using various things. We get these things from the physical

components. All biotic components are inter-related with

each other for their food, shelter and reproduction. They

depend upon the abiotic components. Similarly, various

abiotic components are formed or depend upon the biotic

components. The biotic components and abiotic components

of the environment are interdependent. Hence, the number of

living beings and the amount of substances in the environment

is in a state of balance.

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Interrelationship between living beings and
physical components

Biotic components depend upon abiotic components like air,
water, sunlight, minerals, etc. The abiotic components also
depend upon biotic components in many ways. Scan for practical experiment

Living things depend upon abiotic
components for many things. Some of them
are as follows:

Air URl: csp.codes/c04e12

All animals and plants get oxygen from air for respiration. For
them, oxygen is required to release energy by reacting with foods.

Plants use carbon dioxide from the air to prepare their
food during photosynthesis process.

Water

All animals need water to dissolve the digested food and
to excre te the metabolic wastes. Animals can not survive
without water. Plants use water to prepare their food. Plants
take water through roots from the soil.

Sunlight

Sunlight provides warmth to the earth. All animals need
warmth to survive and for various life processes. Plants can
not prepare their food in the absence of sunlight. Chlorophyll
absorbs energy from sunlight to prepare food during
photosynthesis. The seeds can not germinate when they do not
get enough warmth from sunlight.

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Soil

Soil is the habitat of many living beings. All terrestrial
plants grow in soil. They get water and other minerals from
the soil by their roots. Most of the animals make their shelters
in the soil. Some animals like snakes, rabbits, rats, moles,
earthworms, etc make their shelters in the soil.

Earthworm in soil Ants in ant hill Snake in hole

Physical components depend upon biotic
components

Living beings take many things such as oxygen, carbon
dioxide, water, minerals, etc from the nature. In fact, living
beings borrow such physical things from nature. They return
such things again to the nature. Animals release many wastes
such as urine, stool, carbon dioxide, water, etc to the nature.

All animals and plants get mixed in the water after their
death. Their bodies decay and change into the soil.

All the minerals found in the bodies of animals and plants
return back to the soil. Roots of plants hold the soil and store
water in the soil.

In this way abiotic components depend upon the biotic
components.

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Interrelation between plants and animals

Animals depend upon plants

Animals depend upon plants in many different ways.
Some important ways by which animals depend upon plants
are explained here in brief.

Food

Animals depend upon plants for their food. Herbivorous
animals like cow, buffalo, goat, rabbit, deer, etc. directly
depend upon plants for food. They eat plants or plant products
as their food. Carnivorous animals such as tiger, wolf, snake,
fox, etc depend upon herbivorous animals for their food. As
herbivorous animals depend upon plants, carnivores also
depend upon plants indirectly. In this way, animals depend
upon plants directly or indirectly for food.

A goat grazing A deer grazing A tiger eating flesh

Oxygen

Animals need oxygen for respiration. In respiration, food
reacts with oxygen to give energy. Plants take carbon dioxide
and release oxygen during photosynthesis. This oxygen is
mixed in the air which is used by the animals for respiration.

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Scan for practical experiment

URl: csp.codes/c04e13

Exchange of gases in animals and plants

Shelter

Plants provide shelter to many animals. Some animals like
monkey, rat, squirrel, etc live on trees. Birds make their nest
on the trees and many insects make their homes in tree leaves
and branches. Many wild animals like elephant, zebra, etc live
under the trees.

Plants as shelter of animals

We also depend upon plants for many purposes. We can
not survive without plants.

We depend upon many different plants and their products
for ourfood. We get cereals, pulses, vegetables, fruits, tea,
coffee, spices, etc from the plants. We make our shelters and
furnitures by using plants. Our clothes are mainly made from
cotton fibres.

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We also use other fibres like jute, ketuki, etc to make mat,
sacs and ropes. The paper is prepared from straw, bamboo, etc.
Many plants are planted in our garden for flowers. They make
our house beautiful. We use flowers to make garland, bouquet
and to worship Gods during puja.

Plants depend upon animals

Plants depend upon animals in many ways. Some of the
ways by which plants depend upon animals are given below.

Carbon dioxide

Animals throw out carbon dioxide in the process of
respiration. Plants need carbon dioxide to prepare food during
photosynthesis. Plants take carbon dioxide from the air. So,
animals provide carbon dioxide to the plants.

Fertilizers

Animals provide various things to the plants as manure.
Urine and faeces of animals can be used as the fertilizers for
plants. When dead bodies are decayed by the microorganisms,
they are changed into the fertilizers for the plants.

Dispersal of seed

Animals help for the dispersal of seeds. Some animals and
birds swallow the seeds of fruits like guava, cucumber, tomato,
etc and pass the seeds out through the stool. These seeds may
germinate and grow into new plants. Some seeds or fruits are
transfered by clinging on the body of animals from one place
to another.

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Pollination

In plants, pollen grains are
transfered from stamen to pistil.
The pollen grains are transferred
by different agents. Animals are
one of the agents that transfer the
pollen grains. When insects sit on
the flower, the pollen grains stick
on their bodies. These pollen grains are transfered to other
flowers when these insects sit on those flowers.

Food chain

All living things need food to survive. Plants prepare their food
by using water and carbon dioxide from the environment. Animals
get the food from plants or other animals. They can not prepare their
food themselves and depend on plants for their food.

Green plants trap the energy of sunlight to prepare their
food. Some part of this energy is utilized by plants for their
growth and the other is stored in them. Animals get energy
when they eat plants as food. When animals eat plants as food,
the energy is transfered along it. When this animal is eaten by
another animal, energy again passes in that animal. One living
thing gets energy from the other living thing in the form of
food. The transfer of energy from one living thing to another
through the food is called food chain.

We get energy from plants in the form of cereals, pulses,
vegetables, lentils, nuts, fruits, etc.

There are many food chains existing in nature. In a food
chain, energy is transfered in the form of food from one
organism to another.

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Plants prepare their food themselves by the process called
photosynthesis process. They produce energy for themselves
and other animals also. They are called as producers.
Plants are eaten by herbivorous animals like deers, goats,
rabbits, rats, etc. These animals are called primary consumers.
Primary consumers are eaten by carnivorous animals like
tiger, fox, lion, eagle, snake, etc. These are called secondary
consumers.
When the plants and animals die, their dead bodies get
decomposed by bacteria. These are called as decomposers.
After decomposition, the dead organisms are mixed with soil
and provide manures to the plants.

Some food chains

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Key words

Shelter – home of an animal

Minerals – any of the inorganic elements needed for the
development of plants
Cling –
Manure – stick to

any natural or artificial substance for
fertilizing the soil

Main Points to Remember

 The surrounding that consists of living and non-living things is called environment.

 The living beings of the environment are called biotic components and the non-
living things of the environment are called physical or abiotic components.

 The biotic and abiotic components are inter-dependent with each other.

 Living beings depend on air, water, sunlight and soil.

 Abiotic components are formed and are returned back to the environment by
biotic components in many ways.

 Animals depend upon plants for food, oxygen and shelter.

 Plants depend upon animals for carbon dioxide, fertilizers, dispersal of seeds and
pollination.

 Animals and plants are interrelated with each other.

 The transfer of energy from one living thing to another through food is called
food chain.

 In nature, energy is transfered from producers to primary consumers and then
to secondary consumers in the form of food.

Blooming Science, Health and Physical Education Book 4 83

Project work

1. Observe your surrounding and find the organisms (Plants
and animals) to form various food chain. Make two food
chain you could observe. Discuss with your friends and
teacher in the classroom.

2. Make a list of any 6 biotic or abiotic components on which
we depend upon and mention their use.

S. No. Name of things Biotic/Abiotic Use
1.
2.
3.
4.
5.
6

Exercise

1. Fill in the blanks with suitable words.
a. ........................... is made by living beings and non-
living things of our surrounding.
b. Animals depend upon plants for ...........................,
shelter and oxygen.
c. ........................... absorbs energy from sunlight for
photosynthesis.
d. In a ..........................., energy is transfered from one
organism to another in the form of food.

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e. ........................... give energy to the primary consumers.
f. Plants are eaten by ........................... animals.

2 Write ‘True’ for the correct sentences and ‘False’ for the
wrong ones.
a. All living things depend upon non-living things.
b. Animals get carbon dioxide from plants.
c. Dead bodies of animals provide manures to
the soil.
d. The seeds disperse themselves in nature.
e. Energy is transfered in the form of food from
one organism to another.
f. Plants take carbon dioxide by the roots to
prepare food.

3. Which one is not suitable in the food chain.
a. Goat, tiger, grass, cat.
b. Eagle, grass, snake, chicken.
c. Hare, lizard, spider, housefly.
d. Butterfly, sparrow, a flowering plant, rat.
e. Grains, cat, rat, goat.

4. Answer the following questions
a. What is an environment?
b. How do biotic components depend upon abiotic
components? Write down in three points.

Blooming Science, Health and Physical Education Book 4 85

c. What do the green plants need to prepare their food?

d. Write down any two points for which animals need
plants.

e. Write down any two things that the plants get from
the animals.

f. What is a food chain?

g. Can animals prepare their own food? Why?

h. Why are green plants called producers?

5. Make a food chain from the following organisms.

a. eagle grains rat

b. goat man grass

c. maize cat rat

d. deer grass tiger

e. grass lizard grasshopper

6. Draw the diagrams to show any one of the food chain
mentioned in question number 5.

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Lesson Natural Disasters

8

Learning outcomes

At the end of this lesson, the students will be able to:
 introduce natural disasters with examples.
 explain the causes and impacts of some natural disasters like flood, land slide,

fire and earthquake.
 adopt preventive and control measures of above mentioned natural disasters.

Boost Up

Which natural event is shown in the given diagram?

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

There are various activities taking place in the nature.
Some natural activities like rain, cloud formation, weather
change, snow fall, etc are not harmful to us. But some natural
activities like heavy rain, landslide, earthquake, forest fire,
excessive hail stones fall, etc are harmful to us which may

Blooming Science, Health and Physical Education Book 4 87

cause the loss of life and property. A sudden natural event that
damages lots of lives and properties is called a natural disaster.
Floods, landslides, earthquake, volcano, fire, drought, etc are
the natural disasters. Some natural disasters are caused by
water, some are caused by earth’s internal structure and some
are caused by negligence of the people. Although there are
many different types of natural disasters, in this lesson you
will learn the causes, effects and preventive measures of flood,
landslide, fire and earthquake.

Some natural disasters

Flood

When water falls on dry land, it is absorbed. If heavy rain
occurs for a long time, the soil can not absorb all the water.
Water from various sources like river, lake, stream, etc also
cover the plain area. It may keep the crops and houses under
water. The overflow of a large amount of water beyond its
normal limit over the dry land is called flood.

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Causes

A Flood is caused by a heavy rainfall, deforestation and
outburst of glacial lakes. Sometimes, destruction of dams and
landslide also leads to a flood.

Effects

Flood damages buildings, bridges, roads and other
developmental structures. It damages crops and agricultural land.
It sweeps away fertile soil from agricultural land. Fertile land of
Terai region of our country is covered by sand due to the flood. It
kills many domestic and wild animals. Flood may kill the people
and is responsible for spreading different diseases.

Preventive measures

Flood occurs naturally. But we can play an important role
to minimize the adverse effects of a flood. Some methods are
as follows:

1. Afforestation, conservation of forest and tree plantation
should be done. Roots of plants can capture and hold the soil.
So, we should plant trees near the bank of rivers or streams.

2. We should construct river embankments on the bank of
river to control soil erosion due to flood.

3. We should construct dams and diversion-channels in the
rivers.

4. We should conserve our watersheds like ponds, lakes and rivers.

5. We should not take out sand and gravels from the river
haphazardly.

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Landslides

During rainy season, soil of sloppy land becomes heavier
and falls downward along with the rocks. The falling down
of the soil and rocks from a slope of hill downwards is called
landslide. The falling mass of land buries the houses, farms,
fields, etc resulting in the damage of lives and properties. Most
of the land of our country is sloppy with high hills. So, we can
hear many news related to landslides in rainy season.

Causes

Landslide is also
caused by the heavy
rainfall as it makes
the soil of hilly region
heavier. The soil is
hold tightly by the
tree roots. If the trees
are cut down, the soil
of that area becomes weak and loose and easily falls down as
landslides. Landslides are also caused by shaking of the earth
due to earthquake and explosion of bombs while constructing
various infrastructures like roads, hydropowers, etc. It is also
caused by the overgrazing of animals in the sloppy land.

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Effects

Landslide causes the loss of life and property of people
in many ways. It causes the destruction of agricultural land.
It destroys the houses, bridges, roads and other human made
structures. It washes off the crops and forests of sloppy land
and cover the plain down the slope by depositing. It may cause
water pollution which can spread many diseases. The falling
mass of soil and rocks may block the flow of river and stream
which can cause floods.

Preventive measures

We can apply following measures to minimize the effects
of landslides.

1. We should promote afforestation and plantation of trees
on uncultivated areas and sloppy land.

2. Terrace farming should be done on sloppy area which
prevents the sliding of the soil during rainfall.

3. Overgrazing of animals should be checked.

4. Retaining walls should be constructed in the areas affected
by landslides.

Terraces with crops Retaining wall Hill with forest

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Forest fire

Forest fire is the fire in the
jungle. It is very dangerous.
It occurs mainly in summer
season when the leaves and
grasses become dry. It can kill
wild animals and destroys
their habitat. The grass, bushes
and trees are destroyed by the
forest fire. Forest fire affects the houses and other man made
structures constructed nearby the forest.

Causes

A fire can be caused naturally or by the negligence of
human beings. Rubbing of branches of trees, striking of stones
while falling down and lightening may cause fire naturally.
But in general, forest fire is caused by negligence of the people.
When people throw burning matchsticks, cigarette butts and
leave fire after cooking food, forest fire may occur.

Effects

Forest fire destroys plants and animals of the forest. It
destroys the habitat of wild animals and birds. It causes air
pollution by mixing smoke to the air. Forest fire affects the
houses and other man made structures constructed nearby the
forest. It also ruins the beauty of nature. The land looks bare
and ugly after forest fire. The chances of landslide increases
and it also may cause the disturbance in natural balance.

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Preventive measures

The following measures can be taken to minimize the
adverse effects of forest fire.

1. We should not throw burning matchsticks and cigarette
butts in the forest.

2. People should not leave fire without putting it out.

3. Forest fire can be controlled by clearing up the part of the
ground by digging. This is called a fire line. It helps to stop
the spreading of fire to larger area.

Earthquake

The interior of the earth is made by various things. Many
changes take place inside the earth leading to the formation
of energy. Due to various changes, the earth’s surface may
shake time and often and can cause various disturbances. A
sudden and violent shaking or vibration of the earth’s surface
is called as an earthquake. It is a very dangerous phenomenon.
An earthquake cannot be forecasted. Most of the earthquakes
are caused by the movement of the continental plates called
tectonic drifts.

Effects

An earthquake causes 93
collapse of buildings, destruction
of development structures and
fire. Thousands of people die
in different countries due to
earthquake. It causes a great loss
of lives and properties.

Blooming Science, Health and Physical Education Book 4

Preventive measures

We can not control earthquake but we can minimize the
effects of earthquake. We can take the following preventive
measures to minimize the adverse effects of an earthquake.

1. If we are outside the building during an earthquake, we
have to stay in an open area.

2. If we are inside a house during an earthquake, we have to
move to safe places like inner corner of the rooms, under
the furniture, under the door frame, etc.

3. If we are inside the classroom, we have to hide under the
bench, table, desk, etc.

4. We should build earthquake- resistant houses and school.

Key words

Out burst – to break out

Glacial – relating to large ice mass.

Embankment – a bank raised to hold back water.

Cultivated – prepared and used for raising crops.

Terrace – a horizontal flat area of land, often one of a
series in slope.

Continental plates – one of the large pieces of the surface of the
earth that move separately.

Main Points to Remember

 A sudden natural event that damages lots of lives and properties is called natural
disaster.

 Some natural disasters are caused by various natural processes and some are
caused by negligence of human beings.

 The overflow of a large amount of water over the dry land is called flood.

94 Blooming Science, Health and Physical Education Book 4

 Flood is caused by heavy rainfall and damages various development structures,
houses, agricultural lands and crops.

 The process of sliding of a heavy mass of rock on the slope of hills is called
landslide.

 Landslides basically occur in hills in rainy season and cause many damages in
the lives and property.

 Both flood and landslide can be controlled by afforestation.
 Forest fire is also one of the dangerous natural disaster. It is caused by negligence

of people and causes great loss of lives and properties.
 A sudden shaking or vibration of the earth’s surface is called an earthquake.

It can not be predicted. Thousands of people die in different countries due to
earthquake.

Project work

1. Collect some pictures of different natural disasters and
paste them in your project work copy.

2. Visit a place struck by any natural disaster in your locality.
Prepare a short note on it and show to your teacher.

Exercise

1. Fill in the blanks with suitable words.

a. Flood, landslide, earthquake, forest fire, etc are ..............

b. Overflow of water on dry land is called ..............

c. .............. is the falling down of rock and soil from
sloppy hill.

d. .............. farming should be done to prevent landslide.

e. Cigarette butts can cause ..............

f. .............. are caused by movement of tectonic plates.

Blooming Science, Health and Physical Education Book 4 95

2. Write ‘True’ for correct sentences and ‘False’ for wrong ones.
a. The main preventive measure of natural
disasters is afforestation.
b. The overgrazing of animals can cause landslide.
c. Landslide occurs mainly in plain area.
d. Earthquake is caused by human activities.
e. River embankments can minimize the flood.
f. Forest fire may cause the loss of habitat of
wild animals

3. Answer the following questions:
a. What is flood? Write down any two effects of flood.
b. Write down any two preventive measures of flood.
c. Why do landslides occur in hilly region of our country?
d. How do the trees minimize landslide? Explain in brief.
e. How can we control forest fire? Suggest any two methods.
f. What is an earthquake? What can we do to be safe
from earthquake? Write down in two points.
g. Write down any two effects and any two preventive
measures of landslides.
h. What is forest fire? Write down any two causes of
forest fire.

4. Draw a diagram to show a natural disaster.

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Lesson Matter

9

Learning outcomes Scan for practical experiment

At the end of this lesson, the students will be able to:
 define matter with examples.
 state matter has mass and volume.
 explain three states of matter.
 introduce change of state.

URl: csp.codes/c04e16

Boost Up

In which states are the following substances found?

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

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

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There are many things around us. Some of the things
found around us are book, copy, ink, brick, glass, water, milk,
etc. All of them do not have same shapes and sizes. Some are
bigger and some are smaller. But they take the space according
to their size. When we keep some substances like brick, book,
nail, etc on the table, they occupy some space. Similarly, when
we take some water or milk in a glass these take the space of
glass. So, the things around us occupy the space. The space
occupied by a body is called volume. Similarly, we can weigh
various substances. Some things found around us are heavier
and some are lighter. We can weigh these substances like brick,
book, nail, water, milk, etc by using a balance. This shows that
these things have mass.
We do not see air but we can feel its presence. For example,
we feel the presence of air when we use a fan. Air also has weight
like other things. For example, a football filled with air is heavier
than a football without air in it. Air occupies space as well. In same
example, the football filled with air is seen bigger.
The things around us are similar to one another in the
following two ways.
i. All of them occupy space.
ii. All of them have mass.

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Anything that occupies space and has mass is called matter.

The matters are different from each other because they are
formed by different materials. For example book, table, and
milk are different as they are formed by different materials like
book is made by paper and table is made by wood.

Matter is made from very small particles. These small
particles by which a matter is made are called molecules. They
are very small so that we can not see them with our naked eyes.

Activity: 1

To show matters have weight and occupy space.
Take some substances like a book, a nail, a brick, a glass of milk, some water, etc. keep
book, nail and brick on a table and observe whether they occupy some space on the
table or not. Similarly, pour milk and water in a measuring cylinder and observe it.

You can observe that all matters have volume or they occupy space.

Similarly, take a balance and find the weight of above mentioned objects turn by turn
and note down their weight.

Activity: 2

To show air has weight and occupy space.
Take two balloons. Fill both balloons with
air to equal size and tie both of them in two
sides of a scale or a small stick with the help
of a thread. Put the thread in the middle of the
stick and suspend it to a nail so that the stick
remains straight or balanced. Now prick one
balloon with a pin and observe what happens?

You will see that the stick does not remain balanced as the air comes out of the
balloon.

This shows air has weight and occupies space.

Blooming Science, Health and Physical Education Book 4 99

States of matter

Matter exists in three states. They are solid, liquid and gas.

Solid

Solids are the substances which have definite shape and
volume. We can carry the solid substances in our hands as
they are rigid and have shape. Things like brick, book, pen,
stone, wood, ice cubes, pots, etc are solid. In solid, molecules
are tightly packed. Solid substances can be broken into small
pieces also.

Book Brick Pencil Ice cube

Some solid substances

Liquid

Liquids are the substances which have fixed volume but
no fixed shape. In liquid, molecules are loosely packed. They
can move freely. Therefore, liquids can flow from a higher level
to a lower level. It can be poured from one vessel to another. It
gains the shape of the vessel in which it is kept. Liquids can not
be stored without a vessel and can not be compressed. Water,
milk, alcohol, kerosene, oil, etc are the examples of liquids.

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