HPE-book-5-for-press

KEDC Approved by Government of Nepal, Ministry of Education,
Curriculum Development Centre, Sanothimi, Bhaktapur

KEDC's

Science, Health and Physical
Education

5

Writer
Kishor Nepal

M.Sc., M.A., B.Ed.

Kantipur Education Development Council

Maharajgunj, Chakrapath, Kathmandu, Nepal
Phone: 4720202/2151710
Email: [email protected]
Website: www.kedcnepal.com

KEDC

Kantipur Education Development Council
Maharajgunj, Chakrapath, Kathmandu, Nepal
Phone: 4202027/2151710
Email: [email protected]
Website: www.kedcnepal.com
Kantipur Education Development Council 2058 ALL
RIGHTS RESERVED. No part of this book may be
reproduced or transmitted in any form by any means,
electronic or mechanical, including photocopying and
recording, or by any information storage and retrieval
system, except as may be expressly permitted in writing
by the publisher.

Written by:
Kishor Nepal

Contributor:
Ghanashyam Dhakal

Edition:
First, 2018

Layout/Design
Sarika Koirala

Illustrator:
Umesh Chandra Adhikari

Preface

Science is a fascinating subject which is widely spread in the world
we live in, as it focuses on the cause and effect, besides the reasons.
Science becomes fun and interesting to a student when it is taught in an
interactive manner and is related to his/her surroundings.

The early schooling years in a student's life is of extreme importance.
These are the times when they focus their eyes and mind on everything
that is new and appealing. Their attention span is short and they require
constant reinforcement and what interests them the most is things and
events around them. This is the golden opportunity to inculcate in them
a spirit of adventure and inquiry, to teach them to ask, to reason and to
pick up healthy habits.

With this in mind, KEDC decided to bring out a science series for the
junior classes which would be simple to read and still convey the idea
of scientific discovery to the students. Moreover, an effort was made to
make the book extensively illustrative. Most of the concept is presented
and demonstrated by simple experiments which the teacher can help
the students to perform on their own. This series also addresses the
objectives of the present curriculum, appropriately planning and
fulfilling the needs of students and teachers.

We sincerely hope that this series would prove to be an interesting
experience for students. Any suggestions for further improvement will
be welcomed.

Contents 1
19
1. Classification of Animals 28
2. Cell 35
3. Life Cycle of a Butterfly 53
4. Parts of Flowering Plant 63
5. Life Processes 79
6. Effects of Human Activities on Environment 91
7. Environment Conservation 98
8. States of Matter 108
9. Energy 122
10. Weather 134
11. Solar System 143
12. The Earth 150
13. Information and Communication 160
14. Local Technology 172
15. Personal Hygiene 189
16. Food and Nutrition 196
17. Health Service and Community Health 205
18. Communicable Diseases 214
19. Tobacco, Alcohol and Drugs 227
20. Safety and First Aid 238
21. Locomotor Skills 245
22. Drill and Physical Training 253
23. Simple and Local games
24. Gymnastics and Balancing

1Lesson Classification Science
of Animals

Specific After the completion of the lesson, students will be able to:
Objectives
• identify different types of animals.
• list the different groups of vertebrates and invertebrates.
• state the main features of the different classes of vertebrates and

invertebrates.

Mind Opener

• Can you distinguish vertebrates and invertebrates? Explain.

• Name some cold blooded and warm blooded animals.

• What are the organisms that can be seen only through microscope?

• Is earthworm harmful for us? Why?

• Find out the odd one in each case with suitable reason.

a. spider crab starfish cockroach butterfly

b. dog cow human lizard whale

c. snake pigeon crocodile tortoise lizard

d. whale fish seahorse shark dolphin

e. peacock parrot duck pigeon bat

f. paramecium amoeba sycon euglena giardia

Science, Health and Physical Education Book - 5 1

Introduction

Look around us. There are various type of animals. Do they have same shape,
size and colour? Do they live in similar place? Do they feed same type of food?
You would observe that all these animals differ from each other. Among them,
some animals are very large and some animals can't be seen with naked eyes.
Such organisms which can't be seen with naked eyes and can be seen only
through microscope are called microscopic organisms.

Some animals like amoeba, paramecium, euglena, etc are unicellular
microscopic organisms. They cannot be seen through our naked eyes. Some
animals like elephant, cow, blue whale are very big animals on the earth.
Despite vast difference in their shape and size, they all are animals.

Some animals live in water, some live on land, some live under soil and others
live in air. Thus, various type of animals have different type of body structure,
habitat, living style, movement nature, feeding habit. All these animals are
divided into two major groups on the basis of presence or absence of backbone.
They are vertebrates and invertebrates.

On the basis of features they bear, vertebrates and invertebrates are further
classified into different groups.

Animals

Vertebrate Invertebrate
• Protozoa
• Pisces • Porifera
• Amphibia • Coelenterata
• Reptilia • Platyhelminthes
• Aves • Nemathelminthes
• Mammalia • Annelida
• Arthropoda
• Mollusca
• Echinodermata

2 Science, Health and Physical Education Book - 5

Vertebrates

Some multicellular animals are well developed with bones in their body. They
have backbone or vertebral column to support the body.

The animals having backbones are called vertebrates. The backbone of
vertebrates are also called vertebral column. It is composed of segment of bones
to support the body. The vertebrates have well developed nervous system with
brain and spinal cord. Blood circulatory system is also well developed and
heart helps to circulate blood throughout the body. Vertebrates are found both
in water and on land. They may be cold blooded or warm blooded.

Fish, frog, snake, crocodile, etc are some examples of cold blooded vertebrates
whereas human and bird are examples of warm blooded vertebrates.

All vertebrate animals are also not of same kind. Based on their shape, size,
structure and growth, they can be further divided into five different classes
which are explained below.

Pisces

Pisces are the animals which are aquatic in nature. All kind of fishes are
included in this class. They live in both fresh and salty water and can be found
all over the world. The main features of Pisces are as follows.

1. Their body is streamlined (boat shaped) covered with smooth and water
proof scales.

2. Their body can be divided into head, trunk and tail.

3. They have fins for locomotion and gills for respiration.

4. They lay eggs without shells.

5. They have two chambered heart.

6. They are cold blooded animals.

7. They have swim bladder that makes their body light.

Common examples: rohu, catla, electric ray fish, dog fish, silver carp, sea horse,
flying fish, etc.

Barracuda Salmon Shark Beta fish

Science, Health and Physical Education Book - 5 3

Amphibia

Amphibians are the animals which live both on land and in water. They spend
some part of their life in water and some part in land. The main features of
amphibia are as follows.

1. They live in water as well as on land but lay their eggs in water.
2. They are cold blooded animals.
3. Their body is divided into head and trunk.
4. They have two pair of limbs. The hind limbs are longer and stronger than

the forelimbs. So, they can jump easily.
5. They have soft and moist skin.
6. They breathe through the gills in their larva stage and through skin and

lungs in adult stage.

7. They have three chambered heart.
Common examples: toad, mud slipper, frog, salamander, newt etc.

Toad Frog Salamander Newt

Activity 1

Ask your teacher to place before
you a preserved specimen of a
fish. Observe the fish and note
its important features. Draw
the diagram of the fish in your
practical note book and label its
various parts. While labelling the
parts, you can take the help of the
adjoining figure:

4 Science, Health and Physical Education Book - 5

Reptilia

Reptiles are the crawling animals. So, they are also known as crawling
vertebrates. Most of the reptiles live on land but some live in water also. The
main features of reptiles are as follows.

1. They creep or crawl on land or on walls.
2. They have dry and scaly skin.
3. Their body is divided into head, neck, trunk and tail.
4. They have two pair of limbs for movement except snakes.
5. They lay eggs on land for reproduction.
6. They breathe through the lungs on land and through skin in water.
7. They are cold blooded animals with three chambered heart. (Crocodile has

4 chambered heart)

Common examples: crocodile, chameleon, water monitor, lizard, snake,
tortoise, alligator, etc.

Crocodile Lizard Snake Tortoise

Aves

Aves belong to both terrestrial and aquatic animals. They are the only animals
with feathers. Though all birds have wings, all birds cannot fly. The main
features of aves are as follows.

1. Their body is covered with feathers and legs with scales.
2. Their body is divided into head, neck, trunk and tail.
3. Their body is streamlined.
4. Their forelimbs are modified into wings and jaws into beak without teeth.
5. They breathe through lungs and have four chambered heart.
6. They have air sacs inside the body which makes their body light.
7. Their bones are hollow, light and spongy.
8. They are warm blooded animals.

Science, Health and Physical Education Book - 5 5

9. Female aves lay hard shelled eggs that hatch into the adult bird.
Common examples: peacock, ostrich, parrot, pigeon, sparrow, duck,
kingfisher etc.

Kingfisher Duck Ostrich Pigeon

Mammalia

Mammals are both terrestrial and aquatic animals which directly give birth
to their young ones. Most of them live on land and few of them live in water.
Whales and dolphins are mammals that live in water. The blue whale is
the largest animal living on the Earth whereas the human being is the most
advanced mammal. The main features of mammals are as follows.

1. They give direct birth to their young ones.
2. Females have mammary glands or breasts to feed milk to their young ones.
3. Their body is covered with fur or hair.
4. Their body is divided into head, neck and trunk.
5. Most of the mammals have tail.
6. They have well developed brain.
7. Their skin has sweat glands to regulate the body temperature.
8. They breathe through lungs.
9. They have a four chambered heart.
10. They have external ears called pinna.

11. In dolphin and whale, fore limbs are modified into swimming paddles. So,
they can swin in water whereas bat is a flying mammal whose forelimbs
are modified into wings.

Common examples: human, bat, dolphin, whale, dog, etc.

Man Whale Bat Tiger

6 Science, Health and Physical Education Book - 5

Activity

Look at the four animals shown alongside which represent four classes of
vertebrates. Name these classes.

1. 2. 3. 4.

Invertebrates

We can see many simplest and less developed animals around us. They are
without bones and backbones. Such animals which do not have backbone are
called invertebrates. Invertebrates lack backbone or internal skeletons. Some
of the invertebrates possess outer hard coverage called shell. They are less
developed and are primitive animals. But the size of the invertebrate varies
from microscopic to macroscopic. Invertebrates are the most numerous and
widely varied, found in different habitats according to the adaptation. Besides,
the methods of locomotion, nutrition, respiration, etc are different in various
invertebrates.

On the basis of structure and development, invertebrates are classified into
nine phyla. They are as follows:

Protozoa (Single celled animals) Info bits

Protozoa includes most primitive animal The method of reproduction in
and they are considered as first animal which an organism divides into two
on Earth. Protozoa are commonly found or more similar organisms is called
in water and in moist places, but also fission.
found inside the body of other animals

including human as parasites. The main features of protozoa are as follows.

1. They are made up of single cell. So, they are called unicellular organisms.

2. They can be seen only by microscope, so they are called microscopic
organisms.

Science, Health and Physical Education Book - 5 7

3. They breathe through general body surface.
4. They reproduce by fission.
5. They have organs like pseudopodia, flagella or cilia for locomotion.
6. All life processes of protozoa occur within the single cell.

Common examples: amoeba, paramecium, euglena, plasmodium, etc.

Amoeba Paramecium Euglena

Porifera (pores bearing animals)

Porifera are multicellular primitive organisms which bear numerous pores
throughout their bodies. They are also called sponges. These organisms are
mostly found in sea water (marine water), attached to the bottom of the sea.
They have a large opening called osculum. The main features of porifera are
as follows.

1. The body is made up of many cells. So, they are multicellular organisms.
2. They have numerous pores on their bodies.
3. They are aquatic animals. Mostly found in marine water.
4. Most of the animals of this phylum are found attached to the substratum.
5. They have a sac - like hollow body.

Common example: sycon, euspongia, spongilla, etc.

Sycon Euspongia Spongilla

8 Science, Health and Physical Education Book - 5

Coelenterata (animals having body cavity)

Invertebrates having central body cavity or hollow cavity are included in this
phylum. Some important features of coelenterata are as follows.

1. They are multicellular organisms.
2. They are aquatic animals. Most of the coelenterata are found in marine

water but some are found in fresh water.
3. They have sac like hollow body with single opening called mouth for intake

and outlet of food materials.
4. Their mouth is surrounded by tentacles that help in movement and catching

prey.
5. Breathing takes place through the general body surface.
6. They reproduce by budding or regeneration.

Common examples: hydra, sea anemone, jelly fish, corals, obelia, etc.

Hydra Sea anemone Corals Jelly fish

Platyhelminthes (animals having flat body)

Animals of this phylum have a flat ribbon-shaped body. They are commonly
known as flat worms. Some important features of platyhelminthes are as
follows.

1. They are multicellular.
2. They have a long and flat leaf - shaped or ribbon shaped bodies.
3. Usually they are parasites while some live in fresh water.
4. Their alimentary canal is not complete i.e. these animals have mouth but

no anus.
5. They reproduce by sexual method.

Science, Health and Physical Education Book - 5 9

Common examples: tapeworm, liver fluke, planaria, etc.

Liver fluke tapeworm planaria Schistosoma

Nemathelminthes (Aschelminthes)

The animals in this phylum have round and unsegmented body. They
are commonly known as round worms. Some important features of
nemathelminthes are as follows.

1. They are multicellular organism.

2. They have unsegmented, long, narrow and cylindrical body.

3. Their alimentary canal is complete with mouth and anus at the two ends.

4. They are free living found in soil. But Info bits
most of them live in the intestine of Organism having only one type of
other animals as parasites. sex organ either male or female
in its body is called unisexual
5. They have less developed sense organism.
organs.

6. They are unisexual organisms.

Common examples: round worm, hookworm, filarial worm, trichinella, etc.

Roundworm Hookworm Filarial worm Trichinella

10 Science, Health and Physical Education Book - 5

Annelida (segmented worms)

Phylum annelida consists of invertebrates having ring like segmented bodies.
They are found in moist soil and some of them are parasites. The main features
of annelida are as follows.

1. They are multicellular with elongated, cylindrical and segmented body.

2. They have soft and moist skin Mini dictionary
through which they respire. ectoparasite: a parasite, such as a
flea, that lives on the outside of its
3. They are found in both aquatic as host.
well as terrestrial habitats .

4. Some are ectoparasitic but most are
free living.

5. They have a well developed digestive system with mouth and anus at the
two ends.

Common examples: earthworm, leech, nereis, aphrolite, tubifex, etc.

Earthworm Leech Nereis Tubifex

The earthworm lives in the soil. It helps to make the soil fertile. But leech is the
parasite which feeds on the blood of other animals.

Arthropoda (Animals with joint legs)

The term arthropoda means the animals with jointed legs. Phylum arthropoda
have largest number of species on the earth. They are distributed all over the
earth in all climatic conditions. They are also called insects. The main features
of arthropoda are as follows.

1. They have three or more pairs of jointed legs and a pair of compound eyes.
2. Body is divided into three parts; head, thorax and abdomen.
3. Most of them have wings and some have antennae that act as sensors.

Science, Health and Physical Education Book - 5 11

4. They are found in all habitats like desert, sea water, fresh water, wetland,
grassland, dense forest and so on.

5. They breathe through tracheal tubes in terrestrial form and through general
body surface and gills in aquatic form.

6. Their body is covered by hard exoskeleton.

Common examples: butterfly, spider, crab, cockroach, millipede, centipede,
etc.

Ant Bee Butterfly Spider

Among the members of this phylum, some insects like silkworm and honeybee
are very useful to us. Silkworms give us silk fibres whereas honeybees give us
honey. Besides, there are many harmful insects too. The poisonous insects can
bite us causing injury. They may attack our crops, pets and other domestic
animals. Similarly, some of the insects like housefly, mosquito, etc transfer
diseases to us.

Activity 2

Ask your teacher to place before you
the preserved specimens of some
common insects. Observe these
insects and identify them. Note their
important features and draw them in
your practical note book. A diagram of
a butterfly is given here for guidance.
Draw, identify and label the body parts
of other animals in the same manner.

12 Science, Health and Physical Education Book - 5

Mollusca (soft body shelled animals)

Animals of this phylum have soft body covered with hard shell. They are
found in water or moist places. The main features of mollusca are as follows.

1. They have soft and moist bodies which may be protected by hard covering
shells.

2. They have a muscular foot.
3. The head of some molluscs have tentacles as sense organs.
4. The head is distinct and consists of mouth, eyes and tentacles.
5. They respire through gills and lungs.

Common examples: snail, slug, octopus, squid, unio, etc.

Snail Slug Pila Octopus

Echinodermata (Animals with spiny skin)

Phylum echinodermata consists of marine invertebrates having spiny skin.
Some important features of echinodermata are as follows.

1. They have spiny skin that protects them from their enemies.
2. They are found in marine water.
3. Their body may be star like elongated or flower like.
4. They do not have distinct head.
5. Their sense organs are poorly developed.
6. They move with the help of their tube feet.
7. They reproduce by sexual method.

Common examples: starfish, sea cucumber, sea urchin, sea lily, etc.

Science, Health and Physical Education Book - 5 13

Starfish Sea cucumber Sea urchin Sea lily

Classification of animals at a glance

Category Common Examples

VERTEBRATES Pisces: Body covered with scales, fins rahu, catla, shark
(animals with a backbone) for swimming

Amphibia: Live in water as well as on frog, toad
land, but must go to water for laying
eggs

Reptilia: Mostly land vertebrates are lizard, snake
covered with dry and scaly skin

Aves: Body covered with feathers and pigeon, parrot, peacock, crow
have wings for flying

Mammalia: Body covered with hair cow, rat, cat, elephant, lion
and suckle babies on their own milk

Protozoa: Single celled animals amoeba, paramecium

INVERTEBRATES Porifera: Animals with pores for sponges, sycon, grantia
(animals without a backbone) water intake

Coelenterata: Animals with hollow hydra, corals
cavity body structure

Platyhelminths: Flatworms tape worms, liver fluke

Nemathelminthas: Round (Cylindrical) roundworm, hookworm
worms

Annelida: Segmented body earthworm, leech

Arthropoda: Animals with jointed ant, bees, prawn, scorpion,
legs millipede

Mollusca : Soft bodied shelled animals snail, slug

Echinodermata: Spiny skinned starfish, sea cucumber
animals

14 Science, Health and Physical Education Book - 5

Points to Remember

1. Animals that have backbone or vertebral column are called vertebrates.
2. Vertebrates are divided into five classes.
3. All fishes come under the class pisces.
4. The vertebrates that can live both on land and in water are called

amphibians.
5. Reptiles are cold blooded, crawling vertebrates having hard, dry and

horny scales.
6. Aves are warm blooded flying vertebrates having wings and feathers

on their body.
7. Mammals are warm blooded vertebrates that directly give birth to their

young ones and suckle them.
8. Animals which do not have backbone or vertebral column are called

invertebrates.
9. Protozoa are unicellular and microscopic animals.
10. Pore bearing, water stationary animals are porifera.
11. Arthropoda have largest numbers of species in the earth.
12. Phylum mollusca consists of invertebrate animals having soft and

unsegmented body.
13. Echinodermata are animals that have spines on their body to protect

them from their enemies.

Exercise

1. Choose the best answer from the given alternatives.

a. Pisces are ____________ in nature.

i. terrestrial ii. aquatic iii. arboreal iv. marine

b. Fishes breathes through _____________.

i. skin ii. lungs iii. gills iv. scales

c. A ____________ has backbone.

i. Starfish ii. amoeba iii. tapeworm iv. salmon

Science, Health and Physical Education Book - 5 15

d. The larva stage of all amphibians breathe through____________.

i. skin ii. lungs iii. gills iv. tube

e. Cold blooded animals fall on _____________ phylum.

i. reptiles ii. mammals iii. aves iv. animals

f. _____________ is an example of mammal.

i. snake ii. crocodile iii. bat iv. parrot

g. An _____________ is an uncellular organism.

i. tapeworm ii. earthworm iii. cow iv. amoeba

h. A _____________ is a parasite.

i. leech ii. earthworm iii. cow iv. bee

2. Fill in the blanks with appropriate words:
a. Animals having backbone are _____________.
b. A fish has _____________ chambered heart.

c. Animals belong to class ____________ live on both land and in water.

d. The _____________ in birds are modified into wings.
e. _____________ have long hollow bones.
f. Amoeba and paramecium are _____________ organisms.
g. Pores bearing animals are called _____________.
h. A mosquito is an invertebrate because it has no _____________.
i. Arthropods have _____________ legs.
j. _____________ have star shaped body.

3. Write 'T' for true and 'F' for false statements.

a. Lizard and crocodile are vertebrates.

b. Frog can breathe through lungs.

c. Bat is a cold blooded animal.

d. Dolphin is an aquatic mammal.

e. Blue whale is the biggest animal of the earth.

f. Amoeba and hydra are amphibians.

g. Hydra and jellyfish have tube like body.

h. Earthworm is a harmful insect which transfer some diseases.

i. Starfish is found in fresh water only.

j. Spiny skin of echinodermata is used to protect themselves from the
enemies.

16 Science, Health and Physical Education Book - 5

4. Give one word for the following:

a. Animals with a backbone.

b. Animals without a backbone.

c. They have scales, dry skin and usually lay eggs.

d. Furry or hairy vertebrates.

e. These are the first multicellular animals that have ostia.

f. Animals that belong to this group are found in sea water and they
have a spiny skin.

5. Match the following:

Column A Column B

They have beaks instead of teeth Pisces

They do not crawl on land Amphibia

They can live both on land and in water Aves

They are cold blooded, live only in water Reptilla

6. Write the name of the phylum/class of the following animals.

a. salmon b. newt c. lizard d. duck e. bat

f. whale g. paramecium h. hydra i. liver fluke

j. starfish f. sycon l. spider m. octopus

7. Answer the following questions:

a. Differentiate between vertebrates and invertebrates.

b. Write two main characteristics of the five classes of vertebrates giving
an example of each.

c. Name the breathing organs of the following animals.

i. Mammals ii. Reptiles iii. Aves iv. Pisces

d. Draw and label the external structures of a fish and bird.

e. How does a crow differ from a bat?

f. What are mammals? How are they different from reptiles?

g. How can you identify that a given animal is included in group
protozoa?

h. What is the function of tentacles in hydra?

i. What types of animals are grouped in the phylum arthropoda? Give
any two examples.

j. How are mollusca different from other invertebrates? Give three
examples of them.

Science, Health and Physical Education Book - 5 17

k. Why is the octopus kept in Phylum Mollusca?
l. What are echinoderms? Where are they found?
8. Give reasons:
a. All birds are vertebrates.
b. Fish is a cold blooded animal.
c. Dolphin is also catagorized in the phylum mammalia.
d. Amoeba is called a microscopic animal.
e. Tapeworm is grouped in the phylum platyhelminthes.

Think and discuss

Which of the nine phyla of invertebrates is most advanced?

Project work

• Collect pictures of different vertebrates. Paste them in your scrapbook
and write the name of their classes of vertebrate.

• Make a poster of invertebrates with the cut pictures of the animals
of the different phyla from various old magazines and books or draw
if necessary. Paste them on a big chart paper. Mention two main
characteristics of each and the name of the animals. Bring to class and
request your teacher to held a competition.

• Observe notes of Nepali currency of all denominations. Identify the animals on them.
Name the animal and write which class it belongs to.

• Collect pictures of an egg laying mammal, a mammal that can fly, and a reptile with
four legs. Paste them in your scrap book and write their names.

Teacher's note

• Better to introduce cold blooded animals, warm blooded animals, unicellular and
multicellular organisms before elobrating the topics.

• Make a comparative table on the board to explain about all phyla.
• Organize quiz or display competition in class to brain storm knowledge about vertebrate

and invertebrate.
• Display pictures or posters of the different classes of vertebrates as well as invertebrates.

18 Science, Health and Physical Education Book - 5

2Lesson Cell

Specific After the completion of the lesson, students will be able to:
Objectives • explain what a cell is.
• list the different parts of a cell and their functions.
• differentiate between animal cell and plant cell.

Mind Opener

Mention the name of some body organs of human with their functions.

S.N. Name of organs Function
1.
2.
3.
4.
5.
6.
7.
8.

Science, Health and Physical Education Book - 5 19

Introduction

Plant and animal bodies are made up of small living blocks or basic units.
These basic units are called cells. Cells are very minute structures and cannot
be seen with our naked eyes. Therefore, we use a compound microscope to
observe the detailed structure of cells.

Cells are the basic, structural and functional units of life. The living body
consists variable number of cells. Some plants and animals which are composed
up of a single cell are unicellular organisms. So, amoeba and paramecium as
described in the previous lesson are the unicellular organisms. Other organisms
like ant, bird and tree are multicellular organisms as they are composed of
many cells. Similarly, the cells may vary in shape and size and help in various
activities like growth, reproduction, respiration, excretion, etc.

Cells were discovered by British scientist Info bits
Robert Hooke in 1665 A.D using a The cell of a bacteria has a
microscope. He observed the cells of diameter of about one micron.
different shapes. Generally, cells are

round, spherical or elongated in shape. Besides, they may be oval, rod shaped,

rectangular, irregular and others. Some are long and pointed at both ends,

some are branched like nerve cells and some are sphere like the red blood cells.

A nerve cell Red Blood cells

Structure of a cell

Cells are very small in size. However, they are made up of various parts such
as cell wall, cell membrane, vacuoles, centrosomes, ribosomes, etc which are
described in brief. Those parts inside the cell have their own role to conduct
life processes.

20 Science, Health and Physical Education Book - 5

Though, cell is found in both plants and animals, the cells that make up plants
are different from the cells of animals. Before we study the structures of a plant
and animal cells and the differences between them, let us understand about
their structure.

Cell wall
Cell wall is the outer covering of the cell which is thick and rigid. It is absent
in animal cells. Cell wall is made up of non-living material called cellulose. It
provides the cell with both structural support and protection and also acts as
filtering mechanism.
Cell membrane
Cell membrane is the outermost covering of animal cell and the second
layer of plant cell, next to the cell wall. It is also called plasma membrane or
plasmalemma. It is a thin, living and elastic membrane, made up of protein
and lipid. Its function is to protect the integrity of the interior of the cell by
allowing certain substances into the cell, while keeping other substances out.
It also serves to support the cell and maintain its shape.
Cytoplasm
The jelly like substance filled inside a cell is called cytoplasm. Water is the major
constituent of cytoplasm. Cytoplasm also contains protein, fat, carbohydrate
and other substances. Cytoplasm contains different living units called cell
organelles that include mitochondria, golgi bodies, endoplasmic reticulum,
centrosome, ribosomes, lysosomes, etc. Cytoplasm also contains non-living
components called cell inclusions. Vacuole, fat droplet, granule, etc. are cell
inclusions.

Science, Health and Physical Education Book - 5 21

Nucleus

A spherical or oval shaped body present in the cytoplasm of each cell is
called nucleus. It is the most important cell organelle. It consists of nuclear
membrane, nucleoplasm, nucleolus and chromosomes. Nucleus controls all
the activities of cells because of which it
is called the control centre of the cell. The
nucleus is found nearly at the centre in
animal cell but it is slightly shifted towards
the side in plant cells. It plays vital role in cell
division. Besides, it also transfer the parental
characters to the off spring.

Mitochondria

Mitochondria are oval or rod-shaped structures present in
the cytoplasm. They are found in both plant and animal
cells. They are known as the powerhouse of the cell
because they take part in respiration, produces energy and store it.

Vacuole

Vacuoles are non-living, fluid-filled structures found in the cytoplasm. They
are found both in plant cell and animal cell but their number are greater in
animal cell. Similarly, plant cell has larger vacuole than the animal cell.

Vacuoles store food, water and chemicals for the plant cell. They even store
waste products of the cell. They are also called 'storage tanks'. In animal cells,
the vacuole mainly stores waste products. It maintains the shape of the cells
and balances water in them. It also helps in excretion.

Plastids

Plastids are major cell organelle found in only plant cells. They are of various
shapes and found throughout the cytoplasm. There are three types of plastids.
They are chloroplast, chromoplast, and leucoplast.

Chloroplast are green plastids containing chlorophyll which help in preparing
food of green plant during photsynthesis. Thus, this is known as the kitchen
of the cell.

Chromoplast is a colorful plastid other than green. Because of it, flowers
and ripened fruits are attractive and colourful. Further more, it also helps in
reproduction and dispersal of seeds.

22 Science, Health and Physical Education Book - 5

Leucoplast are colourless plastids. They help in storage of food materials. They
are found in root and stem cells.

Activity 1

Take a piece of an onion layer. Place it under the microscope and observe
the cell.

Differences between plant and animal cell

Plant and animal cell have differences and similarities too. Most of the cell
organelles are present in both animal and plant cells. Let us go through the
differences between plant cell and animal cell.

Plant cell Animal Cell

1. Plant cell is usually rectangular 1. Animal cell is almost oval in shape.

in shape.

2. Cell wall is present. 2. Cell wall is absent.

3. It has a single large vacuole 3. It has many vacuoles scattered in

situated in the centre. the cytoplasm.

4. Centrosome is absent. 4. Centrosome is present.

5. Plastid is present 5. Plastid is absent.

Activity 2

Observe permanent slides of a plant and an animal cell with the help of a
microscope.

Points to Remember

1. All living organisms are made up of cell.
2. Cells are the basic, structural and functional units of life.
3. The organisms that are composed of single cell are called unicellular

organisms.

Science, Health and Physical Education Book - 5 23

4. The organisms that are composed of many cells are called multicellular
organisms.

5. A cell can perform different activities like growth, reproduction,
movement, respiration, etc.

6. Cell wall is the outermost covering of a plant cell.

7. Organelles are embedded in the cytoplasm that help a cell to perform
several life processes.

8. Nucleus controls and regulates various activities of the cell.

9. Mitochondria is known as the powerhouse of the cell because they
take part in respiration, produce energy and store energy.

10. Vacuoles are called storehouse of the cell.

11. Chloroplast help the plants in making food during photosynthesis.

Exercise

1. Choose the best answer from the given alternatives.

a. The jelly like substances inside a cell are called ___________ .

i. cytoplasm ii. nucleus iii. organelles iv. vacuole
b. Organelles are embeded in the ___________ .

i. nucleus ii. plastids iii. chloroplast iv. cytoplasm

c. Cell wall is present in ____________ cell.

i. animal ii. plant iii. organisms iv. model

d. Vacuoles of animal cells are ____________ than those of plant cells.

i. larger ii. smaller iii. thicker iv. elongated

e. ___________ acts as the brain of the cell.
i. organelles ii. mitochondria iii. plastid iv. nucleus

2. Fill in the blanks with appropriate words.

a. ___________ are building blocks of plants and animals.

24 Science, Health and Physical Education Book - 5

b. Cell was discovered by __________ in 1665.
c. The outer most covering of plant cell is ______ .
d. Cell wall is absent in ______ cell.
e. The main controlling centre of the cell is ______ .
f. ______ is called the power house of the cell.
g. ______ store water and other mineral fluids in them.
h. Plastids are absent in ______ cell.

3. Write 'T' for true and 'F' for false statements.

a. All living organisms are made up of cell.
b. Cell carry out vital life process.
c. Most of the cells are large in nature.
d. Both plant cell and animal cell consist cell wall.
e. An animal cell is almost rectangular in shape.
f. Nucleus does not control all the functions of a cell.
g. Vacuoles are usually large in plant cell.
h. Shape and size of cell of plant and animal are alike.

4. Match the following:

Column A Column B

Mitochondria Gel like thick liquid

Chloroplast Brain of the cell

Nucleus Power house

Vacuole Storage tank

Cytoplasm Food producer

5. Give one word for the following:

a. The outermost part of a plant cell.

b. Jelly like fluid inside the cell membrane.
c. The green pigment inside plant cell.

d. The living structure inside cytoplasm.

Science, Health and Physical Education Book - 5 25

6. Answer the following questions:

a. What is the building block of living things? What do we use to see
it?

b. Who discovered the cell and when?

c. Mention the shape of plant cell and animal cell.
d. What is cell wall? Write its function.

e. List the things that are found in the cytoplasm.

f. Mention any two differences between cell organelles and cell
inclusions.

g. Where is the nucleus found in the cell? Why is it so important?

h. Why is the nucleus called the control centre of the cell?
i. Which organelle help cell to get energy for life processes?

j. What is the function of vacuoles in a cell?

k. Write two differences between plant and animal cells.

7. Draw well labeled diagrams of the following:

a. animal cell b. plant cell

8. Identify the cell organelles and inclusions from the following and
classify in your exercise book making respective columns.

Plastid ribosomes vacuoles mitochondria

granules centrosome fat droplet

endoplasmic recticulum golgi bodies

9. Give reasons
a. A cell is the basic unit of life.
b. Mitochondria is called a powerhouse of cell.
c. An animal cell cannot perform photosynthesis.

Think and discuss

Prepare a model of a plant or an animal cell using cereals, pulses, thread and
other objects on a chart paper. Display the models in your classroom and ask
your friends to identify the parts of pant cell and the animal cell.

26 Science, Health and Physical Education Book - 5

Teacher's note
• If possible, permanent slides of different types of plant and animal cells could

be shown to students.
• Some students may think that cells are inside their body (rather than the body

itself being made up of cells). Such a misconception should be identified and
removed by questioning the students.
• Functions of various cell organelles and the differences between an animal and
a plant cell should be explained properly to the students.

Science, Health and Physical Education Book - 5 27

3Lesson Life Cycle of
a Butterfly

Specific After the completion of the lesson, students will be able to:
Objectives • define life cycle.
• identify different stages of the life cycle of a butterfly.
• explain the different stages of the life cycle of a butterfly.
• sketch the diagram of life cycle of butterfly.

Mind Opener

• Say the name of 5 insects that can fly and that can't fly.
• List the name of 5 insects with their feeding habit.

• Tick (√) to the useful inseMctsinanddOcrposesn(e×)rfor the harmful insects.

28 Science, Health and Physical Education Book - 5

Introduction

Reproduction is one of the most important characteristics of living organisms
to continue life. Life would not exist on the earth if plant and animal did not
reproduce. Oviparous type of reproduction takes place in insect, i.e., they lay
eggs. The eggs hatch and young ones come out. This is unlike viviparous type
which reproduce by giving birth directly to young ones.

All living organisms, after taking birth, live on the earth for a certain period
of time. They complete their life cycle and die. The time period from birth to
death of an organism is called life span. Some organisms live for few days.
Some live for a few months and some live for many years.

All living organism give birth to their young ones (directly or indirectly)
during their life time. They give birth to the young ones to continue their own
kind on the earth. The process by which a living organism gives birth to its
young ones is called reproduction.

Reproduction in Insects

The body of insects consists of
three parts: head, thorax and
abdomen. They have six legs
attached to the thorax. Most of
them have wings. The life cycle
of all insects start from an egg.
The changes that take place in
the life cycle of an insect from
an egg to adult are known as
metamorphosis. 'Metamorphosis'
(a Greek word), means 'transformation' or 'change of shape'. Two basic types
of metamorphosis take place in insects; incomplete metamorphosis (a 3- stage
life cycle) and complete metamorphosis (a 4 - stage life cycle). Let us learn
about the life cycle of butterfly.

Science, Health and Physical Education Book - 5 29

Butterfly and its life cycle

A butterfly is a brightly

coloured insect. It is very

beautiful, attractive and

flying diurnal insect. Its body

is divided into head, thorax

and abdomen. The head

bears a pair of compound

eyes and a pair of antenna

as sensory organs. It also

has mouth developed into

siphon to suck nectars from

flowers and plant sap. It has

three pair of appendages

(legs) and two pair of wings. life cycle of buttefly
Butterfly is known for its beautiful

coloured wings. They get attracted by the colour and smell of flowers. They

breathe through the trachea present in their abdomen. Butterflies are found in

all parts of the world except in very cold zones.

In insects like butterfly, ladybug, honey bee, mosquito and moth, the young
one which hatches out of egg does not look like their parents. They go through
four stages of growth called complete metamorphosis. The four stages are egg,
larva, pupa and adult. Here in this lesson, we will discuss about these stages
in brief.

Eggs

It is the first stage of growth after mating. The female butterfly lays many tiny
eggs often on the lower surface of leaves of the plants. These eggs are attached
to the leaf with a sticky secretion secreted by the female along with eggs. The
eggs are tiny and oval in shape. The colour of the eggs may be yellow, green
or white depending upon the types of butterfly. After some days, the eggs are
hatched by the warmth of the sun to tiny worm like creature called larva.

Larva

Larva is the second stage in the life cycle of a butterfly. The larva of butterfly
hatched from eggs are called caterpillar. Its body is segmented and contain
paired legs, but no wings. Its body is grey in colour. Larva is primary eating

30 Science, Health and Physical Education Book - 5

stages. It eats leaves of the plants on which it is present. The feeding process
goes on voraciously so that it grows faster. The body of a larva can be divided
into head, thorax and abdomen.

The larva of various species of butterfly have different coloured stripes. The
caterpillers shed their skin, this process is known as moulting. During larva
stage, it moults its skin four times. After fourth moulting, it stops feeding and
start to secrete the sticky fluid forming long thread. The larva wraps itself
around with the help of the thread to form a hard outer covering called pupal
case (cocoon). The larval stage lasts for 25 to 32 days.

Pupa

The larva changes into pupa within cocoon, which is the third stage of life
cycle of butterfly. Pupa of butterfly is also called chrysalis. It is covered with
a hard case called puparium or cocoon. The pupa neither eats nor moves but
some changes take place in their body. Though the changes occur inside the
chrysalis, is not seen outside as pupa remains covered inside cocoon. The
pupal stage lasts for a few days to several months depending on the climatic
condition. The pupa becomes transparent about one day before the adult
butterfly emerges.

Adult

As the cocoon breaks, the young butterfly emerges out. This is called an adult.
The newly emerged adult butterfly is called imago. When the imago emerges,
its wings are wrinkled and moist. It spends sometimes to dry wings and fly.
The adult butterflies are capable to reproduce further.

The sequential growth of butterfly that starts from eggs and goes upto mature
adult is called its life cycle.

Butterflies are useful insects. They fly into the attractive flowers. When they
fly, they transfer pollen grains and support in pollination. The garden looks
pleasant when the colourful butterflies are seen. We should not catch butterflies.
The dust present in their wings and bodies may drop into our eyes which may
damage our eyes badly.

Activity 1

Observe a butterfly in your garden. Draw a neat and well labeled diagram
of an adult butterfly in your work book.

Science, Health and Physical Education Book - 5 31

Points to Remember

1. The time period between the birth and the death of an organism is
called life span.

2. The process by which living organisms give birth to their young ones
in order to continue their own kind on the earth is called reproduction.

3. Body of butterfly is divided into head, thorax and abdomen as of other
insects.

4. ILife cycle of a butterfly completes in four stage. They are egg, larva
(caterpillar), pupa and adult.

5. The larva or caterpillar is a voracious eater.

6. The caterpillar inside the cocoon is called the pupa.

7. Moulting is the process of shedding the skin.

8. The newly emerged adult butterfly is called imago.

9. The life cycle of butterfly is the series of changes in it, from the egg to
the adult stages.

Exercise

1. Choose the best answer from the given alternative.

a. Animals ________ to give birth to new ones.

i. excrete ii. breathe iii. reproduce iv. digest

b. The ________ are hatched from eggs.

i. adult ii. larva iii. pupa iv. imago

c. The larva stage of the butterfly is called ________ .

i. imago ii. cocoon iii. caterpillar iv. chrysalis

d. The ________ of butterfly is inactive and it does not eat any food.

i. pupa ii. egg iii. larva iv. cocoon

e. The third stage in the life cycle of a butterfly is ________ .

i. larva ii. egg iii. adult iv. pupa

32 Science, Health and Physical Education Book - 5

2. Fill in the blanks with appropriate words.

a. The time period between the birth and the death of an organism is
called________ .

b. The body of butterfly is divided into a ________ , a ________ and an
________ .

c. The life cycle of all insects starts from ________ .

d. The four stage life cycle of insects is called ________ .

e. An adult female butterfly lays eggs on ________ .

f. The most active stage during life cycle of butterfly is ________ .

g. The process of shedding outer skin by a larva is called ________ .

h. The hard case that covers a pupa is called ________.

i. The stage of pupa of a butterfly lasts for ________ .

3. Write 'T' for true and 'F' for false statements.

a. All animal lay eggs.

b. Butterfly is not an example of insect.

c. The four phase life cycle is called complete metamorphosis.

d. The thorax of butterfly bears three pairs of legs.

e. Butterfly has four stages of life cycle.

f. The larva of butterfly eats voraciously.

g. The cover of pupa is called caterpillar.

h. The pupa of a butterfly feeds on green leaves.

i. The pupa develops legs, wings and other body parts and turns into
adult.

4. Match the following:

Egg is at head

Caterpillar beautiful are colourful insect

Pupa feeds on leaves

Adult butterfly juice of flowers

Antennae first stage of life cycle of butterfly

Food of butterfly do not eat and move

5. Define the following terms.

a. lifespan b. larva c. moulting

d. imago e. life cycle of insects

6. Answer the following questions.

a. Why is reproduction regarded as one of the most important features

of living things?

Science, Health and Physical Education Book - 5 33

b. Mention the differences between complete and incomplete
metamorphosis.

c. Name any three insects having four stages in their life cycle.
d. Give a brief introduction to butterfly.
e. Which stage of the butterfly is inactive?
f. What does larva of butterfly feed on?
g. How does pupa differ from larva of butterfly?
h. Describe the pupa stage of the butterfly.
i. Sketch a diagram to demonstrate the life cycle of butterfly.
7. Give reasons:
a. Butterfly is called diurnal insects
b. Caterpillar of a butterfly is called a voracious eater.
c. The metamorphosis in the life cycle of a butterfly is a complete

metamorphosis.
8. Answer the following questions in detail.

a. Write the stages in the life cycle of a butterfly in sequence.
b. What is metamorphosis?
c. How does a caterpillar form a cocoon?

Project work

Visit your school's science laboratory to see the specimen of the life cycle
of a butterfly, a mosquito, a frog and a housefly. Draw the diagrams in your
practical file and write your comments.

34 Science, Health and Physical Education Book - 5

4Lesson Parts of
Flowering Plant

Specific After the completion of the lesson, students will be able to:
Objectives • identify the major parts of a plant.
• explain the functions of the different parts of flowering plants.
• describe the structure of a flowering plants.
• distinguish monocotyledons and dicotyledons.

Mind Opener

• How many systems does a plant have?
• Name the system that is under the soil.
• Can you name the different types of roots?
• List out the parts of a flowering plants.
• What is the main role of the stem in a plant body?
• Can all plants prepare their own food?
• What are the essential materials that are needed by a plant body

to prepare food?
• Name the gas that is given out by the green plant during

photosyntheisis.
• Identify the following parts of a plants.

Science, Health and Physical Education Book - 5 35

Introduction

In previous grade, you have
studied different parts of a plant.
All these parts of a plant can be
grouped into the following two
systems: root system and shoot
system.

With the help of a senior,
take a plant out from the soil
carefully so that the roots are
not damaged. Put this plant on
a white paper and observe its
various parts. Does it have all
parts as in the given figure?

Root system

Roots of a plant lie inside the A mustard plant
ground. Observe the roots of Tap root
a mustard or a gram plant. You will
find that there is a main root that
bears branches on its sides. This main
root is called the primary root and
the branches on its sides are called
secondary roots or tertiary roots. This
type of root system is known as tap root system.

Now observe the roots of an onion plant or a grass. In these plants, you will see
that there is no main root. But all the roots arise from one place like a bunch
and they are more or less similar in form and size. This type of root system is
known as fibrous root system.

Activity 1

Visit your school garden. Take the gardener's help to pull out some small
plants from the soil. Observe the type of root they have.

36 Science, Health and Physical Education Book - 5

Functions of the roots

1. Absorption: The main function of the roots is to absorb water and minerals
salts from the soil.

Activity 2

Experiment to show
that roots are essential
for the absorption of
water and mineral salt
from the soil.

Take two pots and fill

them with garden soil. A B
Label them as pot A and

pot B. Now take two

small plants of same form and size. Cut off the roots of one plant and fix

it in pot B. Leave the second plant with the roots intact and fix it in pot

A as shown in the figure. Water both plants daily. Observe them after

three days. Do you find any difference in the two plants? You will see

that the plant in pot A (with intact roots) is normal, while the plant in pot

B (without roots) dries up. This has happened because the plant without

roots is unable to absorb water and minerals salts from the soil. This

shows that roots are essential for the absorption of water and minerals

salts from the soil

With the help of a magnifying glass, try to Fig. Roots and root hairs seen
see the roots of a plant. You will find that under the magnifying glass
the roots have numerous small hair like
structure. These are called root hairs. These
root hairs help the roots to absorb water and
mineral salts from the soil. The root hairs
increase the surface area of the roots for the
absorption of water from the soil.

2. Conduction: The water and mineral salts absorbed by the root hairs are
also transported upward to various parts of the plant.

Science, Health and Physical Education Book - 5 37

Activity 3

Experiment to show water absorbed by the roots is conducted to various
parts of the plants.

Take a small plant of balsam. It has a soft and
thin stem. Be careful that its roots remain
intact and are not damaged. Wash the roots
thoroughly with water. Now take a wide
mouthed bottle and fill it with coloured
water. Fix the plant in the bottle so that only
the roots remain inside the coloured water
as shown in figure. Observe the plant after
two hours. What do you find? You will find
the roots, stem, leaves and flowers have become coloured. Why does this
happen? This is because the coloured water is absorbed by the roots and
is conducted up to the stem, leaves and flowers.

Now cut either the stem or the root of the above plant with a sharp blade.
Observe the inner portion with a magnifying glass. You will find that
only a little part is coloured inside. This is the portion through which the
coloured water has moved up. This coloured part present inside the root
or stem is known as xylem. Thus, we can say that xylem in the root or
stem is responsible for the conduction of water and minerals upwards in
a plant body.

3. Fixation : As root of a plant lie inside the soil, they help to fix the plant in
the soil. Can you imagine a plant standing erect if its roots are not inside
the soil?

4. Storage of food: Roots of some plants also store food. Examples of such
plants are radish, carrot, sweet potato and turnip. We eat the roots of these
plants.

Turnip Carrot Sweet potato Radish

38 Science, Health and Physical Education Book - 5

Shoot system

The parts of the plant body that lie above the soil is called shoot system. It
consists of stem and its branches, leaves, flowers and fruits. Let us study about
them and their functions.

Stem

It is a long and cylindrical structure of the plant that bears branches, leaves,
flowers and fruits. In young and small plants, the stem is soft and green in
colour. This type of stem is called a herbaceous stem. But in tree, the stem
becomes hard and is non green in colour. This type of stem is called a woody
stem.

Look carefully at the stem of a plant. You will find that at some point nodes
are present. The branches of a stem arise at these nodes. The part of the stem
between two nodes is called an internode.

Functions of a stem

1. Conduction: Like roots, the stem also conducts water and minerals from
roots to the leaves, flowers and fruits.

2. Support: The stem provides support to the plant and helps to keep the
plant erect.

3. The stem and its branches bear the leaves, flowers and fruits.

4. Storage of food: Some plants store their food in their stem. Potato, ginger
and colocasia are the stems we eat. These remain inside the ground. In
sugarcane, the stem is above the soil and stores food.

Leaf

The leaves are present on the stem and its branches. The leaves arise from the
nodes of a stem. A leaf is a green, flattened structure of the plant. The colour
of the leaf is green due to the presence of a pigment called chlorophyll. The
flattened surface of a leaf helps to absorb more sunlight.

The leaf prepares food for the whole plant. It is, therefore, called the food
factory of the plant. The leaf is an important part of the stem. The flat and

Science, Health and Physical Education Book - 5 39

broad part of the leaf is called the lamina or leaf blade. In the middle of the leaf
there is a main vein. A number of side veins arise from a main vein. The veins
bring water to the leaf.

The arrangement of veins and veinlets in a leaf is called venation. The leaves
of flowering plants have two types of venation. i.e. reticulate venation and
parallel venation. In reticulate venation, the veins give rise to lateral veinlets
in all directions and form a network. This type of venation is found in leaves of
mustard, apple, orange, bean, rose, etc. In parallel venation, veins are arranged
parallel to each other towards the tip of the leaf. This type of venation is found
in leaves of sugarcane, maize, rice, grass, garlic, onion, etc.

The leaf blade has many tiny pores on its lower side. These are called the
stomata. Air and water can pass through these pores. The stomata throws out
excess water from the plant.

Use your leisure
Some plants are grown for their leaves. Can you name them?

Functions of a leaf

To exchange gases, leaves have minute
pores on the surface. These pores are called
stomata.

With the help of chlorophyll, water from the

soil and carbon dioxide from the atmosphere,

the green leaves prepare food for the plants

body in the presence of sunlight. This Fig. Section of leaf with stomata

process of preparing food is known as

photosynthesis. The process of photosynthesis is summarised below.

Carbon dioxide + Water Sunlight Glucose + Oxygen
Chlorophyll (food)

40 Science, Health and Physical Education Book - 5

The food formed during photosynthesis
is a simple carbohydrate - glucose. Soon,
glucose changes into starch for storage.

During the process of photosynthesis,
plants take carbon dioxide from the
atmosphere and give out oxygen.
Animals use this oxygen in the process of
respiration and give out carbon dioxide.
This carbon dioxide is again used up by
plants in the process of photosynthesis.
That is why, we say that plants purify
air.

Fig. Photosynthesis in plants

Activities on photosynthesis

Process to check the starch: Dissolve a little
starch powder in hot water in a test tube. Now
add iodine solution in the test tube. You will
see a blue black colour. Iodine gives blue black
colour with starch.

1. To show that starch is formed during the

process of photosynthesis in leaves: Pluck

a leaf from a plant that has been exposed

to sunlight for a few hours. Boil this leaf

in water and then in alcohol over a water Fig. Experiment to show
bath. This will remove the chlorophyll presence of starch in leaves.

pigments from the leaf. Now put iodine solution over the leaf. You will see

that the leaf becomes blue-black in colour. This shows that starch is formed

during the process of photosynthesis.

2. Sunlight is essential for photsynthesis: Take a small potted plant and
keep it in the dark room for one day. This will make its leaves free from
starch. Now cover one of its leaves with a strip of black paper on both the
sides as shown in the figure. Now keep this plant in sunlight for a few
hours. After that, pluck the leaf covered with black paper. Boil this leaf

Science, Health and Physical Education Book - 5 41

in water and then in alcohol over a water

bath to remove its chlorophyll pigments.

Now, put iodine solution over the leaf.

What do you observe? You will see that

the portion of the leaf that was covered

with black paper remains pale yellow in

colour, while the outer uncovered portion Plant in sunlight and darkroom
of the leaf turns blue-black in colour

because of the presence of starch. This shows that sunlight is essential

for photosynthesis.

3. Chlorophyll is essential for photosynthesis:

Pluck a leaf from a croton plant that has been kept

in sunlight for a few hours. The leaves of croton

plant are variegated which means they have green

and non green areas. Make a figure of the leaf on

a paper to note its green and non green area. Now

boil this leaf in water and then in alcohol over a

water bath to remove chlorophyll. Put iodine Fig. Experiment to show
solution over the leaf. What do you observe? You chlorophyll is essential for
will see that the green portion of the leaf turned
blue-black in colour while its non green areas photosynthesis.

remained pale yellow in colour. This shows that chlorophyll is essential

for photosynthesis.

4. Oxygen is given out in the Beaker
process of photosynthesis:

Take a few twigs of Hydrilla

(a water plant) and keep Test tube

them in a beaker half filled Hydrilla
with water. Keep an inverted

funnel over the plant so Glass funnel
that all its twigs are totally

within the funnel. Now put Fig. Experiment to show oxygen is given out during
a test tube filled with water photosynthesis

inverted over the funnel as shown in the figure. Keep this experimental set

up in sunlight. After some time you will see bubbles arising from the plant

42 Science, Health and Physical Education Book - 5

and fill the test tube. Remove the test tube by closing its mouth with a thumb
so that the filled gas does not go out. Now bring a burning matchstick near
the test tube. What do you observe? You will see that the matchstick starts
burning brighter. This shows that the gas within the test tube is oxygen.

Other functions of a leaf

Plants absorb a lot of water from the soil through their roots. This water maybe
much more than needed by the plants. Leaves remove this excess amount of
water as water vapour into the atmosphere. The process by which the water is
removed by the leaves as water vapour is called transpiration.

Activity 5

Take a small transparent polythene bag. Tie
this bag around a few leaves of a potted plant
as shown in the figure. Observe the bag after
one hour. You will find small drops of water
in the bag. Where did this water come from?
This water is from the water vapour released
by the leaves during transpiration.

Flower

Do you find flowers on the plant at all the times? When a new plant comes up,
it has only root, stem and leaves. Later, the plant bears flowers. The flowers
help in reproduction.

A flower has mainly four parts.
The outermost part of the flower
is the sepals. Sepals protects the
inner parts of the flower when it
is a bud. Next to sepals are the
petals. The petals are generally
brightly coloured. Petals attract
butterflies.

Towards the centre of the flower Parts of Flower
are the stamens. These are the
male reproductive part of the

Science, Health and Physical Education Book - 5 43

flower. A stamen consists of long filament and anther. Filament is a short stalk
which supports the anther on its top. The anther produces pollen grains which
carry male gametes.

The innermost part of the flower has pistil. It is the female reproductive part of
the flower. Pistil consists of stigma, style and ovary. Stigma is the uppermost
sticky part which receives pollen grains. Style is stalk like middle part. The
lowermost swollen part of pistil is called ovary. The ovary contains a number
of ovules. Ovules contain ova or eggs of female gametes.

Bisexual and unisexual flowers: All Info bits
the flowers do not contain the four
main parts of a flower: calyx, corolla, Androecium: It is the collective
androecium and gynoecium. The flower form of sepals.
which contains all the four parts is called Corolla: It is the collective form of
complete flower. The flower in which calyx.
any one of the four floral parts is absent Androecium: It consists of a
is called incomplete flower. number of male reproductive
organs called stamens.

The complete flowers which have both Gynoecium: It represents the
male and female reproductive parts female reproductive part i.e. pistil.

(androecium and gynoecium) are called

bisexual flowers. Pea, mango and bean have bisexual flowers.

Activity 5

• Collect some flowers from your school garden and observe their

various parts like sepals, petals, stamens and pistil.

• Draw a neat and well labelled diagram of complete flower. Also, write

down the major function of each parts.

The flowers which have only the androecium or the gynoecium are called
unisexual flowers. Unisexual flowers are either male flower or female flower.
Maize, pumpkin and gourd have unisexual flower.

Pollination

The process of transference of pollen grains from the anther to the stigma of a
flower is called pollination. The pollen grains are powdery substance produced

44 Science, Health and Physical Education Book - 5

in anther. They are carried by wind, water, insects and other animals. There
are two types of pollination; self pollination and cross pollination.
The pollination in which the pollen grains reach the stigma of the same flower
is called self pollination whereas the pollination in which the pollen grains
reach the stigma of flower of another plant of the same type is called cross
pollination.
Fertilization
After the process of pollination, the pollen
grains germinate in the stigma to form a
long tube called a pollen tube. The pollen
tube grows towards the ovary carrying
male gametes. The male gamete fuses with
female gamete inside the ovule of ovary.
This process is called fertilization. After fertilization, the ovary increases in
size and develops into a fruit. The ovule develops into seed.
Fruits and seeds
Flowers after reproduction form the fruits. In fact, it is the female reproductive
parts of the flower that develop into fruits. Most fruits store the food.
Function of fruits

1. Fruits develop seeds which help in reproduction.
2. They store food materials.
3. They help in dispersal of seeds
Cut any fruit. Inside the fruit, you will find seeds. These seeds are necessary
for the formation of new plants. The seeds also store food for the new plants.
Fruits and flowers do not last for a long time. They dry up, drop off or are
plucked. Some seeds are dispersed to the soil. On getting the favourable
conditions, they grow up into new plants.

Fig: Seeds in fruits

Science, Health and Physical Education Book - 5 45

Structure and types of seeds

Take a few gram seeds and soak them in water for one day. The next day
carefully remove the outermost covering of the seed with the help of a needle.
This is known as outer seed coat. Inside the outer thick seed coat, there is a
thin and membraneous inner seed coat.

After removing both the seed coats,
observe inside of the seed. The seed has
two thick and large parts. They are the
cotyledons that store the food for the
growth of the new plant. Between the two
cotyledons is a structure called embryo,
that grows to form the new plant. This
embryo is the baby plant. The lower
part of this embryo is known as radicle that grows to form the root system.
The upper part of embryo is known as plumule that grows to form the shoot
system of the new plants.

On the basis of number of cotyledons in the seeds, plants are divided into
monocotyledonous and dicotyledonous plants.

Monocotyledonous plants

The seeds which contain only one cotyledon are called monocotyledonous
seeds. The plants that produce monocotyledonous seeds are called
monocotyledonous plants. Paddy, wheat, rice, millet, maize, etc are some
examples of them.

Rice Maize Wheat Paddy

Monocotyledonous plants have fibrous root system. They have long and
narrow leaves with parallel venation. Floral parts of flower are in the multiple
of three.

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