Solutions for all
Natural Sciences &
Technology
Grade 5
Learner’s Book
W Bezuidenhout
D Bosch
R Engelbrecht
J Marchant
A Scott
A Volker
Solutions for all Natural Sciences and Technology Grade 5 Learner’s Book
© W Bezuidenhout, D Bosch, R Engelbrecht, J Marchant, A Scott, A Volker, 2013
© Illustrations and design Macmillan South Africa (Pty) Ltd, 2013
All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted in any form
or by any means, electronic, photocopying, recording,
or otherwise, without the prior written permission of the
copyright holder or in accordance with the provisions
of the Copyright Act, 1978 (as amended).
Any person who commits any unauthorised act in relation to this
publication may be liable for criminal prosecution and
civil claims for damages.
First published 2013
13 15 17 16 14
0 2 4 6 8 10 9 7 5 3 1
Published by
Macmillan South Africa (Pty) Ltd
Private Bag X19
Northlands
2116
Gauteng
South Africa
Typeset in School Helvetica Roman 14pt on 19pt by Boss Repro & Design Studio
Cover image from Greatstock
Cover design by Deevine Design
Illustrations by: Alan Kennedy, Carla Maritz, Geoff Walton, Luyanda Cwane
Photographs by:
AAI Fotostock: pp. 21 (fig. 2.9), 30, 38 (fig. 3.9b, fig. 3.9c), 70 (fig. 6.2), 87, 107, 117 (fig. 9.5), 118, 123
(fig. 9.11), 124 (top, bottom), 129, 153 (row 4), 174, 201, 209 (left), 224, 226 (fig. 16.7), 233 (fig. 17.1 top left),
239 (activity 1d); African Pictures: pp. 103, 113, 203 (fig. 15.3), 204; AfriPics: pp. 17, 20 (fig. 2.5, fig. 2.6), 21
(fig. 2.7, fig. 2.8), 22, 38 (fig. 3.9a), 46, 61, 68, 69, 70 (fig. 6.3), 71, 77 (left), 78 (top left, middle right, bottom
left, bottom right), 82, 95, 115, 119, 120, 121, 123 (fig. 9.10), 124 (middle), 125, 153 (row 1, row 3), 218, 225,
226 (fig. 16.8), 227 (fig. 16.11, 16.13), 231, 233 (fig. 17.1 right), 239 (fig. 17.7, activity 1e), 244 (fig. 17.12a),
246; Gallo Images: pp. 78 (top right), 153 (row 5), 154 (row 2), 162, 176, 192, 193; Greatstock: pp. 32, 64, 121
(fig. 9.8), 139, 147, 153 (row 2), 154 (row 1), 155, 226 (fig. 16.9), 227 (fig. 16.12), 239 (activity 1c), 243, 244
(fig. 17.11), 248; Ilala Weavers: pp. 123; INPRA: pp. 58, 157, 203 (fig. 15.2); Science Photo Library: pp. 16,
215, 233 (fig. 17.1 bottom left), 239 (fig. 17.6; activity 1a, b), 242, 244 (fig. 17.12b); VMS Images: pp. 60,
77 (right), 78 (middle left), 116, 117 (fig. 9.4), 206
ISBN: 978-1-4310-1032-5
F*4#/
WIP: 4129M001
It is illegal to photocopy any page of this book
without written permission from the publishers.
The publishers have made every effort to trace the copyright holders.
If they have inadvertently overlooked any, they will be pleased to make the
necessary arrangements at the first opportunity.
Contents
How to use this Learner’s Book................................................................................v
Completing a Technology Assessment Task ......................................................... vii
LIFE AND LIVING
Topic 1
Plants and animals on Earth............................................................1
Unit 1
Many different plants and animals ......................................2
Unit 2
Inter-dependence .................................................................5
Unit 3
Animal types .........................................................................8
Topic 2
Animal skeletons .............................................................................. 16
Unit 1
Skeletons of vertebrates .................................................... 17
Unit 2
Movement ...........................................................................24
STRUCTURES
Topic 3
Skeletons as structures ..................................................................30
Unit 1
Frame and shell structures in animals ...............................31
Unit 2
Technology project: Model of a vertebrate skeleton .........34
LIFE AND LIVING
Topic 4
Food chains ......................................................................................46
Unit 1
Food and feeding ................................................................47
Topic 5
Life cycles .........................................................................................58
Unit 1
Growth and development ...................................................59
MATTER AND MATERIALS
Topic 6
Metals and non-metals ...................................................................68
Unit 1
Properties of metals and non-metals ................................69
Topic 7
Uses of metals ..................................................................................82
Unit 1
More properties and uses of metals ..................................83
PROCESSING
Topic 8
Processing materials .......................................................................95
Unit 1
Combining materials...........................................................96
Topic 9
Processed materials ...................................................................... 113
Unit 1
Processed materials ......................................................... 114
ENERGY AND CHANGE
Topic 10
Stored energy in fuels ................................................................... 129
Unit 1
Fuels .................................................................................. 130
Unit 2
Safety with fire.................................................................. 139
Topic 11
Energy and electricity ................................................................... 147
Unit 1
Electricity .......................................................................... 148
Topic 12
Energy and movement .................................................................. 162
Unit 1
Elastics and springs ......................................................... 163
SYSTEMS AND CONTROL
Topic 13
Systems for moving things........................................................... 174
Unit 1
Vehicles are systems for moving things ........................... 175
Unit 2
Technology project: Design, make and evaluate a set
of wheels and axles .......................................................... 182
PLANET EARTH AND BEYOND
Topic 14
Planet Earth .................................................................................... 192
Unit 1
The Earth moves ............................................................... 193
Topic 15
Surface of the Earth ......................................................................201
Unit 1
Rocks and soil...................................................................202
Topic 16
Sedimentary rocks ......................................................................... 218
Unit 1
Sedimentary rock ............................................................. 219
Topic 17
Fossils..............................................................................................231
Unit 1
Fossils in rock ...................................................................232
GLOSSARY .......................................................................................................... 251
How to use this Learner’s Book
Welcome to the Science and Technology Grade 5 Learner’s Book
The content in the Science and Technology Grade 5 Learner’s Book is organised
according to topics and each topic is structured in the same way:
Topic opener page: The topic starts with a full-colour photograph of something
that is related to the content of the topic. The ‘What you will learn about’ box
lists the content to be covered in the topic. There is also a section called ‘Let’s
talk about ...’, which gives you an opportunity to start thinking about new things
that you will learn about in the topic.
Units and lessons: Each topic is divided into units, which are divided into
lessons. A lesson consists of content followed by a Classroom activity. Some
lessons also include Practical tasks. Some of the Classroom activities might be
started in class but completed at home. The lessons break up the work in small
chunks of information. This helps you to make sure you know and understand a
certain section of the work before moving on to the next new section of work. One
Practical task per term is suggested as a Formal Assessment Task. You could be
assessed on these tasks, so watch out for them.
Check what you learnt: These are assessment activities. The questions are
aimed to check your knowledge and test if you can do what you should be able
to do at the end of the topic.
Summary: Each topic ends with a summary of the work covered in the topic. You
could use these summaries as study notes or to revise what you should know by
the end of the topic.
Extra practice: The Extra practice at the end of each topic has been included
as an additional activity. You can use the questions to practise what you have
learnt.
v
Other features to look out for are:
Word bank: These contain words that you may not understand or that you may
have encountered for the first time in the text. An explanation for the word is
given to enable you to understand its meaning better. Always keep a dictionary
handy, because if you understand a word, learning will be a lot easier.
Illustrations and photos: The illustrations and photos have been included
to help you understand the written text. Use the illustrations and photos
when working through the text. When you see a picture of something, you will
remember it a lot better.
The publisher and authors wish you all the best in your study of Natural Sciences
and Technology Grade 5.
Good luck!
vi
Completing a Technology Assessment Task
Solving problems to meet people’s needs is what technology is all about. The
skills taught in Science and Technology will give you the skills you will need to
solve various technological problems.
Steps to follow when completing a
Technology Assessment Task
During this year you need to complete two
Technology Assessment Tasks.
This section explains the steps you need
to follow when completing a Technology
Assessment Task.
It starts with a problem ...
In the Technology Assessment Tasks, the
problems are based on real-life examples.
You design and make something to solve a
given problem. Before you begin designing
and making a solution to a given problem, you
need to understand the problem and what is
required.
Understanding the given problem
To understand the given problem and work out
what you need to design and make, draw up:
O
a list of specifications
O
a list of constraints
O
a design brief.
Specifications, constraints and design briefs
Specifications are the things that must be
included in your product or system.
Constraints are all the limitations that have been
placed on the design.
vii
To draw up your list of specifications and list of constraints, ask yourself these
questions:
O
What do I need to make?
O
What will it be used for?
O
Who will use it?
O
How big does it need to be?
O
Do I need to use any specific materials?
O
Should I include anything specific in my design?
Once you have drawn up your list of specifications and constraints, you can work
out a brief statement of what you have to design and make to solve the problem.
This is called a design brief.
A design brief always starts with ‘Design and make a…’. The design brief, and
your list of specifications and constraints, will help you to understand the
problem and what you need to do to solve the given problem.
Help tasks
Before you can begin solving a given problem, you may need to gain some new
technological skills. You then need to work through different help tasks to learn
these skills.
Help tasks could include learning how to cut, saw, hammer or join. You may need
to work through more than one help task per problem.
Solve the problem using the technological design process
Once you understand the problem and you have learnt all the skills needed to
solve the problem, you can begin solving it. To solve a problem you need to work
through the technological design process.
The design process has five main steps. These are:
O
investigating
O
designing
O
making
O
evaluating
O
communicating.
viii
Usually you will work through these steps of the design process in this order, but
sometimes you may find it easier to change the order, depending on the problem
you want to solve.
Communicating also forms part of the design process. You need to
communicate the steps of the design process to others. There are a few ways of
doing this. One way is to record everything in a book or portfolio. Another way is
to do a presentation.
In the design process one step leads on to another.
There is no definite place where you have to stop
working through the design process. Sometimes,
after evaluating a design idea or the finished
product, you may find the need to work through
the design process again. There is nothing wrong
in doing this. It is how technology solutions are
improved.
How then do we work through each step of the
design process?
Investigating
When you investigate, you gather information about a specific thing. Before
solving a problem you need to collect information that you could use to solve the
problem. You can get information in different ways. The ways that you choose to
collect the information depend on the problem. Sometimes you may need to find
information in books or magazines, or on the internet. Sometimes you need to
ask other people questions to gather information. Learning a new skill is also part
of investigating.
Designing
After you have investigated the problem, you will have some information to help
you solve the problem. You may also have a few ideas of possible solutions to the
problem. You are now ready to begin designing a solution to the problem.
ix
Start the designing part of the process with several ideas. Make drawings of the
different ideas. The drawings should be neat and detailed, and should always
have labels. The labels explain the drawing.
Choose the design idea that will best solve the problem. Write down the reasons
for the choice that you have made. Make a clear final drawing of the best idea.
Making
After completing the design you can make the product or system that is a
solution to the problem. Before you make the product or system, you need to
draw up a step-by-step plan of how to make the product or system. In the stepby-step plan you need to indicate necessary safety precautions to take and the
tools and materials that should be used to make the product or system.
Using the step-by-step plan, you then make the product or system, skilfully and
safely, using the right tools and materials.
Evaluating
Once the product or system has been made, you need to test it or evaluate it.
This means that you need to see if it solves the problem it is meant to solve.
Suggest where and how the design could be improved or modified to make it
solve the problem better.
Communicating
Communicating is an important part of the design process. When you
communicate you are making a record of how you progressed through the design
process until you found a solution to the problem.
Remember that there can be many ways to solve a problem; not everyone will
solve a problem in the same way.
Enjoy doing technology!
x
Topic
1
Plants and animals
on Earth
What you will learn about in this topic
z
z
z
Many different plants and animals
Inter-dependence
Animal types
Let’s talk about plants and animals on Earth
Look at the pictures of various animals on the postage stamps
shown. They are pictures of animals that are found in South
Africa. Name some of the animals. Do all the animals live in the
same habitat? Explain your answer. A rhino is an example of a
large animal with its bones inside its body. Is there a picture of
another animal with its bones inside its body?
Topic 1 Plants and animals on Earth
‡
1
Unit 1 Many different plants and
animals
What you know already
In Grade 4 you learnt about different habitats and how plants
and animals are suited to living there. A habitat provides a place
for plants and animals to grow, feed and reproduce. South Africa
has a wide variety of different habitats. You have already learnt
about grassland, sea, river and forest habitats.
ck
Che elf Name two different animals and state the habitat that
mys
they live in.
Lesson 1
Many different plants and animals
There are many different plants and animals living
in different habitats on Earth. Plants and animals
are suited to living in and sharing their habitats
with other plants and animals. South Africa has a
wide variety of indigenous plants and animals in
its habitats. We refer to this variety of plants and
animals as biodiversity.
Word bank
biodiversity: refers to all
the different living things in a
habitat
indigenous: occurs
naturally in a particular place
variety: different kinds
Practical activity
Study the plants in an area
This is a prescribed activity.
Work in groups.
Aim
To count the number of plants in a given area and tell them apart
2
‡ Topic 1
Plants and animals on Earth
Life and living
You will need:
‡
‡
‡
‡
‡
‡
wool or string
tent pegs or short dowel sticks
metre stick or tape measure
pencil and eraser
notebook
camera or cell phone camera (optional)
Safety warning
You may need to ask permission from your school principal to
study the area you choose. Pay attention to all instructions
from your teacher, especially if your chosen area is outside of
the school property. Do not eat any fruit from plants that you
do not know.
Method
1. Find an area with many different plants on or near the
school grounds. Your teacher will help you.
2. Measure out a square of 2 m × 2 m. Place the tent pegs or
dowel sticks at the corners as markers.
3. Tie the string or wool around the corner markers to mark
the outlines of the area.
4. Count the total number of plants you can see in the area
and record this in your notebook.
5. Describe the different plants in this chosen area:
a) Draw a picture or take a photograph of each different
plant.
b) Look at the
shapes and
colours of the
leaves, flowers
and fruit of
different plants.
Make notes in
your notebook.
Figure 1.1 Fieldwork
Topic 1 Plants and animals on Earth
‡
3
‡
You can use words such as heart-shaped, long,
narrow, round, small leaves within larger leaves,
or any other suitable descriptions to describe
the shapes you see.
‡ You can use words such as light or dark green,
red, yellow, green with white marks, or any other
suitable phrases to describe the colours you see.
Results
1. How many plants do you see in the area?
2. Copy and complete the following table using the notes
from your field work.
Picture of
plant
3.
4.
4
Shape and
Shape and
colour of leaf colour of
flower
Shape and
colour of
fruit
Discuss and compare your notes with your group.
Compare the information about the plants in your area
with that of another group.
‡ Topic 1
Plants and animals on Earth
Life and living
Classroom activity 1
1.
2.
South Africa has many indigenous plants and
animals.
a) What does ‘indigenous’ mean?
b) Name one plant and one animal that is
indigenous to South Africa.
What does the term ‘biodiversity’ mean?
Challenge
Find out what is South Africa’s national:
z
fish
z
bird
z
flower
z
animal
z
tree.
Unit 2 Inter-dependence
What you know already
Plants make their own food. Some animals eat plants and some
animals eat other animals. Animals use plants for shelter.
ck
Che elf Write down which of these things plants need to make
mys
food.
carbon dioxide in air; oxygen; water; soil; bees;
pollen; sunlight; heat
Topic 1 Plants and animals on Earth
‡
5
Lesson 1
Inter-dependence of plants and animals
Animals and plants depend on each other and the resources
in their own habitats for everything they need to survive. We
call this inter-dependence.
All living things depend on their habitat for:
z
a supply of water, food and air
z
shelter and a place to hide
z
a place to reproduce.
Word bank
interdependence:
when living
things rely on
each other and
the resources
within their
habitats for
survival
sustain: to
make something
last
Within a habitat, living things are linked to each other by the
food that they eat. Animals are unable to make their own
food. They eat plants or they eat animals that eat plants, or
both. Therefore, all animals ultimately depend on plants for food.
Sometimes animals also depend on plants for shelter. Plants do
not depend on animals for food. Plants produce or make their own
food using water, air and energy from the sun. Although plants
do not depend on animals for food, they need animals for other
things. For example, sometimes plants need animals to spread
their seeds so that new plants can grow in another place.
The environment is an inter-dependent system. The different
living things on Earth all have important roles in sustaining life on
Earth. Biodiversity ensures that there are several living things that
can perform a similar function. If one type of living thing becomes
extinct, another can take over that function. But if too much
biodiversity is lost, some functions may not be performed. This
could threaten life on Earth. By protecting the natural habitats of
plants and animals we can all help to protect the biodiversity of
our country.
6
‡ Topic 1
Plants and animals on Earth
Life and living
A
B
C
D
Classroom activity 2
Study the pictures in
Figure 1.2. Answer
the questions that follow.
Figure 1.2 Different habitats
1.
2.
3.
4.
5.
6.
Identify three animals in the pictures that eat plants.
There are four animals in the pictures that eat other
living animals. Identify them and the animal that
they are eating.
There are nine locusts but only three frogs in
habitat C. Explain why there are more locusts than
frogs.
Explain how the locusts in habitat C depend on the
plants that grow at the edge of the waterhole.
The buck in habitat B is called a kudu. Kudu live in
grassland habitats. How do the lions in the grassland
depend on the kudu?
In habitat A, birds depend on the plants for food.
a) What does the bird in habitat A eat?
b) The plants in this habitat need the birds to help
them reproduce. Explain how the birds are able
to help the plants reproduce and make new
plants.
Topic 1 Plants and animals on Earth
‡
7
Unit 3 Animal types
earthworm
A
What you know already
There are many different kinds of animals. Some animals are very
small, for example a worm or a bee. Some animals are very big,
for example a rhino or a whale.
ck
Che elf Animals are suited to their habitat. What will happen if
mys
you take an animal out of its habitat?
Lesson 1
Animals without bones: Invertebrates
millipede
B
spider
C
scorpion
D
Animals can be classified into two main groups. One group has
no bones and the other group has bones. Animals without bones
are called invertebrates. Animals that have bones are called
vertebrates.
crab
E
stick
Invertebrates are animals that do not have bones. Some
F insect
invertebrates have a hard ‘skin’ on the outside of their bodies
and some have shells as outer coverings for their bodies. This
outer skin or shell is made from non-living materials and forms the
Figure 1.3
skeleton of the animal. The skeleton protects and supports the
Invertebrates
animal. It is hard so that it can protect the soft internal organs of
the invertebrate. It is waterproof and prevents the
Word bank
animal from drying out.
Invertebrates are usually small because the hard
outer skeleton limits how big they can grow.
Animals without bones include worms, millipedes,
insects, spiders, scorpions and crabs. Examples of
these animals are shown in Figure 1.3.
8
‡ Topic 1
Plants and animals on Earth
invertebrates: animals
that do not have bones but
sometimes have hard outer
‘skins’ or shells
skeleton: a structure that
supports and protects the
body of an animal
vertebrates: animals that
have bones
Life and living
Classroom activity 3
Look at the examples of different invertebrates in
Figure 1.3 and answer the questions that follow.
1. Which invertebrate has the softest outer ‘skin’?
2. Which invertebrate has the most legs? Suggest why
you think all these legs are helpful to this animal.
3. The scorpion shown in D has two ways to defend
itself against dangers. Explain how it defends itself.
4. Which animal has a shell?
5. A spider can walk on a thin web. Explain how its
body and legs are suited to do this.
6. The insect shown in F is a stick insect. It can sit very
still to hide from other animals that want to eat it.
How is its outer covering adapted to help it hide even
better?
7. Small animals have to protect themselves from other
animals that feed on them. How does their outer skin
or shell protect them?
Lesson 2
Animals with bones: Vertebrates
A vertebrate is an animal with bones. The bones are found inside
the body of the animal and form the skeleton. The skeleton
supports and protects the body of the animal. You will learn
more about skeletons in Topic 2 (Animal skeletons). The
Word bank
bones are made out of living and non-living material and
grow with the body of the vertebrate. Animals with bones,
mammals:
for example an elephant, can grow very big because the
animals that give
birth to live young
bones grow with them. Examples of animals with bones are
reptiles: animals
fish, frogs, reptiles, birds and mammals.
that have dry,
scaly skin and lay
eggs
Topic 1 Plants and animals on Earth
‡
9
Table 1.1 Animals with bones
Type of
animal
Habitats where
Description of
you will find them their bones
Fish
All fish live in water Fish have soft
habitats such as
bones. Soft bones
seas and rivers.
are supported in
water.
Frogs
Frogs are
amphibians. They
can live in water
and on land, for
example in river or
wetland habitats.
Frogs have long
bones in their legs,
which help them to
jump and swim.
Birds
Birds fly over
land and water.
Birds live in
sea, river, forest
and grassland
habitats.
Birds have light,
hollow bones,
which make birds
light enough to fly.
Reptiles
Reptiles live in
grassland, river,
forest and even
sea habitats.
Some reptiles have
long backbones
and short legs.
Snakes have no
limbs.
Mammals Mammals live in
grassland, forest
or other land
habitats. Some
mammals live
in river or sea
habitats.
10
‡ Topic 1
Mammals have
strong, hard
bones.
Plants and animals on Earth
What they look like
Life and living
Classroom activity 4
Word bank
amphibian: a
vertebrate animal
that can live both
in water and on
land
wetland: land
that has marshes
or swamps
Look at the pictures of the animals in Table 1.1 and
answer the following questions.
1. Which animal has light bones? Give a reason why this
animal has light bones.
2. Which animal that lives both in water and on land has
long leg bones? Why does this animal need long leg
bones?
3. Name one type of animal with soft bones that are
supported by water.
4. What is the name of the structure that provides the
body of an animal with support and protection?
Check what you learnt
1.
Fill in the missing words:
a) Plants and animals ____________________ on
each other.
b) Fish have ___________________ inside their
bodies.
c) A spider has a _________________ on the
outside of its body.
Topic 1 Plants and animals on Earth
‡
11
d)
2.
3.
Animals need ________________ to breathe,
____________ to drink, __________________
to eat and a __________________ at night.
They also need a place to
______________________ and have babies. (8)
The Western leopard toad is indigenous to South
Africa. Explain what this means.
(2)
Classify the following animals as vertebrates or
invertebrates. Put a tick mark () in the correct
column. The first one has been done for you.
(13)
Animal
Vertebrate
(with bones)
Invertebrate
(no bones)
12
a)
Locust
b)
Orb spider
c)
Puff adder
d)
Secretary bird
e)
White rhinoceros
‡ Topic 1
Plants and animals on Earth
Life and living
Animal
f)
Lizard
g)
Earthworm
h)
Millipede
i)
Cheetah
j)
Bat
k)
Goldfish
l)
Bullfrog
Vertebrate
(with bones)
Invertebrate
(no bones)
Topic 1 Plants and animals on Earth
‡
13
Animal
Vertebrate
(with bones)
Invertebrate
(no bones)
m) Scorpion
n)
Crab
o)
Stick insect
[23]
Extra practice
1.
2.
3.
14
How is the body of a locust supported and protected?
Name two animals without bones.
What is a skeleton?
‡ Topic 1
Plants and animals on Earth
Life and living
Summary
z
z
z
z
z
z
z
z
z
There are many habitats on Earth.
There are many different plants and animals in a habitat.
There is inter-dependence between plants and animals in
a habitat.
Plants depend on animals and animals depend on plants
to survive.
Plants and animals depend on the resources such as
air, water, soil, food and a place to hide (shelter) in their
habitat to survive.
Invertebrates are animals without bones but with a hard
outer skin or shell.
Examples of invertebrates are worms, millipedes, insects,
spiders, scorpions and crabs.
Vertebrates are animals with a skeleton made up of
bones inside the body.
Examples of vertebrates are fish, frogs, reptiles, birds
and mammals.
Topic 1 Plants and animals on Earth
‡
15
Topic
2
Animal skeletons
What you will learn about in this topic
O
O
Skeletons of vertebrates
Movement
Let’s talk about animal skeletons
Look at the picture of the human skeleton. The bones of the
human skeleton are found inside the body. Identify the ribs. Study
the different bones in the hands and feet. Compare your knee
to the one shown in the picture. Move your foot forwards and
backwards. Put your hand on your leg when you move your foot.
Do you know how your lower leg moves forwards and backwards?
The skeleton is a structure. Structures have jobs or functions.
What do you think is the function of the skeleton?
16
‡ Topic 2
Animal skeletons
Life and living
Unit 1 Skeletons of vertebrates
What you know already
There are different types of structures, which are either human
made or natural. Examples of structures are frame structures
and shell structures. Vertebrates are animals with bones in their
bodies. Different animals have different skeletons. Bones grow
with animals. Bones are hard.
ck
Che elf 1.
mys
2.
What is a vertebrate?
Name five different vertebrates.
Word bank
joint: a part of the
vertebrate skeleton
that connects two
bones
skull: bony casing
that protects the
brain
Lesson 1
Skeletons of vertebrates
The bones inside the body of a vertebrate animal form the
skeleton. If you eat chicken or fish, you can see some of
the bones. The skeleton has a very important job to do in
the body. It forms a hard and strong frame structure for the
body.
A vertebrate skeleton consists of bones and joints.
A joint connects two bones. Some joints allow
movement of the bones.
The skeleton has two important functions. The
skeleton supports an animal’s body, giving it shape.
The skeleton protects the body’s organs.
The skeleton protects the internal organs
Figure 2.1 The skull of an
elephant
The skull protects the brain
The skull forms a case for the brain. It is made up of
many flat bones that are joined together. It has openings
for the eyes and nose. The skull protects the brain, the
eyes and the parts of the ear inside the skull.
Topic 2 Animal skeletons
‡
17
The backbone with vertebrae protects the spinal cord
The backbone is the part of the skeleton that protects
the spinal cord. It is made up of many vertebrae,
which form a rigid but flexible chain. In humans, the
backbone supports the body’s weight to enable us to
walk upright. It helps us to bend over, crouch, and bend
and turn. Figure 2.2 shows the vertebrae that make up
the backbone.
Figure 2.2 Vertebrae
make up the backbone
Ribs protect the lungs and heart
The ribs are long, thin, curved bones that are attached to the
backbone. They form a cage-like structure that protects the
heart and lungs.
Word bank
The skeleton supports the body for movement
Shoulder blades, arms, legs and hip bones give the
body support during movement. The two shoulder
blades are flat, triangular bones that help the bones
of the arms move. These bones form the shoulder
girdle. The two hip bones are flat bones that help the
legs move. The hip bones form the hip girdle.
Shoulder
blades help the
arms move.
Ribs protect
the heart and
lungs.
Bone of arm
Elbow joint
helps the arm
bend.
The skull protects
the brain.
The backbone
protects the spinal
cord and supports
the weight of the
body.
Hip bones and help
the legs move.
Knee joint helps the
leg bend.
Bone of leg
Figure 2.3 Parts of the skeleton and their functions
18
‡ Topic 2
Animal skeletons
backbone: a string of
vertebrae connected to
form a rigid, yet flexible
chain
hip bones: large, flat
bones that form part of the
hip girdle
hip girdle: connected
bones of the hip and leg
ribs: long, thin, curved
bones that form a cagelike structure to protect
the lungs and heart
shoulder blade: a large,
flat, triangular bone that
forms part of the shoulder
girdle
shoulder girdle:
connected bones of the
shoulder and arm
spinal cord: a bundle
of nerves that run from
the brain down along the
backbone
vertebrae: small bones
that make up the
backbone
Life and living
Classroom activity 1
1.
2.
3.
4.
What are skeletons of vertebrates made up of?
What kind of structure does a skeleton of a
vertebrate form?
What are the three main functions of a skeleton?
In a table, list the parts of a skeleton and give the
function of each part.
Challenge
How many bones are there in the human body? Research
this in the library or on the internet.
Check what you learnt
Study the diagram of a human skeleton in Figure 2.4.
A
B
D
C
E
F
I
C
G
H
J
Figure 2.4 The human skeleton
1.
2.
Write the letters A to J in your exercise book. Then
write the name of the part of the skeleton that
corresponds to each letter.
(10)
Give the function of the part labelled A.
(1)
Topic 2 Animal skeletons
‡
19
3.
4.
5.
What is the role of the part labelled H in the
skeleton?
a) What is the part labelled E made up of?
b) What is the function of this part?
Name the two organs that part C protects.
(1)
( 12 )
( 12 )
(1)
[15]
Lesson 2
Skeletons of different vertebrates
The skeletons of vertebrates all consist of the same basic parts
but do not all look the same. Every vertebrate’s skeleton is
adapted so that the animal is suited to live in its habitat.
Skeleton of a fish
Fish live in water. The skeletons of
fish do not have shoulder or hip
girdles. The bones making up the
skeletons are soft and therefore do
not provide much support. Instead,
the fish relies on the water around
it to support its body.
backbone
skull
ribs
Figure 2.5 Skeleton of a fish
Skeleton of a frog
Frogs live on land or in water. A frog needs to
move on land and in water to find food and avoid
dangers. The long bones that make up the back
legs of the frog are adapted to allow the frog to
jump on land and swim in water.
backbone
skull
front leg
rib
back leg
Figure 2.6 Skeleton of a frog
20
‡ Topic 2
Animal skeletons
Life and living
Skeleton of a bird
skull
Most birds can fly. The bones of the
skeleton of a bird are hollow, which
makes the skeleton light. A bird uses
its wings to fly and its legs to walk.
backbone
vertebra
rib
Figure 2.7 Skeleton of a bird
bone of leg
bone of foot
Skeleton of a reptile
backbone
A snake is an example of a reptile. A
snake has a backbone but no limbs.
A snake does not have shoulder or
hip girdles. A snake slithers on the
ground.
vertebra
skull
rib
Figure 2.8 Skeleton of a snake
A crocodile is an
example of a reptile
with limbs. It can
move both in water
and on land. A
crocodile has short
legs to move across
the ground and a long
tail to help it swim in
water.
vertebra
backbone
tail
bone of
foot
back leg
rib
skull
front leg
Figure 2.9 Skeleton of a crocodile
Topic 2 Animal skeletons
‡
21
Skeleton of a mammal
Mammals give birth to live young.
Most mammals live on land. A cat
is an example of a mammal. A cat
can run, walk, jump and climb using
its four limbs. A cat uses its tail for
balance.
skull
vertebra
front leg
backbone
tail
rib
back leg
Figure 2.10 Skeleton of cat
Practical activity
Study vertebrate skeletons
This is a prescribed activity.
Work in groups.
Aim
To identify the parts of different vertebrate skeletons
You will need:
O
models or pictures of vertebrate skeletons, for example:
T fish
T amphibians (frogs)
T reptiles (snake)
T birds
T mammals (including humans)
Method
1. Look at the examples of vertebrate skeletons.
2. Identify the following parts of each skeleton:
a) skull
b) backbone
c) ribs
d) limbs
e) shoulder and hip girdles
22
‡ Topic 2
Animal skeletons
Life and living
Questions
1. Compare the skeletons of the different vertebrates you
looked at. Copy and complete the following table by
placing a tick mark in the correct column.
Animal
Part of skeleton
Skull
Backbone Ribs
Shoulder
Limbs
(number and hip
of pairs) girdles
Fish
Amphibians
(for
example
frogs)
Reptiles
(for
example
snakes)
Birds
Mammals
(including
humans)
2.
3.
4.
5.
a) Do all the skeletons have the same parts?
b) Which part(s) can you find in all the skeletons?
Describe how the skeletons of the frog and the snake
differ.
Describe how the skeletons of the bird and the fish differ.
a) How does the skeleton of a human differ from that of
other mammals?
b) How is the skeleton of a human similar to that of
other mammals?
Topic 2 Animal skeletons
‡
23
Classroom activity 2
1.
2.
3.
4.
5.
6.
Explain how the skeleton of a bird is suited for flight.
How is the skeleton of a cat different from the
skeleton of a human?
What is not present in the skeleton of a snake that
the other reptiles do have?
Look at the skeleton of a frog in Figure 2.6:
a) Which limb is the most developed?
b) What is this limb used for?
Which vertebrates have a soft skeleton? Explain why
they are able to survive without the support of a
strong skeleton.
Name two vertebrates that do not have shoulder or
hip girdles.
Unit 2 Movement
What you know already
Movement is one of the seven processes of life. Vertebrates can
move. Some vertebrates move fast, for example a cheetah. Some
vertebrates move slowly, for example a tortoise.
ck
Che elf Why do animals move?
mys
Lesson 1
How different vertebrate animals move
Vertibrate animals can move because they have muscles and
bones. Vertebrates rely on movement to escape dangers, find
food or to find a mate to reproduce.
24
‡ Topic 2
Animal skeletons
Life and living
Vertebrate animals move in the following ways:
O
Walking and running: Land mammals have limbs that allow
them to walk and for some, to run very fast. The gemsbok
and the cheetah are examples of land mammals.
O
Jumping: Some animals have very strong back legs, which
help them to jump far, for example the frog and the cat.
O
Flying: Birds use the strong muscles in their wings for flight.
O
Climbing: Most frogs, reptiles and birds, as well as some
mammals such as monkeys, can climb on structures such as
trees and branches.
O
Gliding: Since snakes do not have limbs, they glide on the
ground.
O
Swimming: Animals such as fish, frogs, and some types of
birds can swim. Fish use their fins and tails to swim. Birds
and frogs have feet with webs between their toes to help
them push and pull through water.
Vertebrate animals can move because there are:
O
muscles attached to the skeleton
O
joints between the bones.
Muscles
Bones of the skeleton are unable to move the vertebrate body
on their own. Strong muscles are attached to the skeleton
of a vertebrate. It is these muscles that make it possible for
vertebrates to move. Muscles that move the bones in our limbs
work against each other in pairs. As one muscle in the pair
Word bank
contracts, the other muscle relaxes. When a muscle
contract:
contracts, it shortens. This causes a pulling action on the
becomes shorter
bones to which the muscles are attached. The second
relax: returns to
muscle in the pair will then relax, which increases its length
its original length
to its original size, allowing the bones to move at the joint.
An example of how muscles work in pairs is seen in the working
of the human arm, as shown in Figure 2.11. To bend your arm, the
Topic 2 Animal skeletons
‡
25
muscle in the front of the arm contracts while the muscle at the
back of the arm relaxes. To straighten your arm, the muscle at
the back of the arm contracts and the muscle in the front relaxes.
shoulder joint
shoulder
blade
bone
muscle
contracted
muscle relaxed
muscle
relaxed
muscle
contracted
elbow joint
elbow joint
bones in lower arm
Figure 2.11 Pairs of muscles in the arm work together to bend and straighten
the arm.
Muscles in the human body
There are many different types and sizes of muscles in the
human body. The biggest muscle in the human body is used to
straighten legs, climb stairs and sit. This muscle is called the
gluteus maximus. Climbing a lot of stairs in a day may cause your
gluteus maximus to cramp and ache. The human body has many
smaller muscles too. Tiny muscles in your face contract and relax
to make you blink, smile and pull faces!
Joints
Bones are strong. Joints between the bones allow the bones
to move when muscles pull on them. Some joints move like
hinges in a linear way, which is in a straight line. Other joints
move in a rotary way, which is in a circular motion. The
elbow and knee are hinge joints. They move linearly. The hip
and shoulder joints are ball-and-socket joints. The long bone
26
‡ Topic 2
Animal skeletons
Word bank
linear: in a
straight line
rotary: in a
circle
Life and living
of the thigh or arm has a ball on the end of it, which fits snuggly
into the socket of the hip or shoulder girdle. These joints allow the
long bones to move in a circular motion at the joint.
Practical activity
Make a hinge joint similar to the one in your elbow or knee
Optional activity
Aim
To make a basic model of a hinge joint
You will need:
O
two pencils
O
sticky tape or masking tape
Method
1. Line up the ends of the two pencils.
2. Join the pencils with the tape.
Results
Test your model joint for movement. Describe the way in
which the joint moves.
Figure 2.12 Model of a joint
Topic 2 Animal skeletons
‡
27
Classroom activity 3
Copy and complete the table that summarises how
different vertebrate animals move.
Vertebrate animal
How it moves
Fish
Jumping
Snake
Flying
Running and walking;
flying; swimming
Human
Challenge
Do some research about the muscles of the human
body in the library or on the internet. Find out how many
muscles are in the human body. Also find out what the
smallest muscle in the human body is.
Extra practice
1.
2.
3.
4.
5.
6.
7.
28
State the two main functions of the human skeleton.
How are the bones that make up a skeleton joined
together?
Which bone protects the brain?
Name one vertebrate that has a skeleton inside its body
but no limbs.
What parts of the body contract and relax to make
bones move?
Describe how muscles work in pairs to make movement
possible.
Dali wrote a paragraph about joints but got his facts
muddled up. Re-write his paragraph to make it true.
‡ Topic 2
Animal skeletons
Life and living
The elbow and knee joints
work in a rotary motion.
They can swing in a circular
motion. They are ball-andsocket joints. The hip and
shoulder joints are hinge
joints. They move in a linear
way, up and down in a
straight line.
Summary
A skeleton provides support for an
animal’s body and protects its organs:
‡ VNXOO¤SURWHFWV
the brain
‡ EDFNERQHZLWK
YHUWHEUDH¤
A vertebrate skeleton consists
protects the
of bones and joints and is
spinal cord
inside the body.
‡ ULEV¤SURWHFWWKH
lungs and heart
‡ VKRXOGHUEODGHV
form shoulder
girdle with arms
‡ KLSERQHVIRUP
pelvic girdle with
Animal skeletons
legs.
Bones are hard and
form a strong frame
structure.
Vertebrates move because they have:
‡PXVFOHVDWWDFKHGWRWKHVNHOHWRQ
‡MRLQWVEHWZHHQWKHERQHV
Topic 2 Animal skeletons
‡
29
Topic
3
Skeletons as
structures
What you will learn about in this topic
z
Frame and shell structures in animals
Let’s talk about skeletons as structures
Study the skeleton in this picture. What animal do you think it is
from? Is it a skeleton of a vertebrate animal or an invertebrate
animal? Why do you say so? What is the function of a skeleton?
30
‡ Topic 3
Skeletons as structures
Structures
Unit 1 Frame and shell structures
in animals
What you know already
Structures can be natural or human made. Animal skeletons are
examples of natural structures. A skeleton provides support for an
animal’s body and protection for its organs. A vertebrate skeleton
is a frame structure that consists of bones and joints, and is
inside the body.
ck
Che elf Study the pictures in Figure 3.1 to answer the
mys
questions.
balloon
chair
wasp nest
Xhosa
hut
tree
Figure 3.1 Examples of natural and human-made structures
1.
2.
3.
a) Which are natural structures?
b) Which are human-made structures?
Which of the human-made structures are frame
structures?
In which of these structures are struts being used?
Topic 3 Skeletons as structures
‡
31
Lesson 1
Skeletons as shell structures
A shell structure is a type of structure with support on the
outside. The weight of the structure is supported by the outer
material of the structure. Shell structures can be natural or
human made. Figure 3.2 and Figure 3.3 show examples of some
human-made shell structures.
helmet
box
Word bank
fish bowl
briefcase
Figure 3.2 Human-made shell
structures
Figure 3.3 Zulu warriors made
shields that protected their
bodies during battle.
chitin: a hard
natural material
that exoskeletons
are made of
exoskeleton: a
skeleton on the
outside of the
body
Invertebrate skeletons are shell structures
Invertebrates do not have bones. Instead,
invertebrates such as crabs and cockroaches
have exoskeletons. An exoskeleton is a hard,
crusty shell found on the outside of the body of
an animal.
The exoskeleton of an invertebrate covers the
whole body. It is made of a tough material
called chitin. Chitin is similar to the material of
which our fingernails are made.
32
‡ Topic 3
Skeletons as structures
Figure 3.4 A crab has a hard
exoskeleton, which is a natural shell
structure.
Structures
The exoskeleton holds and supports the body of an animal. The
exoskeleton protects the soft organs of the animal. In this way an
exoskeleton is a shell structure.
Classroom activity 1
1.
2.
What is a shell structure?
Explain how an exoskeleton can be described as a shell
structure.
Lesson 2
Skeletons as frame structures
pylon
crane
cellphone
tower
bridge
chair
Figure 3.5 Examples of human-made frame structures
Word bank
endoskeleton:
a skeleton on
the inside of the
body
A frame structure is a
structure that is found
on the inside and is
made up of many stiff
parts that are joined
together. These parts
are either beams or
struts. The beams or
struts have gaps or
spaces in between
them. Figure 3.5 shows
examples of humanmade frame structures.
Vertebrate skeletons are frame structures
Vertebrates such as humans and birds have an
endoskeleton. An endoskeleton is found inside of the body
of the animal and consists of bones that are joined together
by joints.
The endoskeleton protects the soft organs of the animal. The
endoskeleton supports the animal’s body weight and gives the
body its shape. In this way an endoskeleton is an example of a
frame structure.
Topic 3 Skeletons as structures
‡
33
All large structures need a skeleton to support their weight. Inside
every large building or tall skyscraper is a frame structure of steel
beams and struts. Just as our skeleton supports our bodies, this
frame structure supports the weight of the building.
Figure 3.6 The skeleton of an elephant supports a very
large and heavy body. It is a frame structure.
Figure 3.7 A skyscraper being built.
You can see the frame structure
that supports the building.
Classroom activity 2
1.
2.
What is a frame structure?
Describe how an endoskeleton can be described as a
frame structure.
Unit 2 Technology project:
Model of a vertebrate skeleton
What you know already
Frame structures consist of supporting pieces called struts that are
joined together. Since frame structures often provide support for
large and heavy bodies, they have to be strong, rigid and stable.
34
‡ Topic 3
Skeletons as structures
Structures
An endoskeleton of an animal is a natural frame structure. There
are different ways to strengthen frame structures. There are
different ways to strengthen the materials that are used to make
frame structures.
ck
Che elf 1.
mys
2.
3.
Explain two ways in which paper can be
strengthened.
Describe the types of shapes that make a
structure strong?
What part of an endoskeleton would be a strut?
Lesson 1
Identify the design: A model of a vertebrate skeleton
You will complete a Technology project by making and designing
a model of a vertebrate skeleton. You have learnt about different
vertebrate skeletons, such as the crocodile skeleton, the human
skeleton and the bird skeleton. For more information on how to do
a Technology project see pages vii–x.
Use the technology process to help you solve the problem set out
in the following case study. Along the way there will be several
help tasks to work through. These are there to help you gain any
additional knowledge and skills you will need to complete the
project. For more information on the technology process, see
page vii.
Read the case study. Identify what it is that needs to be
designed and made.
Case study
The Natural Science and Technology teacher has told
one of the Grade 2 teachers that you have been learning
about animal skeletons.
Topic 3 Skeletons as structures
‡
35
The Grade 2 teacher was very
interested because her class is
learning about reptiles. She has
asked if the class can come and
tell the Grade 2 learners about
skeletons.
The teacher has divided the
class into groups. Your group
has decided to tell the Grade 2
learners about reptile skeletons. As
part of the presentation you are going to show them a
model of a reptile skeleton.
Figure 3.8 Your group
has decided to make
a model of a reptile
skeleton.
The model should:
z
be a frame structure
z
be of a reptile skeleton
z
be made from struts in the shape of tubes (such as
drinking straws or rolled paper tubes.)
z
be strong
z
have all parts joined
z
have a skull (made from cardboard)
z
have a backbone, ribs and limbs
z
have shoulder blades and hip bones (made from
cardboard)
z
be built together in a group.
Identifying
You need to understand the problem, identify the need set out
in the case study and work out exactly what you need to design
and make. Ask questions, such as:
z
What is it I have to design and make?
z
What is it for?
z
Who will be using it?
36
‡ Topic 3
Skeletons as structures
Structures
Word bank
z
z
constraints: a
list of the limits
that have been
placed on the
designer
design brief:
a short, clear
statement that
explains what
needs to be
done to solve a
problem
specifications:
a description
of features to
include in a
design
z
z
z
z
How big does it need to be?
What material will be used to make it?
How can I make it strong?
How can I make the joints strong and secure?
Who in the group will make what part of the model?
Is there anything specific that needs to be included?
Answer these questions to make a list of specifications and
constraints for the model of the reptile skeleton. Use this
list of specifications to develop a design brief for the model
as shown in Help task 1.
Help task 1
Developing a design brief
1. Make a list of all the specifications needed to make
the model of the reptile skeleton.
2. Make a list of the constraints placed on the design.
3. Write a design brief for the model of the reptile
skeleton. Use the following phrase to begin your
design brief with. Rewrite the phrase and complete
it by filling in the gaps.
‘Design and make a___________that is
____________, __________and has ___________. It
will be made out of _____________________.’
Lesson 2
Investigating reptile skeletons
To investigate the problem set out in the case study, you will
need to do Help task 2. The task will help you with what you need
to know when designing your reptile skeleton.
Topic 3 Skeletons as structures
‡
37
Help task 2
Investigating reptile skeletons
1. Study the photographs of reptile skeletons in Figure 3.9.
B Snake skeleton
B Lizard skeleton
C Crocodile skeleton
Figure 3.9 Examples of reptile skeletons
2.
Choose one reptile skeleton.
a) Make a simple drawing of one of the reptile
skeletons.
b) Label your drawing with these labels:
z
skull
z
backbone
z
front limbs (if limbs are present)
z
back limbs (if limbs are present)
z
ribs.
The drawing
backbone
back limbs
of a crocodile
skeleton has
been done
for you (see
Figure 3.10).
tail
ribs
neck
front limbs
Figure 3.10 Drawing of a crocodile skeleton
38
‡ Topic 3
Skeletons as structures
skull
Structures
Lesson 3
Design and plan a reptile skeleton
To help you design your reptile skeleton, complete Help task 3.
Help task 3
Making design sketches
Look at the photograph of the reptile skeleton you chose and
at the drawing you made of the skeleton in Help task 2. Draw
a possible design for a model you could make of the reptile
skeleton, using drinking straws or rolled paper tubes.
Planning
Plan the making of the reptile skeleton model. As a group you
need to discuss the following:
z
Who will build which part of the model?
z
How many straws or paper tubes do you need?
z
What other equipment do you need?
z
How long will it take to make the model?
Making
Before making the reptile skeleton, work through Help tasks 4–6.
These tasks will show you how to join the straws or the tubes you
will use to make the reptile skeleton. You will also learn how to
make a reptile skull out of cardboard.
Help task 4
How to make a flexible backbone out of bendy straws
You will need:
z
bendy straws
z
scissors
‡
‡
a ruler
a marker pen
Topic 3 Skeletons as structures
‡
39
Method
1.
2.
3.
4.
5.
Measure 2 cm on either side of the ‘bendy’ part of a
straw. Mark it with a marker pen.
Cut the straws along the marks. Put away the two ends
that you have cut off each straw for Help task 6.
Squash one of the straw ends so that it can fit into the
one end of another straw. Push it into another straw
end, in this way joining all the cut straws together.
Continue to join the cut straws this way until you have
made a long ‘backbone’.
Bend the straws where you want them to be bent to
make them look like the backbone of the animal you
want to make a model of.
A
B
C
Figure 3.11 Making the backbone for a model of a reptile skeleton
Help task 5
How to make a basic reptile skull out of cardboard
You will need:
z
scissors
z
tracing paper
40
‡ Topic 3
Skeletons as structures