A variety of animalslrrpublic.cli.det.nsw.edu.au/lrrSecure/Sites/LRRView/... · · 2010-09-10Dog Snail Slug Cat Magpie ... Read the passage on the next page called ‘The tale of

Lesson 11/20 More about classifying animals 1

A variety of animals

In this lesson, you will be investigating features that can be used to

classify animals. A feature is something that distinguishes one thing

from another. A feature, or characteristic, may be the way something

looks or some other quality.

Animals, animalsHow many different types of animals are there? You probably realise

that there are lots – over one million! Some are alike and some are very

different.

What sorts of animals live atyour place?

Think about the animals at your place.

Can you think of two animals at your place that are similar?

___________________________________________________________

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What about two animals at your place that are different?

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Here are the animals that are found at Kim’s place.

Bee Fly

Butterfly Moth

WaspCockroach

King parrotDog

SnailSlug

CatMagpie

Animals that live at Kim’s place

© State of New South Wales, Department of Education and Training, 2004


As you can see, there is a large variety of animals here. To make it easier

to investigate these animals, it would be useful to divide them into

smaller groups.

To do this, you need to look closely at the animals and compare them.

Look for the features that the animals have in common. For example, a

dog and a cat are covered in fur, have four legs and teeth. So you could

put them in the same group.

In the next activity you will sort the animals that live at Kim’s place into

four smaller groups. One group has already been made for you.

Remember there are no ’correct’ answers here. Different people will

make different groups, depending on the features they select.

Activity: Animals, animals

Sort the animals into four smaller groups.

Group 1 dog, cat

Group 2 _________________________________________________

Group 3 _________________________________________________

Group 4 _________________________________________________

Check your response by going to the suggested answers section.

You answers may not be the same as those given in the suggested answer

pages.

How can you classify animals?Think about why you grouped the animals as you did. How did you do

it?

When you compared the animals, you probably looked for similarities

and differences. You put the animals that are alike into the same group.

For example, parrots and magpies have got feathers and wings so I put

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them into the same group. Flies, cockroaches, moths, butterflies, and

bees are in another group because they all have wings and lots of legs.

When Kim classified the animals at her place, she used a range of

features, such as skin covering, number of legs, wings and how they

move. But this makes it really hard to group things. Did you have

trouble classifying the animals? How can classifying animals be made

easier?

All the living things on the planet make up one very large group.

It would be much easier if you used just one feature to divide the group

into a small number of groups.

In this Part, you will be dividing animals into two major groups based on

one feature. This will make classifying much simpler. But which feature

should you choose?

Let’s investigate a variety of features that

could be used to classify animals.

Describing similarities and differences

Similarities

• A dog is similar to a cat because they are both covered in fur.

• Both dogs and cats have four legs.

• Neither dogs or cats have feathers.

• Dogs and cats are alike because they have warm blood.

• One feature that dogs and cats have in common is teeth.

Differences

• Dogs are different from birds because dogs have fur but birds have

feathers.

• Dogs differ from birds because dogs have four legs but birds have

two.

• Birds have beaks but dogs do not.

• Birds lay eggs whereas dogs have young born alive.


You'll need to write about similarities and differences in the next section

about the features of animals.

The features of animals

There are many features that you can use to classify animals. But some

features are more useful than others. Useful features lead you to group

animals that are similar.

Let’s try to deduce (work out) whatsorts of features are most useful forclassifying animals.

The features you’ll consider are:

• habitat, or where the animal lives

• usefulness to humans

• colour

• behaviour, or how the animal acts and responds

• body structure, or the parts of the animal's body.

Habitat – where an animal lives

From the top of mountains to the bottom of the sea, there are many

places where plants and animals can live. There are four main habitats –

water, underground, land and the air. Investigate one habitat to see how

useful it is when classifying.

Activity: Habitat – where an animal lives

Read the passage on the next page called ‘The tale of Salty Sam’. As

you read, underline the names of the animals.

And notice that the passage is a story – it is very different from the

scientific definitions you have been reading and writing.

Try to identify the features of the story that make it different from the

way definitions, or report text types, are often written.

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Put a cross in the box if the feature is not in the story of Salty Sam.

Here are some of the featuresof scientific definitions:

Definitions are written in present tense

Definitions often contain technical words

Definitions are usually generalised

Definitions are objective.

The tale of Salty Sam

Salty Sam was a fisherman who sailed the ocean blue. Everyday

he would go out in his boat, cast his net and haul in his catch.

Some days were good, some were bad.

Things were not going too well for Salty. His boat needed repairs,

his wife was sick and his children had no shoes. He really needed

to make some money. Everyday he went out, fished and caught

only enough for the family to eat. Things were grim indeed.

It was a Monday, like any other Monday. At least, that’s what

Salty thought. As usual, he cast off, sailed out of the harbour and

threw out his net. Then, as usual, he started to haul in his net. But,

instead of the net being easy to pull in, it was incredibly heavy. He

strained against the weight. He pulled, tugged, gritted his teeth and

struggled with the weight until at last the net was once again on the

deck.

He could not believe his eyes. He rubbed them and surveyed the

catch with his mouth open in disbelief. This would have to be the

strangest collection of animals that he’d ever landed.

'What will I do with all these animals?' he thought. 'I know, I’ll sell

the animals that can be eaten to the local shops – the squid and

sardines to the Italian restaurant, the tuna to the Japanese

restaurant, the crab and the shark to the fish and chip shop.'

'What about the rest of the catch?' He looked at each animal in

turn. The sea urchin and the starfish he could sell to the shop that

sells sea shells and dried sea animals to the tourists. The jellyfish?

Well, nobody needed or wanted that so he threw it over the side.

So off went Salty Sam, smiling and happy. What a day!



tuna

shark

jellyfish

sardine

starfish

sea urchin

squid

mud crab


The drawings above show the sea creatures that Salty Sam caught that

day.

Can you identify a feature that all these animals has in common?

___________________________________________________________

All these animals live in water.

Apart from their common habitat, these animals are not very similar at

all. They are very different sorts of animals.

Therefore, habitat is probably not a useful feature to use when we

classify animals.

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Usefulness to humans – Salty Sam’sclassification system

Salty Sam decided to use usefulness to humans as his classification

system. He divided his catch into three different groups:

Group 1: animals that can be eaten – squid, sardine, shark, crab, tuna

Group 2: animals for decoration – starfish, sea urchin

Group 3: animals that have no use – jellyfish.

The next exercise will help you to decide the value of using a feature

such as usefulness to humans when you are classifying animals.

Activity: Salty Sam’s classification system

Answer the questions below.

1 Compare the first two animals from Salty’s Group 1. How are these

animals different from each other?

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A sardine has fins and a tail but a squid doesn’t. A squid has tentacles but a

sardine doesn’t. A sardine has gills and scales but a squid doesn’t.

2 Is a squid similar to a sardine?

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They are not really alike at all, except that they both can be eaten and live

in the sea.

3 Are the squid and sardine similar to any other members of Group 1?

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The sardine is more like the tuna and shark than any other group member.

The squid is like nothing at all.

Do you think usefulness to humans is a feature that is very helpful when

classifying?

Not really


The animals in each group ended up being more different than alike.

However, usefulness to humans is a very common non-scientific

classification system. For example, it’s used to separate useful and

useless plants and animals, such as garden plants and weeds, or food

plants and animals from those not eaten.

Colour

Think of all the animals you know that are blue. Blue swimmer crabs,

blue-ringed octopuses, bluebottle jellyfish, blue wrens and blue whales

are just some examples.

Blue whale

Blue wren

BluebottleBlue swimmer crab

Blue-ringed octopus

Some blue animals


Look at whether colour is a useful feature for classifying animals.

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Activity: Colour

Use the animals from the above picture to answer the questions below.

1 Choose two animals. What feature do they have in common?

_______________________________________________________

2 How are the two animals that you have chosen different?

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3 Are the two animals similar to any other members of the group?

_______________________________________________________

4 Is colour a useful feature to use for classifying animals? Explain

your answer.

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Colour is not a very useful feature for classifying animals because the

animals in the group have more differences than similarities.

Behaviour

Animals could be grouped according to their behaviour, or what they do.

For example, you could classify animals by the way they move – whether

they are swimmers, crawlers, fliers or runners.


Let’s investigate animals that fly.

The picture following shows a group of animals that fly: a bee,

dragonfly, cockatoo, pelican and a bat.

bee

bat

cockatoo

dragonflypelican

Some flying animals


Preparing for the Exercise

Compare these flying animals. Make a list of some similarities and

differences of these animals in the exercises.

Go to the exercises section and complete Exercise: – A variety of

animals.

And here's another problem with using behaviour to classify animals.

Imagine that you step on an insect while you are out walking. It's a bit

crushed but definitely dead! You take it home to try to identify it.

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If your classification system used behaviour, what could your insect do?

Nothing because it is dead! Behaviour is not a really good feature to use

when classifying animals since animals are often dead when they are

being classified.

Body structure

Body structures, or structural features, are the parts of an animal’s body,

such as legs, wings, heart, bones, tentacles, blood, beaks, feathers, fur

and scales.

Look again at the picture offlying animals.

Activity: Body structure

Name the animal(s) with:

1 wings ________________________________________________________

2 bones _________________________________________________________

3 feathers. ______________________________________________________


Modern biologists classify animals using structural features because they

are easy to observe. Structural features are also used for classification

because scientists think that they show the evolutionary development of

animals over millions of years. You'll learn more about this later in your

science course.

Most features that you looked at in this lesson didn’t turn out to be very

useful to scientists for classifying animals. All the features could be used

– and there are times and situations where they are appropriate.

However, body structures is the only feature that biologists have chosen

to use in a scientific classification system.


The other features you considered have been used in classification

systems in the past.

In the next lesson, you will be looking at one way that animals were

classified in ancient Greece.

Activity: Summary

Fill in the blanks using the following terms:

similar million not

• There are about one _________________ different types of animals.

• Habitats, colour and behaviour are ____________ useful features

for classifying animals.

• Animals are grouped according to how ___________ they are.


What did you achieve?Tick what you can do.

compare and contrast the features of various organisms

using animal examples, describe why features such as habitat,

usefulness to humans, colour and behaviour are not very useful

for classifying in science

judge whether a passage has features of a scientific definition

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Suggested answers

Check your responses against these suggested answers.

Animals, animals

My groups are as follows:

Group 1: dog, cat

Group 2: parrots, magpies

Group 3: snails, slugs

Group 4: flies, cockroaches, moths, butterflies, bees.

Habitat – where an animal lives

'The tale of Salty Sam' has none of the features of scientific definitions.

• Definitions are written in present tense.

The story is in past tense. It has words such as was and

went and lots of verbs with -ed endings.

• Definitions often contain technical words.

The story uses common, everyday words.

• Definitions are usually generalised.

The story is specific, not generalised. It is about one

particular Monday.

• Definitions are objective.

The story is not objective because it tells you about how

Salty Sam feels.

Colour

Here are some sample answers. Your answers may be correct even if they are

not exactly the same. This is because you might have described different

animals or chosen different ways to write about similarities and differences.

1 Both the blue swimmer crab and the blue whale are coloured blue. They

also both live in the sea.

2 The crab has many legs whereas the whale has none. The whale has

flippers but the crab doesn’t. Unlike the crab, the whale has a long smooth

body.

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3 The crab and the whale are not like each other or similar to any other

members of the group.

4 Colour is not a useful feature since you end up with groups that have only

one main feature in common – their colour. Apart from that, they are not

similar at all.

Body structure

The animal(s) with the following are:

1 wings: cockatoo, dragonfly, pelican, bee, bat

2 bones: cockatoo, pelican, bat

3 feathers: cockatoo, pelican.

Summary

• There are more than one million different types of animals.

• Habitats, colour and behaviour are not useful features for classifying

animals.

• Animals are grouped according to how similar they are.


Exercise

Living things Name ___________________________

Teacher ___________________________

Exercise – A variety of animals

Compare five flying animals – a bee, pelican, dragonfly, cockatoo, and a

bat.

bee

bat

cockatoo

dragonflypelican


Write sentences describing at least three similarities and three differences

of these animals.

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Similarities

• _______________________________________________________

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• _______________________________________________________

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• _______________________________________________________

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• _______________________________________________________

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• _______________________________________________________

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Differences

• _______________________________________________________

_______________________________________________________

• _______________________________________________________

_______________________________________________________

• _______________________________________________________

_______________________________________________________

• _______________________________________________________

_______________________________________________________

• _______________________________________________________

_______________________________________________________

A variety of animalslrrpublic.cli.det.nsw.edu.au/lrrSecure/Sites/LRRView/... · · 2010-09-10Dog Snail Slug Cat Magpie ... Read the passage on the next page called ‘The tale of

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